Fix errors; remove HistoryTree usage

zebra-chain/src/orchard/tree.rs

@@ -111,6 +111,12 @@ impl From<Root> for [u8; 32] {
     }
 }
 
+impl From<&Root> for [u8; 32] {
+    fn from(root: &Root) -> Self {
+        (*root).into()
+    }
+}
+
 impl Hash for Root {
     fn hash<H: Hasher>(&self, state: &mut H) {
         self.0.to_bytes().hash(state)

zebra-chain/src/sprout/tree.rs

@@ -104,10 +104,22 @@ impl From<Root> for [u8; 32] {
     }
 }
 
+impl From<&[u8; 32]> for Root {
+    fn from(bytes: &[u8; 32]) -> Root {
+        (*bytes).into()
+    }
+}
+
+impl From<&Root> for [u8; 32] {
+    fn from(root: &Root) -> Self {
+        (*root).into()
+    }
+}
+
 /// Sprout Note Commitment Tree
 #[derive(Clone, Debug, Default, Eq, PartialEq)]
 #[cfg_attr(any(test, feature = "proptest-impl"), derive(Arbitrary))]
-struct NoteCommitmentTree {
+pub struct NoteCommitmentTree {
     /// The root node of the tree (often used as an anchor).
     root: Root,
     /// The height of the tree (maximum height for Sprout is 29).
@@ -164,8 +176,13 @@ impl From<Vec<NoteCommitment>> for NoteCommitmentTree {
 impl NoteCommitmentTree {
     /// Get the Jubjub-based Pedersen hash of root node of this merkle tree of
     /// commitment notes.
-    pub fn hash(&self) -> [u8; 32] {
-        self.root.0
+    pub fn hash(&self) -> Root {
+        self.root
+    }
+
+    /// Add a note commitment to the tree.
+    pub fn append(&self, _cm: &NoteCommitment) {
+        // TODO
     }
 }
 
@@ -277,7 +294,7 @@ mod tests {
 
             let tree = NoteCommitmentTree::from(leaves.clone());
 
-            assert_eq!(hex::encode(tree.hash()), roots[i]);
+            assert_eq!(hex::encode(<[u8; 32]>::from(tree.hash())), roots[i]);
         }
     }
 }

zebra-state/src/service.rs

@@ -726,6 +726,9 @@ impl Service<Request> for StateService {
                     .collect();
                 async move { Ok(Response::BlockHeaders(res)) }.boxed()
             }
+            Request::AwaitSproutAnchor(_) => todo!(),
+            Request::AwaitSaplingAnchor(_) => todo!(),
+            Request::AwaitOrchardAnchor(_) => todo!(),
         }
     }
 }

zebra-state/src/service/non_finalized_state/chain.rs

@@ -13,7 +13,7 @@ use zebra_chain::{
 
 use crate::{service::check, PreparedBlock, ValidateContextError};
 
-#[derive(Debug, Default, Clone)]
+#[derive(Debug, Clone, Default)]
 pub struct Chain {
     pub blocks: BTreeMap<block::Height, PreparedBlock>,
     pub height_by_hash: HashMap<block::Hash, block::Height>,
@@ -26,8 +26,6 @@ pub struct Chain {
     sapling_note_commitment_tree: sapling::tree::NoteCommitmentTree,
     orchard_note_commitment_tree: orchard::tree::NoteCommitmentTree,
 
-    pub(crate) history_tree: HistoryTree,
-
     pub(super) sprout_anchors: HashSet<sprout::tree::Root>,
     pub(super) sapling_anchors: HashSet<sapling::tree::Root>,
     pub(super) orchard_anchors: HashSet<orchard::tree::Root>,
@@ -40,30 +38,6 @@ pub struct Chain {
 }
 
 impl Chain {
-    /// Is the internal state of `self` the same as `other`?
-    ///
-    /// The history tree must contain the history of the previous (finalized) blocks.
-    pub fn new(history_tree: HistoryTree) -> Self {
-        Chain {
-            blocks: Default::default(),
-            height_by_hash: Default::default(),
-            tx_by_hash: Default::default(),
-            created_utxos: Default::default(),
-            spent_utxos: Default::default(),
-            sprout_note_commitment_tree: Default::default(),
-            sapling_note_commitment_tree: Default::default(),
-            orchard_note_commitment_tree: Default::default(),
-            sprout_anchors: Default::default(),
-            sapling_anchors: Default::default(),
-            orchard_anchors: Default::default(),
-            sprout_nullifiers: Default::default(),
-            sapling_nullifiers: Default::default(),
-            orchard_nullifiers: Default::default(),
-            partial_cumulative_work: Default::default(),
-            history_tree,
-        }
-    }
-
     /// Is the internal state of `self` the same as `other`?
     ///
     /// [`Chain`] has custom [`Eq`] and [`Ord`] implementations based on proof of work,
@@ -152,20 +126,6 @@ impl Chain {
             forked.pop_tip();
         }
 
-        // Rebuild the history tree starting from the finalized tip tree.
-        // TODO: change to a more efficient approach by removing nodes
-        // from the tree of the original chain (in `pop_tip()`).
-        // See https://github.com/ZcashFoundation/zebra/issues/2378
-        forked
-            .history_tree
-            .try_extend(forked.blocks.values().map(|prepared_block| {
-                (
-                    prepared_block.block.clone(),
-                    &forked.sapling_note_commitment_tree.root(),
-                    Some(&forked.orchard_note_commitment_tree.root()),
-                )
-            }))?;
-
         Ok(Some(forked))
     }
 
@@ -205,35 +165,6 @@ impl Chain {
     pub fn is_empty(&self) -> bool {
         self.blocks.is_empty()
     }
-
-    pub fn history_root_hash(&self) -> ChainHistoryMmrRootHash {
-        self.history_tree.hash()
-    }
-
-    /// Clone the Chain but not the history tree, using the history tree
-    /// specified instead.
-    ///
-    /// Useful when forking, where the history tree is rebuilt anyway.
-    fn with_history_tree(&self, history_tree: HistoryTree) -> Self {
-        Chain {
-            blocks: self.blocks.clone(),
-            height_by_hash: self.height_by_hash.clone(),
-            tx_by_hash: self.tx_by_hash.clone(),
-            created_utxos: self.created_utxos.clone(),
-            spent_utxos: self.spent_utxos.clone(),
-            sprout_note_commitment_tree: self.sprout_note_commitment_tree.clone(),
-            sapling_note_commitment_tree: self.sapling_note_commitment_tree.clone(),
-            orchard_note_commitment_tree: self.orchard_note_commitment_tree.clone(),
-            sprout_anchors: self.sprout_anchors.clone(),
-            sapling_anchors: self.sapling_anchors.clone(),
-            orchard_anchors: self.orchard_anchors.clone(),
-            sprout_nullifiers: self.sprout_nullifiers.clone(),
-            sapling_nullifiers: self.sapling_nullifiers.clone(),
-            orchard_nullifiers: self.orchard_nullifiers.clone(),
-            partial_cumulative_work: self.partial_cumulative_work,
-            history_tree,
-        }
-    }
 }
 
 /// Helper trait to organize inverse operations done on the `Chain` type. Used to
@@ -341,17 +272,13 @@ impl UpdateWith<PreparedBlock> for Chain {
         // Having updated all the note commitment trees and nullifier sets in
         // this block, the roots of the note commitment trees as of the last
         // transaction are the treestates of this block.
-        let sprout_root = self.sprout_note_commitment_tree.root();
+        let sprout_root = self.sprout_note_commitment_tree.hash();
         let sapling_root = self.sapling_note_commitment_tree.root();
         let orchard_root = self.orchard_note_commitment_tree.root();
 
-        self.sprout_anchors.insert(&sprout_root);
-        self.sapling_anchors.insert(&sapling_root);
-        self.orchard_anchors.insert(&orchard_root);
-
-        // TODO: pass Sapling and Orchard roots
-        self.history_tree
-            .push(prepared.block.clone(), &sapling_root, Some(&orchard_root))?;
+        self.sprout_anchors.insert(sprout_root);
+        self.sapling_anchors.insert(sapling_root);
+        self.orchard_anchors.insert(orchard_root);
 
         Ok(())
     }
@@ -530,7 +457,7 @@ where
     ) -> Result<(), ValidateContextError> {
         if let Some(sapling_shielded_data) = sapling_shielded_data {
             for cm_u in sapling_shielded_data.note_commitments() {
-                self.sapling_note_commitment_tree.append(cm_u);
+                self.sapling_note_commitment_tree.append(*cm_u);
             }
 
             for nullifier in sapling_shielded_data.nullifiers() {
@@ -564,7 +491,7 @@ impl UpdateWith<Option<orchard::ShieldedData>> for Chain {
     ) -> Result<(), ValidateContextError> {
         if let Some(orchard_shielded_data) = orchard_shielded_data {
             for cm_x in orchard_shielded_data.note_commitments() {
-                self.orchard_note_commitment_tree.append(cm_x);
+                self.orchard_note_commitment_tree.append(*cm_x);
             }
 
             // TODO: check orchard nullifiers are unique (#2231)