refactor(persist): update file_store, sqlite, wallet to use bdk_chain::persist

Also update examples and remove bdk_persist crate.

crates/file_store/Cargo.toml

@@ -5,15 +5,13 @@ edition = "2021"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/bitcoindevkit/bdk"
 documentation = "https://docs.rs/bdk_file_store"
-description = "A simple append-only flat file implementation of Persist for Bitcoin Dev Kit."
+description = "A simple append-only flat file implementation of PersistBackend for Bitcoin Dev Kit."
 keywords = ["bitcoin", "persist", "persistence", "bdk", "file"]
 authors = ["Bitcoin Dev Kit Developers"]
 readme = "README.md"
 
 [dependencies]
-anyhow = { version = "1", default-features = false }
 bdk_chain = { path = "../chain", version = "0.15.0", features = [ "serde", "miniscript" ] }
-bdk_persist = { path = "../persist", version = "0.3.0"}
 bincode = { version = "1" }
 serde = { version = "1", features = ["derive"] }
 

crates/file_store/README.md

@@ -1,6 +1,6 @@
 # BDK File Store
 
-This is a simple append-only flat file implementation of [`PersistBackend`](bdk_persist::PersistBackend).
+This is a simple append-only flat file implementation of [`PersistBackend`](bdk_chain::persist::PersistBackend).
 
 The main structure is [`Store`] which works with any [`bdk_chain`] based changesets to persist data into a flat file.
 

crates/file_store/src/store.rs

@@ -1,7 +1,6 @@
 use crate::{bincode_options, EntryIter, FileError, IterError};
-use anyhow::anyhow;
+use bdk_chain::persist::PersistBackend;
 use bdk_chain::Append;
-use bdk_persist::PersistBackend;
 use bincode::Options;
 use std::{
     fmt::{self, Debug},
@@ -25,19 +24,21 @@ where
 impl<C> PersistBackend<C> for Store<C>
 where
     C: Append
+        + Debug
         + serde::Serialize
         + serde::de::DeserializeOwned
         + core::marker::Send
         + core::marker::Sync,
 {
-    fn write_changes(&mut self, changeset: &C) -> anyhow::Result<()> {
+    type WriteError = io::Error;
+    type LoadError = AggregateChangesetsError<C>;
+
+    fn write_changes(&mut self, changeset: &C) -> Result<(), Self::WriteError> {
         self.append_changeset(changeset)
-            .map_err(|e| anyhow!(e).context("failed to write changes to persistence backend"))
     }
 
-    fn load_from_persistence(&mut self) -> anyhow::Result<Option<C>> {
+    fn load_changes(&mut self) -> Result<Option<C>, Self::LoadError> {
         self.aggregate_changesets()
-            .map_err(|e| anyhow!(e.iter_error).context("error loading from persistence backend"))
     }
 }