Merge branch 'master' into release/0.14.0

b9fc06195b Fix typo in check_miniscript method declaration and use (thunderbiscuit)

Pull request description:

  ### Description

  This PR renames the `check_minsicript()` method on the `CheckMiniscript` trait  and its uses throughout the codebase to `check_miniscript()`.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

ACKs for top commit:
  notmandatory:
    ACK b9fc06195b

Tree-SHA512: cc4406c653cb86f9b15e60c6f87b95c300784d6b2992abc98b3f2db4b02ce252304cc0ab2c638f080b0caf3889e832885eca19e2d6582a3557c8709311b69644

.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.
+-->
+
+**Descriptive Title**  
+<!-- 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

@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         rust:
-          - 1.53.0 # STABLE
+          - 1.56.0 # STABLE
           - 1.46.0 # MSRV
         features:
           - default
@@ -26,6 +26,7 @@ jobs:
           - verify
           - async-interface
           - use-esplora-reqwest
+          - sqlite
     steps:
       - name: checkout
         uses: actions/checkout@v2
@@ -78,15 +79,20 @@ jobs:
         run: cargo test --features test-md-docs --no-default-features -- doctest::ReadmeDoctests
 
   test-blockchains:
-    name: Test ${{ matrix.blockchain.name }}
+    name: Blockchain ${{ matrix.blockchain.features }}
     runs-on: ubuntu-20.04
     strategy:
       fail-fast: false
       matrix:
         blockchain:
           - name: electrum
+            features: test-electrum
           - name: rpc
+            features: test-rpc
           - name: esplora
+            features: test-esplora,use-esplora-reqwest
+          - name: esplora
+            features: test-esplora,use-esplora-ureq    
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -95,8 +101,6 @@ jobs:
         with:
           path: |
             ~/.cargo/registry
-            ~/.cargo/bitcoin
-            ~/.cargo/electrs
             ~/.cargo/git
             target
           key: ${{ runner.os }}-cargo-${{ github.job }}-${{ hashFiles('**/Cargo.toml','**/Cargo.lock') }}
@@ -106,11 +110,11 @@ jobs:
           toolchain: stable
           override: true
       - name: Test
-        run: cargo test --features test-${{ matrix.blockchain.name }} ${{ matrix.blockchain.name }}::bdk_blockchain_tests
-
+        run: cargo test --no-default-features --features ${{ matrix.blockchain.features }} ${{ matrix.blockchain.name }}::bdk_blockchain_tests
+  
   check-wasm:
     name: Check WASM
-    runs-on: ubuntu-16.04
+    runs-on: ubuntu-20.04
     env:
       CC: clang-10
       CFLAGS: -I/usr/include
@@ -127,11 +131,11 @@ jobs:
           key: ${{ runner.os }}-cargo-${{ github.job }}-${{ hashFiles('**/Cargo.toml','**/Cargo.lock') }}
         # Install a recent version of clang that supports wasm32
       - run: wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add - || exit 1
-      - run: sudo apt-add-repository "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main" || exit 1
+      - run: sudo apt-add-repository "deb http://apt.llvm.org/focal/ llvm-toolchain-focal-10 main" || exit 1
       - 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
@@ -141,7 +145,6 @@ jobs:
       - name: Check
         run: cargo check --target wasm32-unknown-unknown --features use-esplora-reqwest --no-default-features
 
-
   fmt:
     name: Rust fmt
     runs-on: ubuntu-latest

.github/workflows/nightly_docs.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Update toolchain
         run: rustup update
       - name: Build docs
-        run: cargo rustdoc --verbose --features=compiler,electrum,esplora,ureq,compact_filters,key-value-db,all-keys -- --cfg docsrs -Dwarnings
+        run: cargo rustdoc --verbose --features=compiler,electrum,esplora,ureq,compact_filters,key-value-db,all-keys,sqlite -- --cfg docsrs -Dwarnings
       - name: Upload artifact
         uses: actions/upload-artifact@v2
         with:

CHANGELOG.md

@@ -6,6 +6,31 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- 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.
+
+## [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]
+
+- Activate `miniscript/use-serde` feature to allow consumers of the library to access it via the re-exported `miniscript` crate.
+- Add support for proxies in `EsploraBlockchain`
+- Added `SqliteDatabase` that implements `Database` backed by a sqlite database using `rusqlite` crate.
+
+## [v0.11.0] - [v0.10.0]
+
+- Added `flush` method to the `Database` trait to explicitly flush to disk latest changes on the db.
+
 ## [v0.10.0] - [v0.9.0]
 
 - Added `RpcBlockchain` in the `AnyBlockchain` struct to allow using Rpc backend where `AnyBlockchain` is used (eg `bdk-cli`)
@@ -360,7 +385,7 @@ final transaction is created by calling `finish` on the builder.
 - Use `MemoryDatabase` in the compiler example
 - Make the REPL return JSON
 
-[unreleased]: https://github.com/bitcoindevkit/bdk/compare/v0.9.0...HEAD
+[unreleased]: https://github.com/bitcoindevkit/bdk/compare/v0.11.0...HEAD
 [0.1.0-beta.1]: https://github.com/bitcoindevkit/bdk/compare/96c87ea5...0.1.0-beta.1
 [v0.2.0]: https://github.com/bitcoindevkit/bdk/compare/0.1.0-beta.1...v0.2.0
 [v0.3.0]: https://github.com/bitcoindevkit/bdk/compare/v0.2.0...v0.3.0
@@ -372,3 +397,7 @@ final transaction is created by calling `finish` on the builder.
 [v0.8.0]: https://github.com/bitcoindevkit/bdk/compare/v0.7.0...v0.8.0
 [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
+[v0.13.0]: 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

CONTRIBUTING.md

@@ -57,6 +57,21 @@ comment suggesting that you're working on it. If someone is already assigned,
 don't hesitate to ask if the assigned party or previous commenters are still
 working on it if it has been awhile.
 
+Deprecation policy
+------------------
+
+Where possible, breaking existing APIs should be avoided. Instead, add new APIs and
+use [`#[deprecated]`](https://github.com/rust-lang/rfcs/blob/master/text/1270-deprecation.md)
+to discourage use of the old one.
+
+Deprecated APIs are typically maintained for one release cycle. In other words, an
+API that has been deprecated with the 0.10 release can be expected to be removed in the
+0.11 release. This allows for smoother upgrades without incurring too much technical
+debt inside this library.
+
+If you deprecated an API as part of a contribution, we encourage you to "own" that API
+and send a follow-up to remove it as part of the next release cycle.
+
 Peer review
 -----------
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bdk"
-version = "0.10.0"
+version = "0.14.1-dev"
 edition = "2018"
 authors = ["Alekos Filini <alekos.filini@gmail.com>", "Riccardo Casatta <riccardo@casatta.it>"]
 homepage = "https://bitcoindevkit.org"
@@ -12,31 +12,37 @@ readme = "README.md"
 license = "MIT OR Apache-2.0"
 
 [dependencies]
-bdk-macros = "0.5"
+bdk-macros = "^0.6"
 log = "^0.4"
-miniscript = "5.1"
-bitcoin = { version = "~0.26.2", features = ["use-serde", "base64"] }
+miniscript = { version = "^6.0", features = ["use-serde"] }
+bitcoin = { version = "^0.27", features = ["use-serde", "base64"] }
 serde = { version = "^1.0", features = ["derive"] }
 serde_json = { version = "^1.0" }
 rand = "^0.7"
 
 # Optional dependencies
 sled = { version = "0.34", optional = true }
-electrum-client = { version = "0.7", optional = true }
+electrum-client = { version = "0.8", optional = true }
+rusqlite = { version = "0.25.3", optional = true }
+ahash = { version = "=0.7.4", optional = true }
 reqwest = { version = "0.11", optional = true, features = ["json"] }
-ureq = { version = "2.1", default-features = false, features = ["json"], optional = true }
+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", optional = true }
+rocksdb = { version = "0.14", default-features = false, features = ["snappy"], optional = true }
 cc = { version = ">=1.0.64", optional = true }
 socks = { version = "0.3", optional = true }
 lazy_static = { version = "1.4", optional = true }
-tiny-bip39 = { version = "^0.8", optional = true }
-zeroize = { version = "<1.4.0", optional = true }
+
+bip39 = { version = "1.0.1", optional = true }
 bitcoinconsensus = { version = "0.19.0-3", optional = true }
 
 # Needed by bdk_blockchain_tests macro
-bitcoincore-rpc = { version = "0.13", optional = true }
+bitcoincore-rpc = { version = "0.14", optional = true }
+
+# Platform-specific dependencies
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+tokio = { version = "1", features = ["rt"] }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 async-trait = "0.1"
@@ -48,10 +54,11 @@ minimal = []
 compiler = ["miniscript/compiler"]
 verify = ["bitcoinconsensus"]
 default = ["key-value-db", "electrum"]
+sqlite = ["rusqlite", "ahash"]
 compact_filters = ["rocksdb", "socks", "lazy_static", "cc"]
 key-value-db = ["sled"]
 all-keys = ["keys-bip39"]
-keys-bip39 = ["tiny-bip39", "zeroize"]
+keys-bip39 = ["bip39"]
 rpc = ["bitcoincore-rpc"]
 
 # We currently provide mulitple implementations of `Blockchain`, all are
@@ -70,8 +77,8 @@ rpc = ["bitcoincore-rpc"]
 async-interface = ["async-trait"]
 electrum = ["electrum-client"]
 # MUST ALSO USE `--no-default-features`.
-use-esplora-reqwest = ["async-interface", "esplora", "reqwest", "futures"]
-use-esplora-ureq = ["esplora", "ureq"]
+use-esplora-reqwest = ["esplora", "reqwest", "reqwest/socks", "futures"]
+use-esplora-ureq = ["esplora", "ureq", "ureq/socks"]
 # Typical configurations will not need to use `esplora` feature directly.
 esplora = []
 
@@ -80,14 +87,14 @@ esplora = []
 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 = ["esplora", "ureq", "electrsd/legacy", "electrsd/esplora_a33e97e1", "test-blockchains"]
+test-esplora = ["electrsd/legacy", "electrsd/esplora_a33e97e1", "test-blockchains"]
 test-md-docs = ["electrum"]
 
 [dev-dependencies]
 lazy_static = "1.4"
 env_logger = "0.7"
 clap = "2.33"
-electrsd = { version= "0.8", features = ["trigger", "bitcoind_0_21_1"] }
+electrsd = { version= "0.12", features = ["trigger", "bitcoind_22_0"] }
 
 [[example]]
 name = "address_validator"
@@ -103,6 +110,6 @@ 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

@@ -32,14 +32,14 @@ Pre-`v1.0.0` our "major" releases only affect the "minor" semver value. Accordin
     - If it's a minor issue you can just fix it in the release branch, since it will be merged back to `master` eventually
     - For bigger issues you can fix them on `master` and then *cherry-pick* the commit to the release branch
 6. Update the changelog with the new release version.
-7. Update `src/lib.rs` with the new version (line ~59)
+7. Update `src/lib.rs` with the new version (line ~43)
 8. On release day, make a commit on the release branch to bump the version to `x.y.z`. The message should be "Bump version to x.y.z".
 9. Add a tag to this commit. The tag name should be `vx.y.z` (for example `v0.5.0`), and the message "Release x.y.z". Make sure the tag is signed, for extra safety use the explicit `--sign` flag.
 10. Push the new commits to the upstream release branch, wait for the CI to finish one last time.
 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.

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()?)?,

macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bdk-macros"
-version = "0.5.0"
+version = "0.6.0"
 authors = ["Alekos Filini <alekos.filini@gmail.com>"]
 edition = "2018"
 homepage = "https://bitcoindevkit.org"

macros/src/lib.rs

@@ -121,3 +121,26 @@ pub fn maybe_await(expr: TokenStream) -> TokenStream {
 
     quoted.into()
 }
+
+/// Awaits if target_arch is "wasm32", uses `tokio::Runtime::block_on()` otherwise
+///
+/// Requires the `tokio` crate as a dependecy with `rt-core` or `rt-threaded` to build on non-wasm32 platforms.
+#[proc_macro]
+pub fn await_or_block(expr: TokenStream) -> TokenStream {
+    let expr: proc_macro2::TokenStream = expr.into();
+    let quoted = quote! {
+        {
+            #[cfg(all(not(target_arch = "wasm32"), not(feature = "async-interface")))]
+            {
+                tokio::runtime::Builder::new_current_thread().enable_all().build().unwrap().block_on(#expr)
+            }
+
+            #[cfg(any(target_arch = "wasm32", feature = "async-interface"))]
+            {
+                #expr.await
+            }
+        }
+    };
+
+    quoted.into()
+}

src/blockchain/compact_filters/mod.rs

@@ -71,7 +71,7 @@ use super::{Blockchain, Capability, ConfigurableBlockchain, Progress};
 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)),
             };
@@ -254,7 +254,7 @@ 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 +275,7 @@ 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 +294,7 @@ 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);
@@ -472,7 +472,7 @@ 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

@@ -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
 ///
@@ -71,10 +71,139 @@ impl Blockchain for ElectrumBlockchain {
     fn setup<D: BatchDatabase, P: Progress>(
         &self,
         database: &mut D,
-        progress_update: P,
+        _progress_update: P,
     ) -> Result<(), Error> {
-        self.client
-            .electrum_like_setup(self.stop_gap, database, progress_update)
+        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(())
     }
 
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
@@ -101,43 +230,48 @@ impl Blockchain for ElectrumBlockchain {
     }
 }
 
-impl ElectrumLikeSync for Client {
-    fn els_batch_script_get_history<'s, I: IntoIterator<Item = &'s Script> + Clone>(
-        &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)
+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

@@ -21,75 +21,42 @@ use std::collections::HashMap;
 use std::fmt;
 use std::io;
 
-use serde::Deserialize;
-
 use bitcoin::consensus;
 use bitcoin::{BlockHash, Txid};
 
 use crate::error::Error;
 use crate::FeeRate;
 
-#[cfg(all(
-    feature = "esplora",
-    feature = "reqwest",
-    any(feature = "async-interface", target_arch = "wasm32"),
-))]
+#[cfg(feature = "reqwest")]
 mod reqwest;
 
-#[cfg(all(
-    feature = "esplora",
-    feature = "reqwest",
-    any(feature = "async-interface", target_arch = "wasm32"),
-))]
+#[cfg(feature = "reqwest")]
 pub use self::reqwest::*;
 
-#[cfg(all(
-    feature = "esplora",
-    not(any(
-        feature = "async-interface",
-        feature = "reqwest",
-        target_arch = "wasm32"
-    )),
-))]
+#[cfg(feature = "ureq")]
 mod ureq;
 
-#[cfg(all(
-    feature = "esplora",
-    not(any(
-        feature = "async-interface",
-        feature = "reqwest",
-        target_arch = "wasm32"
-    )),
-))]
+#[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 {
@@ -129,10 +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")]
@@ -141,3 +148,65 @@ impl_error!(io::Error, Io, EsploraError);
 impl_error!(std::num::ParseIntError, Parsing, EsploraError);
 impl_error!(consensus::encode::Error, BitcoinEncoding, EsploraError);
 impl_error!(bitcoin::hashes::hex::Error, Hex, EsploraError);
+
+#[cfg(test)]
+#[cfg(feature = "test-esplora")]
+crate::bdk_blockchain_tests! {
+    fn test_instance(test_client: &TestClient) -> EsploraBlockchain {
+        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,
         }
@@ -98,36 +94,112 @@ impl Blockchain for EsploraBlockchain {
     fn setup<D: BatchDatabase, P: Progress>(
         &self,
         database: &mut D,
-        progress_update: P,
+        _progress_update: P,
     ) -> Result<(), Error> {
-        maybe_await!(self
-            .url_client
-            .electrum_like_setup(self.stop_gap, database, progress_update))
+        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(())
     }
 
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(self.url_client._get_tx(txid).await?)
+        Ok(await_or_block!(self.url_client._get_tx(txid))?)
     }
 
     fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        Ok(self.url_client._broadcast(tx).await?)
+        Ok(await_or_block!(self.url_client._broadcast(tx))?)
     }
 
     fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.url_client._get_height().await?)
+        Ok(await_or_block!(self.url_client._get_height())?)
     }
 
     fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        let estimates = self.url_client._get_fee_estimates().await?;
+        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()
-    }
-
     async fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
         let resp = self
             .client
@@ -196,71 +268,27 @@ 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> {
@@ -275,86 +303,29 @@ 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>> = futs.try_collect().await?;
-            results.extend(partial_results);
-        }
-        Ok(stream::iter(results).collect().await)
-    }
-
-    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> = futs.try_collect().await?;
-            results.extend(partial_results);
-        }
-        Ok(stream::iter(results).collect().await)
-    }
-
-    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> = futs.try_collect().await?;
-            results.extend(partial_results);
-        }
-        Ok(stream::iter(results).collect().await)
-    }
-}
-
-/// 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,
-    /// 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()));
+
         let mut blockchain = EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap);
         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 {
+            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)
     }
 }
-
-#[cfg(test)]
-#[cfg(feature = "test-esplora")]
-crate::bdk_blockchain_tests! {
-    fn test_instance(test_client: &TestClient) -> EsploraBlockchain {
-        EsploraBlockchain::new(&format!("http://{}",test_client.electrsd.esplora_url.as_ref().unwrap()), None, 20)
-    }
-}

src/blockchain/esplora/ureq.rs

@@ -19,21 +19,21 @@ use std::time::Duration;
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use ureq::{Agent, Response};
+use ureq::{Agent, Proxy, Response};
 
 use bitcoin::consensus::{deserialize, serialize};
 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,
@@ -47,25 +47,18 @@ 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 {
-    /// Create a new instance of the client from a base URL and `stop_gap`.
+    /// Create a new instance of the client from a base URL and the `stop_gap`.
     pub fn new(base_url: &str, stop_gap: usize) -> Self {
         EsploraBlockchain {
             url_client: UrlClient {
                 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 {
@@ -91,10 +90,94 @@ impl Blockchain for EsploraBlockchain {
     fn setup<D: BatchDatabase, P: Progress>(
         &self,
         database: &mut D,
-        progress_update: P,
+        _progress_update: P,
     ) -> Result<(), Error> {
-        self.url_client
-            .electrum_like_setup(self.stop_gap, database, progress_update)
+        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(())
     }
 
     fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
@@ -117,10 +200,6 @@ impl Blockchain for EsploraBlockchain {
 }
 
 impl UrlClient {
-    fn script_to_scripthash(script: &Script) -> String {
-        sha256::Hash::hash(script.as_bytes()).into_inner().to_hex()
-    }
-
     fn _get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, EsploraError> {
         let resp = self
             .agent
@@ -200,81 +279,6 @@ 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 +296,22 @@ 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 {
@@ -315,65 +335,37 @@ 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,
-    /// 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 agent: Agent = ureq::AgentBuilder::new()
-            .timeout_read(Duration::from_secs(config.timeout_read))
-            .timeout_write(Duration::from_secs(config.timeout_write))
-            .build();
-        Ok(EsploraBlockchain::new(config.base_url.as_str(), config.stop_gap).with_agent(agent))
+        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())))?);
+        }
+
+        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",
@@ -201,7 +200,7 @@ impl Progress for NoopProgress {
 #[derive(Clone, Copy)]
 pub struct LogProgress;
 
-/// Create a nwe instance of [`LogProgress`]
+/// Create a new instance of [`LogProgress`]
 pub fn log_progress() -> LogProgress {
     LogProgress
 }

src/blockchain/rpc.rs

@@ -35,9 +35,7 @@ use crate::bitcoin::consensus::deserialize;
 use crate::bitcoin::{Address, Network, OutPoint, Transaction, TxOut, Txid};
 use crate::blockchain::{Blockchain, Capability, ConfigurableBlockchain, Progress};
 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 crate::{BlockTime, Error, FeeRate, KeychainKind, LocalUtxo, TransactionDetails};
 use bitcoincore_rpc::json::{
     GetAddressInfoResultLabel, ImportMultiOptions, ImportMultiRequest,
     ImportMultiRequestScriptPubkey, ImportMultiRescanSince,
@@ -76,7 +74,7 @@ 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>,
@@ -84,7 +82,7 @@ pub struct RpcConfig {
 
 /// 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)]
@@ -156,7 +154,7 @@ 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()
             })
@@ -169,22 +167,25 @@ impl Blockchain for RpcBlockchain {
         //TODO maybe convenient using import_descriptor for compatible descriptor and import_multi as fallback
         self.client.import_multi(&requests, Some(&options))?;
 
-        let current_height = self.get_height()?;
+        loop {
+            let current_height = self.get_height()?;
 
-        // min because block invalidate may cause height to go down
-        let node_synced = self.get_node_synced_height()?.min(current_height);
+            // min because block invalidate may cause height to go down
+            let node_synced = self.get_node_synced_height()?.min(current_height);
 
-        //TODO call rescan in chunks (updating node_synced_height) so that in case of
-        // interruption work can be partially recovered
-        debug!(
-            "rescan_blockchain from:{} to:{}",
-            node_synced, current_height
-        );
-        self.client
-            .rescan_blockchain(Some(node_synced as usize), Some(current_height as usize))?;
-        progress_update.update(1.0, None)?;
+            let sync_up_to = node_synced.saturating_add(10_000).min(current_height);
 
-        self.set_node_synced_height(current_height)?;
+            debug!("rescan_blockchain from:{} to:{}", node_synced, sync_up_to);
+            self.client
+                .rescan_blockchain(Some(node_synced as usize), Some(sync_up_to as usize))?;
+            progress_update.update((sync_up_to as f32) / (current_height as f32), None)?;
+
+            self.set_node_synced_height(sync_up_to)?;
+
+            if sync_up_to == current_height {
+                break;
+            }
+        }
 
         self.sync(database, progress_update)
     }
@@ -227,7 +228,7 @@ 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!(
@@ -235,7 +236,7 @@ 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?
@@ -263,7 +264,7 @@ 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,
                     ),
@@ -357,7 +358,7 @@ impl ConfigurableBlockchain for RpcBlockchain {
         let wallet_url = format!("{}/wallet/{}", config.url, &wallet_name);
         debug!("connecting to {} auth:{:?}", wallet_url, config.auth);
 
-        let client = Client::new(wallet_url, config.auth.clone().into())?;
+        let client = Client::new(wallet_url.as_str(), config.auth.clone().into())?;
         let loaded_wallets = client.list_wallets()?;
         if loaded_wallets.contains(&wallet_name) {
             debug!("wallet already loaded {:?}", wallet_name);
@@ -412,35 +413,6 @@ 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

@@ -65,6 +65,8 @@ macro_rules! impl_inner_method {
             $enum_name::Memory(inner) => inner.$name( $($args, )* ),
             #[cfg(feature = "key-value-db")]
             $enum_name::Sled(inner) => inner.$name( $($args, )* ),
+            #[cfg(feature = "sqlite")]
+            $enum_name::Sqlite(inner) => inner.$name( $($args, )* ),
         }
     }
 }
@@ -82,10 +84,15 @@ pub enum AnyDatabase {
     #[cfg_attr(docsrs, doc(cfg(feature = "key-value-db")))]
     /// Simple key-value embedded database based on [`sled`]
     Sled(sled::Tree),
+    #[cfg(feature = "sqlite")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "sqlite")))]
+    /// Sqlite embedded database using [`rusqlite`]
+    Sqlite(sqlite::SqliteDatabase),
 }
 
 impl_from!(memory::MemoryDatabase, AnyDatabase, Memory,);
 impl_from!(sled::Tree, AnyDatabase, Sled, #[cfg(feature = "key-value-db")]);
+impl_from!(sqlite::SqliteDatabase, AnyDatabase, Sqlite, #[cfg(feature = "sqlite")]);
 
 /// Type that contains any of the [`BatchDatabase::Batch`] types defined by the library
 pub enum AnyBatch {
@@ -95,6 +102,10 @@ pub enum AnyBatch {
     #[cfg_attr(docsrs, doc(cfg(feature = "key-value-db")))]
     /// Simple key-value embedded database based on [`sled`]
     Sled(<sled::Tree as BatchDatabase>::Batch),
+    #[cfg(feature = "sqlite")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "sqlite")))]
+    /// Sqlite embedded database using [`rusqlite`]
+    Sqlite(<sqlite::SqliteDatabase as BatchDatabase>::Batch),
 }
 
 impl_from!(
@@ -103,6 +114,7 @@ impl_from!(
     Memory,
 );
 impl_from!(<sled::Tree as BatchDatabase>::Batch, AnyBatch, Sled, #[cfg(feature = "key-value-db")]);
+impl_from!(<sqlite::SqliteDatabase as BatchDatabase>::Batch, AnyBatch, Sqlite, #[cfg(feature = "sqlite")]);
 
 impl BatchOperations for AnyDatabase {
     fn set_script_pubkey(
@@ -132,6 +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,
@@ -168,6 +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 {
@@ -229,10 +247,17 @@ 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)
     }
+
+    fn flush(&mut self) -> Result<(), Error> {
+        impl_inner_method!(AnyDatabase, self, flush)
+    }
 }
 
 impl BatchOperations for AnyBatch {
@@ -256,6 +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,
@@ -286,6 +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 {
@@ -296,19 +327,26 @@ impl BatchDatabase for AnyDatabase {
             AnyDatabase::Memory(inner) => inner.begin_batch().into(),
             #[cfg(feature = "key-value-db")]
             AnyDatabase::Sled(inner) => inner.begin_batch().into(),
+            #[cfg(feature = "sqlite")]
+            AnyDatabase::Sqlite(inner) => inner.begin_batch().into(),
         }
     }
     fn commit_batch(&mut self, batch: Self::Batch) -> Result<(), Error> {
         match self {
             AnyDatabase::Memory(db) => match batch {
                 AnyBatch::Memory(batch) => db.commit_batch(batch),
-                #[cfg(feature = "key-value-db")]
-                _ => unimplemented!("Sled batch shouldn't be used with Memory db."),
+                #[cfg(any(feature = "key-value-db", feature = "sqlite"))]
+                _ => unimplemented!("Other batch shouldn't be used with Memory db."),
             },
             #[cfg(feature = "key-value-db")]
             AnyDatabase::Sled(db) => match batch {
                 AnyBatch::Sled(batch) => db.commit_batch(batch),
-                _ => unimplemented!("Memory batch shouldn't be used with Sled db."),
+                _ => unimplemented!("Other batch shouldn't be used with Sled db."),
+            },
+            #[cfg(feature = "sqlite")]
+            AnyDatabase::Sqlite(db) => match batch {
+                AnyBatch::Sqlite(batch) => db.commit_batch(batch),
+                _ => unimplemented!("Other batch shouldn't be used with Sqlite db."),
             },
         }
     }
@@ -333,6 +371,23 @@ impl ConfigurableDatabase for sled::Tree {
     }
 }
 
+/// Configuration type for a [`sqlite::SqliteDatabase`] database
+#[cfg(feature = "sqlite")]
+#[derive(Debug, serde::Serialize, serde::Deserialize)]
+pub struct SqliteDbConfiguration {
+    /// Main directory of the db
+    pub path: String,
+}
+
+#[cfg(feature = "sqlite")]
+impl ConfigurableDatabase for sqlite::SqliteDatabase {
+    type Config = SqliteDbConfiguration;
+
+    fn from_config(config: &Self::Config) -> Result<Self, Error> {
+        Ok(sqlite::SqliteDatabase::new(config.path.clone()))
+    }
+}
+
 /// Type that can contain any of the database configurations defined by the library
 ///
 /// This allows storing a single configuration that can be loaded into an [`AnyDatabase`]
@@ -346,6 +401,10 @@ pub enum AnyDatabaseConfig {
     #[cfg_attr(docsrs, doc(cfg(feature = "key-value-db")))]
     /// Simple key-value embedded database based on [`sled`]
     Sled(SledDbConfiguration),
+    #[cfg(feature = "sqlite")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "sqlite")))]
+    /// Sqlite embedded database using [`rusqlite`]
+    Sqlite(SqliteDbConfiguration),
 }
 
 impl ConfigurableDatabase for AnyDatabase {
@@ -358,9 +417,14 @@ impl ConfigurableDatabase for AnyDatabase {
             }
             #[cfg(feature = "key-value-db")]
             AnyDatabaseConfig::Sled(inner) => AnyDatabase::Sled(sled::Tree::from_config(inner)?),
+            #[cfg(feature = "sqlite")]
+            AnyDatabaseConfig::Sqlite(inner) => {
+                AnyDatabase::Sqlite(sqlite::SqliteDatabase::from_config(inner)?)
+            }
         })
     }
 }
 
 impl_from!((), AnyDatabaseConfig, Memory,);
 impl_from!(SledDbConfiguration, AnyDatabaseConfig, Sled, #[cfg(feature = "key-value-db")]);
+impl_from!(SqliteDbConfiguration, AnyDatabaseConfig, Sqlite, #[cfg(feature = "sqlite")]);

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();
@@ -367,6 +390,10 @@ impl Database for Tree {
             Ok(val)
         })
     }
+
+    fn flush(&mut self) -> Result<(), Error> {
+        Ok(Tree::flush(self).map(|_| ())?)
+    }
 }
 
 impl BatchDatabase for Tree {
@@ -466,4 +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(),
         }
     }
@@ -110,7 +114,7 @@ fn after(key: &[u8]) -> Vec<u8> {
 /// [`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();
@@ -419,6 +444,10 @@ impl Database for MemoryDatabase {
 
         Ok(*value)
     }
+
+    fn flush(&mut self) -> Result<(), Error> {
+        Ok(())
+    }
 }
 
 impl BatchDatabase for MemoryDatabase {
@@ -452,20 +481,21 @@ impl ConfigurableDatabase for MemoryDatabase {
 /// don't have `test` set.
 macro_rules! populate_test_db {
     ($db:expr, $tx_meta:expr, $current_height:expr$(,)?) => {{
+        use std::str::FromStr;
         use $crate::database::BatchOperations;
         let mut db = $db;
         let tx_meta = $tx_meta;
         let current_height: Option<u32> = $current_height;
-        let tx = Transaction {
+        let tx = $crate::bitcoin::Transaction {
             version: 1,
             lock_time: 0,
             input: vec![],
             output: tx_meta
                 .output
                 .iter()
-                .map(|out_meta| bitcoin::TxOut {
+                .map(|out_meta| $crate::bitcoin::TxOut {
                     value: out_meta.value,
-                    script_pubkey: bitcoin::Address::from_str(&out_meta.to_address)
+                    script_pubkey: $crate::bitcoin::Address::from_str(&out_meta.to_address)
                         .unwrap()
                         .script_pubkey(),
                 })
@@ -473,12 +503,12 @@ macro_rules! populate_test_db {
         };
 
         let txid = tx.txid();
-        let confirmation_time = tx_meta.min_confirmations.map(|conf| ConfirmationTime {
+        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 = TransactionDetails {
+        let tx_details = $crate::TransactionDetails {
             transaction: Some(tx.clone()),
             txid,
             fee: Some(0),
@@ -490,13 +520,13 @@ macro_rules! populate_test_db {
 
         db.set_tx(&tx_details).unwrap();
         for (vout, out) in tx.output.iter().enumerate() {
-            db.set_utxo(&LocalUtxo {
+            db.set_utxo(&$crate::LocalUtxo {
                 txout: out.clone(),
-                outpoint: OutPoint {
+                outpoint: $crate::bitcoin::OutPoint {
                     txid,
                     vout: vout as u32,
                 },
-                keychain: KeychainKind::External,
+                keychain: $crate::KeychainKind::External,
             })
             .unwrap();
         }
@@ -582,4 +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};
 
@@ -36,9 +38,23 @@ pub use any::{AnyDatabase, AnyDatabaseConfig};
 #[cfg(feature = "key-value-db")]
 pub(crate) mod keyvalue;
 
+#[cfg(feature = "sqlite")]
+pub(crate) mod sqlite;
+#[cfg(feature = "sqlite")]
+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
@@ -59,6 +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(
@@ -84,6 +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
@@ -129,11 +151,16 @@ pub trait Database: BatchOperations {
     fn get_tx(&self, txid: &Txid, include_raw: bool) -> Result<Option<TransactionDetails>, Error>;
     /// Return the last defivation 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
     ///
     /// It should insert and return `0` if not present in the database
     fn increment_last_index(&mut self, keychain: KeychainKind) -> Result<u32, Error>;
+
+    /// Force changes to be written to disk
+    fn flush(&mut self) -> Result<(), Error>;
 }
 
 /// Trait for a database that supports batch operations
@@ -317,7 +344,7 @@ pub mod test {
             received: 1337,
             sent: 420420,
             fee: Some(140),
-            confirmation_time: Some(ConfirmationTime {
+            confirmation_time: Some(BlockTime {
                 timestamp: 123456,
                 height: 1000,
             }),
@@ -369,5 +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/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))
             })
@@ -571,8 +571,9 @@ macro_rules! fragment {
     ( pk ( $key:expr ) ) => ({
         $crate::fragment!(c:pk_k ( $key ))
     });
-    ( pk_h ( $key_hash:expr ) ) => ({
-        $crate::impl_leaf_opcode_value!(PkH, $key_hash)
+    ( pk_h ( $key:expr ) ) => ({
+        let secp = $crate::bitcoin::secp256k1::Secp256k1::new();
+        $crate::keys::make_pkh($key, &secp)
     });
     ( after ( $value:expr ) ) => ({
         $crate::impl_leaf_opcode_value!(After, $value)
@@ -601,6 +602,9 @@ macro_rules! fragment {
     ( and_or ( $( $inner:tt )* ) ) => ({
         $crate::impl_node_opcode_three!(AndOr, $( $inner )*)
     });
+    ( andor ( $( $inner:tt )* ) ) => ({
+        $crate::impl_node_opcode_three!(AndOr, $( $inner )*)
+    });
     ( or_b ( $( $inner:tt )* ) ) => ({
         $crate::impl_node_opcode_two!(OrB, $( $inner )*)
     });

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(())

src/descriptor/policy.rs

@@ -47,14 +47,12 @@ use bitcoin::util::bip32::Fingerprint;
 use bitcoin::PublicKey;
 
 use miniscript::descriptor::{DescriptorPublicKey, ShInner, SortedMultiVec, WshInner};
-use miniscript::{
-    Descriptor, Miniscript, MiniscriptKey, Satisfier, ScriptContext, Terminal, ToPublicKey,
-};
+use miniscript::{Descriptor, Miniscript, MiniscriptKey, Satisfier, ScriptContext, Terminal};
 
 #[allow(unused_imports)]
 use log::{debug, error, info, trace};
 
-use crate::descriptor::{DerivedDescriptorKey, ExtractPolicy};
+use crate::descriptor::ExtractPolicy;
 use crate::wallet::signer::{SignerId, SignersContainer};
 use crate::wallet::utils::{self, After, Older, SecpCtx};
 
@@ -88,13 +86,6 @@ impl PkOrF {
             },
         }
     }
-
-    fn from_key_hash(k: hash160::Hash) -> Self {
-        PkOrF {
-            pubkey_hash: Some(k),
-            ..Default::default()
-        }
-    }
 }
 
 /// An item that needs to be satisfied
@@ -779,25 +770,6 @@ fn signature_in_psbt(psbt: &Psbt, key: &DescriptorPublicKey, secp: &SecpCtx) ->
     })
 }
 
-fn signature_key(
-    key: &<DescriptorPublicKey as MiniscriptKey>::Hash,
-    signers: &SignersContainer,
-    secp: &SecpCtx,
-) -> Policy {
-    let key_hash = DerivedDescriptorKey::new(key.clone(), secp)
-        .to_public_key()
-        .to_pubkeyhash();
-    let mut policy: Policy = SatisfiableItem::Signature(PkOrF::from_key_hash(key_hash)).into();
-
-    if signers.find(SignerId::PkHash(key_hash)).is_some() {
-        policy.contribution = Satisfaction::Complete {
-            condition: Default::default(),
-        }
-    }
-
-    policy
-}
-
 impl<Ctx: ScriptContext> ExtractPolicy for Miniscript<DescriptorPublicKey, Ctx> {
     fn extract_policy(
         &self,
@@ -809,7 +781,7 @@ impl<Ctx: ScriptContext> ExtractPolicy for Miniscript<DescriptorPublicKey, Ctx>
             // Leaves
             Terminal::True | Terminal::False => None,
             Terminal::PkK(pubkey) => Some(signature(pubkey, signers, build_sat, secp)),
-            Terminal::PkH(pubkey_hash) => Some(signature_key(pubkey_hash, signers, secp)),
+            Terminal::PkH(pubkey_hash) => Some(signature(pubkey_hash, signers, build_sat, secp)),
             Terminal::After(value) => {
                 let mut policy: Policy = SatisfiableItem::AbsoluteTimelock { value: *value }.into();
                 policy.contribution = Satisfaction::Complete {
@@ -1444,6 +1416,7 @@ mod test {
 
     const ALICE_TPRV_STR:&str = "tprv8ZgxMBicQKsPf6T5X327efHnvJDr45Xnb8W4JifNWtEoqXu9MRYS4v1oYe6DFcMVETxy5w3bqpubYRqvcVTqovG1LifFcVUuJcbwJwrhYzP";
     const BOB_TPRV_STR:&str = "tprv8ZgxMBicQKsPeinZ155cJAn117KYhbaN6MV3WeG6sWhxWzcvX1eg1awd4C9GpUN1ncLEM2rzEvunAg3GizdZD4QPPCkisTz99tXXB4wZArp";
+    const CAROL_TPRV_STR:&str = "tprv8ZgxMBicQKsPdC3CicFifuLCEyVVdXVUNYorxUWj3iGZ6nimnLAYAY9SYB7ib8rKzRxrCKFcEytCt6szwd2GHnGPRCBLAEAoSVDefSNk4Bt";
     const ALICE_BOB_PATH: &str = "m/0'";
 
     #[test]
@@ -1602,4 +1575,28 @@ mod test {
         );
         //println!("{}", serde_json::to_string(&policy_expired_signed).unwrap());
     }
+
+    #[test]
+    fn test_extract_pkh() {
+        let secp = Secp256k1::new();
+
+        let (prvkey_alice, _, _) = setup_keys(ALICE_TPRV_STR, ALICE_BOB_PATH, &secp);
+        let (prvkey_bob, _, _) = setup_keys(BOB_TPRV_STR, ALICE_BOB_PATH, &secp);
+        let (prvkey_carol, _, _) = setup_keys(CAROL_TPRV_STR, ALICE_BOB_PATH, &secp);
+
+        let desc = descriptor!(wsh(c: andor(
+            pk(prvkey_alice),
+            pk_k(prvkey_bob),
+            pk_h(prvkey_carol),
+        )))
+        .unwrap();
+
+        let (wallet_desc, keymap) = desc
+            .into_wallet_descriptor(&secp, Network::Testnet)
+            .unwrap();
+        let signers_container = Arc::new(SignersContainer::from(keymap));
+
+        let policy = wallet_desc.extract_policy(&signers_container, BuildSatisfaction::None, &secp);
+        assert!(policy.is_ok());
+    }
 }

src/error.rs

@@ -140,6 +140,9 @@ pub enum Error {
     #[cfg(feature = "rpc")]
     /// Rpc client error
     Rpc(bitcoincore_rpc::Error),
+    #[cfg(feature = "sqlite")]
+    /// Rusqlite client error
+    Rusqlite(rusqlite::Error),
 }
 
 impl fmt::Display for Error {
@@ -194,6 +197,8 @@ impl_error!(electrum_client::Error, Electrum);
 impl_error!(sled::Error, Sled);
 #[cfg(feature = "rpc")]
 impl_error!(bitcoincore_rpc::Error, Rpc);
+#[cfg(feature = "sqlite")]
+impl_error!(rusqlite::Error, Rusqlite);
 
 #[cfg(feature = "compact_filters")]
 impl From<crate::blockchain::compact_filters::CompactFiltersError> for Error {

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

@@ -460,9 +460,9 @@ 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 +748,21 @@ 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))
+}
+
+// Used internally by `bdk::fragment!` to build `pk_h()` fragments
+#[doc(hidden)]
+pub fn make_pkh<Pk: IntoDescriptorKey<Ctx>, Ctx: ScriptContext>(
+    descriptor_key: Pk,
+    secp: &SecpCtx,
+) -> Result<(Miniscript<DescriptorPublicKey, Ctx>, KeyMap, ValidNetworks), DescriptorError> {
+    let (key, key_map, valid_networks) = descriptor_key.into_descriptor_key()?.extract(secp)?;
+    let minisc = Miniscript::from_ast(Terminal::PkH(key))?;
+
+    minisc.check_miniscript()?;
 
     Ok((minisc, key_map, valid_networks))
 }
@@ -763,7 +777,7 @@ 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))
 }

src/lib.rs

@@ -40,7 +40,7 @@
 //! interact with the bitcoin P2P network.
 //!
 //! ```toml
-//! bdk = "0.10.0"
+//! bdk = "0.14.0"
 //! ```
 #![cfg_attr(
     feature = "electrum",
@@ -244,6 +244,9 @@ pub extern crate electrum_client;
 #[cfg(feature = "key-value-db")]
 pub extern crate sled;
 
+#[cfg(feature = "sqlite")]
+pub extern crate rusqlite;
+
 #[allow(unused_imports)]
 #[macro_use]
 pub(crate) mod error;

src/psbt/mod.rs

@@ -43,8 +43,8 @@ impl PsbtUtils for Psbt {
 mod test {
     use crate::bitcoin::TxIn;
     use crate::psbt::Psbt;
-    use crate::wallet::test::{get_funded_wallet, get_test_wpkh};
     use crate::wallet::AddressIndex;
+    use crate::wallet::{get_funded_wallet, test::get_test_wpkh};
     use crate::SignOptions;
     use std::str::FromStr;
 

src/testutils/blockchain_tests.rs

@@ -7,10 +7,10 @@ pub use bitcoincore_rpc::bitcoincore_rpc_json::AddressType;
 pub use bitcoincore_rpc::{Auth, Client as RpcClient, RpcApi};
 use core::str::FromStr;
 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, trace};
+use log::{debug, error, info, log_enabled, trace, Level};
 use std::collections::HashMap;
 use std::env;
 use std::ops::Deref;
@@ -24,14 +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 bitcoind = BitcoinD::new(bitcoind_exe).unwrap();
 
-        let http_enabled = cfg!(feature = "test-esplora");
+        let mut conf = bitcoind::Conf::default();
+        conf.view_stdout = log_enabled!(Level::Debug);
+        let bitcoind = BitcoinD::with_conf(bitcoind_exe, &conf).unwrap();
+
+        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,
-            ..Default::default()
-        };
         let electrsd = ElectrsD::with_conf(electrs_exe, &bitcoind, &conf).unwrap();
 
         let node_address = bitcoind.client.get_new_address(None, None).unwrap();
@@ -144,9 +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);
@@ -393,6 +392,9 @@ macro_rules! bdk_blockchain_tests {
 
             #[test]
             fn test_sync_simple() {
+                use std::ops::Deref;
+                use crate::database::Database;
+
                 let (wallet, descriptors, mut test_client) = init_single_sig();
 
                 let tx = testutils! {
@@ -401,7 +403,13 @@ macro_rules! bdk_blockchain_tests {
                 println!("{:?}", tx);
                 let txid = test_client.receive(tx);
 
+                // 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(noop_progress(), None).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");
@@ -593,7 +601,7 @@ 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.broadcast(&tx).unwrap();
                 wallet.sync(noop_progress(), None).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect balance after send");
 
@@ -601,6 +609,74 @@ macro_rules! bdk_blockchain_tests {
                 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, descriptors, mut test_client) = init_single_sig();
+                let receiver_wallet = get_wallet_from_descriptors(&("wpkh(cVpPVruEDdmutPzisEsYvtST1usBR3ntr8pXSyt6D2YYqXRyPcFW)".to_string(), None), &test_client);
+                // need to sync so rpc can start watching
+                receiver_wallet.sync(noop_progress(), None).unwrap();
+
+                test_client.receive(testutils! {
+                    @tx ( (@external descriptors, 0) => 50_000, (@external descriptors, 1) => 25_000 ) (@confirmations 1)
+                });
+
+                wallet.sync(noop_progress(), None).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()
+                };
+
+                wallet.broadcast(&tx1).unwrap();
+                wallet.broadcast(&tx2).unwrap();
+
+                receiver_wallet.sync(noop_progress(), None).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, 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(noop_progress(), None).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();
@@ -644,7 +720,7 @@ 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_txid = wallet.broadcast(&psbt.extract_tx()).unwrap();
 
                 wallet.sync(noop_progress(), None).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), details.received, "incorrect balance after receive");
@@ -687,7 +763,7 @@ 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.broadcast(&psbt.extract_tx()).unwrap();
 
                     wallet.sync(noop_progress(), None).unwrap();
 
@@ -726,7 +802,7 @@ 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.broadcast(&psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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");
@@ -736,7 +812,7 @@ 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.broadcast(&new_psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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");
@@ -761,7 +837,7 @@ 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.broadcast(&psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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");
@@ -771,7 +847,7 @@ 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.broadcast(&new_psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).unwrap();
                 assert_eq!(wallet.get_balance().unwrap(), 0, "incorrect balance after change removal");
                 assert_eq!(new_details.received, 0, "incorrect received after change removal");
@@ -796,7 +872,7 @@ 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.broadcast(&psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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");
@@ -806,7 +882,7 @@ 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.broadcast(&new_psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).unwrap();
                 assert_eq!(new_details.sent, 75_000, "incorrect sent");
                 assert_eq!(wallet.get_balance().unwrap(), new_details.received, "incorrect balance after add input");
@@ -829,7 +905,7 @@ 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.broadcast(&psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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");
@@ -841,13 +917,44 @@ 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.broadcast(&new_psbt.extract_tx()).unwrap();
                 wallet.sync(noop_progress(), None).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, 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(noop_progress(), None).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");
+                let sent_txid = wallet.broadcast(&tx).unwrap();
+                test_client.generate(1, Some(node_addr));
+                wallet.sync(noop_progress(), None).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(&sent_txid).unwrap();
+            }
+
             #[test]
             fn test_sync_receive_coinbase() {
                 let (wallet, _, mut test_client) = init_single_sig();
@@ -870,6 +977,102 @@ macro_rules! bdk_blockchain_tests {
                 wallet.sync(noop_progress(), None).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, 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(noop_progress(), None).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();
+                wallet.broadcast(&tx).unwrap();
+                wallet.sync(noop_progress(), None).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/testutils/mod.rs

@@ -100,8 +100,8 @@ impl TranslateDescriptor for Descriptor<DescriptorPublicKey> {
 #[macro_export]
 macro_rules! testutils {
     ( @external $descriptors:expr, $child:expr ) => ({
-        use bitcoin::secp256k1::Secp256k1;
-        use miniscript::descriptor::{Descriptor, DescriptorPublicKey, DescriptorTrait};
+        use $crate::bitcoin::secp256k1::Secp256k1;
+        use $crate::miniscript::descriptor::{Descriptor, DescriptorPublicKey, DescriptorTrait};
 
         use $crate::testutils::TranslateDescriptor;
 
@@ -111,15 +111,15 @@ macro_rules! testutils {
         parsed.derive_translated(&secp, $child).address(bitcoin::Network::Regtest).expect("No address form")
     });
     ( @internal $descriptors:expr, $child:expr ) => ({
-        use bitcoin::secp256k1::Secp256k1;
-        use miniscript::descriptor::{Descriptor, DescriptorPublicKey, DescriptorTrait};
+        use $crate::bitcoin::secp256k1::Secp256k1;
+        use $crate::miniscript::descriptor::{Descriptor, DescriptorPublicKey, DescriptorTrait};
 
         use $crate::testutils::TranslateDescriptor;
 
         let secp = Secp256k1::new();
 
         let parsed = Descriptor::<DescriptorPublicKey>::parse_descriptor(&secp, &$descriptors.1.expect("Missing internal descriptor")).expect("Failed to parse descriptor in `testutils!(@internal)`").0;
-        parsed.derive_translated(&secp, $child).address(bitcoin::Network::Regtest).expect("No address form")
+        parsed.derive_translated(&secp, $child).address($crate::bitcoin::Network::Regtest).expect("No address form")
     });
     ( @e $descriptors:expr, $child:expr ) => ({ testutils!(@external $descriptors, $child) });
     ( @i $descriptors:expr, $child:expr ) => ({ testutils!(@internal $descriptors, $child) });
@@ -145,8 +145,8 @@ macro_rules! testutils {
         let mut seed = [0u8; 32];
         rand::thread_rng().fill(&mut seed[..]);
 
-        let key = bitcoin::util::bip32::ExtendedPrivKey::new_master(
-            bitcoin::Network::Testnet,
+        let key = $crate::bitcoin::util::bip32::ExtendedPrivKey::new_master(
+            $crate::bitcoin::Network::Testnet,
             &seed,
         );
 
@@ -158,13 +158,13 @@ macro_rules! testutils {
     ( @generate_wif ) => ({
         use rand::Rng;
 
-        let mut key = [0u8; bitcoin::secp256k1::constants::SECRET_KEY_SIZE];
+        let mut key = [0u8; $crate::bitcoin::secp256k1::constants::SECRET_KEY_SIZE];
         rand::thread_rng().fill(&mut key[..]);
 
-        (bitcoin::PrivateKey {
+        ($crate::bitcoin::PrivateKey {
             compressed: true,
-            network: bitcoin::Network::Testnet,
-            key: bitcoin::secp256k1::SecretKey::from_slice(&key).unwrap(),
+            network: $crate::bitcoin::Network::Testnet,
+            key: $crate::bitcoin::secp256k1::SecretKey::from_slice(&key).unwrap(),
         }.to_string(), None::<String>, None::<String>)
     });
 
@@ -181,8 +181,8 @@ macro_rules! testutils {
     ( @descriptors ( $external_descriptor:expr ) $( ( $internal_descriptor:expr ) )? $( ( @keys $( $keys:tt )* ) )* ) => ({
         use std::str::FromStr;
         use std::collections::HashMap;
-        use miniscript::descriptor::Descriptor;
-        use miniscript::TranslatePk;
+        use $crate::miniscript::descriptor::Descriptor;
+        use $crate::miniscript::TranslatePk;
 
         #[allow(unused_assignments, unused_mut)]
         let mut keys: HashMap<&'static str, (String, Option<String>, Option<String>)> = HashMap::new();

src/types.rs

@@ -210,7 +210,7 @@ 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
@@ -222,20 +222,26 @@ pub struct TransactionDetails {
     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

@@ -115,8 +115,8 @@ mod test {
     use std::sync::Arc;
 
     use super::*;
-    use crate::wallet::test::{get_funded_wallet, get_test_wpkh};
     use crate::wallet::AddressIndex::New;
+    use crate::wallet::{get_funded_wallet, test::get_test_wpkh};
 
     #[derive(Debug)]
     struct TestValidator;

src/wallet/export.rs

@@ -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,
             }),

src/wallet/mod.rs

@@ -18,6 +18,7 @@ use std::collections::HashMap;
 use std::collections::{BTreeMap, HashSet};
 use std::fmt;
 use std::ops::{Deref, DerefMut};
+use std::str::FromStr;
 use std::sync::Arc;
 
 use bitcoin::secp256k1::Secp256k1;
@@ -55,7 +56,8 @@ use tx_builder::{BumpFee, CreateTx, FeePolicy, TxBuilder, TxParams};
 use utils::{check_nlocktime, check_nsequence_rbf, After, Older, SecpCtx, DUST_LIMIT_SATOSHI};
 
 use crate::blockchain::{Blockchain, Progress};
-use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils};
+use crate::database::memory::MemoryDatabase;
+use crate::database::{BatchDatabase, BatchOperations, DatabaseUtils, SyncTime};
 use crate::descriptor::derived::AsDerived;
 use crate::descriptor::policy::BuildSatisfaction;
 use crate::descriptor::{
@@ -66,6 +68,7 @@ use crate::descriptor::{
 use crate::error::Error;
 use crate::psbt::PsbtUtils;
 use crate::signer::SignerError;
+use crate::testutils;
 use crate::types::*;
 
 const CACHE_ADDR_BATCH_SIZE: u32 = 100;
@@ -167,6 +170,11 @@ where
             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
@@ -315,7 +323,7 @@ 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()
@@ -327,6 +335,21 @@ 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
@@ -578,7 +601,7 @@ 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.is_provably_unspendable() {
                 return Err(Error::OutputBelowDustLimit(index));
             }
 
@@ -1424,6 +1447,11 @@ where
 
         Ok(())
     }
+
+    /// Return an immutable reference to the internal database
+    pub fn database(&self) -> impl std::ops::Deref<Target = D> + '_ {
+        self.database.borrow()
+    }
 }
 
 impl<B, D> Wallet<B, D>
@@ -1526,6 +1554,15 @@ where
             }
         }
 
+        let sync_time = SyncTime {
+            block_time: BlockTime {
+                height: maybe_await!(self.client.get_height())?,
+                timestamp: time::get_timestamp(),
+            },
+        };
+        debug!("Saving `sync_time` = {:?}", sync_time);
+        self.database.borrow_mut().set_sync_time(sync_time)?;
+
         Ok(())
     }
 
@@ -1534,33 +1571,69 @@ where
         &self.client
     }
 
-    /// Get the Bitcoin network the wallet is using.
-    pub fn network(&self) -> Network {
-        self.network
-    }
-
     /// Broadcast a transaction to the network
     #[maybe_async]
-    pub fn broadcast(&self, tx: Transaction) -> Result<Txid, Error> {
-        maybe_await!(self.client.broadcast(&tx))?;
+    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>,
+    (String, Option<String>),
+    bitcoin::Txid,
+) {
+    let descriptors = testutils!(@descriptors (descriptor));
+    let wallet = Wallet::new_offline(
+        &descriptors.0,
+        None,
+        Network::Regtest,
+        MemoryDatabase::new(),
+    )
+    .unwrap();
+
+    let funding_address_kix = 0;
+
+    let tx_meta = testutils! {
+            @tx ( (@external descriptors, funding_address_kix) => 50_000 ) (@confirmations 1)
+    };
+
+    wallet
+        .database
+        .borrow_mut()
+        .set_script_pubkey(
+            &bitcoin::Address::from_str(&tx_meta.output.get(0).unwrap().to_address)
+                .unwrap()
+                .script_pubkey(),
+            KeychainKind::External,
+            funding_address_kix,
+        )
+        .unwrap();
+    wallet
+        .database
+        .borrow_mut()
+        .set_last_index(KeychainKind::External, funding_address_kix)
+        .unwrap();
+
+    let txid = crate::populate_test_db!(wallet.database.borrow_mut(), tx_meta, Some(100));
+
+    (wallet, descriptors, txid)
+}
+
 #[cfg(test)]
 pub(crate) mod test {
-    use std::str::FromStr;
-
     use bitcoin::{util::psbt, Network};
 
-    use crate::database::memory::MemoryDatabase;
     use crate::database::Database;
     use crate::types::KeychainKind;
 
     use super::*;
     use crate::signer::{SignOptions, SignerError};
-    use crate::testutils;
     use crate::wallet::AddressIndex::{LastUnused, New, Peek, Reset};
 
     #[test]
@@ -1672,50 +1745,6 @@ pub(crate) mod test {
         "wsh(and_v(v:pk(cVpPVruEDdmutPzisEsYvtST1usBR3ntr8pXSyt6D2YYqXRyPcFW),after(100000)))"
     }
 
-    pub(crate) fn get_funded_wallet(
-        descriptor: &str,
-    ) -> (
-        Wallet<(), MemoryDatabase>,
-        (String, Option<String>),
-        bitcoin::Txid,
-    ) {
-        let descriptors = testutils!(@descriptors (descriptor));
-        let wallet = Wallet::new_offline(
-            &descriptors.0,
-            None,
-            Network::Regtest,
-            MemoryDatabase::new(),
-        )
-        .unwrap();
-
-        let funding_address_kix = 0;
-
-        let tx_meta = testutils! {
-                @tx ( (@external descriptors, funding_address_kix) => 50_000 ) (@confirmations 1)
-        };
-
-        wallet
-            .database
-            .borrow_mut()
-            .set_script_pubkey(
-                &bitcoin::Address::from_str(&tx_meta.output.get(0).unwrap().to_address)
-                    .unwrap()
-                    .script_pubkey(),
-                KeychainKind::External,
-                funding_address_kix,
-            )
-            .unwrap();
-        wallet
-            .database
-            .borrow_mut()
-            .set_last_index(KeychainKind::External, funding_address_kix)
-            .unwrap();
-
-        let txid = crate::populate_test_db!(wallet.database.borrow_mut(), tx_meta, Some(100));
-
-        (wallet, descriptors, txid)
-    }
-
     macro_rules! assert_fee_rate {
         ($tx:expr, $fees:expr, $fee_rate:expr $( ,@dust_change $( $dust_change:expr )* )* $( ,@add_signature $( $add_signature:expr )* )* ) => ({
             let mut tx = $tx.clone();
@@ -2763,7 +2792,7 @@ 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,
         });
@@ -3965,4 +3994,44 @@ 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/tx_builder.rs

@@ -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

src/wallet/utils.rs

@@ -138,40 +138,6 @@ 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::{