zcash_client_backend: Add Orchard note commitment tree size to block …

…metadata.

zcash_client_backend/CHANGELOG.md

@@ -9,8 +9,11 @@ and this library adheres to Rust's notion of
 
 ### Added
 - `zcash_client_backend::data_api`:
+  - `BlockMetadata::orchard_tree_size`.
   - `TransparentInputSource`
   - `SaplingInputSource`
+  - `ScannedBlock::sapling_tree_size`.
+  - `ScannedBlock::orchard_tree_size`.
   - `wallet::propose_standard_transfer_to_address`
   - `wallet::input_selection::SaplingInputs`
   - `wallet::input_selection::ShieldingSelector` has been
@@ -33,6 +36,8 @@ and this library adheres to Rust's notion of
       backend-specific note identifier. The related `NoteRef` type parameter has
       been removed from `error::Error`.
     - A new variant `UnsupportedPoolType` has been added.
+  - `ScannedBlock::metadata` has been renamed to `to_block_metadata` and now
+    returns an owned value rather than a reference.
   - `wallet::shield_transparent_funds` no longer
     takes a `memo` argument; instead, memos to be associated with the shielded
     outputs should be specified in the construction of the value of the

zcash_client_backend/src/data_api.rs

@@ -409,21 +409,23 @@ pub trait WalletRead {
 pub struct BlockMetadata {
     block_height: BlockHeight,
     block_hash: BlockHash,
-    sapling_tree_size: u32,
-    //TODO: orchard_tree_size: u32
+    sapling_tree_size: Option<u32>,
+    orchard_tree_size: Option<u32>,
 }
 
 impl BlockMetadata {
     /// Constructs a new [`BlockMetadata`] value from its constituent parts.
     pub fn from_parts(
         block_height: BlockHeight,
         block_hash: BlockHash,
-        sapling_tree_size: u32,
+        sapling_tree_size: Option<u32>,
+        orchard_tree_size: Option<u32>,
     ) -> Self {
         Self {
             block_height,
             block_hash,
             sapling_tree_size,
+            orchard_tree_size,
         }
     }
 
@@ -437,20 +439,29 @@ impl BlockMetadata {
         self.block_hash
     }
 
-    /// Returns the size of the Sapling note commitment tree as of the block that this
+    /// Returns the size of the Sapling note commitment tree as of the end of the block that this
     /// [`BlockMetadata`] describes.
-    pub fn sapling_tree_size(&self) -> u32 {
+    pub fn sapling_tree_size(&self) -> Option<u32> {
         self.sapling_tree_size
     }
+
+    /// Returns the size of the Orchard note commitment tree as of the end of the block that this
+    /// [`BlockMetadata`] describes.
+    pub fn orchard_tree_size(&self) -> Option<u32> {
+        self.orchard_tree_size
+    }
 }
 
 /// The subset of information that is relevant to this wallet that has been
 /// decrypted and extracted from a [`CompactBlock`].
 ///
 /// [`CompactBlock`]: crate::proto::compact_formats::CompactBlock
 pub struct ScannedBlock<Nf> {
-    metadata: BlockMetadata,
+    block_height: BlockHeight,
+    block_hash: BlockHash,
     block_time: u32,
+    sapling_tree_size: u32,
+    orchard_tree_size: u32,
     transactions: Vec<WalletTx<Nf>>,
     sapling_nullifier_map: Vec<(TxId, u16, Vec<sapling::Nullifier>)>,
     sapling_commitments: Vec<(sapling::Node, Retention<BlockHeight>)>,
@@ -459,15 +470,21 @@ pub struct ScannedBlock<Nf> {
 impl<Nf> ScannedBlock<Nf> {
     /// Constructs a new `ScannedBlock`
     pub fn from_parts(
-        metadata: BlockMetadata,
+        block_height: BlockHeight,
+        block_hash: BlockHash,
         block_time: u32,
+        sapling_tree_size: u32,
+        orchard_tree_size: u32,
         transactions: Vec<WalletTx<Nf>>,
         sapling_nullifier_map: Vec<(TxId, u16, Vec<sapling::Nullifier>)>,
         sapling_commitments: Vec<(sapling::Node, Retention<BlockHeight>)>,
     ) -> Self {
         Self {
-            metadata,
+            block_height,
+            block_hash,
             block_time,
+            sapling_tree_size,
+            orchard_tree_size,
             transactions,
             sapling_nullifier_map,
             sapling_commitments,
@@ -476,26 +493,27 @@ impl<Nf> ScannedBlock<Nf> {
 
     /// Returns the height of the block that was scanned.
     pub fn height(&self) -> BlockHeight {
-        self.metadata.block_height
+        self.block_height
     }
 
     /// Returns the block hash of the block that was scanned.
     pub fn block_hash(&self) -> BlockHash {
-        self.metadata.block_hash
+        self.block_hash
     }
 
     /// Returns the block time of the block that was scanned, as a Unix timestamp in seconds.
     pub fn block_time(&self) -> u32 {
         self.block_time
     }
 
-    /// Returns the metadata describing the state of the note commitment trees as of the end of the
-    /// scanned block.
-    ///
-    /// The metadata returned from this method is guaranteed to be consistent with what is returned
-    /// by [`Self::height`] and [`Self::block_hash`].
-    pub fn metadata(&self) -> &BlockMetadata {
-        &self.metadata
+    /// Returns the size of the Sapling note commitment tree as of the end of the scanned block.
+    pub fn sapling_tree_size(&self) -> u32 {
+        self.sapling_tree_size
+    }
+
+    /// Returns the size of the Orchard note commitment tree as of the end of the scanned block.
+    pub fn orchard_tree_size(&self) -> u32 {
+        self.orchard_tree_size
     }
 
     /// Returns the list of transactions from the block that are relevant to the wallet.
@@ -524,6 +542,16 @@ impl<Nf> ScannedBlock<Nf> {
     pub fn into_sapling_commitments(self) -> Vec<(sapling::Node, Retention<BlockHeight>)> {
         self.sapling_commitments
     }
+
+    /// Returns the [`BlockMetadata`] corresponding to the scanned block.
+    pub fn to_block_metadata(&self) -> BlockMetadata {
+        BlockMetadata {
+            block_height: self.block_height,
+            block_hash: self.block_hash,
+            sapling_tree_size: Some(self.sapling_tree_size),
+            orchard_tree_size: Some(self.orchard_tree_size),
+        }
+    }
 }
 
 /// A transaction that was detected during scanning of the blockchain,

zcash_client_backend/src/data_api/chain.rs

@@ -345,23 +345,37 @@ where
                 continuity_check_metadata = Some(BlockMetadata::from_parts(
                     BlockHeight::from(0),
                     BlockHash([0; 32]),
-                    0,
+                    Some(0),
+                    Some(0),
                 ));
             }
-            continuity_check_metadata = continuity_check_metadata.as_ref().map(|m| {
+            continuity_check_metadata = continuity_check_metadata.as_ref().map(|bm| {
                 BlockMetadata::from_parts(
                     block.height(),
                     block.hash(),
                     block
                         .chain_metadata
                         .as_ref()
-                        .map(|m| m.sapling_commitment_tree_size)
-                        .unwrap_or_else(|| {
-                            m.sapling_tree_size()
-                                + u32::try_from(
+                        .map(|bcm| bcm.sapling_commitment_tree_size)
+                        .or_else(|| {
+                            bm.sapling_tree_size().map(|s| {
+                                s + u32::try_from(
                                     block.vtx.iter().map(|tx| tx.outputs.len()).sum::<usize>(),
                                 )
                                 .unwrap()
+                            })
+                        }),
+                    block
+                        .chain_metadata
+                        .as_ref()
+                        .map(|bcm| bcm.orchard_commitment_tree_size)
+                        .or_else(|| {
+                            bm.orchard_tree_size().map(|s| {
+                                s + u32::try_from(
+                                    block.vtx.iter().map(|tx| tx.actions.len()).sum::<usize>(),
+                                )
+                                .unwrap()
+                            })
                         }),
                 )
             });
@@ -415,7 +429,7 @@ where
                     .map(|out| (out.account(), *out.nf()))
             }));
 
-            prior_block_metadata = Some(*scanned_block.metadata());
+            prior_block_metadata = Some(scanned_block.to_block_metadata());
             scanned_blocks.push(scanned_block);
 
             Ok(())