feat(bdk-persist): extract persistence traits to new crate

crates/file_store/Cargo.toml

@@ -13,6 +13,7 @@ readme = "README.md"
 [dependencies]
 anyhow = { version = "1", default-features = false }
 bdk_chain = { path = "../chain", version = "0.12.0", features = [ "serde", "miniscript" ] }
+bdk_persist = { path = "../persist", version = "0.1.0"}
 bincode = { version = "1" }
 serde = { version = "1", features = ["derive"] }
 

crates/file_store/README.md

@@ -1,10 +1,10 @@
 # BDK File Store
 
 This is a simple append-only flat file implementation of
-[`Persist`](`bdk_chain::Persist`).
+[`PersistBackend`](bdk_persist::PersistBackend).
 
-The main structure is [`Store`](`crate::Store`), which can be used with [`bdk`]'s
+The main structure is [`Store`](crate::Store), which can be used with [`bdk`]'s
 `Wallet` to persist wallet data into a flat file.
 
 [`bdk`]: https://docs.rs/bdk/latest
-[`bdk_chain`]: https://docs.rs/bdk_chain/latest
+[`bdk_persist`]: https://docs.rs/bdk_persist/latest

crates/file_store/src/store.rs

@@ -1,6 +1,7 @@
 use crate::{bincode_options, EntryIter, FileError, IterError};
 use anyhow::anyhow;
-use bdk_chain::{Append, PersistBackend};
+use bdk_chain::Append;
+use bdk_persist::PersistBackend;
 use bincode::Options;
 use std::{
     fmt::{self, Debug},
@@ -11,8 +12,6 @@ use std::{
 };
 
 /// Persists an append-only list of changesets (`C`) to a single file.
-///
-/// The changesets are the results of altering a tracker implementation (`T`).
 #[derive(Debug)]
 pub struct Store<C>
 where
@@ -152,7 +151,7 @@ where
     ///
     /// You should usually check the error. In many applications, it may make sense to do a full
     /// wallet scan with a stop-gap after getting an error, since it is likely that one of the
-    /// changesets it was unable to read changed the derivation indices of the tracker.
+    /// changesets was unable to read changes of the derivation indices of a keychain.
     ///
     /// **WARNING**: This method changes the write position of the underlying file. The next
     /// changeset will be written over the erroring entry (or the end of the file if none existed).
@@ -240,9 +239,6 @@ mod test {
 
     type TestChangeSet = BTreeSet<String>;
 
-    #[derive(Debug)]
-    struct TestTracker;
-
     /// Check behavior of [`Store::create_new`] and [`Store::open`].
     #[test]
     fn construct_store() {