Add SyncOptions as the second argument to Wallet::sync

The current options are awkware and it would be good if we could
introduce more in the future without breaking changes.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,26 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: 'bug'
+assignees: ''
+
+---
+
+**Describe the bug**  
+<!-- A clear and concise description of what the bug is. -->
+
+**To Reproduce**  
+<!-- Steps or code to reproduce the behavior. -->
+
+**Expected behavior**  
+<!-- A clear and concise description of what you expected to happen. -->
+
+**Build environment**  
+ - BDK tag/commit: <!-- e.g. v0.13.0, 3a07614 --> 
+ - OS+version: <!-- e.g. ubuntu 20.04.01, macOS 12.0.1, windows -->  
+ - Rust/Cargo version: <!-- e.g. 1.56.0 --> 
+ - Rust/Cargo target: <!-- e.g. x86_64-apple-darwin, x86_64-unknown-linux-gnu, etc. -->  
+
+**Additional context**  
+<!-- Add any other context about the problem here. --> 

.github/ISSUE_TEMPLATE/summer_project.md

@@ -0,0 +1,77 @@
+---
+name: Summer of Bitcoin Project
+about: Template to suggest a new https://www.summerofbitcoin.org/ project.
+title: ''
+labels: 'summer-of-bitcoin'
+assignees: ''
+
+---
+
+<!--
+## Overview  
+
+Project ideas are scoped for a university-level student with a basic background in CS and bitcoin 
+fundamentals - achievable over 12-weeks. Below are just a few types of ideas: 
+
+ - Low-hanging fruit: Relatively short projects with clear goals; requires basic technical knowledge 
+   and minimal familiarity with the codebase.
+ - Core development: These projects derive from the ongoing work from the core of your development 
+   team. The list of features and bugs is never-ending, and help is always welcome.
+ - Risky/Exploratory: These projects push the scope boundaries of your development effort. They 
+   might require expertise in an area not covered by your current development team. They might take 
+   advantage of a new technology. There is a reasonable chance that the project might be less 
+   successful, but the potential rewards make it worth the attempt.
+ - Infrastructure/Automation: These projects are the code that your organization uses to get its 
+   development work done; for example, projects that improve the automation of releases, regression 
+   tests and automated builds. This is a category where a Summer of Bitcoin student can be really 
+   helpful, doing work that the development team has been putting off while they focus on core 
+   development.
+ - Quality Assurance/Testing: Projects that work on and test your project's software development 
+   process. Additionally, projects that involve a thorough test and review of individual PRs.
+ - Fun/Peripheral: These projects might not be related to the current core development focus, but 
+   create new innovations and new perspectives for your project.
+-->
+
+**Description**
+<!-- Description: 3-7 sentences describing the project background and tasks to be done. -->  
+
+**Expected Outcomes**  
+<!-- Short bullet list describing what is to be accomplished -->   
+
+**Resources**  
+<!-- 2-3 reading materials for candidate to learn about the repo, project, scope etc -->  
+<!-- Recommended reading such as a developer/contributor guide -->  
+<!-- [Another example a paper citation](https://arxiv.org/pdf/1802.08091.pdf) -->  
+<!-- [Another example an existing issue](https://github.com/opencv/opencv/issues/11013) -->  
+<!-- [An existing related module](https://github.com/opencv/opencv_contrib/tree/master/modules/optflow) -->  
+
+**Skills Required**  
+<!-- 3-4 technical skills that the candidate should know -->  
+<!-- hands on experience with git -->  
+<!-- mastery plus experience coding in C++ -->  
+<!-- basic knowledge in matrix and tensor computations, college course work in cryptography -->  
+<!-- strong mathematical background -->
+<!-- Bonus - has experience with React Native. Best if you have also worked with OSSFuzz -->
+
+**Mentor(s)**  
+<!-- names of mentor(s) for this project go here -->
+
+**Difficulty**  
+<!-- Easy, Medium, Hard -->
+
+**Competency Test (optional)**  
+<!-- 2-3 technical tasks related to the project idea or repository you’d like a candidate to 
+    perform in order to demonstrate competency, good first bugs, warm-up exercises -->
+<!-- ex. Read the instructions here to get Bitcoin core running on your machine -->
+<!-- ex. pick an issue labeled as “newcomer” in the repository, and send a merge request to the 
+    repository. You can also suggest some other improvement that we did not think of yet, or 
+    something that you find interesting or useful -->
+<!-- ex. fixes for coding style are usually easy to do, and are good issues for first time 
+    contributions for those learning how to interact with the project. After you are done with the 
+    coding style issue, try making a different contribution. -->
+<!-- ex. setup a full Debian packaging development environment and learn the basics of Debian 
+    packaging. Then identify and package the missing dependencies to package Specter Desktop -->
+<!-- ex. write a pull parser for CSV files. You'll be judged by the decisions to store the parser 
+    state and how flexible it is to wrap this parser in other scenarios. -->
+<!-- ex. Stretch Goal: Implement some basic metaprogram/app to prove you're very familiar with BDK. 
+    Be prepared to make adjustments as we judge your solution. -->

.github/workflows/code_coverage.yml

@@ -31,7 +31,7 @@ jobs:
         uses: actions-rs/grcov@v0.1.5
 
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v1
+        uses: codecov/codecov-action@v2
         with:
           file: ${{ steps.coverage.outputs.report }}
           directory: ./coverage/reports/

.github/workflows/cont_integration.yml

@@ -10,8 +10,9 @@ jobs:
     strategy:
       matrix:
         rust:
-          - 1.53.0 # STABLE
-          - 1.46.0 # MSRV
+          - version: 1.56.0 # STABLE
+            clippy: true
+          - version: 1.46.0 # MSRV
         features:
           - default
           - minimal
@@ -31,7 +32,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v2
       - name: Generate cache key
-        run: echo "${{ matrix.rust }} ${{ matrix.features }}" | tee .cache_key
+        run: echo "${{ matrix.rust.version }} ${{ matrix.features }}" | tee .cache_key
       - name: cache
         uses: actions/cache@v2
         with:
@@ -41,16 +42,18 @@ jobs:
             target
           key: ${{ runner.os }}-cargo-${{ hashFiles('.cache_key') }}-${{ hashFiles('**/Cargo.toml','**/Cargo.lock') }}
       - name: Set default toolchain
-        run: rustup default ${{ matrix.rust }}
+        run: rustup default ${{ matrix.rust.version }}
       - name: Set profile
         run: rustup set profile minimal
       - name: Add clippy
+        if: ${{ matrix.rust.clippy }}
         run: rustup component add clippy
       - name: Update toolchain
         run: rustup update
       - name: Build
         run: cargo build --features ${{ matrix.features }} --no-default-features
       - name: Clippy
+        if: ${{ matrix.rust.clippy }}
         run: cargo clippy --all-targets --features ${{ matrix.features }} --no-default-features -- -D warnings
       - name: Test
         run: cargo test --features ${{ matrix.features }} --no-default-features
@@ -135,7 +138,7 @@ jobs:
       - run: sudo apt-get update || exit 1
       - run: sudo apt-get install -y libclang-common-10-dev clang-10 libc6-dev-i386 || exit 1
       - name: Set default toolchain
-        run: rustup default 1.53.0 # STABLE
+        run: rustup default 1.56.0 # STABLE
       - name: Set profile
         run: rustup set profile minimal
       - name: Add target wasm32

.github/workflows/nightly_docs.yml

@@ -44,18 +44,18 @@ jobs:
           repository: bitcoindevkit/bitcoindevkit.org
           ref: master
       - name: Create directories
-        run: mkdir -p ./static/docs-rs/bdk/nightly
+        run: mkdir -p ./docs/.vuepress/public/docs-rs/bdk/nightly
       - name: Remove old latest
-        run: rm -rf ./static/docs-rs/bdk/nightly/latest
+        run: rm -rf ./docs/.vuepress/public/docs-rs/bdk/nightly/latest
       - name: Download built docs
         uses: actions/download-artifact@v1
         with:
           name: built-docs
-          path: ./static/docs-rs/bdk/nightly/latest
+          path: ./docs/.vuepress/public/docs-rs/bdk/nightly/latest
       - name: Configure git
         run: git config user.email "github-actions@github.com" && git config user.name "github-actions"
       - name: Commit
         continue-on-error: true         # If there's nothing to commit this step fails, but it's fine
-        run: git add ./static && git commit -m "Publish autogenerated nightly docs"
+        run: git add ./docs/.vuepress/public/docs-rs && git commit -m "Publish autogenerated nightly docs"
       - name: Push
         run: git push origin master

CHANGELOG.md

@@ -6,6 +6,36 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Sync API change
+
+To decouple the `Wallet` from the `Blockchain` we've made major changes:
+
+- Removed `Blockchain` from Wallet.
+- Removed `Wallet::broadcast` (just use `Blockchain::broadcast`)
+- Depreciated `Wallet::new_offline` (all wallets are offline now)
+- Changed `Wallet::sync` to take a `Blockchain`.
+- Stop making a request for the block height when calling `Wallet:new`.
+- Added `SyncOptions` to capture extra (future) arguments to `Wallet::sync`.
+
+## [v0.15.0] - [v0.14.0]
+
+- Overhauled sync logic for electrum and esplora.
+- Unify ureq and reqwest esplora backends to have the same configuration parameters. This means reqwest now has a timeout parameter and ureq has a concurrency parameter.
+- Fixed esplora fee estimation.
+- Fixed generating WIF in the correct network format.
+- Disable `reqwest` default features.
+- Added `reqwest-default-tls` feature: Use this to restore the TLS defaults of reqwest if you don't want to add a dependency to it in your own manifest.
+
+## [v0.14.0] - [v0.13.0]
+
+- BIP39 implementation dependency, in `keys::bip39` changed from tiny-bip39 to rust-bip39.
+- Add new method on the `TxBuilder` to embed data in the transaction via `OP_RETURN`. To allow that a fix to check the dust only on spendable output has been introduced.
+- Update the `Database` trait to store the last sync timestamp and block height
+- Rename `ConfirmationTime` to `BlockTime`
+
+## [v0.13.0] - [v0.12.0]
+
+- Exposed `get_tx()` method from `Database` to `Wallet`.
 
 ## [v0.12.0] - [v0.11.0]
 
@@ -384,4 +414,7 @@ final transaction is created by calling `finish` on the builder.
 [v0.9.0]: https://github.com/bitcoindevkit/bdk/compare/v0.8.0...v0.9.0
 [v0.10.0]: https://github.com/bitcoindevkit/bdk/compare/v0.9.0...v0.10.0
 [v0.11.0]: https://github.com/bitcoindevkit/bdk/compare/v0.10.0...v0.11.0
-[v0.12.0]: https://github.com/bitcoindevkit/bdk/compare/v0.11.0...v0.12.0
+[v0.12.0]: https://github.com/bitcoindevkit/bdk/compare/v0.11.0...v0.12.0
+[v0.13.0]: https://github.com/bitcoindevkit/bdk/compare/v0.12.0...v0.13.0
+[v0.14.0]: https://github.com/bitcoindevkit/bdk/compare/v0.13.0...v0.14.0
+[v0.15.0]: https://github.com/bitcoindevkit/bdk/compare/v0.14.0...v0.15.0

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bdk"
-version = "0.12.0"
+version = "0.15.1-dev"
 edition = "2018"
 authors = ["Alekos Filini <alekos.filini@gmail.com>", "Riccardo Casatta <riccardo@casatta.it>"]
 homepage = "https://bitcoindevkit.org"
@@ -24,8 +24,9 @@ rand = "^0.7"
 sled = { version = "0.34", optional = true }
 electrum-client = { version = "0.8", optional = true }
 rusqlite = { version = "0.25.3", optional = true }
-reqwest = { version = "0.11", optional = true, features = ["json"] }
-ureq = { version = "2.1", features = ["json"], optional = true }
+ahash = { version = "=0.7.4", optional = true }
+reqwest = { version = "0.11", optional = true, default-features = false, features = ["json"] }
+ureq = { version = "~2.2.0", features = ["json"], optional = true }
 futures = { version = "0.3", optional = true }
 async-trait = { version = "0.1", optional = true }
 rocksdb = { version = "0.14", default-features = false, features = ["snappy"], optional = true }
@@ -33,15 +34,11 @@ cc = { version = ">=1.0.64", optional = true }
 socks = { version = "0.3", optional = true }
 lazy_static = { version = "1.4", optional = true }
 
-# the latest 0.8 version of tiny-bip39 depends on zeroize_derive 1.2 which has MSRV 1.51 and our 
-# MSRV is 1.46, to fix this until we update our MSRV or replace the tiny-bip39 
-# dependency https://github.com/bitcoindevkit/bdk/issues/399 we can only use an older version
-tiny-bip39 = { version = "< 0.8", optional = true }
-
+bip39 = { version = "1.0.1", optional = true }
 bitcoinconsensus = { version = "0.19.0-3", optional = true }
 
 # Needed by bdk_blockchain_tests macro
-core-rpc = { version = "0.14", optional = true }
+bitcoincore-rpc = { version = "0.14", optional = true }
 
 # Platform-specific dependencies
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
@@ -57,12 +54,12 @@ minimal = []
 compiler = ["miniscript/compiler"]
 verify = ["bitcoinconsensus"]
 default = ["key-value-db", "electrum"]
-sqlite = ["rusqlite"]
+sqlite = ["rusqlite", "ahash"]
 compact_filters = ["rocksdb", "socks", "lazy_static", "cc"]
 key-value-db = ["sled"]
 all-keys = ["keys-bip39"]
-keys-bip39 = ["tiny-bip39"]
-rpc = ["core-rpc"]
+keys-bip39 = ["bip39"]
+rpc = ["bitcoincore-rpc"]
 
 # We currently provide mulitple implementations of `Blockchain`, all are
 # blocking except for the `EsploraBlockchain` which can be either async or
@@ -85,9 +82,11 @@ use-esplora-ureq = ["esplora", "ureq", "ureq/socks"]
 # Typical configurations will not need to use `esplora` feature directly.
 esplora = []
 
+# Use below feature with `use-esplora-reqwest` to enable reqwest default TLS support
+reqwest-default-tls = ["reqwest/default-tls"]
 
 # Debug/Test features
-test-blockchains = ["core-rpc", "electrum-client"]
+test-blockchains = ["bitcoincore-rpc", "electrum-client"]
 test-electrum = ["electrum", "electrsd/electrs_0_8_10", "test-blockchains"]
 test-rpc = ["rpc", "electrsd/electrs_0_8_10", "test-blockchains"]
 test-esplora = ["electrsd/legacy", "electrsd/esplora_a33e97e1", "test-blockchains"]
@@ -97,7 +96,7 @@ test-md-docs = ["electrum"]
 lazy_static = "1.4"
 env_logger = "0.7"
 clap = "2.33"
-electrsd = { version= "0.10", features = ["trigger", "bitcoind_0_21_1"] }
+electrsd = { version= "0.13", features = ["trigger", "bitcoind_22_0"] }
 
 [[example]]
 name = "address_validator"
@@ -113,6 +112,6 @@ required-features = ["compiler"]
 [workspace]
 members = ["macros"]
 [package.metadata.docs.rs]
-features = ["compiler", "electrum", "esplora", "ureq", "compact_filters", "rpc", "key-value-db", "all-keys", "verify"]
+features = ["compiler", "electrum", "esplora", "ureq", "compact_filters", "rpc", "key-value-db", "sqlite", "all-keys", "verify"]
 # defines the configuration attribute `docsrs`
 rustdoc-args = ["--cfg", "docsrs"]

DEVELOPMENT_CYCLE.md

@@ -39,7 +39,7 @@ Pre-`v1.0.0` our "major" releases only affect the "minor" semver value. Accordin
 11. Publish **all** the updated crates to crates.io.
 12. Make a new commit to bump the version value to `x.y.(z+1)-dev`. The message should be "Bump version to x.y.(z+1)-dev".
 13. Merge the release branch back into `master`.
-14. If the `master` branch contains any unreleased changes to the `bdk-macros`, `bdk-testutils`, or `bdk-testutils-macros` crates, change the `bdk` Cargo.toml `[dev-dependencies]` to point to the local path (ie. `bdk-testutils-macros = { path = "./testutils-macros"}`)
+14. If the `master` branch contains any unreleased changes to the `bdk-macros` crate, change the `bdk` Cargo.toml `[dependencies]` to point to the local path (ie. `bdk-macros = { path = "./macros"}`)
 15. Create the release on GitHub: go to "tags", click on the dots on the right and select "Create Release". Then set the title to `vx.y.z` and write down some brief release notes.
 16. Make sure the new release shows up on crates.io and that the docs are built correctly on docs.rs.
 17. Announce the release on Twitter, Discord and Telegram.

README.md

@@ -1,7 +1,7 @@
 <div align="center">
   <h1>BDK</h1>
 
-  <img src="./static/bdk.svg" width="220" />
+  <img src="./static/bdk.png" width="220" />
 
   <p>
     <strong>A modern, lightweight, descriptor-based wallet library written in Rust!</strong>
@@ -41,21 +41,21 @@ The `bdk` library aims to be the core building block for Bitcoin wallets of any
 ```rust,no_run
 use bdk::Wallet;
 use bdk::database::MemoryDatabase;
-use bdk::blockchain::{noop_progress, ElectrumBlockchain};
+use bdk::blockchain::ElectrumBlockchain;
+use bdk::SyncOptions;
 
 use bdk::electrum_client::Client;
 
 fn main() -> Result<(), bdk::Error> {
-    let client = Client::new("ssl://electrum.blockstream.info:60002")?;
+    let blockchain = ElectrumBlockchain::from(Client::new("ssl://electrum.blockstream.info:60002")?);
     let wallet = Wallet::new(
         "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",
         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
         bitcoin::Network::Testnet,
         MemoryDatabase::default(),
-        ElectrumBlockchain::from(client)
     )?;
 
-    wallet.sync(noop_progress(), None)?;
+    wallet.sync(&blockchain, SyncOptions::default())?;
 
     println!("Descriptor balance: {} SAT", wallet.get_balance()?);
 
@@ -70,7 +70,7 @@ use bdk::{Wallet, database::MemoryDatabase};
 use bdk::wallet::AddressIndex::New;
 
 fn main() -> Result<(), bdk::Error> {
-    let wallet = Wallet::new_offline(
+    let wallet = Wallet::new(
         "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",
         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
         bitcoin::Network::Testnet,
@@ -88,9 +88,9 @@ fn main() -> Result<(), bdk::Error> {
 ### Create a transaction
 
 ```rust,no_run
-use bdk::{FeeRate, Wallet};
+use bdk::{FeeRate, Wallet, SyncOptions};
 use bdk::database::MemoryDatabase;
-use bdk::blockchain::{noop_progress, ElectrumBlockchain};
+use bdk::blockchain::ElectrumBlockchain;
 
 use bdk::electrum_client::Client;
 use bdk::wallet::AddressIndex::New;
@@ -98,16 +98,15 @@ use bdk::wallet::AddressIndex::New;
 use bitcoin::consensus::serialize;
 
 fn main() -> Result<(), bdk::Error> {
-    let client = Client::new("ssl://electrum.blockstream.info:60002")?;
+    let blockchain = ElectrumBlockchain::from(Client::new("ssl://electrum.blockstream.info:60002")?);
     let wallet = Wallet::new(
         "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",
         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
         bitcoin::Network::Testnet,
         MemoryDatabase::default(),
-        ElectrumBlockchain::from(client)
     )?;
 
-    wallet.sync(noop_progress(), None)?;
+    wallet.sync(&blockchain, SyncOptions::default())?;
 
     let send_to = wallet.get_address(New)?;
     let (psbt, details) = {
@@ -135,7 +134,7 @@ use bdk::{Wallet, SignOptions, database::MemoryDatabase};
 use bitcoin::consensus::deserialize;
 
 fn main() -> Result<(), bdk::Error> {
-    let wallet = Wallet::new_offline(
+    let wallet = Wallet::new(
         "wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/0/*)",
         Some("wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/1/*)"),
         bitcoin::Network::Testnet,

examples/address_validator.rs

@@ -48,8 +48,7 @@ impl AddressValidator for DummyValidator {
 
 fn main() -> Result<(), bdk::Error> {
     let descriptor = "sh(and_v(v:pk(tpubDDpWvmUrPZrhSPmUzCMBHffvC3HyMAPnWDSAQNBTnj1iZeJa7BZQEttFiP4DS4GCcXQHezdXhn86Hj6LHX5EDstXPWrMaSneRWM8yUf6NFd/*),after(630000)))";
-    let mut wallet =
-        Wallet::new_offline(descriptor, None, Network::Regtest, MemoryDatabase::new())?;
+    let mut wallet = Wallet::new(descriptor, None, Network::Regtest, MemoryDatabase::new())?;
 
     wallet.add_address_validator(Arc::new(DummyValidator));
 

examples/compact_filters_balance.rs

@@ -10,7 +10,6 @@
 // licenses.
 
 use bdk::blockchain::compact_filters::*;
-use bdk::blockchain::noop_progress;
 use bdk::database::MemoryDatabase;
 use bdk::*;
 use bitcoin::*;
@@ -35,9 +34,8 @@ fn main() -> Result<(), CompactFiltersError> {
     let descriptor = "wpkh(tpubD6NzVbkrYhZ4X2yy78HWrr1M9NT8dKeWfzNiQqDdMqqa9UmmGztGGz6TaLFGsLfdft5iu32gxq1T4eMNxExNNWzVCpf9Y6JZi5TnqoC9wJq/*)";
 
     let database = MemoryDatabase::default();
-    let wallet =
-        Arc::new(Wallet::new(descriptor, None, Network::Testnet, database, blockchain).unwrap());
-    wallet.sync(noop_progress(), None).unwrap();
+    let wallet = Arc::new(Wallet::new(descriptor, None, Network::Testnet, database).unwrap());
+    wallet.sync(&blockchain, SyncOptions::default()).unwrap();
     info!("balance: {}", wallet.get_balance()?);
     Ok(())
 }

examples/compiler.rs

@@ -70,7 +70,7 @@ fn main() -> Result<(), Box<dyn Error>> {
     let policy_str = matches.value_of("POLICY").unwrap();
     info!("Compiling policy: {}", policy_str);
 
-    let policy = Concrete::<String>::from_str(&policy_str)?;
+    let policy = Concrete::<String>::from_str(policy_str)?;
 
     let descriptor = match matches.value_of("TYPE").unwrap() {
         "sh" => Descriptor::new_sh(policy.compile()?)?,
@@ -89,7 +89,7 @@ fn main() -> Result<(), Box<dyn Error>> {
         .transpose()
         .unwrap()
         .unwrap_or(Network::Testnet);
-    let wallet = Wallet::new_offline(&format!("{}", descriptor), None, network, database)?;
+    let wallet = Wallet::new(&format!("{}", descriptor), None, network, database)?;
 
     info!("... First address: {}", wallet.get_address(New)?);
 

src/blockchain/any.rs

@@ -16,61 +16,17 @@
 //!
 //! ## Example
 //!
-//! In this example both `wallet_electrum` and `wallet_esplora` have the same type of
-//! `Wallet<AnyBlockchain, MemoryDatabase>`. This means that they could both, for instance, be
-//! assigned to a struct member.
-//!
-//! ```no_run
-//! # use bitcoin::Network;
-//! # use bdk::blockchain::*;
-//! # use bdk::database::MemoryDatabase;
-//! # use bdk::Wallet;
-//! # #[cfg(feature = "electrum")]
-//! # {
-//! let electrum_blockchain = ElectrumBlockchain::from(electrum_client::Client::new("...")?);
-//! let wallet_electrum: Wallet<AnyBlockchain, _> = Wallet::new(
-//!     "...",
-//!     None,
-//!     Network::Testnet,
-//!     MemoryDatabase::default(),
-//!     electrum_blockchain.into(),
-//! )?;
-//! # }
-//!
-//! # #[cfg(all(feature = "esplora", feature = "ureq"))]
-//! # {
-//! let esplora_blockchain = EsploraBlockchain::new("...", 20);
-//! let wallet_esplora: Wallet<AnyBlockchain, _> = Wallet::new(
-//!     "...",
-//!     None,
-//!     Network::Testnet,
-//!     MemoryDatabase::default(),
-//!     esplora_blockchain.into(),
-//! )?;
-//! # }
-//!
-//! # Ok::<(), bdk::Error>(())
-//! ```
-//!
 //! When paired with the use of [`ConfigurableBlockchain`], it allows creating wallets with any
 //! blockchain type supported using a single line of code:
 //!
 //! ```no_run
 //! # use bitcoin::Network;
 //! # use bdk::blockchain::*;
-//! # use bdk::database::MemoryDatabase;
-//! # use bdk::Wallet;
 //! # #[cfg(all(feature = "esplora", feature = "ureq"))]
 //! # {
 //! let config = serde_json::from_str("...")?;
 //! let blockchain = AnyBlockchain::from_config(&config)?;
-//! let wallet = Wallet::new(
-//!     "...",
-//!     None,
-//!     Network::Testnet,
-//!     MemoryDatabase::default(),
-//!     blockchain,
-//! )?;
+//! let height = blockchain.get_height();
 //! # }
 //! # Ok::<(), bdk::Error>(())
 //! ```
@@ -133,21 +89,6 @@ impl Blockchain for AnyBlockchain {
         maybe_await!(impl_inner_method!(self, get_capabilities))
     }
 
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        maybe_await!(impl_inner_method!(self, setup, database, progress_update))
-    }
-    fn sync<D: BatchDatabase, P: 'static + Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        maybe_await!(impl_inner_method!(self, sync, database, progress_update))
-    }
-
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
         maybe_await!(impl_inner_method!(self, get_tx, txid))
     }
@@ -155,11 +96,42 @@ impl Blockchain for AnyBlockchain {
         maybe_await!(impl_inner_method!(self, broadcast, tx))
     }
 
+    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
+        maybe_await!(impl_inner_method!(self, estimate_fee, target))
+    }
+}
+
+impl GetHeight for AnyBlockchain {
     fn get_height(&self) -> Result<u32, Error> {
         maybe_await!(impl_inner_method!(self, get_height))
     }
-    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        maybe_await!(impl_inner_method!(self, estimate_fee, target))
+}
+
+impl WalletSync for AnyBlockchain {
+    fn wallet_sync<D: BatchDatabase>(
+        &self,
+        database: &mut D,
+        progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        maybe_await!(impl_inner_method!(
+            self,
+            wallet_sync,
+            database,
+            progress_update
+        ))
+    }
+
+    fn wallet_setup<D: BatchDatabase>(
+        &self,
+        database: &mut D,
+        progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        maybe_await!(impl_inner_method!(
+            self,
+            wallet_setup,
+            database,
+            progress_update
+        ))
     }
 }
 

src/blockchain/compact_filters/mod.rs

@@ -67,11 +67,11 @@ mod peer;
 mod store;
 mod sync;
 
-use super::{Blockchain, Capability, ConfigurableBlockchain, Progress};
+use super::{Blockchain, Capability, ConfigurableBlockchain, GetHeight, Progress, WalletSync};
 use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils};
 use crate::error::Error;
 use crate::types::{KeychainKind, LocalUtxo, TransactionDetails};
-use crate::{ConfirmationTime, FeeRate};
+use crate::{BlockTime, FeeRate};
 
 use peer::*;
 use store::*;
@@ -206,7 +206,7 @@ impl CompactFiltersBlockchain {
                 transaction: Some(tx.clone()),
                 received: incoming,
                 sent: outgoing,
-                confirmation_time: ConfirmationTime::new(height, timestamp),
+                confirmation_time: BlockTime::new(height, timestamp),
                 verified: height.is_some(),
                 fee: Some(inputs_sum.saturating_sub(outputs_sum)),
             };
@@ -226,11 +226,36 @@ impl Blockchain for CompactFiltersBlockchain {
         vec![Capability::FullHistory].into_iter().collect()
     }
 
+    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+        Ok(self.peers[0]
+            .get_mempool()
+            .get_tx(&Inventory::Transaction(*txid)))
+    }
+
+    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
+        self.peers[0].broadcast_tx(tx.clone())?;
+
+        Ok(())
+    }
+
+    fn estimate_fee(&self, _target: usize) -> Result<FeeRate, Error> {
+        // TODO
+        Ok(FeeRate::default())
+    }
+}
+
+impl GetHeight for CompactFiltersBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        Ok(self.headers.get_height()? as u32)
+    }
+}
+
+impl WalletSync for CompactFiltersBlockchain {
     #[allow(clippy::mutex_atomic)] // Mutex is easier to understand than a CAS loop.
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
+    fn wallet_setup<D: BatchDatabase>(
         &self,
         database: &mut D,
-        progress_update: P,
+        progress_update: Box<dyn Progress>,
     ) -> Result<(), Error> {
         let first_peer = &self.peers[0];
 
@@ -254,7 +279,7 @@ impl Blockchain for CompactFiltersBlockchain {
         let total_cost = headers_cost + filters_cost + PROCESS_BLOCKS_COST;
 
         if let Some(snapshot) = sync::sync_headers(
-            Arc::clone(&first_peer),
+            Arc::clone(first_peer),
             Arc::clone(&self.headers),
             |new_height| {
                 let local_headers_cost =
@@ -275,7 +300,7 @@ impl Blockchain for CompactFiltersBlockchain {
         let buried_height = synced_height.saturating_sub(sync::BURIED_CONFIRMATIONS);
         info!("Synced headers to height: {}", synced_height);
 
-        cf_sync.prepare_sync(Arc::clone(&first_peer))?;
+        cf_sync.prepare_sync(Arc::clone(first_peer))?;
 
         let all_scripts = Arc::new(
             database
@@ -294,7 +319,7 @@ impl Blockchain for CompactFiltersBlockchain {
         let mut threads = Vec::with_capacity(self.peers.len());
         for peer in &self.peers {
             let cf_sync = Arc::clone(&cf_sync);
-            let peer = Arc::clone(&peer);
+            let peer = Arc::clone(peer);
             let headers = Arc::clone(&self.headers);
             let all_scripts = Arc::clone(&all_scripts);
             let last_synced_block = Arc::clone(&last_synced_block);
@@ -431,27 +456,6 @@ impl Blockchain for CompactFiltersBlockchain {
 
         Ok(())
     }
-
-    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(self.peers[0]
-            .get_mempool()
-            .get_tx(&Inventory::Transaction(*txid)))
-    }
-
-    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        self.peers[0].broadcast_tx(tx.clone())?;
-
-        Ok(())
-    }
-
-    fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.headers.get_height()? as u32)
-    }
-
-    fn estimate_fee(&self, _target: usize) -> Result<FeeRate, Error> {
-        // TODO
-        Ok(FeeRate::default())
-    }
 }
 
 /// Data to connect to a Bitcoin P2P peer
@@ -472,7 +476,7 @@ pub struct CompactFiltersBlockchainConfig {
     pub peers: Vec<BitcoinPeerConfig>,
     /// Network used
     pub network: Network,
-    /// Storage dir to save partially downloaded headers and full blocks
+    /// Storage dir to save partially downloaded headers and full blocks. Should be a separate directory per descriptor. Consider using [crate::wallet::wallet_name_from_descriptor] for this.
     pub storage_dir: String,
     /// Optionally skip initial `skip_blocks` blocks (default: 0)
     pub skip_blocks: Option<usize>,

src/blockchain/compact_filters/peer.rs

@@ -262,7 +262,7 @@ impl Peer {
         let message_resp = {
             let mut lock = responses.write().unwrap();
             let message_resp = lock.entry(wait_for).or_default();
-            Arc::clone(&message_resp)
+            Arc::clone(message_resp)
         };
 
         let (lock, cvar) = &*message_resp;
@@ -379,7 +379,7 @@ impl Peer {
             let message_resp = {
                 let mut lock = reader_thread_responses.write().unwrap();
                 let message_resp = lock.entry(in_message.cmd()).or_default();
-                Arc::clone(&message_resp)
+                Arc::clone(message_resp)
             };
 
             let (lock, cvar) = &*message_resp;

src/blockchain/compact_filters/store.rs

@@ -398,7 +398,7 @@ impl ChainStore<Full> {
             );
         }
 
-        // Delete full blocks overriden by snapshot
+        // Delete full blocks overridden by snapshot
         let from_key = StoreEntry::Block(Some(snaphost.min_height)).get_key();
         let to_key = StoreEntry::Block(Some(usize::MAX)).get_key();
         batch.delete_range(&from_key, &to_key);
@@ -760,7 +760,7 @@ impl CfStore {
         let cf_headers: Vec<FilterHeader> = filter_hashes
             .into_iter()
             .scan(checkpoint, |prev_header, filter_hash| {
-                let filter_header = filter_hash.filter_header(&prev_header);
+                let filter_header = filter_hash.filter_header(prev_header);
                 *prev_header = filter_header;
 
                 Some(filter_header)
@@ -801,7 +801,7 @@ impl CfStore {
             .zip(headers.into_iter())
             .scan(checkpoint, |prev_header, ((_, filter_content), header)| {
                 let filter = BlockFilter::new(&filter_content);
-                if header != filter.filter_header(&prev_header) {
+                if header != filter.filter_header(prev_header) {
                     return Some(Err(CompactFiltersError::InvalidFilter));
                 }
                 *prev_header = header;

src/blockchain/compact_filters/sync.rs

@@ -205,7 +205,7 @@ impl CfSync {
                     let block_hash = self.headers_store.get_block_hash(height)?.unwrap();
 
                     // TODO: also download random blocks?
-                    if process(&block_hash, &BlockFilter::new(&filter))? {
+                    if process(&block_hash, &BlockFilter::new(filter))? {
                         log::debug!("Downloading block {}", block_hash);
 
                         let block = peer

src/blockchain/electrum.rs

@@ -24,20 +24,20 @@
 //! # Ok::<(), bdk::Error>(())
 //! ```
 
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use bitcoin::{BlockHeader, Script, Transaction, Txid};
+use bitcoin::{Transaction, Txid};
 
 use electrum_client::{Client, ConfigBuilder, ElectrumApi, Socks5Config};
 
-use self::utils::{ElectrumLikeSync, ElsGetHistoryRes};
+use super::script_sync::Request;
 use super::*;
-use crate::database::BatchDatabase;
+use crate::database::{BatchDatabase, Database};
 use crate::error::Error;
-use crate::FeeRate;
+use crate::{BlockTime, FeeRate};
 
 /// Wrapper over an Electrum Client that implements the required blockchain traits
 ///
@@ -68,15 +68,6 @@ impl Blockchain for ElectrumBlockchain {
         .collect()
     }
 
-    fn setup<D: BatchDatabase, P: Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        self.client
-            .electrum_like_setup(self.stop_gap, database, progress_update)
-    }
-
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
         Ok(self.client.transaction_get(txid).map(Option::Some)?)
     }
@@ -85,15 +76,6 @@ impl Blockchain for ElectrumBlockchain {
         Ok(self.client.transaction_broadcast(tx).map(|_| ())?)
     }
 
-    fn get_height(&self) -> Result<u32, Error> {
-        // TODO: unsubscribe when added to the client, or is there a better call to use here?
-
-        Ok(self
-            .client
-            .block_headers_subscribe()
-            .map(|data| data.height as u32)?)
-    }
-
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
         Ok(FeeRate::from_btc_per_kvb(
             self.client.estimate_fee(target)? as f32
@@ -101,43 +83,199 @@ impl Blockchain for ElectrumBlockchain {
     }
 }
 
-impl ElectrumLikeSync for Client {
-    fn els_batch_script_get_history<'s, I: IntoIterator<Item = &'s Script> + Clone>(
+impl GetHeight for ElectrumBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        // TODO: unsubscribe when added to the client, or is there a better call to use here?
+
+        Ok(self
+            .client
+            .block_headers_subscribe()
+            .map(|data| data.height as u32)?)
+    }
+}
+
+impl WalletSync for ElectrumBlockchain {
+    fn wallet_setup<D: BatchDatabase>(
         &self,
-        scripts: I,
-    ) -> Result<Vec<Vec<ElsGetHistoryRes>>, Error> {
-        self.batch_script_get_history(scripts)
-            .map(|v| {
-                v.into_iter()
-                    .map(|v| {
-                        v.into_iter()
-                            .map(
-                                |electrum_client::GetHistoryRes {
-                                     height, tx_hash, ..
-                                 }| ElsGetHistoryRes {
-                                    height,
-                                    tx_hash,
-                                },
-                            )
-                            .collect()
-                    })
-                    .collect()
-            })
-            .map_err(Error::Electrum)
+        database: &mut D,
+        _progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        let mut request = script_sync::start(database, self.stop_gap)?;
+        let mut block_times = HashMap::<u32, u32>::new();
+        let mut txid_to_height = HashMap::<Txid, u32>::new();
+        let mut tx_cache = TxCache::new(database, &self.client);
+        let chunk_size = self.stop_gap;
+        // The electrum server has been inconsistent somehow in its responses during sync. For
+        // example, we do a batch request of transactions and the response contains less
+        // tranascations than in the request. This should never happen but we don't want to panic.
+        let electrum_goof = || Error::Generic("electrum server misbehaving".to_string());
+
+        let batch_update = loop {
+            request = match request {
+                Request::Script(script_req) => {
+                    let scripts = script_req.request().take(chunk_size);
+                    let txids_per_script: Vec<Vec<_>> = self
+                        .client
+                        .batch_script_get_history(scripts)
+                        .map_err(Error::Electrum)?
+                        .into_iter()
+                        .map(|txs| {
+                            txs.into_iter()
+                                .map(|tx| {
+                                    let tx_height = match tx.height {
+                                        none if none <= 0 => None,
+                                        height => {
+                                            txid_to_height.insert(tx.tx_hash, height as u32);
+                                            Some(height as u32)
+                                        }
+                                    };
+                                    (tx.tx_hash, tx_height)
+                                })
+                                .collect()
+                        })
+                        .collect();
+
+                    script_req.satisfy(txids_per_script)?
+                }
+
+                Request::Conftime(conftime_req) => {
+                    // collect up to chunk_size heights to fetch from electrum
+                    let needs_block_height = {
+                        let mut needs_block_height_iter = conftime_req
+                            .request()
+                            .filter_map(|txid| txid_to_height.get(txid).cloned())
+                            .filter(|height| block_times.get(height).is_none());
+                        let mut needs_block_height = HashSet::new();
+
+                        while needs_block_height.len() < chunk_size {
+                            match needs_block_height_iter.next() {
+                                Some(height) => needs_block_height.insert(height),
+                                None => break,
+                            };
+                        }
+                        needs_block_height
+                    };
+
+                    let new_block_headers = self
+                        .client
+                        .batch_block_header(needs_block_height.iter().cloned())?;
+
+                    for (height, header) in needs_block_height.into_iter().zip(new_block_headers) {
+                        block_times.insert(height, header.time);
+                    }
+
+                    let conftimes = conftime_req
+                        .request()
+                        .take(chunk_size)
+                        .map(|txid| {
+                            let confirmation_time = txid_to_height
+                                .get(txid)
+                                .map(|height| {
+                                    let timestamp =
+                                        *block_times.get(height).ok_or_else(electrum_goof)?;
+                                    Result::<_, Error>::Ok(BlockTime {
+                                        height: *height,
+                                        timestamp: timestamp.into(),
+                                    })
+                                })
+                                .transpose()?;
+                            Ok(confirmation_time)
+                        })
+                        .collect::<Result<_, Error>>()?;
+
+                    conftime_req.satisfy(conftimes)?
+                }
+                Request::Tx(tx_req) => {
+                    let needs_full = tx_req.request().take(chunk_size);
+                    tx_cache.save_txs(needs_full.clone())?;
+                    let full_transactions = needs_full
+                        .map(|txid| tx_cache.get(*txid).ok_or_else(electrum_goof))
+                        .collect::<Result<Vec<_>, _>>()?;
+                    let input_txs = full_transactions.iter().flat_map(|tx| {
+                        tx.input
+                            .iter()
+                            .filter(|input| !input.previous_output.is_null())
+                            .map(|input| &input.previous_output.txid)
+                    });
+                    tx_cache.save_txs(input_txs)?;
+
+                    let full_details = full_transactions
+                        .into_iter()
+                        .map(|tx| {
+                            let prev_outputs = tx
+                                .input
+                                .iter()
+                                .map(|input| {
+                                    if input.previous_output.is_null() {
+                                        return Ok(None);
+                                    }
+                                    let prev_tx = tx_cache
+                                        .get(input.previous_output.txid)
+                                        .ok_or_else(electrum_goof)?;
+                                    let txout = prev_tx
+                                        .output
+                                        .get(input.previous_output.vout as usize)
+                                        .ok_or_else(electrum_goof)?;
+                                    Ok(Some(txout.clone()))
+                                })
+                                .collect::<Result<Vec<_>, Error>>()?;
+                            Ok((prev_outputs, tx))
+                        })
+                        .collect::<Result<Vec<_>, Error>>()?;
+
+                    tx_req.satisfy(full_details)?
+                }
+                Request::Finish(batch_update) => break batch_update,
+            }
+        };
+
+        database.commit_batch(batch_update)?;
+        Ok(())
+    }
+}
+
+struct TxCache<'a, 'b, D> {
+    db: &'a D,
+    client: &'b Client,
+    cache: HashMap<Txid, Transaction>,
+}
+
+impl<'a, 'b, D: Database> TxCache<'a, 'b, D> {
+    fn new(db: &'a D, client: &'b Client) -> Self {
+        TxCache {
+            db,
+            client,
+            cache: HashMap::default(),
+        }
+    }
+    fn save_txs<'c>(&mut self, txids: impl Iterator<Item = &'c Txid>) -> Result<(), Error> {
+        let mut need_fetch = vec![];
+        for txid in txids {
+            if self.cache.get(txid).is_some() {
+                continue;
+            } else if let Some(transaction) = self.db.get_raw_tx(txid)? {
+                self.cache.insert(*txid, transaction);
+            } else {
+                need_fetch.push(txid);
+            }
+        }
+
+        if !need_fetch.is_empty() {
+            let txs = self
+                .client
+                .batch_transaction_get(need_fetch.clone())
+                .map_err(Error::Electrum)?;
+            for (tx, _txid) in txs.into_iter().zip(need_fetch) {
+                debug_assert_eq!(*_txid, tx.txid());
+                self.cache.insert(tx.txid(), tx);
+            }
+        }
+
+        Ok(())
     }
 
-    fn els_batch_transaction_get<'s, I: IntoIterator<Item = &'s Txid> + Clone>(
-        &self,
-        txids: I,
-    ) -> Result<Vec<Transaction>, Error> {
-        self.batch_transaction_get(txids).map_err(Error::Electrum)
-    }
-
-    fn els_batch_block_header<I: IntoIterator<Item = u32> + Clone>(
-        &self,
-        heights: I,
-    ) -> Result<Vec<BlockHeader>, Error> {
-        self.batch_block_header(heights).map_err(Error::Electrum)
+    fn get(&self, txid: Txid) -> Option<Transaction> {
+        self.cache.get(&txid).map(Clone::clone)
     }
 }
 

src/blockchain/esplora/api.rs

@@ -0,0 +1,117 @@
+//! structs from the esplora API
+//!
+//! see: <https://github.com/Blockstream/esplora/blob/master/API.md>
+use crate::BlockTime;
+use bitcoin::{OutPoint, Script, Transaction, TxIn, TxOut, Txid};
+
+#[derive(serde::Deserialize, Clone, Debug)]
+pub struct PrevOut {
+    pub value: u64,
+    pub scriptpubkey: Script,
+}
+
+#[derive(serde::Deserialize, Clone, Debug)]
+pub struct Vin {
+    pub txid: Txid,
+    pub vout: u32,
+    // None if coinbase
+    pub prevout: Option<PrevOut>,
+    pub scriptsig: Script,
+    #[serde(deserialize_with = "deserialize_witness")]
+    pub witness: Vec<Vec<u8>>,
+    pub sequence: u32,
+    pub is_coinbase: bool,
+}
+
+#[derive(serde::Deserialize, Clone, Debug)]
+pub struct Vout {
+    pub value: u64,
+    pub scriptpubkey: Script,
+}
+
+#[derive(serde::Deserialize, Clone, Debug)]
+pub struct TxStatus {
+    pub confirmed: bool,
+    pub block_height: Option<u32>,
+    pub block_time: Option<u64>,
+}
+
+#[derive(serde::Deserialize, Clone, Debug)]
+pub struct Tx {
+    pub txid: Txid,
+    pub version: i32,
+    pub locktime: u32,
+    pub vin: Vec<Vin>,
+    pub vout: Vec<Vout>,
+    pub status: TxStatus,
+    pub fee: u64,
+}
+
+impl Tx {
+    pub fn to_tx(&self) -> Transaction {
+        Transaction {
+            version: self.version,
+            lock_time: self.locktime,
+            input: self
+                .vin
+                .iter()
+                .cloned()
+                .map(|vin| TxIn {
+                    previous_output: OutPoint {
+                        txid: vin.txid,
+                        vout: vin.vout,
+                    },
+                    script_sig: vin.scriptsig,
+                    sequence: vin.sequence,
+                    witness: vin.witness,
+                })
+                .collect(),
+            output: self
+                .vout
+                .iter()
+                .cloned()
+                .map(|vout| TxOut {
+                    value: vout.value,
+                    script_pubkey: vout.scriptpubkey,
+                })
+                .collect(),
+        }
+    }
+
+    pub fn confirmation_time(&self) -> Option<BlockTime> {
+        match self.status {
+            TxStatus {
+                confirmed: true,
+                block_height: Some(height),
+                block_time: Some(timestamp),
+            } => Some(BlockTime { timestamp, height }),
+            _ => None,
+        }
+    }
+
+    pub fn previous_outputs(&self) -> Vec<Option<TxOut>> {
+        self.vin
+            .iter()
+            .cloned()
+            .map(|vin| {
+                vin.prevout.map(|po| TxOut {
+                    script_pubkey: po.scriptpubkey,
+                    value: po.value,
+                })
+            })
+            .collect()
+    }
+}
+
+fn deserialize_witness<'de, D>(d: D) -> Result<Vec<Vec<u8>>, D::Error>
+where
+    D: serde::de::Deserializer<'de>,
+{
+    use crate::serde::Deserialize;
+    use bitcoin::hashes::hex::FromHex;
+    let list = Vec::<String>::deserialize(d)?;
+    list.into_iter()
+        .map(|hex_str| Vec::<u8>::from_hex(&hex_str))
+        .collect::<Result<Vec<Vec<u8>>, _>>()
+        .map_err(serde::de::Error::custom)
+}

src/blockchain/esplora/mod.rs

@@ -21,8 +21,6 @@ use std::collections::HashMap;
 use std::fmt;
 use std::io;
 
-use serde::Deserialize;
-
 use bitcoin::consensus;
 use bitcoin::{BlockHash, Txid};
 
@@ -41,33 +39,24 @@ mod ureq;
 #[cfg(feature = "ureq")]
 pub use self::ureq::*;
 
+mod api;
+
 fn into_fee_rate(target: usize, estimates: HashMap<String, f64>) -> Result<FeeRate, Error> {
-    let fee_val = estimates
-        .into_iter()
-        .map(|(k, v)| Ok::<_, std::num::ParseIntError>((k.parse::<usize>()?, v)))
-        .collect::<Result<Vec<_>, _>>()
-        .map_err(|e| Error::Generic(e.to_string()))?
-        .into_iter()
-        .take_while(|(k, _)| k <= &target)
-        .map(|(_, v)| v)
-        .last()
-        .unwrap_or(1.0);
-
+    let fee_val = {
+        let mut pairs = estimates
+            .into_iter()
+            .filter_map(|(k, v)| Some((k.parse::<usize>().ok()?, v)))
+            .collect::<Vec<_>>();
+        pairs.sort_unstable_by_key(|(k, _)| std::cmp::Reverse(*k));
+        pairs
+            .into_iter()
+            .find(|(k, _)| k <= &target)
+            .map(|(_, v)| v)
+            .unwrap_or(1.0)
+    };
     Ok(FeeRate::from_sat_per_vb(fee_val as f32))
 }
 
-/// Data type used when fetching transaction history from Esplora.
-#[derive(Deserialize)]
-pub struct EsploraGetHistory {
-    txid: Txid,
-    status: EsploraGetHistoryStatus,
-}
-
-#[derive(Deserialize)]
-struct EsploraGetHistoryStatus {
-    block_height: Option<usize>,
-}
-
 /// Errors that can happen during a sync with [`EsploraBlockchain`]
 #[derive(Debug)]
 pub enum EsploraError {
@@ -107,10 +96,50 @@ impl fmt::Display for EsploraError {
     }
 }
 
+/// Configuration for an [`EsploraBlockchain`]
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone, PartialEq)]
+pub struct EsploraBlockchainConfig {
+    /// Base URL of the esplora service
+    ///
+    /// eg. `https://blockstream.info/api/`
+    pub base_url: String,
+    /// Optional URL of the proxy to use to make requests to the Esplora server
+    ///
+    /// The string should be formatted as: `<protocol>://<user>:<password>@host:<port>`.
+    ///
+    /// Note that the format of this value and the supported protocols change slightly between the
+    /// sync version of esplora (using `ureq`) and the async version (using `reqwest`). For more
+    /// details check with the documentation of the two crates. Both of them are compiled with
+    /// the `socks` feature enabled.
+    ///
+    /// The proxy is ignored when targeting `wasm32`.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub proxy: Option<String>,
+    /// Number of parallel requests sent to the esplora service (default: 4)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub concurrency: Option<u8>,
+    /// Stop searching addresses for transactions after finding an unused gap of this length.
+    pub stop_gap: usize,
+    /// Socket timeout.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub timeout: Option<u64>,
+}
+
+impl EsploraBlockchainConfig {
+    /// create a config with default values given the base url and stop gap
+    pub fn new(base_url: String, stop_gap: usize) -> Self {
+        Self {
+            base_url,
+            proxy: None,
+            timeout: None,
+            stop_gap,
+            concurrency: None,
+        }
+    }
+}
+
 impl std::error::Error for EsploraError {}
 
-#[cfg(feature = "ureq")]
-impl_error!(::ureq::Error, Ureq, EsploraError);
 #[cfg(feature = "ureq")]
 impl_error!(::ureq::Transport, UreqTransport, EsploraError);
 #[cfg(feature = "reqwest")]
@@ -127,3 +156,57 @@ crate::bdk_blockchain_tests! {
         EsploraBlockchain::new(&format!("http://{}",test_client.electrsd.esplora_url.as_ref().unwrap()), 20)
     }
 }
+
+const DEFAULT_CONCURRENT_REQUESTS: u8 = 4;
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn feerate_parsing() {
+        let esplora_fees = serde_json::from_str::<HashMap<String, f64>>(
+            r#"{
+  "25": 1.015,
+  "5": 2.3280000000000003,
+  "12": 2.0109999999999997,
+  "15": 1.018,
+  "17": 1.018,
+  "11": 2.0109999999999997,
+  "3": 3.01,
+  "2": 4.9830000000000005,
+  "6": 2.2359999999999998,
+  "21": 1.018,
+  "13": 1.081,
+  "7": 2.2359999999999998,
+  "8": 2.2359999999999998,
+  "16": 1.018,
+  "20": 1.018,
+  "22": 1.017,
+  "23": 1.017,
+  "504": 1,
+  "9": 2.2359999999999998,
+  "14": 1.018,
+  "10": 2.0109999999999997,
+  "24": 1.017,
+  "1008": 1,
+  "1": 4.9830000000000005,
+  "4": 2.3280000000000003,
+  "19": 1.018,
+  "144": 1,
+  "18": 1.018
+}
+"#,
+        )
+        .unwrap();
+        assert_eq!(
+            into_fee_rate(6, esplora_fees.clone()).unwrap(),
+            FeeRate::from_sat_per_vb(2.236)
+        );
+        assert_eq!(
+            into_fee_rate(26, esplora_fees).unwrap(),
+            FeeRate::from_sat_per_vb(1.015),
+            "should inherit from value for 25"
+        );
+    }
+}

src/blockchain/esplora/reqwest.rs

@@ -21,20 +21,16 @@ use bitcoin::{BlockHeader, Script, Transaction, Txid};
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use futures::stream::{self, FuturesOrdered, StreamExt, TryStreamExt};
-
 use ::reqwest::{Client, StatusCode};
+use futures::stream::{FuturesOrdered, TryStreamExt};
 
-use crate::blockchain::esplora::{EsploraError, EsploraGetHistory};
-use crate::blockchain::utils::{ElectrumLikeSync, ElsGetHistoryRes};
+use super::api::Tx;
+use crate::blockchain::esplora::EsploraError;
 use crate::blockchain::*;
 use crate::database::BatchDatabase;
 use crate::error::Error;
-use crate::wallet::utils::ChunksIterator;
 use crate::FeeRate;
 
-const DEFAULT_CONCURRENT_REQUESTS: u8 = 4;
-
 #[derive(Debug)]
 struct UrlClient {
     url: String,
@@ -70,7 +66,7 @@ impl EsploraBlockchain {
             url_client: UrlClient {
                 url: base_url.to_string(),
                 client: Client::new(),
-                concurrency: DEFAULT_CONCURRENT_REQUESTS,
+                concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
             },
             stop_gap,
         }
@@ -95,16 +91,6 @@ impl Blockchain for EsploraBlockchain {
         .collect()
     }
 
-    fn setup<D: BatchDatabase, P: Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        maybe_await!(self
-            .url_client
-            .electrum_like_setup(self.stop_gap, database, progress_update))
-    }
-
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
         Ok(await_or_block!(self.url_client._get_tx(txid))?)
     }
@@ -113,21 +99,113 @@ impl Blockchain for EsploraBlockchain {
         Ok(await_or_block!(self.url_client._broadcast(tx))?)
     }
 
-    fn get_height(&self) -> Result<u32, Error> {
-        Ok(await_or_block!(self.url_client._get_height())?)
-    }
-
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
         let estimates = await_or_block!(self.url_client._get_fee_estimates())?;
         super::into_fee_rate(target, estimates)
     }
 }
 
-impl UrlClient {
-    fn script_to_scripthash(script: &Script) -> String {
-        sha256::Hash::hash(script.as_bytes()).into_inner().to_hex()
+#[maybe_async]
+impl GetHeight for EsploraBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        Ok(await_or_block!(self.url_client._get_height())?)
     }
+}
 
+#[maybe_async]
+impl WalletSync for EsploraBlockchain {
+    fn wallet_setup<D: BatchDatabase, P: Progress>(
+        &self,
+        database: &mut D,
+        _progress_update: P,
+    ) -> Result<(), Error> {
+        use crate::blockchain::script_sync::Request;
+        let mut request = script_sync::start(database, self.stop_gap)?;
+        let mut tx_index: HashMap<Txid, Tx> = HashMap::new();
+
+        let batch_update = loop {
+            request = match request {
+                Request::Script(script_req) => {
+                    let futures: FuturesOrdered<_> = script_req
+                        .request()
+                        .take(self.url_client.concurrency as usize)
+                        .map(|script| async move {
+                            let mut related_txs: Vec<Tx> =
+                                self.url_client._scripthash_txs(script, None).await?;
+
+                            let n_confirmed =
+                                related_txs.iter().filter(|tx| tx.status.confirmed).count();
+                            // esplora pages on 25 confirmed transactions. If there's 25 or more we
+                            // keep requesting to see if there's more.
+                            if n_confirmed >= 25 {
+                                loop {
+                                    let new_related_txs: Vec<Tx> = self
+                                        .url_client
+                                        ._scripthash_txs(
+                                            script,
+                                            Some(related_txs.last().unwrap().txid),
+                                        )
+                                        .await?;
+                                    let n = new_related_txs.len();
+                                    related_txs.extend(new_related_txs);
+                                    // we've reached the end
+                                    if n < 25 {
+                                        break;
+                                    }
+                                }
+                            }
+                            Result::<_, Error>::Ok(related_txs)
+                        })
+                        .collect();
+                    let txs_per_script: Vec<Vec<Tx>> = await_or_block!(futures.try_collect())?;
+                    let mut satisfaction = vec![];
+
+                    for txs in txs_per_script {
+                        satisfaction.push(
+                            txs.iter()
+                                .map(|tx| (tx.txid, tx.status.block_height))
+                                .collect(),
+                        );
+                        for tx in txs {
+                            tx_index.insert(tx.txid, tx);
+                        }
+                    }
+
+                    script_req.satisfy(satisfaction)?
+                }
+                Request::Conftime(conftime_req) => {
+                    let conftimes = conftime_req
+                        .request()
+                        .map(|txid| {
+                            tx_index
+                                .get(txid)
+                                .expect("must be in index")
+                                .confirmation_time()
+                        })
+                        .collect();
+                    conftime_req.satisfy(conftimes)?
+                }
+                Request::Tx(tx_req) => {
+                    let full_txs = tx_req
+                        .request()
+                        .map(|txid| {
+                            let tx = tx_index.get(txid).expect("must be in index");
+                            (tx.previous_outputs(), tx.to_tx())
+                        })
+                        .collect();
+                    tx_req.satisfy(full_txs)?
+                }
+                Request::Finish(batch_update) => break batch_update,
+            }
+        };
+
+        database.commit_batch(batch_update)?;
+
+        Ok(())
+    }
+}
+
+impl UrlClient {
     async fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
         let resp = self
             .client
@@ -196,71 +274,27 @@ impl UrlClient {
         Ok(req.error_for_status()?.text().await?.parse()?)
     }
 
-    async fn _script_get_history(
+    async fn _scripthash_txs(
         &self,
         script: &Script,
-    ) -> Result<Vec<ElsGetHistoryRes>, EsploraError> {
-        let mut result = Vec::new();
-        let scripthash = Self::script_to_scripthash(script);
-
-        // Add the unconfirmed transactions first
-        result.extend(
-            self.client
-                .get(&format!(
-                    "{}/scripthash/{}/txs/mempool",
-                    self.url, scripthash
-                ))
-                .send()
-                .await?
-                .error_for_status()?
-                .json::<Vec<EsploraGetHistory>>()
-                .await?
-                .into_iter()
-                .map(|x| ElsGetHistoryRes {
-                    tx_hash: x.txid,
-                    height: x.status.block_height.unwrap_or(0) as i32,
-                }),
-        );
-
-        debug!(
-            "Found {} mempool txs for {} - {:?}",
-            result.len(),
-            scripthash,
-            script
-        );
-
-        // Then go through all the pages of confirmed transactions
-        let mut last_txid = String::new();
-        loop {
-            let response = self
-                .client
-                .get(&format!(
-                    "{}/scripthash/{}/txs/chain/{}",
-                    self.url, scripthash, last_txid
-                ))
-                .send()
-                .await?
-                .error_for_status()?
-                .json::<Vec<EsploraGetHistory>>()
-                .await?;
-            let len = response.len();
-            if let Some(elem) = response.last() {
-                last_txid = elem.txid.to_hex();
-            }
-
-            debug!("... adding {} confirmed transactions", len);
-
-            result.extend(response.into_iter().map(|x| ElsGetHistoryRes {
-                tx_hash: x.txid,
-                height: x.status.block_height.unwrap_or(0) as i32,
-            }));
-
-            if len < 25 {
-                break;
-            }
-        }
-
-        Ok(result)
+        last_seen: Option<Txid>,
+    ) -> Result<Vec<Tx>, EsploraError> {
+        let script_hash = sha256::Hash::hash(script.as_bytes()).into_inner().to_hex();
+        let url = match last_seen {
+            Some(last_seen) => format!(
+                "{}/scripthash/{}/txs/chain/{}",
+                self.url, script_hash, last_seen
+            ),
+            None => format!("{}/scripthash/{}/txs", self.url, script_hash),
+        };
+        Ok(self
+            .client
+            .get(url)
+            .send()
+            .await?
+            .error_for_status()?
+            .json::<Vec<Tx>>()
+            .await?)
     }
 
     async fn _get_fee_estimates(&self) -> Result<HashMap<String, f64>, EsploraError> {
@@ -275,83 +309,8 @@ impl UrlClient {
     }
 }
 
-#[maybe_async]
-impl ElectrumLikeSync for UrlClient {
-    fn els_batch_script_get_history<'s, I: IntoIterator<Item = &'s Script>>(
-        &self,
-        scripts: I,
-    ) -> Result<Vec<Vec<ElsGetHistoryRes>>, Error> {
-        let mut results = vec![];
-        for chunk in ChunksIterator::new(scripts.into_iter(), self.concurrency as usize) {
-            let mut futs = FuturesOrdered::new();
-            for script in chunk {
-                futs.push(self._script_get_history(script));
-            }
-            let partial_results: Vec<Vec<ElsGetHistoryRes>> = await_or_block!(futs.try_collect())?;
-            results.extend(partial_results);
-        }
-        Ok(await_or_block!(stream::iter(results).collect()))
-    }
-
-    fn els_batch_transaction_get<'s, I: IntoIterator<Item = &'s Txid>>(
-        &self,
-        txids: I,
-    ) -> Result<Vec<Transaction>, Error> {
-        let mut results = vec![];
-        for chunk in ChunksIterator::new(txids.into_iter(), self.concurrency as usize) {
-            let mut futs = FuturesOrdered::new();
-            for txid in chunk {
-                futs.push(self._get_tx_no_opt(txid));
-            }
-            let partial_results: Vec<Transaction> = await_or_block!(futs.try_collect())?;
-            results.extend(partial_results);
-        }
-        Ok(await_or_block!(stream::iter(results).collect()))
-    }
-
-    fn els_batch_block_header<I: IntoIterator<Item = u32>>(
-        &self,
-        heights: I,
-    ) -> Result<Vec<BlockHeader>, Error> {
-        let mut results = vec![];
-        for chunk in ChunksIterator::new(heights.into_iter(), self.concurrency as usize) {
-            let mut futs = FuturesOrdered::new();
-            for height in chunk {
-                futs.push(self._get_header(height));
-            }
-            let partial_results: Vec<BlockHeader> = await_or_block!(futs.try_collect())?;
-            results.extend(partial_results);
-        }
-        Ok(await_or_block!(stream::iter(results).collect()))
-    }
-}
-
-/// Configuration for an [`EsploraBlockchain`]
-#[derive(Debug, serde::Deserialize, serde::Serialize, Clone, PartialEq)]
-pub struct EsploraBlockchainConfig {
-    /// Base URL of the esplora service
-    ///
-    /// eg. `https://blockstream.info/api/`
-    pub base_url: String,
-    /// Optional URL of the proxy to use to make requests to the Esplora server
-    ///
-    /// The string should be formatted as: `<protocol>://<user>:<password>@host:<port>`.
-    ///
-    /// Note that the format of this value and the supported protocols change slightly between the
-    /// sync version of esplora (using `ureq`) and the async version (using `reqwest`). For more
-    /// details check with the documentation of the two crates. Both of them are compiled with
-    /// the `socks` feature enabled.
-    ///
-    /// The proxy is ignored when targeting `wasm32`.
-    pub proxy: Option<String>,
-    /// Number of parallel requests sent to the esplora service (default: 4)
-    pub concurrency: Option<u8>,
-    /// Stop searching addresses for transactions after finding an unused gap of this length.
-    pub stop_gap: usize,
-}
-
 impl ConfigurableBlockchain for EsploraBlockchain {
-    type Config = EsploraBlockchainConfig;
+    type Config = super::EsploraBlockchainConfig;
 
     fn from_config(config: &Self::Config) -> Result<Self, Error> {
         let map_e = |e: reqwest::Error| Error::Esplora(Box::new(e.into()));
@@ -360,13 +319,19 @@ impl ConfigurableBlockchain for EsploraBlockchain {
         if let Some(concurrency) = config.concurrency {
             blockchain.url_client.concurrency = concurrency;
         }
+        let mut builder = Client::builder();
         #[cfg(not(target_arch = "wasm32"))]
         if let Some(proxy) = &config.proxy {
-            blockchain.url_client.client = Client::builder()
-                .proxy(reqwest::Proxy::all(proxy).map_err(map_e)?)
-                .build()
-                .map_err(map_e)?;
+            builder = builder.proxy(reqwest::Proxy::all(proxy).map_err(map_e)?);
         }
+
+        #[cfg(not(target_arch = "wasm32"))]
+        if let Some(timeout) = config.timeout {
+            builder = builder.timeout(core::time::Duration::from_secs(timeout));
+        }
+
+        blockchain.url_client.client = builder.build().map_err(map_e)?;
+
         Ok(blockchain)
     }
 }

src/blockchain/esplora/ureq.rs

@@ -26,14 +26,14 @@ use bitcoin::hashes::hex::{FromHex, ToHex};
 use bitcoin::hashes::{sha256, Hash};
 use bitcoin::{BlockHeader, Script, Transaction, Txid};
 
-use crate::blockchain::esplora::{EsploraError, EsploraGetHistory};
-use crate::blockchain::utils::{ElectrumLikeSync, ElsGetHistoryRes};
+use super::api::Tx;
+use crate::blockchain::esplora::EsploraError;
 use crate::blockchain::*;
 use crate::database::BatchDatabase;
 use crate::error::Error;
 use crate::FeeRate;
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 struct UrlClient {
     url: String,
     agent: Agent,
@@ -47,15 +47,7 @@ struct UrlClient {
 pub struct EsploraBlockchain {
     url_client: UrlClient,
     stop_gap: usize,
-}
-
-impl std::convert::From<UrlClient> for EsploraBlockchain {
-    fn from(url_client: UrlClient) -> Self {
-        EsploraBlockchain {
-            url_client,
-            stop_gap: 20,
-        }
-    }
+    concurrency: u8,
 }
 
 impl EsploraBlockchain {
@@ -66,6 +58,7 @@ impl EsploraBlockchain {
                 url: base_url.to_string(),
                 agent: Agent::new(),
             },
+            concurrency: super::DEFAULT_CONCURRENT_REQUESTS,
             stop_gap,
         }
     }
@@ -75,6 +68,12 @@ impl EsploraBlockchain {
         self.url_client.agent = agent;
         self
     }
+
+    /// Set the number of parallel requests the client can make.
+    pub fn with_concurrency(mut self, concurrency: u8) -> Self {
+        self.concurrency = concurrency;
+        self
+    }
 }
 
 impl Blockchain for EsploraBlockchain {
@@ -88,15 +87,6 @@ impl Blockchain for EsploraBlockchain {
         .collect()
     }
 
-    fn setup<D: BatchDatabase, P: Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        self.url_client
-            .electrum_like_setup(self.stop_gap, database, progress_update)
-    }
-
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
         Ok(self.url_client._get_tx(txid)?)
     }
@@ -106,21 +96,114 @@ impl Blockchain for EsploraBlockchain {
         Ok(())
     }
 
-    fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.url_client._get_height()?)
-    }
-
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
         let estimates = self.url_client._get_fee_estimates()?;
         super::into_fee_rate(target, estimates)
     }
 }
 
-impl UrlClient {
-    fn script_to_scripthash(script: &Script) -> String {
-        sha256::Hash::hash(script.as_bytes()).into_inner().to_hex()
+impl GetHeight for EsploraBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        Ok(self.url_client._get_height()?)
     }
+}
 
+impl WalletSync for EsploraBlockchain {
+    fn wallet_setup<D: BatchDatabase>(
+        &self,
+        database: &mut D,
+        _progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        use crate::blockchain::script_sync::Request;
+        let mut request = script_sync::start(database, self.stop_gap)?;
+        let mut tx_index: HashMap<Txid, Tx> = HashMap::new();
+        let batch_update = loop {
+            request = match request {
+                Request::Script(script_req) => {
+                    let scripts = script_req
+                        .request()
+                        .take(self.concurrency as usize)
+                        .cloned();
+
+                    let handles = scripts.map(move |script| {
+                        let client = self.url_client.clone();
+                        // make each request in its own thread.
+                        std::thread::spawn(move || {
+                            let mut related_txs: Vec<Tx> = client._scripthash_txs(&script, None)?;
+
+                            let n_confirmed =
+                                related_txs.iter().filter(|tx| tx.status.confirmed).count();
+                            // esplora pages on 25 confirmed transactions. If there's 25 or more we
+                            // keep requesting to see if there's more.
+                            if n_confirmed >= 25 {
+                                loop {
+                                    let new_related_txs: Vec<Tx> = client._scripthash_txs(
+                                        &script,
+                                        Some(related_txs.last().unwrap().txid),
+                                    )?;
+                                    let n = new_related_txs.len();
+                                    related_txs.extend(new_related_txs);
+                                    // we've reached the end
+                                    if n < 25 {
+                                        break;
+                                    }
+                                }
+                            }
+                            Result::<_, Error>::Ok(related_txs)
+                        })
+                    });
+
+                    let txs_per_script: Vec<Vec<Tx>> = handles
+                        .map(|handle| handle.join().unwrap())
+                        .collect::<Result<_, _>>()?;
+                    let mut satisfaction = vec![];
+
+                    for txs in txs_per_script {
+                        satisfaction.push(
+                            txs.iter()
+                                .map(|tx| (tx.txid, tx.status.block_height))
+                                .collect(),
+                        );
+                        for tx in txs {
+                            tx_index.insert(tx.txid, tx);
+                        }
+                    }
+
+                    script_req.satisfy(satisfaction)?
+                }
+                Request::Conftime(conftime_req) => {
+                    let conftimes = conftime_req
+                        .request()
+                        .map(|txid| {
+                            tx_index
+                                .get(txid)
+                                .expect("must be in index")
+                                .confirmation_time()
+                        })
+                        .collect();
+                    conftime_req.satisfy(conftimes)?
+                }
+                Request::Tx(tx_req) => {
+                    let full_txs = tx_req
+                        .request()
+                        .map(|txid| {
+                            let tx = tx_index.get(txid).expect("must be in index");
+                            (tx.previous_outputs(), tx.to_tx())
+                        })
+                        .collect();
+                    tx_req.satisfy(full_txs)?
+                }
+                Request::Finish(batch_update) => break batch_update,
+            }
+        };
+
+        database.commit_batch(batch_update)?;
+
+        Ok(())
+    }
+}
+
+impl UrlClient {
     fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
         let resp = self
             .agent
@@ -200,81 +283,6 @@ impl UrlClient {
         }
     }
 
-    fn _script_get_history(&self, script: &Script) -> Result<Vec<ElsGetHistoryRes>, EsploraError> {
-        let mut result = Vec::new();
-        let scripthash = Self::script_to_scripthash(script);
-
-        // Add the unconfirmed transactions first
-
-        let resp = self
-            .agent
-            .get(&format!(
-                "{}/scripthash/{}/txs/mempool",
-                self.url, scripthash
-            ))
-            .call();
-
-        let v = match resp {
-            Ok(resp) => {
-                let v: Vec<EsploraGetHistory> = resp.into_json()?;
-                Ok(v)
-            }
-            Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-            Err(e) => Err(EsploraError::Ureq(e)),
-        }?;
-
-        result.extend(v.into_iter().map(|x| ElsGetHistoryRes {
-            tx_hash: x.txid,
-            height: x.status.block_height.unwrap_or(0) as i32,
-        }));
-
-        debug!(
-            "Found {} mempool txs for {} - {:?}",
-            result.len(),
-            scripthash,
-            script
-        );
-
-        // Then go through all the pages of confirmed transactions
-        let mut last_txid = String::new();
-        loop {
-            let resp = self
-                .agent
-                .get(&format!(
-                    "{}/scripthash/{}/txs/chain/{}",
-                    self.url, scripthash, last_txid
-                ))
-                .call();
-
-            let v = match resp {
-                Ok(resp) => {
-                    let v: Vec<EsploraGetHistory> = resp.into_json()?;
-                    Ok(v)
-                }
-                Err(ureq::Error::Status(code, _)) => Err(EsploraError::HttpResponse(code)),
-                Err(e) => Err(EsploraError::Ureq(e)),
-            }?;
-
-            let len = v.len();
-            if let Some(elem) = v.last() {
-                last_txid = elem.txid.to_hex();
-            }
-
-            debug!("... adding {} confirmed transactions", len);
-
-            result.extend(v.into_iter().map(|x| ElsGetHistoryRes {
-                tx_hash: x.txid,
-                height: x.status.block_height.unwrap_or(0) as i32,
-            }));
-
-            if len < 25 {
-                break;
-            }
-        }
-
-        Ok(result)
-    }
-
     fn _get_fee_estimates(&self) -> Result<HashMap<String, f64>, EsploraError> {
         let resp = self
             .agent
@@ -292,6 +300,22 @@ impl UrlClient {
 
         Ok(map)
     }
+
+    fn _scripthash_txs(
+        &self,
+        script: &Script,
+        last_seen: Option<Txid>,
+    ) -> Result<Vec<Tx>, EsploraError> {
+        let script_hash = sha256::Hash::hash(script.as_bytes()).into_inner().to_hex();
+        let url = match last_seen {
+            Some(last_seen) => format!(
+                "{}/scripthash/{}/txs/chain/{}",
+                self.url, script_hash, last_seen
+            ),
+            None => format!("{}/scripthash/{}/txs", self.url, script_hash),
+        };
+        Ok(self.agent.get(&url).call()?.into_json()?)
+    }
 }
 
 fn is_status_not_found(status: u16) -> bool {
@@ -315,84 +339,37 @@ fn into_bytes(resp: Response) -> Result<Vec<u8>, io::Error> {
     Ok(buf)
 }
 
-impl ElectrumLikeSync for UrlClient {
-    fn els_batch_script_get_history<'s, I: IntoIterator<Item = &'s Script>>(
-        &self,
-        scripts: I,
-    ) -> Result<Vec<Vec<ElsGetHistoryRes>>, Error> {
-        let mut results = vec![];
-        for script in scripts.into_iter() {
-            let v = self._script_get_history(script)?;
-            results.push(v);
-        }
-        Ok(results)
-    }
-
-    fn els_batch_transaction_get<'s, I: IntoIterator<Item = &'s Txid>>(
-        &self,
-        txids: I,
-    ) -> Result<Vec<Transaction>, Error> {
-        let mut results = vec![];
-        for txid in txids.into_iter() {
-            let tx = self._get_tx_no_opt(txid)?;
-            results.push(tx);
-        }
-        Ok(results)
-    }
-
-    fn els_batch_block_header<I: IntoIterator<Item = u32>>(
-        &self,
-        heights: I,
-    ) -> Result<Vec<BlockHeader>, Error> {
-        let mut results = vec![];
-        for height in heights.into_iter() {
-            let header = self._get_header(height)?;
-            results.push(header);
-        }
-        Ok(results)
-    }
-}
-
-/// Configuration for an [`EsploraBlockchain`]
-#[derive(Debug, serde::Deserialize, serde::Serialize, Clone, PartialEq)]
-pub struct EsploraBlockchainConfig {
-    /// Base URL of the esplora service eg. `https://blockstream.info/api/`
-    pub base_url: String,
-    /// Optional URL of the proxy to use to make requests to the Esplora server
-    ///
-    /// The string should be formatted as: `<protocol>://<user>:<password>@host:<port>`.
-    ///
-    /// Note that the format of this value and the supported protocols change slightly between the
-    /// sync version of esplora (using `ureq`) and the async version (using `reqwest`). For more
-    /// details check with the documentation of the two crates. Both of them are compiled with
-    /// the `socks` feature enabled.
-    ///
-    /// The proxy is ignored when targeting `wasm32`.
-    pub proxy: Option<String>,
-    /// Socket read timeout.
-    pub timeout_read: u64,
-    /// Socket write timeout.
-    pub timeout_write: u64,
-    /// Stop searching addresses for transactions after finding an unused gap of this length.
-    pub stop_gap: usize,
-}
-
 impl ConfigurableBlockchain for EsploraBlockchain {
-    type Config = EsploraBlockchainConfig;
+    type Config = super::EsploraBlockchainConfig;
 
     fn from_config(config: &Self::Config) -> Result<Self, Error> {
-        let mut agent_builder = ureq::AgentBuilder::new()
-            .timeout_read(Duration::from_secs(config.timeout_read))
-            .timeout_write(Duration::from_secs(config.timeout_write));
+        let mut agent_builder = ureq::AgentBuilder::new();
+
+        if let Some(timeout) = config.timeout {
+            agent_builder = agent_builder.timeout(Duration::from_secs(timeout));
+        }
 
         if let Some(proxy) = &config.proxy {
             agent_builder = agent_builder
                 .proxy(Proxy::new(proxy).map_err(|e| Error::Esplora(Box::new(e.into())))?);
         }
 
-        Ok(
-            EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap)
-                .with_agent(agent_builder.build()),
-        )
+        let mut blockchain = EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap)
+            .with_agent(agent_builder.build());
+
+        if let Some(concurrency) = config.concurrency {
+            blockchain = blockchain.with_concurrency(concurrency);
+        }
+
+        Ok(blockchain)
+    }
+}
+
+impl From<ureq::Error> for EsploraError {
+    fn from(e: ureq::Error) -> Self {
+        match e {
+            ureq::Error::Status(code, _) => EsploraError::HttpResponse(code),
+            e => EsploraError::Ureq(e),
+        }
     }
 }

src/blockchain/mod.rs

@@ -27,9 +27,6 @@ use crate::database::BatchDatabase;
 use crate::error::Error;
 use crate::FeeRate;
 
-#[cfg(any(feature = "electrum", feature = "esplora"))]
-pub(crate) mod utils;
-
 #[cfg(any(
     feature = "electrum",
     feature = "esplora",
@@ -37,6 +34,8 @@ pub(crate) mod utils;
     feature = "rpc"
 ))]
 pub mod any;
+mod script_sync;
+
 #[cfg(any(
     feature = "electrum",
     feature = "esplora",
@@ -87,28 +86,45 @@ pub enum Capability {
 
 /// Trait that defines the actions that must be supported by a blockchain backend
 #[maybe_async]
-pub trait Blockchain {
+pub trait Blockchain: WalletSync + GetHeight {
     /// Return the set of [`Capability`] supported by this backend
     fn get_capabilities(&self) -> HashSet<Capability>;
+    /// Fetch a transaction from the blockchain given its txid
+    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error>;
+    /// Broadcast a transaction
+    fn broadcast(&self, tx: &Transaction) -> Result<(), Error>;
+    /// Estimate the fee rate required to confirm a transaction in a given `target` of blocks
+    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error>;
+}
 
+/// Trait for getting the current height of the blockchain.
+#[maybe_async]
+pub trait GetHeight {
+    /// Return the current height
+    fn get_height(&self) -> Result<u32, Error>;
+}
+
+/// Trait for blockchains that can sync by updating the database directly.
+#[maybe_async]
+pub trait WalletSync {
     /// Setup the backend and populate the internal database for the first time
     ///
-    /// This method is the equivalent of [`Blockchain::sync`], but it's guaranteed to only be
+    /// This method is the equivalent of [`Self::wallet_sync`], but it's guaranteed to only be
     /// called once, at the first [`Wallet::sync`](crate::wallet::Wallet::sync).
     ///
     /// The rationale behind the distinction between `sync` and `setup` is that some custom backends
     /// might need to perform specific actions only the first time they are synced.
     ///
     /// For types that do not have that distinction, only this method can be implemented, since
-    /// [`Blockchain::sync`] defaults to calling this internally if not overridden.
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
+    /// [`WalletSync::wallet_sync`] defaults to calling this internally if not overridden.
+    /// Populate the internal database with transactions and UTXOs
+    fn wallet_setup<D: BatchDatabase>(
         &self,
         database: &mut D,
-        progress_update: P,
+        progress_update: Box<dyn Progress>,
     ) -> Result<(), Error>;
-    /// Populate the internal database with transactions and UTXOs
-    ///
-    /// If not overridden, it defaults to calling [`Blockchain::setup`] internally.
+
+    /// If not overridden, it defaults to calling [`Self::wallet_setup`] internally.
     ///
     /// This method should implement the logic required to iterate over the list of the wallet's
     /// script_pubkeys using [`Database::iter_script_pubkeys`] and look for relevant transactions
@@ -125,23 +141,13 @@ pub trait Blockchain {
     /// [`BatchOperations::set_tx`]: crate::database::BatchOperations::set_tx
     /// [`BatchOperations::set_utxo`]: crate::database::BatchOperations::set_utxo
     /// [`BatchOperations::del_utxo`]: crate::database::BatchOperations::del_utxo
-    fn sync<D: BatchDatabase, P: 'static + Progress>(
+    fn wallet_sync<D: BatchDatabase>(
         &self,
         database: &mut D,
-        progress_update: P,
+        progress_update: Box<dyn Progress>,
     ) -> Result<(), Error> {
-        maybe_await!(self.setup(database, progress_update))
+        maybe_await!(self.wallet_setup(database, progress_update))
     }
-
-    /// Fetch a transaction from the blockchain given its txid
-    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error>;
-    /// Broadcast a transaction
-    fn broadcast(&self, tx: &Transaction) -> Result<(), Error>;
-
-    /// Return the current height
-    fn get_height(&self) -> Result<u32, Error>;
-    /// Estimate the fee rate required to confirm a transaction in a given `target` of blocks
-    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error>;
 }
 
 /// Trait for [`Blockchain`] types that can be created given a configuration
@@ -156,9 +162,9 @@ pub trait ConfigurableBlockchain: Blockchain + Sized {
 /// Data sent with a progress update over a [`channel`]
 pub type ProgressData = (f32, Option<String>);
 
-/// Trait for types that can receive and process progress updates during [`Blockchain::sync`] and
-/// [`Blockchain::setup`]
-pub trait Progress: Send {
+/// Trait for types that can receive and process progress updates during [`WalletSync::wallet_sync`] and
+/// [`WalletSync::wallet_setup`]
+pub trait Progress: Send + 'static + core::fmt::Debug {
     /// Send a new progress update
     ///
     /// The `progress` value should be in the range 0.0 - 100.0, and the `message` value is an
@@ -183,7 +189,7 @@ impl Progress for Sender<ProgressData> {
 }
 
 /// Type that implements [`Progress`] and drops every update received
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Default, Debug)]
 pub struct NoopProgress;
 
 /// Create a new instance of [`NoopProgress`]
@@ -198,7 +204,7 @@ impl Progress for NoopProgress {
 }
 
 /// Type that implements [`Progress`] and logs at level `INFO` every update received
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Default, Debug)]
 pub struct LogProgress;
 
 /// Create a new instance of [`LogProgress`]
@@ -224,22 +230,6 @@ impl<T: Blockchain> Blockchain for Arc<T> {
         maybe_await!(self.deref().get_capabilities())
     }
 
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        maybe_await!(self.deref().setup(database, progress_update))
-    }
-
-    fn sync<D: BatchDatabase, P: 'static + Progress>(
-        &self,
-        database: &mut D,
-        progress_update: P,
-    ) -> Result<(), Error> {
-        maybe_await!(self.deref().sync(database, progress_update))
-    }
-
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
         maybe_await!(self.deref().get_tx(txid))
     }
@@ -247,10 +237,33 @@ impl<T: Blockchain> Blockchain for Arc<T> {
         maybe_await!(self.deref().broadcast(tx))
     }
 
-    fn get_height(&self) -> Result<u32, Error> {
-        maybe_await!(self.deref().get_height())
-    }
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
         maybe_await!(self.deref().estimate_fee(target))
     }
 }
+
+#[maybe_async]
+impl<T: GetHeight> GetHeight for Arc<T> {
+    fn get_height(&self) -> Result<u32, Error> {
+        maybe_await!(self.deref().get_height())
+    }
+}
+
+#[maybe_async]
+impl<T: WalletSync> WalletSync for Arc<T> {
+    fn wallet_setup<D: BatchDatabase>(
+        &self,
+        database: &mut D,
+        progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        maybe_await!(self.deref().wallet_setup(database, progress_update))
+    }
+
+    fn wallet_sync<D: BatchDatabase>(
+        &self,
+        database: &mut D,
+        progress_update: Box<dyn Progress>,
+    ) -> Result<(), Error> {
+        maybe_await!(self.deref().wallet_sync(database, progress_update))
+    }
+}

src/blockchain/rpc.rs

@@ -33,18 +33,18 @@
 
 use crate::bitcoin::consensus::deserialize;
 use crate::bitcoin::{Address, Network, OutPoint, Transaction, TxOut, Txid};
-use crate::blockchain::{Blockchain, Capability, ConfigurableBlockchain, Progress};
+use crate::blockchain::{
+    Blockchain, Capability, ConfigurableBlockchain, GetHeight, Progress, WalletSync,
+};
 use crate::database::{BatchDatabase, DatabaseUtils};
-use crate::descriptor::{get_checksum, IntoWalletDescriptor};
-use crate::wallet::utils::SecpCtx;
-use crate::{ConfirmationTime, Error, FeeRate, KeychainKind, LocalUtxo, TransactionDetails};
-use core_rpc::json::{
+use crate::{BlockTime, Error, FeeRate, KeychainKind, LocalUtxo, TransactionDetails};
+use bitcoincore_rpc::json::{
     GetAddressInfoResultLabel, ImportMultiOptions, ImportMultiRequest,
     ImportMultiRequestScriptPubkey, ImportMultiRescanSince,
 };
-use core_rpc::jsonrpc::serde_json::Value;
-use core_rpc::Auth as RpcAuth;
-use core_rpc::{Client, RpcApi};
+use bitcoincore_rpc::jsonrpc::serde_json::Value;
+use bitcoincore_rpc::Auth as RpcAuth;
+use bitcoincore_rpc::{Client, RpcApi};
 use log::debug;
 use serde::{Deserialize, Serialize};
 use std::collections::{HashMap, HashSet};
@@ -76,15 +76,15 @@ pub struct RpcConfig {
     pub auth: Auth,
     /// The network we are using (it will be checked the bitcoin node network matches this)
     pub network: Network,
-    /// The wallet name in the bitcoin node, consider using [wallet_name_from_descriptor] for this
+    /// The wallet name in the bitcoin node, consider using [crate::wallet::wallet_name_from_descriptor] for this
     pub wallet_name: String,
     /// Skip this many blocks of the blockchain at the first rescan, if None the rescan is done from the genesis block
     pub skip_blocks: Option<u32>,
 }
 
-/// This struct is equivalent to [core_rpc::Auth] but it implements [serde::Serialize]
+/// This struct is equivalent to [bitcoincore_rpc::Auth] but it implements [serde::Serialize]
 /// To be removed once upstream equivalent is implementing Serialize (json serialization format
-/// should be the same) https://github.com/rust-bitcoin/rust-bitcoincore-rpc/pull/181
+/// should be the same), see [rust-bitcoincore-rpc/pull/181](https://github.com/rust-bitcoin/rust-bitcoincore-rpc/pull/181)
 #[derive(Clone, Debug, Hash, Eq, PartialEq, Ord, PartialOrd, Serialize, Deserialize)]
 #[serde(rename_all = "snake_case")]
 #[serde(untagged)]
@@ -141,10 +141,37 @@ impl Blockchain for RpcBlockchain {
         self.capabilities.clone()
     }
 
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
+    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+        Ok(Some(self.client.get_raw_transaction(txid, None)?))
+    }
+
+    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
+        Ok(self.client.send_raw_transaction(tx).map(|_| ())?)
+    }
+
+    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
+        let sat_per_kb = self
+            .client
+            .estimate_smart_fee(target as u16, None)?
+            .fee_rate
+            .ok_or(Error::FeeRateUnavailable)?
+            .as_sat() as f64;
+
+        Ok(FeeRate::from_sat_per_vb((sat_per_kb / 1000f64) as f32))
+    }
+}
+
+impl GetHeight for RpcBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        Ok(self.client.get_blockchain_info().map(|i| i.blocks as u32)?)
+    }
+}
+
+impl WalletSync for RpcBlockchain {
+    fn wallet_setup<D: BatchDatabase>(
         &self,
         database: &mut D,
-        progress_update: P,
+        progress_update: Box<dyn Progress>,
     ) -> Result<(), Error> {
         let mut scripts_pubkeys = database.iter_script_pubkeys(Some(KeychainKind::External))?;
         scripts_pubkeys.extend(database.iter_script_pubkeys(Some(KeychainKind::Internal))?);
@@ -156,7 +183,7 @@ impl Blockchain for RpcBlockchain {
             .iter()
             .map(|s| ImportMultiRequest {
                 timestamp: ImportMultiRescanSince::Timestamp(0),
-                script_pubkey: Some(ImportMultiRequestScriptPubkey::Script(&s)),
+                script_pubkey: Some(ImportMultiRequestScriptPubkey::Script(s)),
                 watchonly: Some(true),
                 ..Default::default()
             })
@@ -189,13 +216,13 @@ impl Blockchain for RpcBlockchain {
             }
         }
 
-        self.sync(database, progress_update)
+        self.wallet_sync(database, progress_update)
     }
 
-    fn sync<D: BatchDatabase, P: 'static + Progress>(
+    fn wallet_sync<D: BatchDatabase>(
         &self,
         db: &mut D,
-        _progress_update: P,
+        _progress_update: Box<dyn Progress>,
     ) -> Result<(), Error> {
         let mut indexes = HashMap::new();
         for keykind in &[KeychainKind::External, KeychainKind::Internal] {
@@ -230,7 +257,7 @@ impl Blockchain for RpcBlockchain {
             list_txs_ids.insert(txid);
             if let Some(mut known_tx) = known_txs.get_mut(&txid) {
                 let confirmation_time =
-                    ConfirmationTime::new(tx_result.info.blockheight, tx_result.info.blocktime);
+                    BlockTime::new(tx_result.info.blockheight, tx_result.info.blocktime);
                 if confirmation_time != known_tx.confirmation_time {
                     // reorg may change tx height
                     debug!(
@@ -238,7 +265,7 @@ impl Blockchain for RpcBlockchain {
                         txid, confirmation_time
                     );
                     known_tx.confirmation_time = confirmation_time;
-                    db.set_tx(&known_tx)?;
+                    db.set_tx(known_tx)?;
                 }
             } else {
                 //TODO check there is already the raw tx in db?
@@ -266,7 +293,7 @@ impl Blockchain for RpcBlockchain {
                 let td = TransactionDetails {
                     transaction: Some(tx),
                     txid: tx_result.info.txid,
-                    confirmation_time: ConfirmationTime::new(
+                    confirmation_time: BlockTime::new(
                         tx_result.info.blockheight,
                         tx_result.info.blocktime,
                     ),
@@ -325,29 +352,6 @@ impl Blockchain for RpcBlockchain {
 
         Ok(())
     }
-
-    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(Some(self.client.get_raw_transaction(txid, None)?))
-    }
-
-    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        Ok(self.client.send_raw_transaction(tx).map(|_| ())?)
-    }
-
-    fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.client.get_blockchain_info().map(|i| i.blocks as u32)?)
-    }
-
-    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        let sat_per_kb = self
-            .client
-            .estimate_smart_fee(target as u16, None)?
-            .fee_rate
-            .ok_or(Error::FeeRateUnavailable)?
-            .as_sat() as f64;
-
-        Ok(FeeRate::from_sat_per_vb((sat_per_kb / 1000f64) as f32))
-    }
 }
 
 impl ConfigurableBlockchain for RpcBlockchain {
@@ -415,35 +419,6 @@ impl ConfigurableBlockchain for RpcBlockchain {
     }
 }
 
-/// Deterministically generate a unique name given the descriptors defining the wallet
-pub fn wallet_name_from_descriptor<T>(
-    descriptor: T,
-    change_descriptor: Option<T>,
-    network: Network,
-    secp: &SecpCtx,
-) -> Result<String, Error>
-where
-    T: IntoWalletDescriptor,
-{
-    //TODO check descriptors contains only public keys
-    let descriptor = descriptor
-        .into_wallet_descriptor(&secp, network)?
-        .0
-        .to_string();
-    let mut wallet_name = get_checksum(&descriptor[..descriptor.find('#').unwrap()])?;
-    if let Some(change_descriptor) = change_descriptor {
-        let change_descriptor = change_descriptor
-            .into_wallet_descriptor(&secp, network)?
-            .0
-            .to_string();
-        wallet_name.push_str(
-            get_checksum(&change_descriptor[..change_descriptor.find('#').unwrap()])?.as_str(),
-        );
-    }
-
-    Ok(wallet_name)
-}
-
 /// return the wallets available in default wallet directory
 //TODO use bitcoincore_rpc method when PR #179 lands
 fn list_wallet_dir(client: &Client) -> Result<Vec<String>, Error> {

src/blockchain/script_sync.rs

@@ -0,0 +1,394 @@
+/*!
+This models a how a sync happens where you have a server that you send your script pubkeys to and it
+returns associated transactions i.e. electrum.
+*/
+#![allow(dead_code)]
+use crate::{
+    database::{BatchDatabase, BatchOperations, DatabaseUtils},
+    wallet::time::Instant,
+    BlockTime, Error, KeychainKind, LocalUtxo, TransactionDetails,
+};
+use bitcoin::{OutPoint, Script, Transaction, TxOut, Txid};
+use log::*;
+use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet, VecDeque};
+
+/// A request for on-chain information
+pub enum Request<'a, D: BatchDatabase> {
+    /// A request for transactions related to script pubkeys.
+    Script(ScriptReq<'a, D>),
+    /// A request for confirmation times for some transactions.
+    Conftime(ConftimeReq<'a, D>),
+    /// A request for full transaction details of some transactions.
+    Tx(TxReq<'a, D>),
+    /// Requests are finished here's a batch database update to reflect data gathered.
+    Finish(D::Batch),
+}
+
+/// starts a sync
+pub fn start<D: BatchDatabase>(db: &D, stop_gap: usize) -> Result<Request<'_, D>, Error> {
+    use rand::seq::SliceRandom;
+    let mut keychains = vec![KeychainKind::Internal, KeychainKind::External];
+    // shuffling improve privacy, the server doesn't know my first request is from my internal or external addresses
+    keychains.shuffle(&mut rand::thread_rng());
+    let keychain = keychains.pop().unwrap();
+    let scripts_needed = db
+        .iter_script_pubkeys(Some(keychain))?
+        .into_iter()
+        .collect();
+    let state = State::new(db);
+
+    Ok(Request::Script(ScriptReq {
+        state,
+        scripts_needed,
+        script_index: 0,
+        stop_gap,
+        keychain,
+        next_keychains: keychains,
+    }))
+}
+
+pub struct ScriptReq<'a, D: BatchDatabase> {
+    state: State<'a, D>,
+    script_index: usize,
+    scripts_needed: VecDeque<Script>,
+    stop_gap: usize,
+    keychain: KeychainKind,
+    next_keychains: Vec<KeychainKind>,
+}
+
+/// The sync starts by returning script pubkeys we are interested in.
+impl<'a, D: BatchDatabase> ScriptReq<'a, D> {
+    pub fn request(&self) -> impl Iterator<Item = &Script> + Clone {
+        self.scripts_needed.iter()
+    }
+
+    pub fn satisfy(
+        mut self,
+        // we want to know the txids assoiciated with the script and their height
+        txids: Vec<Vec<(Txid, Option<u32>)>>,
+    ) -> Result<Request<'a, D>, Error> {
+        for (txid_list, script) in txids.iter().zip(self.scripts_needed.iter()) {
+            debug!(
+                "found {} transactions for script pubkey {}",
+                txid_list.len(),
+                script
+            );
+            if !txid_list.is_empty() {
+                // the address is active
+                self.state
+                    .last_active_index
+                    .insert(self.keychain, self.script_index);
+            }
+
+            for (txid, height) in txid_list {
+                // have we seen this txid already?
+                match self.state.db.get_tx(txid, true)? {
+                    Some(mut details) => {
+                        let old_height = details.confirmation_time.as_ref().map(|x| x.height);
+                        match (old_height, height) {
+                            (None, Some(_)) => {
+                                // It looks like the tx has confirmed since we last saw it -- we
+                                // need to know the confirmation time.
+                                self.state.tx_missing_conftime.insert(*txid, details);
+                            }
+                            (Some(old_height), Some(new_height)) if old_height != *new_height => {
+                                // The height of the tx has changed !? -- It's a reorg get the new confirmation time.
+                                self.state.tx_missing_conftime.insert(*txid, details);
+                            }
+                            (Some(_), None) => {
+                                // A re-org where the tx is not in the chain anymore.
+                                details.confirmation_time = None;
+                                self.state.finished_txs.push(details);
+                            }
+                            _ => self.state.finished_txs.push(details),
+                        }
+                    }
+                    None => {
+                        // we've never seen it let's get the whole thing
+                        self.state.tx_needed.insert(*txid);
+                    }
+                };
+            }
+
+            self.script_index += 1;
+        }
+
+        for _ in txids {
+            self.scripts_needed.pop_front();
+        }
+
+        let last_active_index = self
+            .state
+            .last_active_index
+            .get(&self.keychain)
+            .map(|x| x + 1)
+            .unwrap_or(0); // so no addresses active maps to 0
+
+        Ok(
+            if self.script_index > last_active_index + self.stop_gap
+                || self.scripts_needed.is_empty()
+            {
+                debug!(
+                    "finished scanning for transactions for keychain {:?} at index {}",
+                    self.keychain, last_active_index
+                );
+                // we're done here -- check if we need to do the next keychain
+                if let Some(keychain) = self.next_keychains.pop() {
+                    self.keychain = keychain;
+                    self.script_index = 0;
+                    self.scripts_needed = self
+                        .state
+                        .db
+                        .iter_script_pubkeys(Some(keychain))?
+                        .into_iter()
+                        .collect();
+                    Request::Script(self)
+                } else {
+                    Request::Tx(TxReq { state: self.state })
+                }
+            } else {
+                Request::Script(self)
+            },
+        )
+    }
+}
+
+/// Then we get full transactions
+pub struct TxReq<'a, D> {
+    state: State<'a, D>,
+}
+
+impl<'a, D: BatchDatabase> TxReq<'a, D> {
+    pub fn request(&self) -> impl Iterator<Item = &Txid> + Clone {
+        self.state.tx_needed.iter()
+    }
+
+    pub fn satisfy(
+        mut self,
+        tx_details: Vec<(Vec<Option<TxOut>>, Transaction)>,
+    ) -> Result<Request<'a, D>, Error> {
+        let tx_details: Vec<TransactionDetails> = tx_details
+            .into_iter()
+            .zip(self.state.tx_needed.iter())
+            .map(|((vout, tx), txid)| {
+                debug!("found tx_details for {}", txid);
+                assert_eq!(tx.txid(), *txid);
+                let mut sent: u64 = 0;
+                let mut received: u64 = 0;
+                let mut inputs_sum: u64 = 0;
+                let mut outputs_sum: u64 = 0;
+
+                for (txout, input) in vout.into_iter().zip(tx.input.iter()) {
+                    let txout = match txout {
+                        Some(txout) => txout,
+                        None => {
+                            // skip coinbase inputs
+                            debug_assert!(
+                                input.previous_output.is_null(),
+                                "prevout should only be missing for coinbase"
+                            );
+                            continue;
+                        }
+                    };
+
+                    inputs_sum += txout.value;
+                    if self.state.db.is_mine(&txout.script_pubkey)? {
+                        sent += txout.value;
+                    }
+                }
+
+                for out in &tx.output {
+                    outputs_sum += out.value;
+                    if self.state.db.is_mine(&out.script_pubkey)? {
+                        received += out.value;
+                    }
+                }
+                // we need to saturating sub since we want coinbase txs to map to 0 fee and
+                // this subtraction will be negative for coinbase txs.
+                let fee = inputs_sum.saturating_sub(outputs_sum);
+                Result::<_, Error>::Ok(TransactionDetails {
+                    txid: *txid,
+                    transaction: Some(tx),
+                    received,
+                    sent,
+                    // we're going to fill this in later
+                    confirmation_time: None,
+                    fee: Some(fee),
+                    verified: false,
+                })
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+
+        for tx_detail in tx_details {
+            self.state.tx_needed.remove(&tx_detail.txid);
+            self.state
+                .tx_missing_conftime
+                .insert(tx_detail.txid, tx_detail);
+        }
+
+        if !self.state.tx_needed.is_empty() {
+            Ok(Request::Tx(self))
+        } else {
+            Ok(Request::Conftime(ConftimeReq { state: self.state }))
+        }
+    }
+}
+
+/// Final step is to get confirmation times
+pub struct ConftimeReq<'a, D> {
+    state: State<'a, D>,
+}
+
+impl<'a, D: BatchDatabase> ConftimeReq<'a, D> {
+    pub fn request(&self) -> impl Iterator<Item = &Txid> + Clone {
+        self.state.tx_missing_conftime.keys()
+    }
+
+    pub fn satisfy(
+        mut self,
+        confirmation_times: Vec<Option<BlockTime>>,
+    ) -> Result<Request<'a, D>, Error> {
+        let conftime_needed = self
+            .request()
+            .cloned()
+            .take(confirmation_times.len())
+            .collect::<Vec<_>>();
+        for (confirmation_time, txid) in confirmation_times.into_iter().zip(conftime_needed.iter())
+        {
+            debug!("confirmation time for {} was {:?}", txid, confirmation_time);
+            if let Some(mut tx_details) = self.state.tx_missing_conftime.remove(txid) {
+                tx_details.confirmation_time = confirmation_time;
+                self.state.finished_txs.push(tx_details);
+            }
+        }
+
+        if self.state.tx_missing_conftime.is_empty() {
+            Ok(Request::Finish(self.state.into_db_update()?))
+        } else {
+            Ok(Request::Conftime(self))
+        }
+    }
+}
+
+struct State<'a, D> {
+    db: &'a D,
+    last_active_index: HashMap<KeychainKind, usize>,
+    /// Transactions where we need to get the full details
+    tx_needed: BTreeSet<Txid>,
+    /// Transacitions that we know everything about
+    finished_txs: Vec<TransactionDetails>,
+    /// Transactions that discovered conftimes should be inserted into
+    tx_missing_conftime: BTreeMap<Txid, TransactionDetails>,
+    /// The start of the sync
+    start_time: Instant,
+}
+
+impl<'a, D: BatchDatabase> State<'a, D> {
+    fn new(db: &'a D) -> Self {
+        State {
+            db,
+            last_active_index: HashMap::default(),
+            finished_txs: vec![],
+            tx_needed: BTreeSet::default(),
+            tx_missing_conftime: BTreeMap::default(),
+            start_time: Instant::new(),
+        }
+    }
+    fn into_db_update(self) -> Result<D::Batch, Error> {
+        debug_assert!(self.tx_needed.is_empty() && self.tx_missing_conftime.is_empty());
+        let existing_txs = self.db.iter_txs(false)?;
+        let existing_txids: HashSet<Txid> = existing_txs.iter().map(|tx| tx.txid).collect();
+        let finished_txs = make_txs_consistent(&self.finished_txs);
+        let observed_txids: HashSet<Txid> = finished_txs.iter().map(|tx| tx.txid).collect();
+        let txids_to_delete = existing_txids.difference(&observed_txids);
+        let mut batch = self.db.begin_batch();
+
+        // Delete old txs that no longer exist
+        for txid in txids_to_delete {
+            if let Some(raw_tx) = self.db.get_raw_tx(txid)? {
+                for i in 0..raw_tx.output.len() {
+                    // Also delete any utxos from the txs that no longer exist.
+                    let _ = batch.del_utxo(&OutPoint {
+                        txid: *txid,
+                        vout: i as u32,
+                    })?;
+                }
+            } else {
+                unreachable!("we should always have the raw tx");
+            }
+            batch.del_tx(txid, true)?;
+        }
+
+        // Set every tx we observed
+        for finished_tx in &finished_txs {
+            let tx = finished_tx
+                .transaction
+                .as_ref()
+                .expect("transaction will always be present here");
+            for (i, output) in tx.output.iter().enumerate() {
+                if let Some((keychain, _)) =
+                    self.db.get_path_from_script_pubkey(&output.script_pubkey)?
+                {
+                    // add utxos we own from the new transactions we've seen.
+                    batch.set_utxo(&LocalUtxo {
+                        outpoint: OutPoint {
+                            txid: finished_tx.txid,
+                            vout: i as u32,
+                        },
+                        txout: output.clone(),
+                        keychain,
+                    })?;
+                }
+            }
+            batch.set_tx(finished_tx)?;
+        }
+
+        // we don't do this in the loop above since we may want to delete some of the utxos we
+        // just added in case there are new tranasactions that spend form each other.
+        for finished_tx in &finished_txs {
+            let tx = finished_tx
+                .transaction
+                .as_ref()
+                .expect("transaction will always be present here");
+            for input in &tx.input {
+                // Delete any spent utxos
+                batch.del_utxo(&input.previous_output)?;
+            }
+        }
+
+        for (keychain, last_active_index) in self.last_active_index {
+            batch.set_last_index(keychain, last_active_index as u32)?;
+        }
+
+        info!(
+            "finished setup, elapsed {:?}ms",
+            self.start_time.elapsed().as_millis()
+        );
+        Ok(batch)
+    }
+}
+
+/// Remove conflicting transactions -- tie breaking them by fee.
+fn make_txs_consistent(txs: &[TransactionDetails]) -> Vec<&TransactionDetails> {
+    let mut utxo_index: HashMap<OutPoint, &TransactionDetails> = HashMap::default();
+    for tx in txs {
+        for input in &tx.transaction.as_ref().unwrap().input {
+            utxo_index
+                .entry(input.previous_output)
+                .and_modify(|existing| match (tx.fee, existing.fee) {
+                    (Some(fee), Some(existing_fee)) if fee > existing_fee => *existing = tx,
+                    (Some(_), None) => *existing = tx,
+                    _ => { /* leave it the same */ }
+                })
+                .or_insert(tx);
+        }
+    }
+
+    utxo_index
+        .into_iter()
+        .map(|(_, tx)| (tx.txid, tx))
+        .collect::<HashMap<_, _>>()
+        .into_iter()
+        .map(|(_, tx)| tx)
+        .collect()
+}

src/blockchain/utils.rs

@@ -1,388 +0,0 @@
-// Bitcoin Dev Kit
-// Written in 2020 by Alekos Filini <alekos.filini@gmail.com>
-//
-// Copyright (c) 2020-2021 Bitcoin Dev Kit Developers
-//
-// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
-// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
-// You may not use this file except in accordance with one or both of these
-// licenses.
-
-use std::collections::{HashMap, HashSet};
-
-#[allow(unused_imports)]
-use log::{debug, error, info, trace};
-use rand::seq::SliceRandom;
-use rand::thread_rng;
-
-use bitcoin::{BlockHeader, OutPoint, Script, Transaction, Txid};
-
-use super::*;
-use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils};
-use crate::error::Error;
-use crate::types::{ConfirmationTime, KeychainKind, LocalUtxo, TransactionDetails};
-use crate::wallet::time::Instant;
-use crate::wallet::utils::ChunksIterator;
-
-#[derive(Debug)]
-pub struct ElsGetHistoryRes {
-    pub height: i32,
-    pub tx_hash: Txid,
-}
-
-/// Implements the synchronization logic for an Electrum-like client.
-#[maybe_async]
-pub trait ElectrumLikeSync {
-    fn els_batch_script_get_history<'s, I: IntoIterator<Item = &'s Script> + Clone>(
-        &self,
-        scripts: I,
-    ) -> Result<Vec<Vec<ElsGetHistoryRes>>, Error>;
-
-    fn els_batch_transaction_get<'s, I: IntoIterator<Item = &'s Txid> + Clone>(
-        &self,
-        txids: I,
-    ) -> Result<Vec<Transaction>, Error>;
-
-    fn els_batch_block_header<I: IntoIterator<Item = u32> + Clone>(
-        &self,
-        heights: I,
-    ) -> Result<Vec<BlockHeader>, Error>;
-
-    // Provided methods down here...
-
-    fn electrum_like_setup<D: BatchDatabase, P: Progress>(
-        &self,
-        stop_gap: usize,
-        db: &mut D,
-        _progress_update: P,
-    ) -> Result<(), Error> {
-        // TODO: progress
-        let start = Instant::new();
-        debug!("start setup");
-
-        let chunk_size = stop_gap;
-
-        let mut history_txs_id = HashSet::new();
-        let mut txid_height = HashMap::new();
-        let mut max_indexes = HashMap::new();
-
-        let mut wallet_chains = vec![KeychainKind::Internal, KeychainKind::External];
-        // shuffling improve privacy, the server doesn't know my first request is from my internal or external addresses
-        wallet_chains.shuffle(&mut thread_rng());
-        // download history of our internal and external script_pubkeys
-        for keychain in wallet_chains.iter() {
-            let script_iter = db.iter_script_pubkeys(Some(*keychain))?.into_iter();
-
-            for (i, chunk) in ChunksIterator::new(script_iter, stop_gap).enumerate() {
-                // TODO if i == last, should create another chunk of addresses in db
-                let call_result: Vec<Vec<ElsGetHistoryRes>> =
-                    maybe_await!(self.els_batch_script_get_history(chunk.iter()))?;
-                let max_index = call_result
-                    .iter()
-                    .enumerate()
-                    .filter_map(|(i, v)| v.first().map(|_| i as u32))
-                    .max();
-                if let Some(max) = max_index {
-                    max_indexes.insert(keychain, max + (i * chunk_size) as u32);
-                }
-                let flattened: Vec<ElsGetHistoryRes> = call_result.into_iter().flatten().collect();
-                debug!("#{} of {:?} results:{}", i, keychain, flattened.len());
-                if flattened.is_empty() {
-                    // Didn't find anything in the last `stop_gap` script_pubkeys, breaking
-                    break;
-                }
-
-                for el in flattened {
-                    // el.height = -1 means unconfirmed with unconfirmed parents
-                    // el.height =  0 means unconfirmed with confirmed parents
-                    // but we treat those tx the same
-                    if el.height <= 0 {
-                        txid_height.insert(el.tx_hash, None);
-                    } else {
-                        txid_height.insert(el.tx_hash, Some(el.height as u32));
-                    }
-                    history_txs_id.insert(el.tx_hash);
-                }
-            }
-        }
-
-        // saving max indexes
-        info!("max indexes are: {:?}", max_indexes);
-        for keychain in wallet_chains.iter() {
-            if let Some(index) = max_indexes.get(keychain) {
-                db.set_last_index(*keychain, *index)?;
-            }
-        }
-
-        // get db status
-        let txs_details_in_db: HashMap<Txid, TransactionDetails> = db
-            .iter_txs(false)?
-            .into_iter()
-            .map(|tx| (tx.txid, tx))
-            .collect();
-        let txs_raw_in_db: HashMap<Txid, Transaction> = db
-            .iter_raw_txs()?
-            .into_iter()
-            .map(|tx| (tx.txid(), tx))
-            .collect();
-        let utxos_deps = utxos_deps(db, &txs_raw_in_db)?;
-
-        // download new txs and headers
-        let new_txs = maybe_await!(self.download_and_save_needed_raw_txs(
-            &history_txs_id,
-            &txs_raw_in_db,
-            chunk_size,
-            db
-        ))?;
-        let new_timestamps = maybe_await!(self.download_needed_headers(
-            &txid_height,
-            &txs_details_in_db,
-            chunk_size
-        ))?;
-
-        let mut batch = db.begin_batch();
-
-        // save any tx details not in db but in history_txs_id or with different height/timestamp
-        for txid in history_txs_id.iter() {
-            let height = txid_height.get(txid).cloned().flatten();
-            let timestamp = new_timestamps.get(txid).cloned();
-            if let Some(tx_details) = txs_details_in_db.get(txid) {
-                // check if tx height matches, otherwise updates it. timestamp is not in the if clause
-                // because we are not asking headers for confirmed tx we know about
-                if tx_details.confirmation_time.as_ref().map(|c| c.height) != height {
-                    let confirmation_time = ConfirmationTime::new(height, timestamp);
-                    let mut new_tx_details = tx_details.clone();
-                    new_tx_details.confirmation_time = confirmation_time;
-                    batch.set_tx(&new_tx_details)?;
-                }
-            } else {
-                save_transaction_details_and_utxos(
-                    txid,
-                    db,
-                    timestamp,
-                    height,
-                    &mut batch,
-                    &utxos_deps,
-                )?;
-            }
-        }
-
-        // remove any tx details in db but not in history_txs_id
-        for txid in txs_details_in_db.keys() {
-            if !history_txs_id.contains(txid) {
-                batch.del_tx(txid, false)?;
-            }
-        }
-
-        // remove any spent utxo
-        for new_tx in new_txs.iter() {
-            for input in new_tx.input.iter() {
-                batch.del_utxo(&input.previous_output)?;
-            }
-        }
-
-        db.commit_batch(batch)?;
-        info!("finish setup, elapsed {:?}ms", start.elapsed().as_millis());
-
-        Ok(())
-    }
-
-    /// download txs identified by `history_txs_id` and theirs previous outputs if not already present in db
-    fn download_and_save_needed_raw_txs<D: BatchDatabase>(
-        &self,
-        history_txs_id: &HashSet<Txid>,
-        txs_raw_in_db: &HashMap<Txid, Transaction>,
-        chunk_size: usize,
-        db: &mut D,
-    ) -> Result<Vec<Transaction>, Error> {
-        let mut txs_downloaded = vec![];
-        let txids_raw_in_db: HashSet<Txid> = txs_raw_in_db.keys().cloned().collect();
-        let txids_to_download: Vec<&Txid> = history_txs_id.difference(&txids_raw_in_db).collect();
-        if !txids_to_download.is_empty() {
-            info!("got {} txs to download", txids_to_download.len());
-            txs_downloaded.extend(maybe_await!(self.download_and_save_in_chunks(
-                txids_to_download,
-                chunk_size,
-                db,
-            ))?);
-            let mut prev_txids = HashSet::new();
-            let mut txids_downloaded = HashSet::new();
-            for tx in txs_downloaded.iter() {
-                txids_downloaded.insert(tx.txid());
-                // add every previous input tx, but skip coinbase
-                for input in tx.input.iter().filter(|i| !i.previous_output.is_null()) {
-                    prev_txids.insert(input.previous_output.txid);
-                }
-            }
-            let already_present: HashSet<Txid> =
-                txids_downloaded.union(&txids_raw_in_db).cloned().collect();
-            let prev_txs_to_download: Vec<&Txid> =
-                prev_txids.difference(&already_present).collect();
-            info!("{} previous txs to download", prev_txs_to_download.len());
-            txs_downloaded.extend(maybe_await!(self.download_and_save_in_chunks(
-                prev_txs_to_download,
-                chunk_size,
-                db,
-            ))?);
-        }
-
-        Ok(txs_downloaded)
-    }
-
-    /// download headers at heights in `txid_height` if tx details not already present, returns a map Txid -> timestamp
-    fn download_needed_headers(
-        &self,
-        txid_height: &HashMap<Txid, Option<u32>>,
-        txs_details_in_db: &HashMap<Txid, TransactionDetails>,
-        chunk_size: usize,
-    ) -> Result<HashMap<Txid, u64>, Error> {
-        let mut txid_timestamp = HashMap::new();
-        let txid_in_db_with_conf: HashSet<_> = txs_details_in_db
-            .values()
-            .filter_map(|details| details.confirmation_time.as_ref().map(|_| details.txid))
-            .collect();
-        let needed_txid_height: HashMap<&Txid, u32> = txid_height
-            .iter()
-            .filter(|(t, _)| !txid_in_db_with_conf.contains(*t))
-            .filter_map(|(t, o)| o.map(|h| (t, h)))
-            .collect();
-        let needed_heights: HashSet<u32> = needed_txid_height.values().cloned().collect();
-        if !needed_heights.is_empty() {
-            info!("{} headers to download for timestamp", needed_heights.len());
-            let mut height_timestamp: HashMap<u32, u64> = HashMap::new();
-            for chunk in ChunksIterator::new(needed_heights.into_iter(), chunk_size) {
-                let call_result: Vec<BlockHeader> =
-                    maybe_await!(self.els_batch_block_header(chunk.clone()))?;
-                height_timestamp.extend(
-                    chunk
-                        .into_iter()
-                        .zip(call_result.iter().map(|h| h.time as u64)),
-                );
-            }
-            for (txid, height) in needed_txid_height {
-                let timestamp = height_timestamp
-                    .get(&height)
-                    .ok_or_else(|| Error::Generic("timestamp missing".to_string()))?;
-                txid_timestamp.insert(*txid, *timestamp);
-            }
-        }
-
-        Ok(txid_timestamp)
-    }
-
-    fn download_and_save_in_chunks<D: BatchDatabase>(
-        &self,
-        to_download: Vec<&Txid>,
-        chunk_size: usize,
-        db: &mut D,
-    ) -> Result<Vec<Transaction>, Error> {
-        let mut txs_downloaded = vec![];
-        for chunk in ChunksIterator::new(to_download.into_iter(), chunk_size) {
-            let call_result: Vec<Transaction> =
-                maybe_await!(self.els_batch_transaction_get(chunk))?;
-            let mut batch = db.begin_batch();
-            for new_tx in call_result.iter() {
-                batch.set_raw_tx(new_tx)?;
-            }
-            db.commit_batch(batch)?;
-            txs_downloaded.extend(call_result);
-        }
-
-        Ok(txs_downloaded)
-    }
-}
-
-fn save_transaction_details_and_utxos<D: BatchDatabase>(
-    txid: &Txid,
-    db: &mut D,
-    timestamp: Option<u64>,
-    height: Option<u32>,
-    updates: &mut dyn BatchOperations,
-    utxo_deps: &HashMap<OutPoint, OutPoint>,
-) -> Result<(), Error> {
-    let tx = db.get_raw_tx(txid)?.ok_or(Error::TransactionNotFound)?;
-
-    let mut incoming: u64 = 0;
-    let mut outgoing: u64 = 0;
-
-    let mut inputs_sum: u64 = 0;
-    let mut outputs_sum: u64 = 0;
-
-    // look for our own inputs
-    for input in tx.input.iter() {
-        // skip coinbase inputs
-        if input.previous_output.is_null() {
-            continue;
-        }
-
-        // We already downloaded all previous output txs in the previous step
-        if let Some(previous_output) = db.get_previous_output(&input.previous_output)? {
-            inputs_sum += previous_output.value;
-
-            if db.is_mine(&previous_output.script_pubkey)? {
-                outgoing += previous_output.value;
-            }
-        } else {
-            // The input is not ours, but we still need to count it for the fees
-            let tx = db
-                .get_raw_tx(&input.previous_output.txid)?
-                .ok_or(Error::TransactionNotFound)?;
-            inputs_sum += tx.output[input.previous_output.vout as usize].value;
-        }
-
-        // removes conflicting UTXO if any (generated from same inputs, like for example RBF)
-        if let Some(outpoint) = utxo_deps.get(&input.previous_output) {
-            updates.del_utxo(outpoint)?;
-        }
-    }
-
-    for (i, output) in tx.output.iter().enumerate() {
-        // to compute the fees later
-        outputs_sum += output.value;
-
-        // this output is ours, we have a path to derive it
-        if let Some((keychain, _child)) = db.get_path_from_script_pubkey(&output.script_pubkey)? {
-            debug!("{} output #{} is mine, adding utxo", txid, i);
-            updates.set_utxo(&LocalUtxo {
-                outpoint: OutPoint::new(tx.txid(), i as u32),
-                txout: output.clone(),
-                keychain,
-            })?;
-
-            incoming += output.value;
-        }
-    }
-
-    let tx_details = TransactionDetails {
-        txid: tx.txid(),
-        transaction: Some(tx),
-        received: incoming,
-        sent: outgoing,
-        confirmation_time: ConfirmationTime::new(height, timestamp),
-        fee: Some(inputs_sum.saturating_sub(outputs_sum)), /* if the tx is a coinbase, fees would be negative */
-        verified: height.is_some(),
-    };
-    updates.set_tx(&tx_details)?;
-
-    Ok(())
-}
-
-/// returns utxo dependency as the inputs needed for the utxo to exist
-/// `tx_raw_in_db` must contains utxo's generating txs or errors with [crate::Error::TransactionNotFound]
-fn utxos_deps<D: BatchDatabase>(
-    db: &mut D,
-    tx_raw_in_db: &HashMap<Txid, Transaction>,
-) -> Result<HashMap<OutPoint, OutPoint>, Error> {
-    let utxos = db.iter_utxos()?;
-    let mut utxos_deps = HashMap::new();
-    for utxo in utxos {
-        let from_tx = tx_raw_in_db
-            .get(&utxo.outpoint.txid)
-            .ok_or(Error::TransactionNotFound)?;
-        for input in from_tx.input.iter() {
-            utxos_deps.insert(input.previous_output, utxo.outpoint);
-        }
-    }
-    Ok(utxos_deps)
-}

src/database/any.rs

@@ -23,12 +23,12 @@
 //! # use bdk::database::{AnyDatabase, MemoryDatabase};
 //! # use bdk::{Wallet};
 //! let memory = MemoryDatabase::default();
-//! let wallet_memory = Wallet::new_offline("...", None, Network::Testnet, memory)?;
+//! let wallet_memory = Wallet::new("...", None, Network::Testnet, memory)?;
 //!
 //! # #[cfg(feature = "key-value-db")]
 //! # {
 //! let sled = sled::open("my-database")?.open_tree("default_tree")?;
-//! let wallet_sled = Wallet::new_offline("...", None, Network::Testnet, sled)?;
+//! let wallet_sled = Wallet::new("...", None, Network::Testnet, sled)?;
 //! # }
 //! # Ok::<(), bdk::Error>(())
 //! ```
@@ -42,7 +42,7 @@
 //! # use bdk::{Wallet};
 //! let config = serde_json::from_str("...")?;
 //! let database = AnyDatabase::from_config(&config)?;
-//! let wallet = Wallet::new_offline("...", None, Network::Testnet, database)?;
+//! let wallet = Wallet::new("...", None, Network::Testnet, database)?;
 //! # Ok::<(), bdk::Error>(())
 //! ```
 
@@ -144,6 +144,9 @@ impl BatchOperations for AnyDatabase {
     fn set_last_index(&mut self, keychain: KeychainKind, value: u32) -> Result<(), Error> {
         impl_inner_method!(AnyDatabase, self, set_last_index, keychain, value)
     }
+    fn set_sync_time(&mut self, sync_time: SyncTime) -> Result<(), Error> {
+        impl_inner_method!(AnyDatabase, self, set_sync_time, sync_time)
+    }
 
     fn del_script_pubkey_from_path(
         &mut self,
@@ -180,6 +183,9 @@ impl BatchOperations for AnyDatabase {
     fn del_last_index(&mut self, keychain: KeychainKind) -> Result<Option<u32>, Error> {
         impl_inner_method!(AnyDatabase, self, del_last_index, keychain)
     }
+    fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error> {
+        impl_inner_method!(AnyDatabase, self, del_sync_time)
+    }
 }
 
 impl Database for AnyDatabase {
@@ -241,6 +247,9 @@ impl Database for AnyDatabase {
     fn get_last_index(&self, keychain: KeychainKind) -> Result<Option<u32>, Error> {
         impl_inner_method!(AnyDatabase, self, get_last_index, keychain)
     }
+    fn get_sync_time(&self) -> Result<Option<SyncTime>, Error> {
+        impl_inner_method!(AnyDatabase, self, get_sync_time)
+    }
 
     fn increment_last_index(&mut self, keychain: KeychainKind) -> Result<u32, Error> {
         impl_inner_method!(AnyDatabase, self, increment_last_index, keychain)
@@ -272,6 +281,9 @@ impl BatchOperations for AnyBatch {
     fn set_last_index(&mut self, keychain: KeychainKind, value: u32) -> Result<(), Error> {
         impl_inner_method!(AnyBatch, self, set_last_index, keychain, value)
     }
+    fn set_sync_time(&mut self, sync_time: SyncTime) -> Result<(), Error> {
+        impl_inner_method!(AnyBatch, self, set_sync_time, sync_time)
+    }
 
     fn del_script_pubkey_from_path(
         &mut self,
@@ -302,6 +314,9 @@ impl BatchOperations for AnyBatch {
     fn del_last_index(&mut self, keychain: KeychainKind) -> Result<Option<u32>, Error> {
         impl_inner_method!(AnyBatch, self, del_last_index, keychain)
     }
+    fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error> {
+        impl_inner_method!(AnyBatch, self, del_sync_time)
+    }
 }
 
 impl BatchDatabase for AnyDatabase {

src/database/keyvalue.rs

@@ -18,7 +18,7 @@ use bitcoin::hash_types::Txid;
 use bitcoin::{OutPoint, Script, Transaction};
 
 use crate::database::memory::MapKey;
-use crate::database::{BatchDatabase, BatchOperations, Database};
+use crate::database::{BatchDatabase, BatchOperations, Database, SyncTime};
 use crate::error::Error;
 use crate::types::*;
 
@@ -82,6 +82,13 @@ macro_rules! impl_batch_operations {
             Ok(())
         }
 
+        fn set_sync_time(&mut self, data: SyncTime) -> Result<(), Error> {
+            let key = MapKey::SyncTime.as_map_key();
+            self.insert(key, serde_json::to_vec(&data)?)$($after_insert)*;
+
+            Ok(())
+        }
+
         fn del_script_pubkey_from_path(&mut self, keychain: KeychainKind, path: u32) -> Result<Option<Script>, Error> {
             let key = MapKey::Path((Some(keychain), Some(path))).as_map_key();
             let res = self.remove(key);
@@ -168,6 +175,14 @@ macro_rules! impl_batch_operations {
                 }
             }
         }
+
+        fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error> {
+            let key = MapKey::SyncTime.as_map_key();
+            let res = self.remove(key);
+            let res = $process_delete!(res);
+
+            Ok(res.map(|b| serde_json::from_slice(&b)).transpose()?)
+        }
     }
 }
 
@@ -342,6 +357,14 @@ impl Database for Tree {
             .transpose()
     }
 
+    fn get_sync_time(&self) -> Result<Option<SyncTime>, Error> {
+        let key = MapKey::SyncTime.as_map_key();
+        Ok(self
+            .get(key)?
+            .map(|b| serde_json::from_slice(&b))
+            .transpose()?)
+    }
+
     // inserts 0 if not present
     fn increment_last_index(&mut self, keychain: KeychainKind) -> Result<u32, Error> {
         let key = MapKey::LastIndex(keychain).as_map_key();
@@ -470,4 +493,9 @@ mod test {
     fn test_last_index() {
         crate::database::test::test_last_index(get_tree());
     }
+
+    #[test]
+    fn test_sync_time() {
+        crate::database::test::test_sync_time(get_tree());
+    }
 }

src/database/memory.rs

@@ -14,6 +14,7 @@
 //! This module defines an in-memory database type called [`MemoryDatabase`] that is based on a
 //! [`BTreeMap`].
 
+use std::any::Any;
 use std::collections::BTreeMap;
 use std::ops::Bound::{Excluded, Included};
 
@@ -21,7 +22,7 @@ use bitcoin::consensus::encode::{deserialize, serialize};
 use bitcoin::hash_types::Txid;
 use bitcoin::{OutPoint, Script, Transaction};
 
-use crate::database::{BatchDatabase, BatchOperations, ConfigurableDatabase, Database};
+use crate::database::{BatchDatabase, BatchOperations, ConfigurableDatabase, Database, SyncTime};
 use crate::error::Error;
 use crate::types::*;
 
@@ -32,6 +33,7 @@ use crate::types::*;
 // transactions         t<txid> -> tx details
 // deriv indexes        c{i,e} -> u32
 // descriptor checksum  d{i,e} -> vec<u8>
+// last sync time       l -> { height, timestamp }
 
 pub(crate) enum MapKey<'a> {
     Path((Option<KeychainKind>, Option<u32>)),
@@ -40,6 +42,7 @@ pub(crate) enum MapKey<'a> {
     RawTx(Option<&'a Txid>),
     Transaction(Option<&'a Txid>),
     LastIndex(KeychainKind),
+    SyncTime,
     DescriptorChecksum(KeychainKind),
 }
 
@@ -58,6 +61,7 @@ impl MapKey<'_> {
             MapKey::RawTx(_) => b"r".to_vec(),
             MapKey::Transaction(_) => b"t".to_vec(),
             MapKey::LastIndex(st) => [b"c", st.as_ref()].concat(),
+            MapKey::SyncTime => b"l".to_vec(),
             MapKey::DescriptorChecksum(st) => [b"d", st.as_ref()].concat(),
         }
     }
@@ -105,12 +109,12 @@ fn after(key: &[u8]) -> Vec<u8> {
 /// Once it's dropped its content will be lost.
 ///
 /// If you are looking for a permanent storage solution, you can try with the default key-value
-/// database called [`sled`]. See the [`database`] module documentation for more defailts.
+/// database called [`sled`]. See the [`database`] module documentation for more details.
 ///
 /// [`database`]: crate::database
 #[derive(Debug, Default)]
 pub struct MemoryDatabase {
-    map: BTreeMap<Vec<u8>, Box<dyn std::any::Any>>,
+    map: BTreeMap<Vec<u8>, Box<dyn Any + Send + Sync>>,
     deleted_keys: Vec<Vec<u8>>,
 }
 
@@ -179,6 +183,12 @@ impl BatchOperations for MemoryDatabase {
 
         Ok(())
     }
+    fn set_sync_time(&mut self, data: SyncTime) -> Result<(), Error> {
+        let key = MapKey::SyncTime.as_map_key();
+        self.map.insert(key, Box::new(data));
+
+        Ok(())
+    }
 
     fn del_script_pubkey_from_path(
         &mut self,
@@ -269,6 +279,13 @@ impl BatchOperations for MemoryDatabase {
             Some(b) => Ok(Some(*b.downcast_ref().unwrap())),
         }
     }
+    fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error> {
+        let key = MapKey::SyncTime.as_map_key();
+        let res = self.map.remove(&key);
+        self.deleted_keys.push(key);
+
+        Ok(res.map(|b| b.downcast_ref().cloned().unwrap()))
+    }
 }
 
 impl Database for MemoryDatabase {
@@ -406,6 +423,14 @@ impl Database for MemoryDatabase {
         Ok(self.map.get(&key).map(|b| *b.downcast_ref().unwrap()))
     }
 
+    fn get_sync_time(&self) -> Result<Option<SyncTime>, Error> {
+        let key = MapKey::SyncTime.as_map_key();
+        Ok(self
+            .map
+            .get(&key)
+            .map(|b| b.downcast_ref().cloned().unwrap()))
+    }
+
     // inserts 0 if not present
     fn increment_last_index(&mut self, keychain: KeychainKind) -> Result<u32, Error> {
         let key = MapKey::LastIndex(keychain).as_map_key();
@@ -478,12 +503,10 @@ macro_rules! populate_test_db {
         };
 
         let txid = tx.txid();
-        let confirmation_time = tx_meta
-            .min_confirmations
-            .map(|conf| $crate::ConfirmationTime {
-                height: current_height.unwrap().checked_sub(conf as u32).unwrap(),
-                timestamp: 0,
-            });
+        let confirmation_time = tx_meta.min_confirmations.map(|conf| $crate::BlockTime {
+            height: current_height.unwrap().checked_sub(conf as u32).unwrap(),
+            timestamp: 0,
+        });
 
         let tx_details = $crate::TransactionDetails {
             transaction: Some(tx.clone()),
@@ -532,7 +555,7 @@ macro_rules! doctest_wallet {
             Some(100),
         );
 
-        $crate::Wallet::new_offline(
+        $crate::Wallet::new(
             &descriptors.0,
             descriptors.1.as_ref(),
             Network::Regtest,
@@ -589,4 +612,9 @@ mod test {
     fn test_last_index() {
         crate::database::test::test_last_index(get_tree());
     }
+
+    #[test]
+    fn test_sync_time() {
+        crate::database::test::test_sync_time(get_tree());
+    }
 }

src/database/mod.rs

@@ -24,6 +24,8 @@
 //!
 //! [`Wallet`]: crate::wallet::Wallet
 
+use serde::{Deserialize, Serialize};
+
 use bitcoin::hash_types::Txid;
 use bitcoin::{OutPoint, Script, Transaction, TxOut};
 
@@ -44,6 +46,15 @@ pub use sqlite::SqliteDatabase;
 pub mod memory;
 pub use memory::MemoryDatabase;
 
+/// Blockchain state at the time of syncing
+///
+/// Contains only the block time and height at the moment
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct SyncTime {
+    /// Block timestamp and height at the time of sync
+    pub block_time: BlockTime,
+}
+
 /// Trait for operations that can be batched
 ///
 /// This trait defines the list of operations that must be implemented on the [`Database`] type and
@@ -64,6 +75,8 @@ pub trait BatchOperations {
     fn set_tx(&mut self, transaction: &TransactionDetails) -> Result<(), Error>;
     /// Store the last derivation index for a given keychain.
     fn set_last_index(&mut self, keychain: KeychainKind, value: u32) -> Result<(), Error>;
+    /// Store the sync time
+    fn set_sync_time(&mut self, sync_time: SyncTime) -> Result<(), Error>;
 
     /// Delete a script_pubkey given the keychain and its child number.
     fn del_script_pubkey_from_path(
@@ -89,6 +102,10 @@ pub trait BatchOperations {
     ) -> Result<Option<TransactionDetails>, Error>;
     /// Delete the last derivation index for a keychain.
     fn del_last_index(&mut self, keychain: KeychainKind) -> Result<Option<u32>, Error>;
+    /// Reset the sync time to `None`
+    ///
+    /// Returns the removed value
+    fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error>;
 }
 
 /// Trait for reading data from a database
@@ -132,8 +149,10 @@ pub trait Database: BatchOperations {
     fn get_raw_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error>;
     /// Fetch the transaction metadata and optionally also the raw transaction
     fn get_tx(&self, txid: &Txid, include_raw: bool) -> Result<Option<TransactionDetails>, Error>;
-    /// Return the last defivation index for a keychain.
+    /// Return the last derivation index for a keychain.
     fn get_last_index(&self, keychain: KeychainKind) -> Result<Option<u32>, Error>;
+    /// Return the sync time, if present
+    fn get_sync_time(&self) -> Result<Option<SyncTime>, Error>;
 
     /// Increment the last derivation index for a keychain and return it
     ///
@@ -325,7 +344,7 @@ pub mod test {
             received: 1337,
             sent: 420420,
             fee: Some(140),
-            confirmation_time: Some(ConfirmationTime {
+            confirmation_time: Some(BlockTime {
                 timestamp: 123456,
                 height: 1000,
             }),
@@ -377,5 +396,25 @@ pub mod test {
         );
     }
 
+    pub fn test_sync_time<D: Database>(mut tree: D) {
+        assert!(tree.get_sync_time().unwrap().is_none());
+
+        tree.set_sync_time(SyncTime {
+            block_time: BlockTime {
+                height: 100,
+                timestamp: 1000,
+            },
+        })
+        .unwrap();
+
+        let extracted = tree.get_sync_time().unwrap();
+        assert!(extracted.is_some());
+        assert_eq!(extracted.as_ref().unwrap().block_time.height, 100);
+        assert_eq!(extracted.as_ref().unwrap().block_time.timestamp, 1000);
+
+        tree.del_sync_time().unwrap();
+        assert!(tree.get_sync_time().unwrap().is_none());
+    }
+
     // TODO: more tests...
 }

src/database/sqlite.rs

@@ -13,7 +13,7 @@ use bitcoin::consensus::encode::{deserialize, serialize};
 use bitcoin::hash_types::Txid;
 use bitcoin::{OutPoint, Script, Transaction, TxOut};
 
-use crate::database::{BatchDatabase, BatchOperations, Database};
+use crate::database::{BatchDatabase, BatchOperations, Database, SyncTime};
 use crate::error::Error;
 use crate::types::*;
 
@@ -35,6 +35,7 @@ static MIGRATIONS: &[&str] = &[
     "CREATE UNIQUE INDEX idx_indices_keychain ON last_derivation_indices(keychain);",
     "CREATE TABLE checksums (keychain TEXT, checksum BLOB);",
     "CREATE INDEX idx_checksums_keychain ON checksums(keychain);",
+    "CREATE TABLE sync_time (id INTEGER PRIMARY KEY, height INTEGER, timestamp INTEGER);"
 ];
 
 /// Sqlite database stored on filesystem
@@ -205,6 +206,19 @@ impl SqliteDatabase {
         Ok(())
     }
 
+    fn update_sync_time(&self, data: SyncTime) -> Result<i64, Error> {
+        let mut statement = self.connection.prepare_cached(
+            "INSERT INTO sync_time (id, height, timestamp) VALUES (0, :height, :timestamp) ON CONFLICT(id) DO UPDATE SET height=:height, timestamp=:timestamp WHERE id = 0",
+        )?;
+
+        statement.execute(named_params! {
+            ":height": data.block_time.height,
+            ":timestamp": data.block_time.timestamp,
+        })?;
+
+        Ok(self.connection.last_insert_rowid())
+    }
+
     fn select_script_pubkeys(&self) -> Result<Vec<Script>, Error> {
         let mut statement = self
             .connection
@@ -375,7 +389,7 @@ impl SqliteDatabase {
             };
 
             let confirmation_time = match (height, timestamp) {
-                (Some(height), Some(timestamp)) => Some(ConfirmationTime { height, timestamp }),
+                (Some(height), Some(timestamp)) => Some(BlockTime { height, timestamp }),
                 _ => None,
             };
 
@@ -409,7 +423,7 @@ impl SqliteDatabase {
             let verified: bool = row.get(6)?;
 
             let confirmation_time = match (height, timestamp) {
-                (Some(height), Some(timestamp)) => Some(ConfirmationTime { height, timestamp }),
+                (Some(height), Some(timestamp)) => Some(BlockTime { height, timestamp }),
                 _ => None,
             };
 
@@ -452,7 +466,7 @@ impl SqliteDatabase {
                 };
 
                 let confirmation_time = match (height, timestamp) {
-                    (Some(height), Some(timestamp)) => Some(ConfirmationTime { height, timestamp }),
+                    (Some(height), Some(timestamp)) => Some(BlockTime { height, timestamp }),
                     _ => None,
                 };
 
@@ -487,6 +501,24 @@ impl SqliteDatabase {
         }
     }
 
+    fn select_sync_time(&self) -> Result<Option<SyncTime>, Error> {
+        let mut statement = self
+            .connection
+            .prepare_cached("SELECT height, timestamp FROM sync_time WHERE id = 0")?;
+        let mut rows = statement.query([])?;
+
+        if let Some(row) = rows.next()? {
+            Ok(Some(SyncTime {
+                block_time: BlockTime {
+                    height: row.get(0)?,
+                    timestamp: row.get(1)?,
+                },
+            }))
+        } else {
+            Ok(None)
+        }
+    }
+
     fn select_checksum_by_keychain(&self, keychain: String) -> Result<Option<Vec<u8>>, Error> {
         let mut statement = self
             .connection
@@ -563,6 +595,14 @@ impl SqliteDatabase {
 
         Ok(())
     }
+
+    fn delete_sync_time(&self) -> Result<(), Error> {
+        let mut statement = self
+            .connection
+            .prepare_cached("DELETE FROM sync_time WHERE id = 0")?;
+        statement.execute([])?;
+        Ok(())
+    }
 }
 
 impl BatchOperations for SqliteDatabase {
@@ -622,6 +662,11 @@ impl BatchOperations for SqliteDatabase {
         Ok(())
     }
 
+    fn set_sync_time(&mut self, ct: SyncTime) -> Result<(), Error> {
+        self.update_sync_time(ct)?;
+        Ok(())
+    }
+
     fn del_script_pubkey_from_path(
         &mut self,
         keychain: KeychainKind,
@@ -707,6 +752,17 @@ impl BatchOperations for SqliteDatabase {
             None => Ok(None),
         }
     }
+
+    fn del_sync_time(&mut self) -> Result<Option<SyncTime>, Error> {
+        match self.select_sync_time()? {
+            Some(value) => {
+                self.delete_sync_time()?;
+
+                Ok(Some(value))
+            }
+            None => Ok(None),
+        }
+    }
 }
 
 impl Database for SqliteDatabase {
@@ -818,6 +874,10 @@ impl Database for SqliteDatabase {
         Ok(value)
     }
 
+    fn get_sync_time(&self) -> Result<Option<SyncTime>, Error> {
+        self.select_sync_time()
+    }
+
     fn increment_last_index(&mut self, keychain: KeychainKind) -> Result<u32, Error> {
         let keychain_string = serde_json::to_string(&keychain)?;
         match self.get_last_index(keychain)? {
@@ -965,4 +1025,9 @@ pub mod test {
     fn test_last_index() {
         crate::database::test::test_last_index(get_database());
     }
+
+    #[test]
+    fn test_sync_time() {
+        crate::database::test::test_sync_time(get_database());
+    }
 }

src/descriptor/dsl.rs

@@ -84,7 +84,7 @@ macro_rules! impl_leaf_opcode {
         )
         .map_err($crate::descriptor::DescriptorError::Miniscript)
         .and_then(|minisc| {
-            minisc.check_minsicript()?;
+            minisc.check_miniscript()?;
             Ok(minisc)
         })
         .map(|minisc| {
@@ -108,7 +108,7 @@ macro_rules! impl_leaf_opcode_value {
         )
         .map_err($crate::descriptor::DescriptorError::Miniscript)
         .and_then(|minisc| {
-            minisc.check_minsicript()?;
+            minisc.check_miniscript()?;
             Ok(minisc)
         })
         .map(|minisc| {
@@ -132,7 +132,7 @@ macro_rules! impl_leaf_opcode_value_two {
         )
         .map_err($crate::descriptor::DescriptorError::Miniscript)
         .and_then(|minisc| {
-            minisc.check_minsicript()?;
+            minisc.check_miniscript()?;
             Ok(minisc)
         })
         .map(|minisc| {
@@ -165,7 +165,7 @@ macro_rules! impl_node_opcode_two {
                     std::sync::Arc::new(b_minisc),
                 ))?;
 
-                minisc.check_minsicript()?;
+                minisc.check_miniscript()?;
 
                 Ok((minisc, a_keymap, $crate::keys::merge_networks(&a_networks, &b_networks)))
             })
@@ -197,7 +197,7 @@ macro_rules! impl_node_opcode_three {
                     std::sync::Arc::new(c_minisc),
                 ))?;
 
-                minisc.check_minsicript()?;
+                minisc.check_miniscript()?;
 
                 Ok((minisc, a_keymap, networks))
             })
@@ -243,7 +243,7 @@ macro_rules! apply_modifier {
                     ),
                 )?;
 
-                minisc.check_minsicript()?;
+                minisc.check_miniscript()?;
 
                 Ok((minisc, keymap, networks))
             })
@@ -521,7 +521,7 @@ macro_rules! fragment_internal {
     // three operands it's (X, (X, (X, ()))), etc.
     //
     // To check that the right number of arguments has been passed we can "cast" those tuples to
-    // more convenient structures like `TupleTwo`. If the conversion succedes, the right number of
+    // more convenient structures like `TupleTwo`. If the conversion succeeds, the right number of
     // args was passed. Otherwise the compilation fails entirely.
     ( @t $op:ident ( $( $args:tt )* ) $( $tail:tt )* ) => ({
         ($crate::fragment!( $op ( $( $args )* ) ), $crate::fragment_internal!( @t $( $tail )* ))

src/descriptor/mod.rs

@@ -238,13 +238,13 @@ pub(crate) fn into_wallet_descriptor_checked<T: IntoWalletDescriptor>(
 #[doc(hidden)]
 /// Used internally mainly by the `descriptor!()` and `fragment!()` macros
 pub trait CheckMiniscript<Ctx: miniscript::ScriptContext> {
-    fn check_minsicript(&self) -> Result<(), miniscript::Error>;
+    fn check_miniscript(&self) -> Result<(), miniscript::Error>;
 }
 
 impl<Ctx: miniscript::ScriptContext, Pk: miniscript::MiniscriptKey> CheckMiniscript<Ctx>
     for miniscript::Miniscript<Pk, Ctx>
 {
-    fn check_minsicript(&self) -> Result<(), miniscript::Error> {
+    fn check_miniscript(&self) -> Result<(), miniscript::Error> {
         Ctx::check_global_validity(self)?;
 
         Ok(())
@@ -667,7 +667,7 @@ mod test {
 
         // make a descriptor out of it
         let desc = crate::descriptor!(wpkh(key)).unwrap();
-        // this should conver the key that supports "any_network" to the right network (testnet)
+        // this should convert the key that supports "any_network" to the right network (testnet)
         let (wallet_desc, _) = desc
             .into_wallet_descriptor(&secp, Network::Testnet)
             .unwrap();

src/descriptor/policy.rs

@@ -354,9 +354,9 @@ impl Satisfaction {
                 indexes
                     .into_iter()
                     // .inspect(|x| println!("--- orig --- {:?}", x))
-                    // we map each of the combinations of elements into a tuple of ([choosen items], [conditions]). unfortunately, those items have potentially more than one
+                    // we map each of the combinations of elements into a tuple of ([chosen items], [conditions]). unfortunately, those items have potentially more than one
                     // condition (think about ORs), so we also use `mix` to expand those, i.e. [[0], [1, 2]] becomes [[0, 1], [0, 2]]. This is necessary to make sure that we
-                    // consider every possibile options and check whether or not they are compatible.
+                    // consider every possible options and check whether or not they are compatible.
                     .map(|i_vec| {
                         mix(i_vec
                             .iter()

src/descriptor/template.rs

@@ -79,7 +79,7 @@ impl<T: DescriptorTemplate> IntoWalletDescriptor for T {
 ///
 /// let key =
 ///     bitcoin::PrivateKey::from_wif("cTc4vURSzdx6QE6KVynWGomDbLaA75dNALMNyfjh3p8DRRar84Um")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     P2Pkh(key),
 ///     None,
 ///     Network::Testnet,
@@ -113,7 +113,7 @@ impl<K: IntoDescriptorKey<Legacy>> DescriptorTemplate for P2Pkh<K> {
 ///
 /// let key =
 ///     bitcoin::PrivateKey::from_wif("cTc4vURSzdx6QE6KVynWGomDbLaA75dNALMNyfjh3p8DRRar84Um")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     P2Wpkh_P2Sh(key),
 ///     None,
 ///     Network::Testnet,
@@ -148,7 +148,7 @@ impl<K: IntoDescriptorKey<Segwitv0>> DescriptorTemplate for P2Wpkh_P2Sh<K> {
 ///
 /// let key =
 ///     bitcoin::PrivateKey::from_wif("cTc4vURSzdx6QE6KVynWGomDbLaA75dNALMNyfjh3p8DRRar84Um")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     P2Wpkh(key),
 ///     None,
 ///     Network::Testnet,
@@ -186,7 +186,7 @@ impl<K: IntoDescriptorKey<Segwitv0>> DescriptorTemplate for P2Wpkh<K> {
 /// use bdk::template::Bip44;
 ///
 /// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip44(key.clone(), KeychainKind::External),
 ///     Some(Bip44(key, KeychainKind::Internal)),
 ///     Network::Testnet,
@@ -226,7 +226,7 @@ impl<K: DerivableKey<Legacy>> DescriptorTemplate for Bip44<K> {
 ///
 /// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDDDzQ31JkZB7VxUr9bjvBivDdqoFLrDPyLWtLapArAi51ftfmCb2DPxwLQzX65iNcXz1DGaVvyvo6JQ6rTU73r2gqdEo8uov9QKRb7nKCSU")?;
 /// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip44Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip44Public(key, fingerprint, KeychainKind::Internal)),
 ///     Network::Testnet,
@@ -262,7 +262,7 @@ impl<K: DerivableKey<Legacy>> DescriptorTemplate for Bip44Public<K> {
 /// use bdk::template::Bip49;
 ///
 /// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip49(key.clone(), KeychainKind::External),
 ///     Some(Bip49(key, KeychainKind::Internal)),
 ///     Network::Testnet,
@@ -302,7 +302,7 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip49<K> {
 ///
 /// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC49r947KGK52X5rBWS4BLs5m9SRY3pYHnvRrm7HcybZ3BfdEsGFyzCMzayi1u58eT82ZeyFZwH7DD6Q83E3fM9CpfMtmnTygnLfP59jL9L")?;
 /// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip49Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip49Public(key, fingerprint, KeychainKind::Internal)),
 ///     Network::Testnet,
@@ -338,7 +338,7 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip49Public<K> {
 /// use bdk::template::Bip84;
 ///
 /// let key = bitcoin::util::bip32::ExtendedPrivKey::from_str("tprv8ZgxMBicQKsPeZRHk4rTG6orPS2CRNFX3njhUXx5vj9qGog5ZMH4uGReDWN5kCkY3jmWEtWause41CDvBRXD1shKknAMKxT99o9qUTRVC6m")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip84(key.clone(), KeychainKind::External),
 ///     Some(Bip84(key, KeychainKind::Internal)),
 ///     Network::Testnet,
@@ -378,7 +378,7 @@ impl<K: DerivableKey<Segwitv0>> DescriptorTemplate for Bip84<K> {
 ///
 /// let key = bitcoin::util::bip32::ExtendedPubKey::from_str("tpubDC2Qwo2TFsaNC4ju8nrUJ9mqVT3eSgdmy1yPqhgkjwmke3PRXutNGRYAUo6RCHTcVQaDR3ohNU9we59brGHuEKPvH1ags2nevW5opEE9Z5Q")?;
 /// let fingerprint = bitcoin::util::bip32::Fingerprint::from_str("c55b303f")?;
-/// let wallet = Wallet::new_offline(
+/// let wallet = Wallet::new(
 ///     Bip84Public(key.clone(), fingerprint, KeychainKind::External),
 ///     Some(Bip84Public(key, fingerprint, KeychainKind::Internal)),
 ///     Network::Testnet,

src/error.rs

@@ -115,7 +115,7 @@ pub enum Error {
     Hex(bitcoin::hashes::hex::Error),
     /// Partially signed bitcoin transaction error
     Psbt(bitcoin::util::psbt::Error),
-    /// Partially signed bitcoin transaction parseerror
+    /// Partially signed bitcoin transaction parse error
     PsbtParse(bitcoin::util::psbt::PsbtParseError),
 
     //KeyMismatch(bitcoin::secp256k1::PublicKey, bitcoin::secp256k1::PublicKey),
@@ -139,7 +139,7 @@ pub enum Error {
     Sled(sled::Error),
     #[cfg(feature = "rpc")]
     /// Rpc client error
-    Rpc(core_rpc::Error),
+    Rpc(bitcoincore_rpc::Error),
     #[cfg(feature = "sqlite")]
     /// Rusqlite client error
     Rusqlite(rusqlite::Error),
@@ -196,7 +196,7 @@ impl_error!(electrum_client::Error, Electrum);
 #[cfg(feature = "key-value-db")]
 impl_error!(sled::Error, Sled);
 #[cfg(feature = "rpc")]
-impl_error!(core_rpc::Error, Rpc);
+impl_error!(bitcoincore_rpc::Error, Rpc);
 #[cfg(feature = "sqlite")]
 impl_error!(rusqlite::Error, Rusqlite);
 

src/keys/bip39.rs

@@ -19,7 +19,23 @@ use bitcoin::Network;
 
 use miniscript::ScriptContext;
 
-pub use bip39::{Language, Mnemonic, MnemonicType, Seed};
+pub use bip39::{Language, Mnemonic};
+
+type Seed = [u8; 64];
+
+/// Type describing entropy length (aka word count) in the mnemonic
+pub enum WordCount {
+    /// 12 words mnemonic (128 bits entropy)
+    Words12 = 128,
+    /// 15 words mnemonic (160 bits entropy)
+    Words15 = 160,
+    /// 18 words mnemonic (192 bits entropy)
+    Words18 = 192,
+    /// 21 words mnemonic (224 bits entropy)
+    Words21 = 224,
+    /// 24 words mnemonic (256 bits entropy)
+    Words24 = 256,
+}
 
 use super::{
     any_network, DerivableKey, DescriptorKey, ExtendedKey, GeneratableKey, GeneratedKey, KeyError,
@@ -40,7 +56,7 @@ pub type MnemonicWithPassphrase = (Mnemonic, Option<String>);
 #[cfg_attr(docsrs, doc(cfg(feature = "keys-bip39")))]
 impl<Ctx: ScriptContext> DerivableKey<Ctx> for Seed {
     fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
-        Ok(bip32::ExtendedPrivKey::new_master(Network::Bitcoin, &self.as_bytes())?.into())
+        Ok(bip32::ExtendedPrivKey::new_master(Network::Bitcoin, &self[..])?.into())
     }
 
     fn into_descriptor_key(
@@ -60,7 +76,7 @@ impl<Ctx: ScriptContext> DerivableKey<Ctx> for Seed {
 impl<Ctx: ScriptContext> DerivableKey<Ctx> for MnemonicWithPassphrase {
     fn into_extended_key(self) -> Result<ExtendedKey<Ctx>, KeyError> {
         let (mnemonic, passphrase) = self;
-        let seed = Seed::new(&mnemonic, passphrase.as_deref().unwrap_or(""));
+        let seed: Seed = mnemonic.to_seed(passphrase.as_deref().unwrap_or(""));
 
         seed.into_extended_key()
     }
@@ -101,15 +117,15 @@ impl<Ctx: ScriptContext> DerivableKey<Ctx> for Mnemonic {
 impl<Ctx: ScriptContext> GeneratableKey<Ctx> for Mnemonic {
     type Entropy = [u8; 32];
 
-    type Options = (MnemonicType, Language);
-    type Error = Option<bip39::ErrorKind>;
+    type Options = (WordCount, Language);
+    type Error = Option<bip39::Error>;
 
     fn generate_with_entropy(
-        (mnemonic_type, language): Self::Options,
+        (word_count, language): Self::Options,
         entropy: Self::Entropy,
     ) -> Result<GeneratedKey<Self, Ctx>, Self::Error> {
-        let entropy = &entropy.as_ref()[..(mnemonic_type.entropy_bits() / 8)];
-        let mnemonic = Mnemonic::from_entropy(entropy, language).map_err(|e| e.downcast().ok())?;
+        let entropy = &entropy.as_ref()[..(word_count as usize / 8)];
+        let mnemonic = Mnemonic::from_entropy_in(language, entropy)?;
 
         Ok(GeneratedKey::new(mnemonic, any_network()))
     }
@@ -121,15 +137,17 @@ mod test {
 
     use bitcoin::util::bip32;
 
-    use bip39::{Language, Mnemonic, MnemonicType};
+    use bip39::{Language, Mnemonic};
 
     use crate::keys::{any_network, GeneratableKey, GeneratedKey};
 
+    use super::WordCount;
+
     #[test]
     fn test_keys_bip39_mnemonic() {
         let mnemonic =
             "aim bunker wash balance finish force paper analyst cabin spoon stable organ";
-        let mnemonic = Mnemonic::from_phrase(mnemonic, Language::English).unwrap();
+        let mnemonic = Mnemonic::parse_in(Language::English, mnemonic).unwrap();
         let path = bip32::DerivationPath::from_str("m/44'/0'/0'/0").unwrap();
 
         let key = (mnemonic, path);
@@ -143,7 +161,7 @@ mod test {
     fn test_keys_bip39_mnemonic_passphrase() {
         let mnemonic =
             "aim bunker wash balance finish force paper analyst cabin spoon stable organ";
-        let mnemonic = Mnemonic::from_phrase(mnemonic, Language::English).unwrap();
+        let mnemonic = Mnemonic::parse_in(Language::English, mnemonic).unwrap();
         let path = bip32::DerivationPath::from_str("m/44'/0'/0'/0").unwrap();
 
         let key = ((mnemonic, Some("passphrase".into())), path);
@@ -157,7 +175,7 @@ mod test {
     fn test_keys_generate_bip39() {
         let generated_mnemonic: GeneratedKey<_, miniscript::Segwitv0> =
             Mnemonic::generate_with_entropy(
-                (MnemonicType::Words12, Language::English),
+                (WordCount::Words12, Language::English),
                 crate::keys::test::TEST_ENTROPY,
             )
             .unwrap();
@@ -169,7 +187,7 @@ mod test {
 
         let generated_mnemonic: GeneratedKey<_, miniscript::Segwitv0> =
             Mnemonic::generate_with_entropy(
-                (MnemonicType::Words24, Language::English),
+                (WordCount::Words24, Language::English),
                 crate::keys::test::TEST_ENTROPY,
             )
             .unwrap();
@@ -180,11 +198,11 @@ mod test {
     #[test]
     fn test_keys_generate_bip39_random() {
         let generated_mnemonic: GeneratedKey<_, miniscript::Segwitv0> =
-            Mnemonic::generate((MnemonicType::Words12, Language::English)).unwrap();
+            Mnemonic::generate((WordCount::Words12, Language::English)).unwrap();
         assert_eq!(generated_mnemonic.valid_networks, any_network());
 
         let generated_mnemonic: GeneratedKey<_, miniscript::Segwitv0> =
-            Mnemonic::generate((MnemonicType::Words24, Language::English)).unwrap();
+            Mnemonic::generate((WordCount::Words24, Language::English)).unwrap();
         assert_eq!(generated_mnemonic.valid_networks, any_network());
     }
 }

src/keys/mod.rs

@@ -319,6 +319,7 @@ impl<Ctx: ScriptContext> ExtendedKey<Ctx> {
         match self {
             ExtendedKey::Private((mut xprv, _)) => {
                 xprv.network = network;
+                xprv.private_key.network = network;
                 Some(xprv)
             }
             ExtendedKey::Public(_) => None,
@@ -356,7 +357,7 @@ impl<Ctx: ScriptContext> From<bip32::ExtendedPrivKey> for ExtendedKey<Ctx> {
 
 /// Trait for keys that can be derived.
 ///
-/// When extra metadata are provided, a [`DerivableKey`] can be transofrmed into a
+/// When extra metadata are provided, a [`DerivableKey`] can be transformed into a
 /// [`DescriptorKey`]: the trait [`IntoDescriptorKey`] is automatically implemented
 /// for `(DerivableKey, DerivationPath)` and
 /// `(DerivableKey, KeySource, DerivationPath)` tuples.
@@ -460,9 +461,9 @@ use bdk::keys::bip39::{Mnemonic, Language};
 
 # fn main() -> Result<(), Box<dyn std::error::Error>> {
 let xkey: ExtendedKey =
-    Mnemonic::from_phrase(
+    Mnemonic::parse_in(
+        Language::English,
         "jelly crash boy whisper mouse ecology tuna soccer memory million news short",
-        Language::English
     )?
     .into_extended_key()?;
 let xprv = xkey.into_xprv(Network::Bitcoin).unwrap();
@@ -748,7 +749,7 @@ pub fn make_pk<Pk: IntoDescriptorKey<Ctx>, Ctx: ScriptContext>(
     let (key, key_map, valid_networks) = descriptor_key.into_descriptor_key()?.extract(secp)?;
     let minisc = Miniscript::from_ast(Terminal::PkK(key))?;
 
-    minisc.check_minsicript()?;
+    minisc.check_miniscript()?;
 
     Ok((minisc, key_map, valid_networks))
 }
@@ -762,7 +763,7 @@ pub fn make_pkh<Pk: IntoDescriptorKey<Ctx>, Ctx: ScriptContext>(
     let (key, key_map, valid_networks) = descriptor_key.into_descriptor_key()?.extract(secp)?;
     let minisc = Miniscript::from_ast(Terminal::PkH(key))?;
 
-    minisc.check_minsicript()?;
+    minisc.check_miniscript()?;
 
     Ok((minisc, key_map, valid_networks))
 }
@@ -777,7 +778,7 @@ pub fn make_multi<Pk: IntoDescriptorKey<Ctx>, Ctx: ScriptContext>(
     let (pks, key_map, valid_networks) = expand_multi_keys(pks, secp)?;
     let minisc = Miniscript::from_ast(Terminal::Multi(thresh, pks))?;
 
-    minisc.check_minsicript()?;
+    minisc.check_miniscript()?;
 
     Ok((minisc, key_map, valid_networks))
 }
@@ -931,4 +932,43 @@ pub mod test {
             "L2wTu6hQrnDMiFNWA5na6jB12ErGQqtXwqpSL7aWquJaZG8Ai3ch"
         );
     }
+
+    #[test]
+    fn test_keys_wif_network() {
+        // test mainnet wif
+        let generated_xprv: GeneratedKey<_, miniscript::Segwitv0> =
+            bip32::ExtendedPrivKey::generate_with_entropy_default(TEST_ENTROPY).unwrap();
+        let xkey = generated_xprv.into_extended_key().unwrap();
+
+        let network = Network::Bitcoin;
+        let xprv = xkey.into_xprv(network).unwrap();
+        let wif = PrivateKey::from_wif(&xprv.private_key.to_wif()).unwrap();
+        assert_eq!(wif.network, network);
+
+        // test testnet wif
+        let generated_xprv: GeneratedKey<_, miniscript::Segwitv0> =
+            bip32::ExtendedPrivKey::generate_with_entropy_default(TEST_ENTROPY).unwrap();
+        let xkey = generated_xprv.into_extended_key().unwrap();
+
+        let network = Network::Testnet;
+        let xprv = xkey.into_xprv(network).unwrap();
+        let wif = PrivateKey::from_wif(&xprv.private_key.to_wif()).unwrap();
+        assert_eq!(wif.network, network);
+    }
+
+    #[cfg(feature = "keys-bip39")]
+    #[test]
+    fn test_keys_wif_network_bip39() {
+        let xkey: ExtendedKey = bip39::Mnemonic::parse_in(
+            bip39::Language::English,
+            "jelly crash boy whisper mouse ecology tuna soccer memory million news short",
+        )
+        .unwrap()
+        .into_extended_key()
+        .unwrap();
+        let xprv = xkey.into_xprv(Network::Testnet).unwrap();
+        let wif = PrivateKey::from_wif(&xprv.private_key.to_wif()).unwrap();
+
+        assert_eq!(wif.network, Network::Testnet);
+    }
 }

src/lib.rs

@@ -14,6 +14,10 @@
 // only enables the `doc_cfg` feature when
 // the `docsrs` configuration attribute is defined
 #![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(
+    docsrs,
+    doc(html_logo_url = "https://github.com/bitcoindevkit/bdk/raw/master/static/bdk.png")
+)]
 
 //! A modern, lightweight, descriptor-based wallet library written in Rust.
 //!
@@ -40,7 +44,7 @@
 //! interact with the bitcoin P2P network.
 //!
 //! ```toml
-//! bdk = "0.12.0"
+//! bdk = "0.15.0"
 //! ```
 #![cfg_attr(
     feature = "electrum",
@@ -49,22 +53,22 @@
 
 ### Example
 ```no_run
-use bdk::Wallet;
+use bdk::{Wallet, SyncOptions};
 use bdk::database::MemoryDatabase;
-use bdk::blockchain::{noop_progress, ElectrumBlockchain};
+use bdk::blockchain::ElectrumBlockchain;
 use bdk::electrum_client::Client;
 
 fn main() -> Result<(), bdk::Error> {
     let client = Client::new("ssl://electrum.blockstream.info:60002")?;
+    let blockchain = ElectrumBlockchain::from(client);
     let wallet = Wallet::new(
         "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",
         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
         bitcoin::Network::Testnet,
         MemoryDatabase::default(),
-        ElectrumBlockchain::from(client)
     )?;
 
-    wallet.sync(noop_progress(), None)?;
+    wallet.sync(&blockchain, SyncOptions::default())?;
 
     println!("Descriptor balance: {} SAT", wallet.get_balance()?);
 
@@ -83,7 +87,7 @@ fn main() -> Result<(), bdk::Error> {
 //! use bdk::wallet::AddressIndex::New;
 //!
 //! fn main() -> Result<(), bdk::Error> {
-//! let wallet = Wallet::new_offline(
+//! let wallet = Wallet::new(
 //!         "wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/0/*)",
 //!         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
 //!         bitcoin::Network::Testnet,
@@ -104,9 +108,9 @@ fn main() -> Result<(), bdk::Error> {
 
 ### Example
 ```no_run
-use bdk::{FeeRate, Wallet};
+use bdk::{FeeRate, Wallet, SyncOptions};
 use bdk::database::MemoryDatabase;
-use bdk::blockchain::{noop_progress, ElectrumBlockchain};
+use bdk::blockchain::ElectrumBlockchain;
 use bdk::electrum_client::Client;
 
 use bitcoin::consensus::serialize;
@@ -119,10 +123,10 @@ fn main() -> Result<(), bdk::Error> {
         Some("wpkh([c258d2e4/84h/1h/0h]tpubDDYkZojQFQjht8Tm4jsS3iuEmKjTiEGjG6KnuFNKKJb5A6ZUCUZKdvLdSDWofKi4ToRCwb9poe1XdqfUnP4jaJjCB2Zwv11ZLgSbnZSNecE/1/*)"),
         bitcoin::Network::Testnet,
         MemoryDatabase::default(),
-        ElectrumBlockchain::from(client)
     )?;
+    let blockchain = ElectrumBlockchain::from(client);
 
-    wallet.sync(noop_progress(), None)?;
+    wallet.sync(&blockchain, SyncOptions::default())?;
 
     let send_to = wallet.get_address(New)?;
     let (psbt, details) = {
@@ -156,7 +160,7 @@ fn main() -> Result<(), bdk::Error> {
 //! use bdk::database::MemoryDatabase;
 //!
 //! fn main() -> Result<(), bdk::Error> {
-//!     let wallet = Wallet::new_offline(
+//!     let wallet = Wallet::new(
 //!         "wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/0/*)",
 //!         Some("wpkh([c258d2e4/84h/1h/0h]tprv8griRPhA7342zfRyB6CqeKF8CJDXYu5pgnj1cjL1u2ngKcJha5jjTRimG82ABzJQ4MQe71CV54xfn25BbhCNfEGGJZnxvCDQCd6JkbvxW6h/1/*)"),
 //!         bitcoin::Network::Testnet,
@@ -236,7 +240,7 @@ extern crate bdk_macros;
 extern crate lazy_static;
 
 #[cfg(feature = "rpc")]
-pub extern crate core_rpc;
+pub extern crate bitcoincore_rpc;
 
 #[cfg(feature = "electrum")]
 pub extern crate electrum_client;
@@ -268,6 +272,7 @@ pub use wallet::address_validator;
 pub use wallet::signer;
 pub use wallet::signer::SignOptions;
 pub use wallet::tx_builder::TxBuilder;
+pub use wallet::SyncOptions;
 pub use wallet::Wallet;
 
 /// Get the version of BDK at runtime
@@ -275,7 +280,7 @@ pub fn version() -> &'static str {
     env!("CARGO_PKG_VERSION", "unknown")
 }
 
-// We should consider putting this under a feature flag but we need the macro in doctets so we need
+// We should consider putting this under a feature flag but we need the macro in doctests so we need
 // to wait until https://github.com/rust-lang/rust/issues/67295 is fixed.
 //
 // Stuff in here is too rough to document atm

src/testutils/blockchain_tests.rs

@@ -3,11 +3,11 @@ use bitcoin::consensus::encode::{deserialize, serialize};
 use bitcoin::hashes::hex::{FromHex, ToHex};
 use bitcoin::hashes::sha256d;
 use bitcoin::{Address, Amount, Script, Transaction, Txid};
+pub use bitcoincore_rpc::bitcoincore_rpc_json::AddressType;
+pub use bitcoincore_rpc::{Auth, Client as RpcClient, RpcApi};
 use core::str::FromStr;
-pub use core_rpc::core_rpc_json::AddressType;
-pub use core_rpc::{Auth, Client as RpcClient, RpcApi};
 use electrsd::bitcoind::BitcoinD;
-use electrsd::{bitcoind, Conf, ElectrsD};
+use electrsd::{bitcoind, ElectrsD};
 pub use electrum_client::{Client as ElectrumClient, ElectrumApi};
 #[allow(unused_imports)]
 use log::{debug, error, info, log_enabled, trace, Level};
@@ -24,19 +24,15 @@ pub struct TestClient {
 impl TestClient {
     pub fn new(bitcoind_exe: String, electrs_exe: String) -> Self {
         debug!("launching {} and {}", &bitcoind_exe, &electrs_exe);
-        let conf = bitcoind::Conf {
-            view_stdout: log_enabled!(Level::Debug),
-            ..Default::default()
-        };
+
+        let mut conf = bitcoind::Conf::default();
+        conf.view_stdout = log_enabled!(Level::Debug);
         let bitcoind = BitcoinD::with_conf(bitcoind_exe, &conf).unwrap();
 
-        let http_enabled = cfg!(feature = "test-esplora");
+        let mut conf = electrsd::Conf::default();
+        conf.view_stderr = log_enabled!(Level::Debug);
+        conf.http_enabled = cfg!(feature = "test-esplora");
 
-        let conf = Conf {
-            http_enabled,
-            view_stderr: log_enabled!(Level::Debug),
-            ..Default::default()
-        };
         let electrsd = ElectrsD::with_conf(electrs_exe, &bitcoind, &conf).unwrap();
 
         let node_address = bitcoind.client.get_new_address(None, None).unwrap();
@@ -149,9 +145,7 @@ impl TestClient {
 
         let bumped: serde_json::Value = self.call("bumpfee", &[txid.to_string().into()]).unwrap();
         let new_txid = Txid::from_str(&bumped["txid"].as_str().unwrap().to_string()).unwrap();
-
-        let monitor_script =
-            tx.vout[0].script_pub_key.addresses.as_ref().unwrap()[0].script_pubkey();
+        let monitor_script = Script::from_hex(&mut tx.vout[0].script_pub_key.hex.to_hex()).unwrap();
         self.wait_for_tx(new_txid, &monitor_script);
 
         debug!("Bumped {}, new txid {}", txid, new_txid);
@@ -361,10 +355,10 @@ macro_rules! bdk_blockchain_tests {
         mod bdk_blockchain_tests {
             use $crate::bitcoin::Network;
             use $crate::testutils::blockchain_tests::TestClient;
-            use $crate::blockchain::noop_progress;
+            use $crate::blockchain::Blockchain;
             use $crate::database::MemoryDatabase;
             use $crate::types::KeychainKind;
-            use $crate::{Wallet, FeeRate};
+            use $crate::{Wallet, FeeRate, SyncOptions};
             use $crate::testutils;
 
             use super::*;
@@ -375,11 +369,11 @@ macro_rules! bdk_blockchain_tests {
                 $block
             }
 
-            fn get_wallet_from_descriptors(descriptors: &(String, Option<String>), test_client: &TestClient) -> Wallet<$blockchain, MemoryDatabase> {
-                Wallet::new(&descriptors.0.to_string(), descriptors.1.as_ref(), Network::Regtest, MemoryDatabase::new(), get_blockchain(test_client)).unwrap()
+            fn get_wallet_from_descriptors(descriptors: &(String, Option<String>)) -> Wallet<MemoryDatabase> {
+                Wallet::new(&descriptors.0.to_string(), descriptors.1.as_ref(), Network::Regtest, MemoryDatabase::new()).unwrap()
             }
 
-            fn init_single_sig() -> (Wallet<$blockchain, MemoryDatabase>, (String, Option<String>), TestClient) {
+            fn init_single_sig() -> (Wallet<MemoryDatabase>, $blockchain, (String, Option<String>), TestClient) {
                 let _ = env_logger::try_init();
 
                 let descriptors = testutils! {
@@ -387,18 +381,22 @@ macro_rules! bdk_blockchain_tests {
                 };
 
                 let test_client = TestClient::default();
-                let wallet = get_wallet_from_descriptors(&descriptors, &test_client);
+                let blockchain = get_blockchain(&test_client);
+                let wallet = get_wallet_from_descriptors(&descriptors);
 
                 // rpc need to call import_multi before receiving any tx, otherwise will not see tx in the mempool
                 #[cfg(feature = "test-rpc")]
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
-                (wallet, descriptors, test_client)
+                (wallet, blockchain, descriptors, test_client)
             }
 
             #[test]
             fn test_sync_simple() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                use std::ops::Deref;
+                use crate::database::Database;
+
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 let tx = testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
@@ -406,7 +404,13 @@ macro_rules! bdk_blockchain_tests {
                 println!("{:?}", tx);
                 let txid = test_client.receive(tx);
 
-                wallet.sync(noop_progress(), None).unwrap();
+                // the RPC blockchain needs to call `sync()` during initialization to import the
+                // addresses (see `init_single_sig()`), so we skip this assertion
+                #[cfg(not(feature = "test-rpc"))]
+                assert!(wallet.database().deref().get_sync_time().unwrap().is_none(), "initial sync_time not none");
+
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert!(wallet.database().deref().get_sync_time().unwrap().is_some(), "sync_time hasn't been updated");
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
                 assert_eq!(wallet.list_unspent().unwrap()[0].keychain, KeychainKind::External, "incorrect keychain kind");
@@ -420,7 +424,7 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_stop_gap_20() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 5) => 50_000 )
@@ -429,7 +433,7 @@ macro_rules! bdk_blockchain_tests {
                     @tx ( (@external descriptors, 25) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 100_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 2, "incorrect number of txs");
@@ -437,16 +441,16 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_before_and_after_receive() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 0);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 1, "incorrect number of txs");
@@ -454,13 +458,13 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_multiple_outputs_same_tx() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 let txid = test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000, (@external descriptors, 1) => 25_000, (@external descriptors, 5) => 30_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 105_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 1, "incorrect number of txs");
@@ -475,7 +479,7 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_receive_multi() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
@@ -484,7 +488,7 @@ macro_rules! bdk_blockchain_tests {
                     @tx ( (@external descriptors, 5) => 25_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 75_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 2, "incorrect number of txs");
@@ -493,32 +497,32 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_address_reuse() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 25_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 75_000, "incorrect balance");
             }
 
             #[test]
             fn test_sync_receive_rbf_replaced() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 let txid = test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 ) ( @replaceable true )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 1, "incorrect number of txs");
@@ -532,7 +536,7 @@ macro_rules! bdk_blockchain_tests {
 
                 let new_txid = test_client.bump_fee(&txid);
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance after bump");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 1, "incorrect number of txs after bump");
@@ -550,13 +554,13 @@ macro_rules! bdk_blockchain_tests {
             #[cfg(not(feature = "esplora"))]
             #[test]
             fn test_sync_reorg_block() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
 
                 let txid = test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 ) ( @confirmations 1 ) ( @replaceable true )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 1, "incorrect number of txs");
@@ -569,7 +573,7 @@ macro_rules! bdk_blockchain_tests {
                 // Invalidate 1 block
                 test_client.invalidate(1);
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance after invalidate");
 
@@ -580,15 +584,15 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_after_send() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                println!("{}", descriptors.0);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                println!("{}", descriptors.0);
                 let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -598,25 +602,93 @@ macro_rules! bdk_blockchain_tests {
                 assert!(finalized, "Cannot finalize transaction");
                 let tx = psbt.extract_tx();
                 println!("{}", bitcoin::consensus::encode::serialize_hex(&tx));
-                wallet.broadcast(tx).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&tx).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect balance after send");
 
                 assert_eq!(wallet.list_transactions(false).unwrap().len(), 2, "incorrect number of txs");
                 assert_eq!(wallet.list_unspent().unwrap().len(), 1, "incorrect number of unspents");
             }
 
+            /// Send two conflicting transactions to the same address twice in a row.
+            /// The coins should only be received once!
+            #[test]
+            fn test_sync_double_receive() {
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let receiver_wallet = get_wallet_from_descriptors(&("wpkh(cVpPVruEDdmutPzisEsYvtST1usBR3ntr8pXSyt6D2YYqXRyPcFW)".to_string(), None));
+                // need to sync so rpc can start watching
+                receiver_wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+
+                test_client.receive(testutils! {
+                    @tx ( (@external descriptors, 0) => 50_000, (@external descriptors, 1) => 25_000 ) (@confirmations 1)
+                });
+
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(wallet.get_balance().unwrap(), 75_000, "incorrect balance");
+                let target_addr = receiver_wallet.get_address($crate::wallet::AddressIndex::New).unwrap().address;
+
+                let tx1 = {
+                    let mut builder = wallet.build_tx();
+                    builder.add_recipient(target_addr.script_pubkey(), 49_000).enable_rbf();
+                    let (mut psbt, _details) = builder.finish().unwrap();
+                    let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
+                    assert!(finalized, "Cannot finalize transaction");
+                    psbt.extract_tx()
+                };
+
+                let tx2 = {
+                    let mut builder = wallet.build_tx();
+                    builder.add_recipient(target_addr.script_pubkey(), 49_000).enable_rbf().fee_rate(FeeRate::from_sat_per_vb(5.0));
+                    let (mut psbt, _details) = builder.finish().unwrap();
+                    let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
+                    assert!(finalized, "Cannot finalize transaction");
+                    psbt.extract_tx()
+                };
+
+                blockchain.broadcast(&tx1).unwrap();
+                blockchain.broadcast(&tx2).unwrap();
+
+                receiver_wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(receiver_wallet.get_balance().unwrap(), 49_000, "should have received coins once and only once");
+            }
+
+            #[test]
+            fn test_sync_many_sends_to_a_single_address() {
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+
+                for _ in 0..4 {
+                    // split this up into multiple blocks so rpc doesn't get angry
+                    for _ in 0..20 {
+                        test_client.receive(testutils! {
+                            @tx ( (@external descriptors, 0) => 1_000 )
+                        });
+                    }
+                    test_client.generate(1, None);
+                }
+
+                // add some to the mempool as well.
+                for _ in 0..20 {
+                    test_client.receive(testutils! {
+                        @tx ( (@external descriptors, 0) => 1_000 )
+                    });
+                }
+
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+
+                assert_eq!(wallet.get_balance().unwrap(), 100_000);
+            }
+
             #[test]
             fn test_update_confirmation_time_after_generate() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                println!("{}", descriptors.0);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                println!("{}", descriptors.0);
                 let node_addr = test_client.get_node_address(None);
 
                 let received_txid = test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let tx_map = wallet.list_transactions(false).unwrap().into_iter().map(|tx| (tx.txid, tx)).collect::<std::collections::HashMap<_, _>>();
@@ -624,7 +696,7 @@ macro_rules! bdk_blockchain_tests {
                 assert!(details.confirmation_time.is_none());
 
                 test_client.generate(1, Some(node_addr));
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                 let tx_map = wallet.list_transactions(false).unwrap().into_iter().map(|tx| (tx.txid, tx)).collect::<std::collections::HashMap<_, _>>();
                 let details = tx_map.get(&received_txid).unwrap();
@@ -634,13 +706,13 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_outgoing_from_scratch() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
                 let received_txid = test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -649,25 +721,26 @@ macro_rules! bdk_blockchain_tests {
 
                 let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                let sent_txid = wallet.broadcast(psbt.extract_tx()).unwrap();
+                let sent_tx = psbt.extract_tx();
+                blockchain.broadcast(&sent_tx).unwrap();
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect balance after receive");
 
                 // empty wallet
-                let wallet = get_wallet_from_descriptors(&descriptors, &test_client);
+                let wallet = get_wallet_from_descriptors(&descriptors);
 
                 #[cfg(feature = "rpc")]  // rpc cannot see mempool tx before importmulti
                 test_client.generate(1, Some(node_addr));
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 let tx_map = wallet.list_transactions(false).unwrap().into_iter().map(|tx| (tx.txid, tx)).collect::<std::collections::HashMap<_, _>>();
 
                 let received = tx_map.get(&received_txid).unwrap();
                 assert_eq!(received.received, 50_000, "incorrect received from receiver");
                 assert_eq!(received.sent, 0, "incorrect sent from receiver");
 
-                let sent = tx_map.get(&sent_txid).unwrap();
+                let sent = tx_map.get(&sent_tx.txid()).unwrap();
                 assert_eq!(sent.received, details.received, "incorrect received from sender");
                 assert_eq!(sent.sent, details.sent, "incorrect sent from sender");
                 assert_eq!(sent.fee.unwrap_or(0), details.fee.unwrap_or(0), "incorrect fees from sender");
@@ -675,14 +748,14 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_long_change_chain() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 )
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let mut total_sent = 0;
@@ -692,38 +765,38 @@ macro_rules! bdk_blockchain_tests {
                     let (mut psbt, details) = builder.finish().unwrap();
                     let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                     assert!(finalized, "Cannot finalize transaction");
-                    wallet.broadcast(psbt.extract_tx()).unwrap();
+                    blockchain.broadcast(&psbt.extract_tx()).unwrap();
 
-                    wallet.sync(noop_progress(), None).unwrap();
+                    wallet.sync(&blockchain, SyncOptions::default()).unwrap();
 
                     total_sent += 5_000 + details.fee.unwrap_or(0);
                 }
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000 - total_sent, "incorrect balance after chain");
 
                 // empty wallet
 
-                let wallet = get_wallet_from_descriptors(&descriptors, &test_client);
+                let wallet = get_wallet_from_descriptors(&descriptors);
 
                 #[cfg(feature = "rpc")]  // rpc cannot see mempool tx before importmulti
                 test_client.generate(1, Some(node_addr));
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000 - total_sent, "incorrect balance empty wallet");
 
             }
 
             #[test]
             fn test_sync_bump_fee_basic() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 ) (@confirmations 1)
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -731,8 +804,8 @@ macro_rules! bdk_blockchain_tests {
                 let (mut psbt, details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000 - details.fee.unwrap_or(0) - 5_000, "incorrect balance from fees");
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect balance from received");
 
@@ -741,8 +814,8 @@ macro_rules! bdk_blockchain_tests {
                 let (mut new_psbt, new_details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut new_psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(new_psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&new_psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000 - new_details.fee.unwrap_or(0) - 5_000, "incorrect balance from fees after bump");
                 assert_eq!(wallet.get_balance().unwrap(), new_details.received, "incorrect balance from received after bump");
 
@@ -751,14 +824,14 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_bump_fee_remove_change() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000 ) (@confirmations 1)
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -766,18 +839,18 @@ macro_rules! bdk_blockchain_tests {
                 let (mut psbt, details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 1_000 - details.fee.unwrap_or(0), "incorrect balance after send");
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect received after send");
 
                 let mut builder = wallet.build_fee_bump(details.txid).unwrap();
-                builder.fee_rate(FeeRate::from_sat_per_vb(5.0));
+                builder.fee_rate(FeeRate::from_sat_per_vb(5.1));
                 let (mut new_psbt, new_details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut new_psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(new_psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&new_psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 0, "incorrect balance after change removal");
                 assert_eq!(new_details.received, 0, "incorrect received after change removal");
 
@@ -786,14 +859,14 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_bump_fee_add_input_simple() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000, (@external descriptors, 1) => 25_000 ) (@confirmations 1)
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 75_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -801,8 +874,8 @@ macro_rules! bdk_blockchain_tests {
                 let (mut psbt, details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 26_000 - details.fee.unwrap_or(0), "incorrect balance after send");
                 assert_eq!(details.received, 1_000 - details.fee.unwrap_or(0), "incorrect received after send");
 
@@ -811,22 +884,22 @@ macro_rules! bdk_blockchain_tests {
                 let (mut new_psbt, new_details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut new_psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(new_psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&new_psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(new_details.sent, 75_000, "incorrect sent");
                 assert_eq!(wallet.get_balance().unwrap(), new_details.received, "incorrect balance after add input");
             }
 
             #[test]
             fn test_sync_bump_fee_add_input_no_change() {
-                let (wallet, descriptors, mut test_client) = init_single_sig();
-                let node_addr = test_client.get_node_address(None);
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
 
                 test_client.receive(testutils! {
                     @tx ( (@external descriptors, 0) => 50_000, (@external descriptors, 1) => 25_000 ) (@confirmations 1)
                 });
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 75_000, "incorrect balance");
 
                 let mut builder = wallet.build_tx();
@@ -834,8 +907,8 @@ macro_rules! bdk_blockchain_tests {
                 let (mut psbt, details) = builder.finish().unwrap();
                 let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 26_000 - details.fee.unwrap_or(0), "incorrect balance after send");
                 assert_eq!(details.received, 1_000 - details.fee.unwrap_or(0), "incorrect received after send");
 
@@ -846,20 +919,51 @@ macro_rules! bdk_blockchain_tests {
 
                 let finalized = wallet.sign(&mut new_psbt, Default::default()).unwrap();
                 assert!(finalized, "Cannot finalize transaction");
-                wallet.broadcast(new_psbt.extract_tx()).unwrap();
-                wallet.sync(noop_progress(), None).unwrap();
+                blockchain.broadcast(&new_psbt.extract_tx()).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(new_details.sent, 75_000, "incorrect sent");
                 assert_eq!(wallet.get_balance().unwrap(), 0, "incorrect balance after add input");
                 assert_eq!(new_details.received, 0, "incorrect received after add input");
             }
 
+
+            #[test]
+            fn test_add_data() {
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+                                let node_addr = test_client.get_node_address(None);
+                let _ = test_client.receive(testutils! {
+                    @tx ( (@external descriptors, 0) => 50_000 )
+                });
+
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(wallet.get_balance().unwrap(), 50_000, "incorrect balance");
+
+                let mut builder = wallet.build_tx();
+                let data = [42u8;80];
+                builder.add_data(&data);
+                let (mut psbt, details) = builder.finish().unwrap();
+
+                let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
+                assert!(finalized, "Cannot finalize transaction");
+                let tx = psbt.extract_tx();
+                let serialized_tx = bitcoin::consensus::encode::serialize(&tx);
+                assert!(serialized_tx.windows(data.len()).any(|e| e==data), "cannot find op_return data in transaction");
+                blockchain.broadcast(&tx).unwrap();
+                test_client.generate(1, Some(node_addr));
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(wallet.get_balance().unwrap(), 50_000 - details.fee.unwrap_or(0), "incorrect balance after send");
+
+                let tx_map = wallet.list_transactions(false).unwrap().into_iter().map(|tx| (tx.txid, tx)).collect::<std::collections::HashMap<_, _>>();
+                let _ = tx_map.get(&tx.txid()).unwrap();
+            }
+
             #[test]
             fn test_sync_receive_coinbase() {
-                let (wallet, _, mut test_client) = init_single_sig();
+                let (wallet, blockchain, _, mut test_client) = init_single_sig();
 
                 let wallet_addr = wallet.get_address($crate::wallet::AddressIndex::New).unwrap().address;
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 0, "incorrect balance");
 
                 test_client.generate(1, Some(wallet_addr));
@@ -872,9 +976,105 @@ macro_rules! bdk_blockchain_tests {
                 }
 
 
-                wallet.sync(noop_progress(), None).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
                 assert!(wallet.get_balance().unwrap() > 0, "incorrect balance after receiving coinbase");
             }
+
+            #[test]
+            fn test_send_to_bech32m_addr() {
+                use std::str::FromStr;
+                use serde;
+                use serde_json;
+                use serde::Serialize;
+                use bitcoincore_rpc::jsonrpc::serde_json::Value;
+                use bitcoincore_rpc::{Auth, Client, RpcApi};
+
+                let (wallet, blockchain, descriptors, mut test_client) = init_single_sig();
+
+                // TODO remove once rust-bitcoincore-rpc with PR 199 released
+                // https://github.com/rust-bitcoin/rust-bitcoincore-rpc/pull/199
+                /// Import Descriptor Request
+                #[derive(Serialize, Clone, PartialEq, Eq, Debug)]
+                pub struct ImportDescriptorRequest {
+                    pub active: bool,
+                    #[serde(rename = "desc")]
+                    pub descriptor: String,
+                    pub range: [i64; 2],
+                    pub next_index: i64,
+                    pub timestamp: String,
+                    pub internal: bool,
+                }
+
+                // TODO remove once rust-bitcoincore-rpc with PR 199 released
+                impl ImportDescriptorRequest {
+                    /// Create a new Import Descriptor request providing just the descriptor and internal flags
+                    pub fn new(descriptor: &str, internal: bool) -> Self {
+                        ImportDescriptorRequest {
+                            descriptor: descriptor.to_string(),
+                            internal,
+                            active: true,
+                            range: [0, 100],
+                            next_index: 0,
+                            timestamp: "now".to_string(),
+                        }
+                    }
+                }
+
+                // 1. Create and add descriptors to a test bitcoind node taproot wallet
+
+                // TODO replace once rust-bitcoincore-rpc with PR 174 released
+                // https://github.com/rust-bitcoin/rust-bitcoincore-rpc/pull/174
+                let _createwallet_result: Value = test_client.bitcoind.client.call("createwallet", &["taproot_wallet".into(),false.into(),true.into(),serde_json::to_value("").unwrap(), false.into(), true.into()]).unwrap();
+
+                // TODO replace once bitcoind released with support for rust-bitcoincore-rpc PR 174
+                let taproot_wallet_client = Client::new(&test_client.bitcoind.rpc_url_with_wallet("taproot_wallet"), Auth::CookieFile(test_client.bitcoind.params.cookie_file.clone())).unwrap();
+
+                let wallet_descriptor = "tr(tprv8ZgxMBicQKsPdBtxmEMPnNq58KGusNAimQirKFHqX2yk2D8q1v6pNLiKYVAdzDHy2w3vF4chuGfMvNtzsbTTLVXBcdkCA1rje1JG6oksWv8/86h/1h/0h/0/*)#y283ssmn";
+                let change_descriptor = "tr(tprv8ZgxMBicQKsPdBtxmEMPnNq58KGusNAimQirKFHqX2yk2D8q1v6pNLiKYVAdzDHy2w3vF4chuGfMvNtzsbTTLVXBcdkCA1rje1JG6oksWv8/86h/1h/0h/1/*)#47zsd9tt";
+
+                let tr_descriptors = vec![
+                            ImportDescriptorRequest::new(wallet_descriptor, false),
+                            ImportDescriptorRequest::new(change_descriptor, false),
+                        ];
+
+                // TODO replace once rust-bitcoincore-rpc with PR 199 released
+                let _import_result: Value = taproot_wallet_client.call("importdescriptors", &[serde_json::to_value(tr_descriptors).unwrap()]).unwrap();
+
+                // 2. Get a new bech32m address from test bitcoind node taproot wallet
+
+                // TODO replace once rust-bitcoincore-rpc with PR 199 released
+                let node_addr: bitcoin::Address = taproot_wallet_client.call("getnewaddress", &["test address".into(), "bech32m".into()]).unwrap();
+                assert_eq!(node_addr, bitcoin::Address::from_str("bcrt1pj5y3f0fu4y7g98k4v63j9n0xvj3lmln0cpwhsjzknm6nt0hr0q7qnzwsy9").unwrap());
+
+                // 3. Send 50_000 sats from test bitcoind node to test BDK wallet
+
+                test_client.receive(testutils! {
+                    @tx ( (@external descriptors, 0) => 50_000 )
+                });
+
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(wallet.get_balance().unwrap(), 50_000, "wallet has incorrect balance");
+
+                // 4. Send 25_000 sats from test BDK wallet to test bitcoind node taproot wallet
+
+                let mut builder = wallet.build_tx();
+                builder.add_recipient(node_addr.script_pubkey(), 25_000);
+                let (mut psbt, details) = builder.finish().unwrap();
+                let finalized = wallet.sign(&mut psbt, Default::default()).unwrap();
+                assert!(finalized, "wallet cannot finalize transaction");
+                let tx = psbt.extract_tx();
+                blockchain.broadcast(&tx).unwrap();
+                wallet.sync(&blockchain, SyncOptions::default()).unwrap();
+                assert_eq!(wallet.get_balance().unwrap(), details.received, "wallet has incorrect balance after send");
+                assert_eq!(wallet.list_transactions(false).unwrap().len(), 2, "wallet has incorrect number of txs");
+                assert_eq!(wallet.list_unspent().unwrap().len(), 1, "wallet has incorrect number of unspents");
+                test_client.generate(1, None);
+
+                // 5. Verify 25_000 sats are received by test bitcoind node taproot wallet
+
+                let taproot_balance = taproot_wallet_client.get_balance(None, None).unwrap();
+                assert_eq!(taproot_balance.as_sat(), 25_000, "node has incorrect taproot wallet balance");
+            }
         }
     };
 

src/types.rs

@@ -210,32 +210,38 @@ pub struct TransactionDetails {
     pub fee: Option<u64>,
     /// If the transaction is confirmed, contains height and timestamp of the block containing the
     /// transaction, unconfirmed transaction contains `None`.
-    pub confirmation_time: Option<ConfirmationTime>,
+    pub confirmation_time: Option<BlockTime>,
     /// Whether the tx has been verified against the consensus rules
     ///
     /// Confirmed txs are considered "verified" by default, while unconfirmed txs are checked to
     /// ensure an unstrusted [`Blockchain`](crate::blockchain::Blockchain) backend can't trick the
     /// wallet into using an invalid tx as an RBF template.
     ///
-    /// The check is only perfomed when the `verify` feature is enabled.
+    /// The check is only performed when the `verify` feature is enabled.
     #[serde(default = "bool::default")] // default to `false` if not specified
     pub verified: bool,
 }
 
-/// Block height and timestamp of the block containing the confirmed transaction
+/// Block height and timestamp of a block
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Default)]
-pub struct ConfirmationTime {
+pub struct BlockTime {
     /// confirmation block height
     pub height: u32,
     /// confirmation block timestamp
     pub timestamp: u64,
 }
 
-impl ConfirmationTime {
-    /// Returns `Some` `ConfirmationTime` if both `height` and `timestamp` are `Some`
+/// **DEPRECATED**: Confirmation time of a transaction
+///
+/// The structure has been renamed to `BlockTime`
+#[deprecated(note = "This structure has been renamed to `BlockTime`")]
+pub type ConfirmationTime = BlockTime;
+
+impl BlockTime {
+    /// Returns `Some` `BlockTime` if both `height` and `timestamp` are `Some`
     pub fn new(height: Option<u32>, timestamp: Option<u64>) -> Option<Self> {
         match (height, timestamp) {
-            (Some(height), Some(timestamp)) => Some(ConfirmationTime { height, timestamp }),
+            (Some(height), Some(timestamp)) => Some(BlockTime { height, timestamp }),
             _ => None,
         }
     }

src/wallet/address_validator.rs

@@ -55,7 +55,7 @@
 //! }
 //!
 //! let descriptor = "wpkh(tpubD6NzVbkrYhZ4Xferm7Pz4VnjdcDPFyjVu5K4iZXQ4pVN8Cks4pHVowTBXBKRhX64pkRyJZJN5xAKj4UDNnLPb5p2sSKXhewoYx5GbTdUFWq/*)";
-//! let mut wallet = Wallet::new_offline(descriptor, None, Network::Testnet, MemoryDatabase::default())?;
+//! let mut wallet = Wallet::new(descriptor, None, Network::Testnet, MemoryDatabase::default())?;
 //! wallet.add_address_validator(Arc::new(PrintAddressAndContinue));
 //!
 //! let address = wallet.get_address(New)?;

src/wallet/coin_selection.rs

@@ -372,7 +372,7 @@ impl<D: Database> CoinSelectionAlgorithm<D> for BranchAndBoundCoinSelection {
 
 impl BranchAndBoundCoinSelection {
     // TODO: make this more Rust-onic :)
-    // (And perhpaps refactor with less arguments?)
+    // (And perhaps refactor with less arguments?)
     #[allow(clippy::too_many_arguments)]
     fn bnb(
         &self,

src/wallet/export.rs

@@ -30,7 +30,7 @@
 //! }"#;
 //!
 //! let import = WalletExport::from_str(import)?;
-//! let wallet = Wallet::new_offline(
+//! let wallet = Wallet::new(
 //!     &import.descriptor(),
 //!     import.change_descriptor().as_ref(),
 //!     Network::Testnet,
@@ -45,7 +45,7 @@
 //! # use bdk::database::*;
 //! # use bdk::wallet::export::*;
 //! # use bdk::*;
-//! let wallet = Wallet::new_offline(
+//! let wallet = Wallet::new(
 //!     "wpkh([c258d2e4/84h/1h/0h]tpubDD3ynpHgJQW8VvWRzQ5WFDCrs4jqVFGHB3vLC3r49XHJSqP8bHKdK4AriuUKLccK68zfzowx7YhmDN8SiSkgCDENUFx9qVw65YyqM78vyVe/0/*)",
 //!     Some("wpkh([c258d2e4/84h/1h/0h]tpubDD3ynpHgJQW8VvWRzQ5WFDCrs4jqVFGHB3vLC3r49XHJSqP8bHKdK4AriuUKLccK68zfzowx7YhmDN8SiSkgCDENUFx9qVw65YyqM78vyVe/1/*)"),
 //!     Network::Testnet,
@@ -111,8 +111,8 @@ impl WalletExport {
     ///
     /// If the database is empty or `include_blockheight` is false, the `blockheight` field
     /// returned will be `0`.
-    pub fn export_wallet<B, D: BatchDatabase>(
-        wallet: &Wallet<B, D>,
+    pub fn export_wallet<D: BatchDatabase>(
+        wallet: &Wallet<D>,
         label: &str,
         include_blockheight: bool,
     ) -> Result<Self, &'static str> {
@@ -212,7 +212,7 @@ mod test {
     use crate::database::{memory::MemoryDatabase, BatchOperations};
     use crate::types::TransactionDetails;
     use crate::wallet::Wallet;
-    use crate::ConfirmationTime;
+    use crate::BlockTime;
 
     fn get_test_db() -> MemoryDatabase {
         let mut db = MemoryDatabase::new();
@@ -226,7 +226,7 @@ mod test {
             received: 100_000,
             sent: 0,
             fee: Some(500),
-            confirmation_time: Some(ConfirmationTime {
+            confirmation_time: Some(BlockTime {
                 timestamp: 12345678,
                 height: 5000,
             }),
@@ -242,7 +242,7 @@ mod test {
         let descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/0/*)";
         let change_descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/1/*)";
 
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             descriptor,
             Some(change_descriptor),
             Network::Bitcoin,
@@ -266,8 +266,7 @@ mod test {
 
         let descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/0/*)";
 
-        let wallet =
-            Wallet::new_offline(descriptor, None, Network::Bitcoin, get_test_db()).unwrap();
+        let wallet = Wallet::new(descriptor, None, Network::Bitcoin, get_test_db()).unwrap();
         WalletExport::export_wallet(&wallet, "Test Label", true).unwrap();
     }
 
@@ -280,7 +279,7 @@ mod test {
         let descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/0/*)";
         let change_descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/50'/0'/1/*)";
 
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             descriptor,
             Some(change_descriptor),
             Network::Bitcoin,
@@ -303,7 +302,7 @@ mod test {
                                        [c98b1535/48'/0'/0'/2']tpubDCDi5W4sP6zSnzJeowy8rQDVhBdRARaPhK1axABi8V1661wEPeanpEXj4ZLAUEoikVtoWcyK26TKKJSecSfeKxwHCcRrge9k1ybuiL71z4a/1/*\
                                  ))";
 
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             descriptor,
             Some(change_descriptor),
             Network::Testnet,
@@ -323,7 +322,7 @@ mod test {
         let descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/0/*)";
         let change_descriptor = "wpkh(xprv9s21ZrQH143K4CTb63EaMxja1YiTnSEWKMbn23uoEnAzxjdUJRQkazCAtzxGm4LSoTSVTptoV9RbchnKPW9HxKtZumdyxyikZFDLhogJ5Uj/44'/0'/0'/1/*)";
 
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             descriptor,
             Some(change_descriptor),
             Network::Bitcoin,

src/wallet/mod.rs

@@ -53,11 +53,11 @@ use address_validator::AddressValidator;
 use coin_selection::DefaultCoinSelectionAlgorithm;
 use signer::{SignOptions, Signer, SignerOrdering, SignersContainer};
 use tx_builder::{BumpFee, CreateTx, FeePolicy, TxBuilder, TxParams};
-use utils::{check_nlocktime, check_nsequence_rbf, After, Older, SecpCtx, DUST_LIMIT_SATOSHI};
+use utils::{check_nlocktime, check_nsequence_rbf, After, Older, SecpCtx};
 
-use crate::blockchain::{Blockchain, Progress};
+use crate::blockchain::{GetHeight, NoopProgress, Progress, WalletSync};
 use crate::database::memory::MemoryDatabase;
-use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils};
+use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils, SyncTime};
 use crate::descriptor::derived::AsDerived;
 use crate::descriptor::policy::BuildSatisfaction;
 use crate::descriptor::{
@@ -75,16 +75,17 @@ const CACHE_ADDR_BATCH_SIZE: u32 = 100;
 
 /// A Bitcoin wallet
 ///
-/// A wallet takes descriptors, a [`database`](trait@crate::database::Database) and a
-/// [`blockchain`](trait@crate::blockchain::Blockchain) and implements the basic functions that a Bitcoin wallets
-/// needs to operate, like [generating addresses](Wallet::get_address), [returning the balance](Wallet::get_balance),
-/// [creating transactions](Wallet::build_tx), etc.
+/// The `Wallet` struct acts as a way of coherently interfacing with output descriptors and related transactions.
+/// Its main components are:
 ///
-/// A wallet can be either "online" if the [`blockchain`](crate::blockchain) type provided
-/// implements [`Blockchain`], or "offline" if it is the unit type `()`. Offline wallets only expose
-/// methods that don't need any interaction with the blockchain to work.
+/// 1. output *descriptors* from which it can derive addresses.
+/// 2. A [`Database`] where it tracks transactions and utxos related to the descriptors.
+/// 3. [`Signer`]s that can contribute signatures to addresses instantiated from the descriptors.
+///
+/// [`Database`]: crate::database::Database
+/// [`Signer`]: crate::signer::Signer
 #[derive(Debug)]
-pub struct Wallet<B, D> {
+pub struct Wallet<D> {
     descriptor: ExtendedDescriptor,
     change_descriptor: Option<ExtendedDescriptor>,
 
@@ -95,88 +96,11 @@ pub struct Wallet<B, D> {
 
     network: Network,
 
-    current_height: Option<u32>,
-
-    client: B,
     database: RefCell<D>,
 
     secp: SecpCtx,
 }
 
-impl<D> Wallet<(), D>
-where
-    D: BatchDatabase,
-{
-    /// Create a new "offline" wallet
-    pub fn new_offline<E: IntoWalletDescriptor>(
-        descriptor: E,
-        change_descriptor: Option<E>,
-        network: Network,
-        database: D,
-    ) -> Result<Self, Error> {
-        Self::_new(descriptor, change_descriptor, network, database, (), None)
-    }
-}
-
-impl<B, D> Wallet<B, D>
-where
-    D: BatchDatabase,
-{
-    fn _new<E: IntoWalletDescriptor>(
-        descriptor: E,
-        change_descriptor: Option<E>,
-        network: Network,
-        mut database: D,
-        client: B,
-        current_height: Option<u32>,
-    ) -> Result<Self, Error> {
-        let secp = Secp256k1::new();
-
-        let (descriptor, keymap) = into_wallet_descriptor_checked(descriptor, &secp, network)?;
-        database.check_descriptor_checksum(
-            KeychainKind::External,
-            get_checksum(&descriptor.to_string())?.as_bytes(),
-        )?;
-        let signers = Arc::new(SignersContainer::from(keymap));
-        let (change_descriptor, change_signers) = match change_descriptor {
-            Some(desc) => {
-                let (change_descriptor, change_keymap) =
-                    into_wallet_descriptor_checked(desc, &secp, network)?;
-                database.check_descriptor_checksum(
-                    KeychainKind::Internal,
-                    get_checksum(&change_descriptor.to_string())?.as_bytes(),
-                )?;
-
-                let change_signers = Arc::new(SignersContainer::from(change_keymap));
-                // if !parsed.same_structure(descriptor.as_ref()) {
-                //     return Err(Error::DifferentDescriptorStructure);
-                // }
-
-                (Some(change_descriptor), change_signers)
-            }
-            None => (None, Arc::new(SignersContainer::new())),
-        };
-
-        Ok(Wallet {
-            descriptor,
-            change_descriptor,
-            signers,
-            change_signers,
-            address_validators: Vec::new(),
-            network,
-            current_height,
-            client,
-            database: RefCell::new(database),
-            secp,
-        })
-    }
-
-    /// Get the Bitcoin network the wallet is using.
-    pub fn network(&self) -> Network {
-        self.network
-    }
-}
-
 /// The address index selection strategy to use to derived an address from the wallet's external
 /// descriptor. See [`Wallet::get_address`]. If you're unsure which one to use use `WalletIndex::New`.
 #[derive(Debug)]
@@ -232,11 +156,72 @@ impl fmt::Display for AddressInfo {
     }
 }
 
-// offline actions, always available
-impl<B, D> Wallet<B, D>
+#[derive(Debug, Default)]
+/// Options to a [`Wallet::sync`]
+pub struct SyncOptions {
+    /// The progress tracker which may be informated when progress is made.
+    pub progress: Option<Box<dyn Progress>>,
+    /// The maximum number of addresses sync on.
+    pub max_addresses: Option<u32>,
+}
+
+impl<D> Wallet<D>
 where
     D: BatchDatabase,
 {
+    /// Create a wallet.
+    ///
+    /// The only way this can fail is if the descriptors passed in do not match the checksums in `database`.
+    pub fn new<E: IntoWalletDescriptor>(
+        descriptor: E,
+        change_descriptor: Option<E>,
+        network: Network,
+        mut database: D,
+    ) -> Result<Self, Error> {
+        let secp = Secp256k1::new();
+
+        let (descriptor, keymap) = into_wallet_descriptor_checked(descriptor, &secp, network)?;
+        database.check_descriptor_checksum(
+            KeychainKind::External,
+            get_checksum(&descriptor.to_string())?.as_bytes(),
+        )?;
+        let signers = Arc::new(SignersContainer::from(keymap));
+        let (change_descriptor, change_signers) = match change_descriptor {
+            Some(desc) => {
+                let (change_descriptor, change_keymap) =
+                    into_wallet_descriptor_checked(desc, &secp, network)?;
+                database.check_descriptor_checksum(
+                    KeychainKind::Internal,
+                    get_checksum(&change_descriptor.to_string())?.as_bytes(),
+                )?;
+
+                let change_signers = Arc::new(SignersContainer::from(change_keymap));
+                // if !parsed.same_structure(descriptor.as_ref()) {
+                //     return Err(Error::DifferentDescriptorStructure);
+                // }
+
+                (Some(change_descriptor), change_signers)
+            }
+            None => (None, Arc::new(SignersContainer::new())),
+        };
+
+        Ok(Wallet {
+            descriptor,
+            change_descriptor,
+            signers,
+            change_signers,
+            address_validators: Vec::new(),
+            network,
+            database: RefCell::new(database),
+            secp,
+        })
+    }
+
+    /// Get the Bitcoin network the wallet is using.
+    pub fn network(&self) -> Network {
+        self.network
+    }
+
     // Return a newly derived address using the external descriptor
     fn get_new_address(&self) -> Result<AddressInfo, Error> {
         let incremented_index = self.fetch_and_increment_index(KeychainKind::External)?;
@@ -323,7 +308,7 @@ where
 
     /// Return the list of unspent outputs of this wallet
     ///
-    /// Note that this methods only operate on the internal database, which first needs to be
+    /// Note that this method only operates on the internal database, which first needs to be
     /// [`Wallet::sync`] manually.
     pub fn list_unspent(&self) -> Result<Vec<LocalUtxo>, Error> {
         self.database.borrow().iter_utxos()
@@ -335,6 +320,21 @@ where
         self.database.borrow().get_utxo(&outpoint)
     }
 
+    /// Return a single transactions made and received by the wallet
+    ///
+    /// Optionally fill the [`TransactionDetails::transaction`] field with the raw transaction if
+    /// `include_raw` is `true`.
+    ///
+    /// Note that this method only operates on the internal database, which first needs to be
+    /// [`Wallet::sync`] manually.
+    pub fn get_tx(
+        &self,
+        txid: &Txid,
+        include_raw: bool,
+    ) -> Result<Option<TransactionDetails>, Error> {
+        self.database.borrow().get_tx(txid, include_raw)
+    }
+
     /// Return the list of transactions made and received by the wallet
     ///
     /// Optionally fill the [`TransactionDetails::transaction`] field with the raw transaction if
@@ -407,7 +407,7 @@ where
     /// ```
     ///
     /// [`TxBuilder`]: crate::TxBuilder
-    pub fn build_tx(&self) -> TxBuilder<'_, B, D, DefaultCoinSelectionAlgorithm, CreateTx> {
+    pub fn build_tx(&self) -> TxBuilder<'_, D, DefaultCoinSelectionAlgorithm, CreateTx> {
         TxBuilder {
             wallet: self,
             params: TxParams::default(),
@@ -586,7 +586,7 @@ where
         let recipients = params.recipients.iter().map(|(r, v)| (r, *v));
 
         for (index, (script_pubkey, value)) in recipients.enumerate() {
-            if value.is_dust() {
+            if value.is_dust(script_pubkey) && !script_pubkey.is_provably_unspendable() {
                 return Err(Error::OutputBelowDustLimit(index));
             }
 
@@ -662,9 +662,9 @@ where
 
         if tx.output.is_empty() {
             if params.drain_to.is_some() {
-                if drain_val.is_dust() {
+                if drain_val.is_dust(&drain_output.script_pubkey) {
                     return Err(Error::InsufficientFunds {
-                        needed: DUST_LIMIT_SATOSHI,
+                        needed: drain_output.script_pubkey.dust_value().as_sat(),
                         available: drain_val,
                     });
                 }
@@ -673,7 +673,7 @@ where
             }
         }
 
-        if drain_val.is_dust() {
+        if drain_val.is_dust(&drain_output.script_pubkey) {
             fee_amount += drain_val;
         } else {
             drain_output.value = drain_val;
@@ -706,7 +706,7 @@ where
     /// Bump the fee of a transaction previously created with this wallet.
     ///
     /// Returns an error if the transaction is already confirmed or doesn't explicitly signal
-    /// *repalce by fee* (RBF). If the transaction can be fee bumped then it returns a [`TxBuilder`]
+    /// *replace by fee* (RBF). If the transaction can be fee bumped then it returns a [`TxBuilder`]
     /// pre-populated with the inputs and outputs of the original transaction.
     ///
     /// ## Example
@@ -748,7 +748,7 @@ where
     pub fn build_fee_bump(
         &self,
         txid: Txid,
-    ) -> Result<TxBuilder<'_, B, D, DefaultCoinSelectionAlgorithm, BumpFee>, Error> {
+    ) -> Result<TxBuilder<'_, D, DefaultCoinSelectionAlgorithm, BumpFee>, Error> {
         let mut details = match self.database.borrow().get_tx(&txid, true)? {
             None => return Err(Error::TransactionNotFound),
             Some(tx) if tx.transaction.is_none() => return Err(Error::TransactionNotFound),
@@ -979,7 +979,11 @@ where
                 .borrow()
                 .get_tx(&input.previous_output.txid, false)?
                 .map(|tx| tx.confirmation_time.map(|c| c.height).unwrap_or(u32::MAX));
-            let current_height = sign_options.assume_height.or(self.current_height);
+            let last_sync_height = self
+                .database()
+                .get_sync_time()?
+                .map(|sync_time| sync_time.block_time.height);
+            let current_height = sign_options.assume_height.or(last_sync_height);
 
             debug!(
                 "Input #{} - {}, using `create_height` = {:?}, `current_height` = {:?}",
@@ -1044,7 +1048,7 @@ where
         &self.secp
     }
 
-    /// Returns the descriptor used to create adddresses for a particular `keychain`.
+    /// Returns the descriptor used to create addresses for a particular `keychain`.
     pub fn get_descriptor_for_keychain(&self, keychain: KeychainKind) -> &ExtendedDescriptor {
         let (descriptor, _) = self._get_descriptor_for_keychain(keychain);
         descriptor
@@ -1432,47 +1436,31 @@ where
 
         Ok(())
     }
-}
 
-impl<B, D> Wallet<B, D>
-where
-    B: Blockchain,
-    D: BatchDatabase,
-{
-    /// Create a new "online" wallet
-    #[maybe_async]
-    pub fn new<E: IntoWalletDescriptor>(
-        descriptor: E,
-        change_descriptor: Option<E>,
-        network: Network,
-        database: D,
-        client: B,
-    ) -> Result<Self, Error> {
-        let current_height = Some(maybe_await!(client.get_height())? as u32);
-        Self::_new(
-            descriptor,
-            change_descriptor,
-            network,
-            database,
-            client,
-            current_height,
-        )
+    /// Return an immutable reference to the internal database
+    pub fn database(&self) -> impl std::ops::Deref<Target = D> + '_ {
+        self.database.borrow()
     }
 
     /// Sync the internal database with the blockchain
     #[maybe_async]
-    pub fn sync<P: 'static + Progress>(
+    pub fn sync<B: WalletSync + GetHeight>(
         &self,
-        progress_update: P,
-        max_address_param: Option<u32>,
+        blockchain: &B,
+        sync_opts: SyncOptions,
     ) -> Result<(), Error> {
         debug!("Begin sync...");
 
         let mut run_setup = false;
+        let SyncOptions {
+            max_addresses,
+            progress,
+        } = sync_opts;
+        let progress = progress.unwrap_or_else(|| Box::new(NoopProgress));
 
         let max_address = match self.descriptor.is_deriveable() {
             false => 0,
-            true => max_address_param.unwrap_or(CACHE_ADDR_BATCH_SIZE),
+            true => max_addresses.unwrap_or(CACHE_ADDR_BATCH_SIZE),
         };
         debug!("max_address {}", max_address);
         if self
@@ -1489,7 +1477,7 @@ where
         if let Some(change_descriptor) = &self.change_descriptor {
             let max_address = match change_descriptor.is_deriveable() {
                 false => 0,
-                true => max_address_param.unwrap_or(CACHE_ADDR_BATCH_SIZE),
+                true => max_addresses.unwrap_or(CACHE_ADDR_BATCH_SIZE),
             };
 
             if self
@@ -1508,13 +1496,11 @@ where
         // TODO: what if i generate an address first and cache some addresses?
         // TODO: we should sync if generating an address triggers a new batch to be stored
         if run_setup {
-            maybe_await!(self
-                .client
-                .setup(self.database.borrow_mut().deref_mut(), progress_update,))?;
+            maybe_await!(
+                blockchain.wallet_setup(self.database.borrow_mut().deref_mut(), progress,)
+            )?;
         } else {
-            maybe_await!(self
-                .client
-                .sync(self.database.borrow_mut().deref_mut(), progress_update,))?;
+            maybe_await!(blockchain.wallet_sync(self.database.borrow_mut().deref_mut(), progress,))?;
         }
 
         #[cfg(feature = "verify")]
@@ -1525,7 +1511,7 @@ where
                     verify::verify_tx(
                         tx.transaction.as_ref().ok_or(Error::TransactionNotFound)?,
                         self.database.borrow().deref(),
-                        &self.client,
+                        blockchain,
                     )?;
 
                     tx.verified = true;
@@ -1534,33 +1520,29 @@ where
             }
         }
 
+        let sync_time = SyncTime {
+            block_time: BlockTime {
+                height: maybe_await!(blockchain.get_height())?,
+                timestamp: time::get_timestamp(),
+            },
+        };
+        debug!("Saving `sync_time` = {:?}", sync_time);
+        self.database.borrow_mut().set_sync_time(sync_time)?;
+
         Ok(())
     }
-
-    /// Return a reference to the internal blockchain client
-    pub fn client(&self) -> &B {
-        &self.client
-    }
-
-    /// Broadcast a transaction to the network
-    #[maybe_async]
-    pub fn broadcast(&self, tx: Transaction) -> Result<Txid, Error> {
-        maybe_await!(self.client.broadcast(&tx))?;
-
-        Ok(tx.txid())
-    }
 }
 
 /// Return a fake wallet that appears to be funded for testing.
 pub fn get_funded_wallet(
     descriptor: &str,
 ) -> (
-    Wallet<(), MemoryDatabase>,
+    Wallet<MemoryDatabase>,
     (String, Option<String>),
     bitcoin::Txid,
 ) {
     let descriptors = testutils!(@descriptors (descriptor));
-    let wallet = Wallet::new_offline(
+    let wallet = Wallet::new(
         &descriptors.0,
         None,
         Network::Regtest,
@@ -1610,7 +1592,7 @@ pub(crate) mod test {
     #[test]
     fn test_cache_addresses_fixed() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             "wpkh(L5EZftvrYaSudiozVRzTqLcHLNDoVn7H5HSfM9BAN6tMJX8oTWz6)",
             None,
             Network::Testnet,
@@ -1644,7 +1626,7 @@ pub(crate) mod test {
     #[test]
     fn test_cache_addresses() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)", None, Network::Testnet, db).unwrap();
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)", None, Network::Testnet, db).unwrap();
 
         assert_eq!(
             wallet.get_address(New).unwrap().to_string(),
@@ -1672,7 +1654,7 @@ pub(crate) mod test {
     #[test]
     fn test_cache_addresses_refill() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)", None, Network::Testnet, db).unwrap();
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)", None, Network::Testnet, db).unwrap();
 
         assert_eq!(
             wallet.get_address(New).unwrap().to_string(),
@@ -2763,7 +2745,7 @@ pub(crate) mod test {
         let txid = tx.txid();
         // skip saving the utxos, we know they can't be used anyways
         details.transaction = Some(tx);
-        details.confirmation_time = Some(ConfirmationTime {
+        details.confirmation_time = Some(BlockTime {
             timestamp: 12345678,
             height: 42,
         });
@@ -3395,7 +3377,7 @@ pub(crate) mod test {
             .unwrap();
 
         let mut builder = wallet.build_fee_bump(txid).unwrap();
-        builder.fee_rate(FeeRate::from_sat_per_vb(140.0));
+        builder.fee_rate(FeeRate::from_sat_per_vb(141.0));
         let (psbt, details) = builder.finish().unwrap();
 
         assert_eq!(
@@ -3770,7 +3752,7 @@ pub(crate) mod test {
     #[test]
     fn test_unused_address() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
                                          None, Network::Testnet, db).unwrap();
 
         assert_eq!(
@@ -3787,7 +3769,7 @@ pub(crate) mod test {
     fn test_next_unused_address() {
         let descriptor = "wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)";
         let descriptors = testutils!(@descriptors (descriptor));
-        let wallet = Wallet::new_offline(
+        let wallet = Wallet::new(
             &descriptors.0,
             None,
             Network::Testnet,
@@ -3816,7 +3798,7 @@ pub(crate) mod test {
     #[test]
     fn test_peek_address_at_index() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
                                          None, Network::Testnet, db).unwrap();
 
         assert_eq!(
@@ -3849,7 +3831,7 @@ pub(crate) mod test {
     #[test]
     fn test_peek_address_at_index_not_derivable() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/1)",
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/1)",
                                          None, Network::Testnet, db).unwrap();
 
         assert_eq!(
@@ -3871,7 +3853,7 @@ pub(crate) mod test {
     #[test]
     fn test_reset_address_index() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
                                          None, Network::Testnet, db).unwrap();
 
         // new index 0
@@ -3908,7 +3890,7 @@ pub(crate) mod test {
     #[test]
     fn test_returns_index_and_address() {
         let db = MemoryDatabase::new();
-        let wallet = Wallet::new_offline("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
+        let wallet = Wallet::new("wpkh(tpubEBr4i6yk5nf5DAaJpsi9N2pPYBeJ7fZ5Z9rmN4977iYLCGco1VyjB9tvvuvYtfZzjD5A8igzgw3HeWeeKFmanHYqksqZXYXGsw5zjnj7KM9/*)",
                                          None, Network::Testnet, db).unwrap();
 
         // new index 0
@@ -3965,4 +3947,44 @@ pub(crate) mod test {
             }
         );
     }
+
+    #[test]
+    fn test_sending_to_bip350_bech32m_address() {
+        let (wallet, _, _) = get_funded_wallet(get_test_wpkh());
+        let addr =
+            Address::from_str("tb1pqqqqp399et2xygdj5xreqhjjvcmzhxw4aywxecjdzew6hylgvsesf3hn0c")
+                .unwrap();
+        let mut builder = wallet.build_tx();
+        builder.add_recipient(addr.script_pubkey(), 45_000);
+        builder.finish().unwrap();
+    }
+}
+
+/// Deterministically generate a unique name given the descriptors defining the wallet
+pub fn wallet_name_from_descriptor<T>(
+    descriptor: T,
+    change_descriptor: Option<T>,
+    network: Network,
+    secp: &SecpCtx,
+) -> Result<String, Error>
+where
+    T: IntoWalletDescriptor,
+{
+    //TODO check descriptors contains only public keys
+    let descriptor = descriptor
+        .into_wallet_descriptor(secp, network)?
+        .0
+        .to_string();
+    let mut wallet_name = get_checksum(&descriptor[..descriptor.find('#').unwrap()])?;
+    if let Some(change_descriptor) = change_descriptor {
+        let change_descriptor = change_descriptor
+            .into_wallet_descriptor(secp, network)?
+            .0
+            .to_string();
+        wallet_name.push_str(
+            get_checksum(&change_descriptor[..change_descriptor.find('#').unwrap()])?.as_str(),
+        );
+    }
+
+    Ok(wallet_name)
 }

src/wallet/signer.rs

@@ -72,7 +72,7 @@
 //! let custom_signer = CustomSigner::connect();
 //!
 //! let descriptor = "wpkh(tpubD6NzVbkrYhZ4Xferm7Pz4VnjdcDPFyjVu5K4iZXQ4pVN8Cks4pHVowTBXBKRhX64pkRyJZJN5xAKj4UDNnLPb5p2sSKXhewoYx5GbTdUFWq/*)";
-//! let mut wallet = Wallet::new_offline(descriptor, None, Network::Testnet, MemoryDatabase::default())?;
+//! let mut wallet = Wallet::new(descriptor, None, Network::Testnet, MemoryDatabase::default())?;
 //! wallet.add_signer(
 //!     KeychainKind::External,
 //!     SignerOrdering(200),
@@ -143,7 +143,7 @@ pub enum SignerError {
     InvalidNonWitnessUtxo,
     /// The `witness_utxo` field of the transaction is required to sign this input
     MissingWitnessUtxo,
-    /// The `witness_script` field of the transaction is requied to sign this input
+    /// The `witness_script` field of the transaction is required to sign this input
     MissingWitnessScript,
     /// The fingerprint and derivation path are missing from the psbt input
     MissingHdKeypath,
@@ -289,7 +289,7 @@ impl Signer for PrivateKey {
         }
 
         // FIXME: use the presence of `witness_utxo` as an indication that we should make a bip143
-        // sig. Does this make sense? Should we add an extra argument to explicitly swith between
+        // sig. Does this make sense? Should we add an extra argument to explicitly switch between
         // these? The original idea was to declare sign() as sign<Ctx: ScriptContex>() and use Ctx,
         // but that violates the rules for trait-objects, so we can't do it.
         let (hash, sighash) = match psbt.inputs[input_index].witness_utxo {

src/wallet/tx_builder.rs

@@ -120,8 +120,8 @@ impl TxBuilderContext for BumpFee {}
 /// [`finish`]: Self::finish
 /// [`coin_selection`]: Self::coin_selection
 #[derive(Debug)]
-pub struct TxBuilder<'a, B, D, Cs, Ctx> {
-    pub(crate) wallet: &'a Wallet<B, D>,
+pub struct TxBuilder<'a, D, Cs, Ctx> {
+    pub(crate) wallet: &'a Wallet<D>,
     pub(crate) params: TxParams,
     pub(crate) coin_selection: Cs,
     pub(crate) phantom: PhantomData<Ctx>,
@@ -170,7 +170,7 @@ impl std::default::Default for FeePolicy {
     }
 }
 
-impl<'a, Cs: Clone, Ctx, B, D> Clone for TxBuilder<'a, B, D, Cs, Ctx> {
+impl<'a, Cs: Clone, Ctx, D> Clone for TxBuilder<'a, D, Cs, Ctx> {
     fn clone(&self) -> Self {
         TxBuilder {
             wallet: self.wallet,
@@ -182,8 +182,8 @@ impl<'a, Cs: Clone, Ctx, B, D> Clone for TxBuilder<'a, B, D, Cs, Ctx> {
 }
 
 // methods supported by both contexts, for any CoinSelectionAlgorithm
-impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>, Ctx: TxBuilderContext>
-    TxBuilder<'a, B, D, Cs, Ctx>
+impl<'a, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>, Ctx: TxBuilderContext>
+    TxBuilder<'a, D, Cs, Ctx>
 {
     /// Set a custom fee rate
     pub fn fee_rate(&mut self, fee_rate: FeeRate) -> &mut Self {
@@ -310,7 +310,7 @@ impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>, Ctx: TxBuilderConte
     /// 2. `psbt_input`: To know the value.
     /// 3. `satisfaction_weight`: To know how much weight/vbytes the input will add to the transaction for fee calculation.
     ///
-    /// There are several security concerns about adding foregin UTXOs that application
+    /// There are several security concerns about adding foreign UTXOs that application
     /// developers should consider. First, how do you know the value of the input is correct? If a
     /// `non_witness_utxo` is provided in the `psbt_input` then this method implicitly verifies the
     /// value by checking it against the transaction. If only a `witness_utxo` is provided then this
@@ -508,7 +508,7 @@ impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>, Ctx: TxBuilderConte
     pub fn coin_selection<P: CoinSelectionAlgorithm<D>>(
         self,
         coin_selection: P,
-    ) -> TxBuilder<'a, B, D, P, Ctx> {
+    ) -> TxBuilder<'a, D, P, Ctx> {
         TxBuilder {
             wallet: self.wallet,
             params: self.params,
@@ -547,7 +547,7 @@ impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>, Ctx: TxBuilderConte
     }
 }
 
-impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>> TxBuilder<'a, B, D, Cs, CreateTx> {
+impl<'a, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>> TxBuilder<'a, D, Cs, CreateTx> {
     /// Replace the recipients already added with a new list
     pub fn set_recipients(&mut self, recipients: Vec<(Script, u64)>) -> &mut Self {
         self.params.recipients = recipients;
@@ -560,6 +560,13 @@ impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>> TxBuilder<'a, B, D,
         self
     }
 
+    /// Add data as an output, using OP_RETURN
+    pub fn add_data(&mut self, data: &[u8]) -> &mut Self {
+        let script = Script::new_op_return(data);
+        self.add_recipient(script, 0u64);
+        self
+    }
+
     /// Sets the address to *drain* excess coins to.
     ///
     /// Usually, when there are excess coins they are sent to a change address generated by the
@@ -607,7 +614,7 @@ impl<'a, B, D: BatchDatabase, Cs: CoinSelectionAlgorithm<D>> TxBuilder<'a, B, D,
 }
 
 // methods supported only by bump_fee
-impl<'a, B, D: BatchDatabase> TxBuilder<'a, B, D, DefaultCoinSelectionAlgorithm, BumpFee> {
+impl<'a, D: BatchDatabase> TxBuilder<'a, D, DefaultCoinSelectionAlgorithm, BumpFee> {
     /// Explicitly tells the wallet that it is allowed to reduce the fee of the output matching this
     /// `script_pubkey` in order to bump the transaction fee. Without specifying this the wallet
     /// will attempt to find a change output to shrink instead.

src/wallet/utils.rs

@@ -9,13 +9,11 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
+use bitcoin::blockdata::script::Script;
 use bitcoin::secp256k1::{All, Secp256k1};
 
 use miniscript::{MiniscriptKey, Satisfier, ToPublicKey};
 
-// De-facto standard "dust limit" (even though it should change based on the output type)
-pub const DUST_LIMIT_SATOSHI: u64 = 546;
-
 // MSB of the nSequence. If set there's no consensus-constraint, so it must be disabled when
 // spending using CSV in order to enforce CSV rules
 pub(crate) const SEQUENCE_LOCKTIME_DISABLE_FLAG: u32 = 1 << 31;
@@ -28,18 +26,19 @@ pub(crate) const SEQUENCE_LOCKTIME_MASK: u32 = 0x0000FFFF;
 // Threshold for nLockTime to be considered a block-height-based timelock rather than time-based
 pub(crate) const BLOCKS_TIMELOCK_THRESHOLD: u32 = 500000000;
 
-/// Trait to check if a value is below the dust limit
+/// Trait to check if a value is below the dust limit.
+/// We are performing dust value calculation for a given script public key using rust-bitcoin to
+/// keep it compatible with network dust rate
 // we implement this trait to make sure we don't mess up the comparison with off-by-one like a <
-// instead of a <= etc. The constant value for the dust limit is not public on purpose, to
-// encourage the usage of this trait.
+// instead of a <= etc.
 pub trait IsDust {
     /// Check whether or not a value is below dust limit
-    fn is_dust(&self) -> bool;
+    fn is_dust(&self, script: &Script) -> bool;
 }
 
 impl IsDust for u64 {
-    fn is_dust(&self) -> bool {
-        *self <= DUST_LIMIT_SATOSHI
+    fn is_dust(&self, script: &Script) -> bool {
+        *self < script.dust_value().as_sat()
     }
 }
 
@@ -138,47 +137,32 @@ impl<Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for Older {
 
 pub(crate) type SecpCtx = Secp256k1<All>;
 
-pub struct ChunksIterator<I: Iterator> {
-    iter: I,
-    size: usize,
-}
-
-#[cfg(any(feature = "electrum", feature = "esplora"))]
-impl<I: Iterator> ChunksIterator<I> {
-    pub fn new(iter: I, size: usize) -> Self {
-        ChunksIterator { iter, size }
-    }
-}
-
-impl<I: Iterator> Iterator for ChunksIterator<I> {
-    type Item = Vec<<I as std::iter::Iterator>::Item>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        let mut v = Vec::new();
-        for _ in 0..self.size {
-            let e = self.iter.next();
-
-            match e {
-                None => break,
-                Some(val) => v.push(val),
-            }
-        }
-
-        if v.is_empty() {
-            return None;
-        }
-
-        Some(v)
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::{
-        check_nlocktime, check_nsequence_rbf, BLOCKS_TIMELOCK_THRESHOLD,
+        check_nlocktime, check_nsequence_rbf, IsDust, BLOCKS_TIMELOCK_THRESHOLD,
         SEQUENCE_LOCKTIME_TYPE_FLAG,
     };
+    use crate::bitcoin::Address;
     use crate::types::FeeRate;
+    use std::str::FromStr;
+
+    #[test]
+    fn test_is_dust() {
+        let script_p2pkh = Address::from_str("1GNgwA8JfG7Kc8akJ8opdNWJUihqUztfPe")
+            .unwrap()
+            .script_pubkey();
+        assert!(script_p2pkh.is_p2pkh());
+        assert!(545.is_dust(&script_p2pkh));
+        assert!(!546.is_dust(&script_p2pkh));
+
+        let script_p2wpkh = Address::from_str("bc1qxlh2mnc0yqwas76gqq665qkggee5m98t8yskd8")
+            .unwrap()
+            .script_pubkey();
+        assert!(script_p2wpkh.is_v0_p2wpkh());
+        assert!(293.is_dust(&script_p2wpkh));
+        assert!(!294.is_dust(&script_p2wpkh));
+    }
 
     #[test]
     fn test_fee_from_btc_per_kb() {