Make txid contents private & use txid for TzeOutPoint

zcash_client_backend/src/data_api.rs

@@ -412,14 +412,14 @@ pub mod testing {
             &mut self,
             _received_tx: &ReceivedTransaction,
         ) -> Result<Self::TxRef, Self::Error> {
-            Ok(TxId([0u8; 32]))
+            Ok(TxId::from_bytes([0u8; 32]))
         }
 
         fn store_sent_tx(
             &mut self,
             _sent_tx: &SentTransaction,
         ) -> Result<Self::TxRef, Self::Error> {
-            Ok(TxId([0u8; 32]))
+            Ok(TxId::from_bytes([0u8; 32]))
         }
 
         fn rewind_to_height(&mut self, _block_height: BlockHeight) -> Result<(), Self::Error> {

zcash_client_backend/src/proto.rs

@@ -8,7 +8,10 @@ use zcash_primitives::{
     block::{BlockHash, BlockHeader},
     consensus::BlockHeight,
     sapling::Nullifier,
-    transaction::components::sapling::{CompactOutputDescription, OutputDescription},
+    transaction::{
+        components::sapling::{CompactOutputDescription, OutputDescription},
+        TxId,
+    },
 };
 
 use zcash_note_encryption::COMPACT_NOTE_SIZE;
@@ -74,6 +77,15 @@ impl compact_formats::CompactBlock {
     }
 }
 
+impl compact_formats::CompactTx {
+    /// Returns the transaction Id
+    pub fn txid(&self) -> TxId {
+        let mut hash = [0u8; 32];
+        hash.copy_from_slice(&self.hash);
+        TxId::from_bytes(hash)
+    }
+}
+
 impl compact_formats::CompactOutput {
     /// Returns the note commitment for this output.
     ///

zcash_client_backend/src/welding_rig.rs

@@ -12,7 +12,7 @@ use zcash_primitives::{
         note_encryption::{try_sapling_compact_note_decryption, SaplingDomain},
         Node, Note, Nullifier, PaymentAddress, SaplingIvk,
     },
-    transaction::{components::sapling::CompactOutputDescription, TxId},
+    transaction::components::sapling::CompactOutputDescription,
     zip32::ExtendedFullViewingKey,
 };
 
@@ -32,7 +32,8 @@ use crate::wallet::{AccountId, WalletShieldedOutput, WalletShieldedSpend, Wallet
 fn scan_output<P: consensus::Parameters, K: ScanningKey>(
     params: &P,
     height: BlockHeight,
-    (index, output): (usize, CompactOutput),
+    index: usize,
+    output: CompactOutput,
     vks: &[(&AccountId, &K)],
     spent_from_accounts: &HashSet<AccountId>,
     tree: &mut CommitmentTree<Node>,
@@ -198,6 +199,8 @@ pub fn scan_block<P: consensus::Parameters, K: ScanningKey>(
     let block_height = block.height();
 
     for tx in block.vtx.into_iter() {
+        let txid = tx.txid();
+        let index = tx.index as usize;
         let num_spends = tx.spends.len();
         let num_outputs = tx.outputs.len();
 
@@ -249,7 +252,7 @@ pub fn scan_block<P: consensus::Parameters, K: ScanningKey>(
                 })
                 .collect();
 
-            for to_scan in tx.outputs.into_iter().enumerate() {
+            for (idx, c_out) in tx.outputs.into_iter().enumerate() {
                 // Grab mutable references to new witnesses from previous outputs
                 // in this transaction so that we can update them. Scoped so we
                 // don't hold mutable references to shielded_outputs for too long.
@@ -261,7 +264,8 @@ pub fn scan_block<P: consensus::Parameters, K: ScanningKey>(
                 if let Some(output) = scan_output(
                     params,
                     block_height,
-                    to_scan,
+                    idx,
+                    c_out,
                     vks,
                     &spent_from_accounts,
                     tree,
@@ -275,11 +279,9 @@ pub fn scan_block<P: consensus::Parameters, K: ScanningKey>(
         }
 
         if !(shielded_spends.is_empty() && shielded_outputs.is_empty()) {
-            let mut txid = TxId([0u8; 32]);
-            txid.0.copy_from_slice(&tx.hash);
             wtxs.push(WalletTx {
                 txid,
-                index: tx.index as usize,
+                index,
                 num_spends,
                 num_outputs,
                 shielded_spends,

zcash_client_sqlite/src/wallet.rs

@@ -389,7 +389,7 @@ pub fn block_height_extrema<P>(
 ///
 /// let data_file = NamedTempFile::new().unwrap();
 /// let db = WalletDb::for_path(data_file, Network::TestNetwork).unwrap();
-/// let height = get_tx_height(&db, TxId([0u8; 32]));
+/// let height = get_tx_height(&db, TxId::from_bytes([0u8; 32]));
 /// ```
 pub fn get_tx_height<P>(
     wdb: &WalletDb<P>,
@@ -398,7 +398,7 @@ pub fn get_tx_height<P>(
     wdb.conn
         .query_row(
             "SELECT block FROM transactions WHERE txid = ?",
-            &[txid.0.to_vec()],
+            &[txid.as_ref().to_vec()],
             |row| row.get(0).map(u32::into),
         )
         .optional()
@@ -616,7 +616,7 @@ pub fn put_tx_meta<'a, P, N>(
     tx: &WalletTx<N>,
     height: BlockHeight,
 ) -> Result<i64, SqliteClientError> {
-    let txid = tx.txid.0.to_vec();
+    let txid = tx.txid.as_ref().to_vec();
     if stmts
         .stmt_update_tx_meta
         .execute(params![u32::from(height), (tx.index as i64), txid])?
@@ -643,7 +643,7 @@ pub fn put_tx_data<'a, P>(
     tx: &Transaction,
     created_at: Option<time::OffsetDateTime>,
 ) -> Result<i64, SqliteClientError> {
-    let txid = tx.txid().0.to_vec();
+    let txid = tx.txid().as_ref().to_vec();
 
     let mut raw_tx = vec![];
     tx.write(&mut raw_tx)?;

zcash_extensions/src/transparent/demo.rs

@@ -625,7 +625,7 @@ mod tests {
         //
 
         let in_b = TzeIn {
-            prevout: TzeOutPoint::new(tx_a.txid().0, 0),
+            prevout: TzeOutPoint::new(tx_a.txid(), 0),
             witness: tze::Witness::from(0, &Witness::open(preimage_1)),
         };
         let out_b = TzeOut {
@@ -642,7 +642,7 @@ mod tests {
         //
 
         let in_c = TzeIn {
-            prevout: TzeOutPoint::new(tx_b.txid().0, 0),
+            prevout: TzeOutPoint::new(tx_b.txid(), 0),
             witness: tze::Witness::from(0, &Witness::close(preimage_2)),
         };
 
@@ -737,7 +737,7 @@ mod tests {
             extension_id: 0,
         };
         let prevout_a = (
-            TzeOutPoint::new(tx_a.txid().0, 0),
+            TzeOutPoint::new(tx_a.txid(), 0),
             tx_a.tze_outputs[0].clone(),
         );
         let value_xfr = (value - DEFAULT_FEE).unwrap();
@@ -759,7 +759,7 @@ mod tests {
             extension_id: 0,
         };
         let prevout_b = (
-            TzeOutPoint::new(tx_a.txid().0, 0),
+            TzeOutPoint::new(tx_a.txid(), 0),
             tx_b.tze_outputs[0].clone(),
         );
         db_c.demo_close(prevout_b, preimage_2)

zcash_primitives/src/transaction/components/tze.rs

@@ -10,6 +10,7 @@ use std::convert::TryFrom;
 use crate::{
     extensions::transparent as tze,
     serialize::{CompactSize, Vector},
+    transaction::TxId,
 };
 
 use super::amount::Amount;
@@ -20,33 +21,32 @@ fn to_io_error(_: std::num::TryFromIntError) -> io::Error {
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct TzeOutPoint {
-    hash: [u8; 32],
+    txid: TxId,
     n: u32,
 }
 
 impl TzeOutPoint {
-    pub fn new(hash: [u8; 32], n: u32) -> Self {
-        TzeOutPoint { hash, n }
+    pub fn new(txid: TxId, n: u32) -> Self {
+        TzeOutPoint { txid, n }
     }
 
     pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
-        let mut hash = [0u8; 32];
-        reader.read_exact(&mut hash)?;
+        let txid = TxId::read(&mut reader)?;
         let n = reader.read_u32::<LittleEndian>()?;
-        Ok(TzeOutPoint { hash, n })
+        Ok(TzeOutPoint { txid, n })
     }
 
     pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        writer.write_all(&self.hash)?;
+        self.txid.write(&mut writer)?;
         writer.write_u32::<LittleEndian>(self.n)
     }
 
     pub fn n(&self) -> u32 {
         self.n
     }
 
-    pub fn hash(&self) -> &[u8; 32] {
-        &self.hash
+    pub fn txid(&self) -> &TxId {
+        &self.txid
     }
 }
 

zcash_primitives/src/transaction/mod.rs

@@ -41,7 +41,7 @@ const ZFUTURE_VERSION_GROUP_ID: u32 = 0xFFFFFFFF;
 const ZFUTURE_TX_VERSION: u32 = 0x0000FFFF;
 
 #[derive(Clone, Copy, Debug, PartialOrd, Ord, PartialEq, Eq, Hash)]
-pub struct TxId(pub [u8; 32]);
+pub struct TxId([u8; 32]);
 
 impl fmt::Display for TxId {
     fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -51,6 +51,29 @@ impl fmt::Display for TxId {
     }
 }
 
+impl AsRef<[u8; 32]> for TxId {
+    fn as_ref(&self) -> &[u8; 32] {
+        &self.0
+    }
+}
+
+impl TxId {
+    pub fn from_bytes(bytes: [u8; 32]) -> Self {
+        TxId(bytes)
+    }
+
+    pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
+        let mut hash = [0u8; 32];
+        reader.read_exact(&mut hash)?;
+        Ok(TxId::from_bytes(hash))
+    }
+
+    pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
+        writer.write_all(&self.0)?;
+        Ok(())
+    }
+}
+
 /// The set of defined transaction format versions.
 ///
 /// This is serialized in the first four or eight bytes of the transaction format, and
@@ -502,7 +525,7 @@ pub mod testing {
 
     use super::{
         components::{amount::MAX_MONEY, Amount, OutPoint, TxIn, TxOut},
-        Transaction, TransactionData, TxVersion,
+        Transaction, TransactionData, TxId, TxVersion,
     };
 
     #[cfg(feature = "zfuture")]
@@ -519,6 +542,10 @@ pub mod testing {
         0x6a, // OP_RETURN,
     ];
 
+    pub fn arb_txid() -> impl Strategy<Value = TxId> {
+        prop::array::uniform32(any::<u8>()).prop_map(TxId::from_bytes)
+    }
+
     prop_compose! {
         pub fn arb_outpoint()(hash in prop::array::uniform32(1u8..), n in 1..100u32) -> OutPoint {
             OutPoint::new(hash, n)
@@ -551,8 +578,8 @@ pub mod testing {
 
     #[cfg(feature = "zfuture")]
     prop_compose! {
-        pub fn arb_tzeoutpoint()(hash in prop::array::uniform32(1u8..), n in 1..100u32) -> TzeOutPoint {
-            TzeOutPoint::new(hash, n)
+        pub fn arb_tzeoutpoint()(txid in arb_txid(), n in 1..100u32) -> TzeOutPoint {
+            TzeOutPoint::new(txid, n)
         }
     }