added generic wallet errors for error handling

zcash_client_backend/src/data_api/chain.rs

@@ -213,26 +213,41 @@ pub trait BlockSource {
         with_block: F,
     ) -> Result<(), error::Error<WalletErrT, Self::Error>>
     where
-        F: FnMut(CompactBlock) -> Result<(), error::Error<WalletErrT, Self::Error>>;
+        F: FnMut(
+            CompactBlock,
+        )
+            -> Result<(), error::Error<WalletErrT, error::Error<WalletErrT, Self::Error>>>;
 }
 
 pub trait BlockCache: BlockSource {
     /// Returns a range of compact blocks from the cache.
-    fn read(&self, range: &ScanRange) -> Result<Vec<CompactBlock>, Self::Error>;
+    fn read<WalletErrT>(
+        &self,
+        range: &ScanRange,
+    ) -> Result<Vec<CompactBlock>, error::Error<WalletErrT, Self::Error>>;
 
     /// Returns the height of highest block known to the block cache, within a specified range.
     /// If `range` is `None`, returns the tip of the entire cache.
-    fn cache_tip(&self, range: Option<&ScanRange>) -> Result<Option<BlockHeight>, Self::Error>;
+    fn cache_tip<WalletErrT>(
+        &self,
+        range: Option<&ScanRange>,
+    ) -> Result<Option<BlockHeight>, error::Error<WalletErrT, Self::Error>>;
 
     /// Inserts a set of compact blocks into the block cache.
     /// Returns a `JoinHandle` for async implementations.
     fn insert(&self, compact_blocks: Vec<CompactBlock>) -> JoinHandle<()>;
 
     /// Removes all cached blocks above a specified block height.
-    fn truncate(&self, block_height: BlockHeight) -> Result<(), Self::Error>;
+    fn truncate<WalletErrT>(
+        &self,
+        block_height: BlockHeight,
+    ) -> Result<(), error::Error<WalletErrT, Self::Error>>;
 
     /// Mark a range of blocks as scanned for cache removal.
-    fn mark_as_scanned(&self, range: &ScanRange) -> Result<(), Self::Error>;
+    fn mark_as_scanned<WalletErrT>(
+        &self,
+        range: &ScanRange,
+    ) -> Result<(), error::Error<WalletErrT, Self::Error>>;
 
     /// Deletes all blocks marked as scanned from the block cache.
     /// Returns a `JoinHandle` for async implementations.