state: insert into nullifier trees

zebra-chain/src/sapling/note/nullifiers.rs

@@ -31,7 +31,7 @@ fn prf_nf(nk: [u8; 32], rho: [u8; 32]) -> [u8; 32] {
     any(test, feature = "proptest-impl"),
     derive(proptest_derive::Arbitrary)
 )]
-pub struct Nullifier([u8; 32]);
+pub struct Nullifier(pub [u8; 32]);
 
 impl From<[u8; 32]> for Nullifier {
     fn from(buf: [u8; 32]) -> Self {

zebra-chain/src/sprout/note/nullifiers.rs

@@ -67,7 +67,7 @@ impl From<NullifierSeed> for [u8; 32] {
     any(test, feature = "proptest-impl"),
     derive(proptest_derive::Arbitrary)
 )]
-pub struct Nullifier(pub(crate) [u8; 32]);
+pub struct Nullifier(pub [u8; 32]);
 
 impl From<[u8; 32]> for Nullifier {
     fn from(bytes: [u8; 32]) -> Self {

zebra-chain/src/transaction.rs

@@ -27,7 +27,7 @@ use crate::{
     block,
     parameters::NetworkUpgrade,
     primitives::{Bctv14Proof, Groth16Proof},
-    transparent,
+    sapling, sprout, transparent,
 };
 
 /// A Zcash transaction.
@@ -147,6 +147,53 @@ impl Transaction {
         }
     }
 
+    /// Access the sprout::Nullifiers in this transaction, regardless of version.
+    pub fn sprout_nullifiers(&self) -> Box<dyn Iterator<Item = &sprout::Nullifier> + '_> {
+        // This function returns a boxed iterator because the different
+        // transaction variants end up having different iterator types
+        match self {
+            // JoinSplits with Bctv14 Proofs
+            Transaction::V2 {
+                joinsplit_data: Some(joinsplit_data),
+                ..
+            }
+            | Transaction::V3 {
+                joinsplit_data: Some(joinsplit_data),
+                ..
+            } => Box::new(
+                joinsplit_data
+                    .joinsplits()
+                    .flat_map(|joinsplit| joinsplit.nullifiers.iter()),
+            ),
+            // JoinSplits with Groth Proofs
+            Transaction::V4 {
+                joinsplit_data: Some(joinsplit_data),
+                ..
+            } => Box::new(
+                joinsplit_data
+                    .joinsplits()
+                    .flat_map(|joinsplit| joinsplit.nullifiers.iter()),
+            ),
+            // No JoinSplits
+            _ => Box::new(std::iter::empty()),
+        }
+    }
+
+    /// Access the sapling::Nullifiers in this transaction, regardless of version.
+    pub fn sapling_nullifiers(&self) -> Box<dyn Iterator<Item = &sapling::Nullifier> + '_> {
+        // This function returns a boxed iterator because the different
+        // transaction variants end up having different iterator types
+        match self {
+            // JoinSplits with Groth Proofs
+            Transaction::V4 {
+                shielded_data: Some(shielded_data),
+                ..
+            } => Box::new(shielded_data.nullifiers()),
+            // No JoinSplits
+            _ => Box::new(std::iter::empty()),
+        }
+    }
+
     /// Returns `true` if transaction contains any coinbase inputs.
     pub fn contains_coinbase_input(&self) -> bool {
         self.inputs()

zebra-chain/src/transaction/shielded_data.rs

@@ -65,13 +65,13 @@ impl ShieldedData {
 
     /// Collect the [`Nullifier`]s for this transaction, if it contains
     /// [`Spend`]s.
-    pub fn nullifiers(&self) -> Vec<Nullifier> {
-        self.spends().map(|spend| spend.nullifier).collect()
+    pub fn nullifiers(&self) -> impl Iterator<Item = &Nullifier> {
+        self.spends().map(|spend| &spend.nullifier)
     }
 
     /// Collect the cm_u's for this transaction, if it contains [`Output`]s.
-    pub fn note_commitments(&self) -> Vec<jubjub::Fq> {
-        self.outputs().map(|output| output.cm_u).collect()
+    pub fn note_commitments(&self) -> impl Iterator<Item = &jubjub::Fq> {
+        self.outputs().map(|output| &output.cm_u)
     }
 
     /// Calculate the Spend/Output binding verification key.

zebra-state/src/sled_state.rs

@@ -41,8 +41,8 @@ pub struct FinalizedState {
     block_by_height: sled::Tree,
     tx_by_hash: sled::Tree,
     utxo_by_outpoint: sled::Tree,
-    // sprout_nullifiers: sled::Tree,
-    // sapling_nullifiers: sled::Tree,
+    sprout_nullifiers: sled::Tree,
+    sapling_nullifiers: sled::Tree,
     // sprout_anchors: sled::Tree,
     // sapling_anchors: sled::Tree,
     /// Commit blocks to the finalized state up to this height, then exit Zebra.
@@ -69,8 +69,8 @@ impl FinalizedState {
             block_by_height: db.open_tree(b"block_by_height").unwrap(),
             tx_by_hash: db.open_tree(b"tx_by_hash").unwrap(),
             utxo_by_outpoint: db.open_tree(b"utxo_by_outpoint").unwrap(),
-            // sprout_nullifiers: db.open_tree(b"sprout_nullifiers").unwrap(),
-            // sapling_nullifiers: db.open_tree(b"sapling_nullifiers").unwrap(),
+            sprout_nullifiers: db.open_tree(b"sprout_nullifiers").unwrap(),
+            sapling_nullifiers: db.open_tree(b"sapling_nullifiers").unwrap(),
             debug_stop_at_height: config.debug_stop_at_height.map(block::Height),
         };
 
@@ -97,8 +97,8 @@ impl FinalizedState {
         total_flushed += self.block_by_height.flush()?;
         total_flushed += self.tx_by_hash.flush()?;
         total_flushed += self.utxo_by_outpoint.flush()?;
-        // total_flushed += self.sprout_nullifiers.flush()?;
-        // total_flushed += self.sapling_nullifiers.flush()?;
+        total_flushed += self.sprout_nullifiers.flush()?;
+        total_flushed += self.sapling_nullifiers.flush()?;
 
         Ok(total_flushed)
     }
@@ -221,6 +221,8 @@ impl FinalizedState {
             &self.block_by_height,
             &self.utxo_by_outpoint,
             &self.tx_by_hash,
+            &self.sprout_nullifiers,
+            &self.sapling_nullifiers,
         )
             .transaction(
                 move |(
@@ -229,6 +231,8 @@ impl FinalizedState {
                     block_by_height,
                     utxo_by_outpoint,
                     tx_by_hash,
+                    sprout_nullifiers,
+                    sapling_nullifiers,
                 )| {
                     // TODO: check highest entry of hash_by_height as in RFC
 
@@ -248,9 +252,14 @@ impl FinalizedState {
 
                             utxo_by_outpoint.zs_insert(outpoint, output)?;
                         }
+
+                        for sprout_nullifier in transaction.sprout_nullifiers() {
+                            sprout_nullifiers.zs_insert(sprout_nullifier, ())?;
+                        }
+                        for sapling_nullifier in transaction.sapling_nullifiers() {
+                            sapling_nullifiers.zs_insert(sapling_nullifier, ())?;
+                        }
                     }
-                    // sprout_nullifiers
-                    // sapling_nullifiers
 
                     // for some reason type inference fails here
                     Ok::<_, sled::transaction::ConflictableTransactionError>(hash)

zebra-state/src/sled_state/sled_format.rs

@@ -4,8 +4,9 @@ use std::{convert::TryInto, sync::Arc};
 use zebra_chain::{
     block,
     block::Block,
+    sapling,
     serialization::{ZcashDeserialize, ZcashSerialize},
-    transaction,
+    sprout, transaction,
     transaction::Transaction,
     transparent,
 };
@@ -89,6 +90,42 @@ impl IntoSled for block::Hash {
     }
 }
 
+impl IntoSled for &sprout::Nullifier {
+    type Bytes = [u8; 32];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        self.0
+    }
+
+    fn into_ivec(self) -> sled::IVec {
+        self.as_bytes().as_ref().into()
+    }
+}
+
+impl IntoSled for &sapling::Nullifier {
+    type Bytes = [u8; 32];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        self.0
+    }
+
+    fn into_ivec(self) -> sled::IVec {
+        self.as_bytes().as_ref().into()
+    }
+}
+
+impl IntoSled for () {
+    type Bytes = [u8; 0];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        []
+    }
+
+    fn into_ivec(self) -> sled::IVec {
+        sled::IVec::default()
+    }
+}
+
 impl FromSled for block::Hash {
     fn from_ivec(bytes: sled::IVec) -> Result<Self, BoxError> {
         let array = bytes.as_ref().try_into().unwrap();