Rename txid to compute_txid

Computing the txid is computationally expensive, so rename the method
accordingly.

bitcoin/examples/taproot-psbt.rs

@@ -425,7 +425,7 @@ impl BenefactorWallet {
             version: transaction::Version::TWO,
             lock_time,
             input: vec![TxIn {
-                previous_output: OutPoint { txid: tx.txid(), vout: 0 },
+                previous_output: OutPoint { txid: tx.compute_txid(), vout: 0 },
                 script_sig: ScriptBuf::new(),
                 sequence: bitcoin::Sequence(0xFFFFFFFD), // enable locktime and opt-in RBF
                 witness: Witness::default(),
@@ -568,7 +568,7 @@ impl BenefactorWallet {
                 version: transaction::Version::TWO,
                 lock_time,
                 input: vec![TxIn {
-                    previous_output: OutPoint { txid: tx.txid(), vout: 0 },
+                    previous_output: OutPoint { txid: tx.compute_txid(), vout: 0 },
                     script_sig: ScriptBuf::new(),
                     sequence: bitcoin::Sequence(0xFFFFFFFD), // enable locktime and opt-in RBF
                     witness: Witness::default(),

bitcoin/src/bip152.rs

@@ -219,7 +219,7 @@ impl HeaderAndShortIds {
             } else {
                 short_ids.push(ShortId::with_siphash_keys(
                     &match version {
-                        1 => tx.txid().to_raw_hash(),
+                        1 => tx.compute_txid().to_raw_hash(),
                         2 => tx.wtxid().to_raw_hash(),
                         _ => unreachable!(),
                     },

bitcoin/src/blockdata/block.rs

@@ -289,7 +289,7 @@ impl Block {
 
     /// Computes the transaction merkle root.
     pub fn compute_merkle_root(&self) -> Option<TxMerkleNode> {
-        let hashes = self.txdata.iter().map(|obj| obj.txid().to_raw_hash());
+        let hashes = self.txdata.iter().map(|obj| obj.compute_txid().to_raw_hash());
         merkle_tree::calculate_root(hashes).map(|h| h.into())
     }
 
@@ -491,7 +491,7 @@ mod tests {
         let block: Block = deserialize(&hex!(BLOCK_HEX)).unwrap();
 
         let cb_txid = "d574f343976d8e70d91cb278d21044dd8a396019e6db70755a0a50e4783dba38";
-        assert_eq!(block.coinbase().unwrap().txid().to_string(), cb_txid);
+        assert_eq!(block.coinbase().unwrap().compute_txid().to_string(), cb_txid);
 
         assert_eq!(block.bip34_block_height(), Ok(100_000));
 

bitcoin/src/blockdata/constants.rs

@@ -88,7 +88,7 @@ fn bitcoin_genesis_tx() -> Transaction {
 /// Constructs and returns the genesis block.
 pub fn genesis_block(network: Network) -> Block {
     let txdata = vec![bitcoin_genesis_tx()];
-    let hash: sha256d::Hash = txdata[0].txid().into();
+    let hash: sha256d::Hash = txdata[0].compute_txid().into();
     let merkle_root = hash.into();
     match network {
         Network::Bitcoin => Block {

bitcoin/src/blockdata/transaction.rs

@@ -698,15 +698,25 @@ impl Transaction {
                 .collect(),
             output: self.output.clone(),
         };
-        cloned_tx.txid().into()
+        cloned_tx.compute_txid().into()
     }
 
+    /// Computes the [`Txid`].
+    ///
+    /// This method is deprecated.  Use `compute_txid` instead.
+    #[deprecated(
+        since = "0.31.0",
+        note = "txid has been renamed to compute_txid to note that it's computationally expensive.  use compute_txid() instead."
+    )]
+    pub fn txid(&self) -> Txid { self.compute_txid() }
+
     /// Computes the [`Txid`].
     ///
     /// Hashes the transaction **excluding** the segwit data (i.e. the marker, flag bytes, and the
     /// witness fields themselves). For non-segwit transactions which do not have any segwit data,
     /// this will be equal to [`Transaction::wtxid()`].
-    pub fn txid(&self) -> Txid {
+    #[doc(alias = "txid")]
+    pub fn compute_txid(&self) -> Txid {
         let mut enc = Txid::engine();
         self.version.consensus_encode(&mut enc).expect("engines don't error");
         self.input.consensus_encode(&mut enc).expect("engines don't error");
@@ -1237,11 +1247,11 @@ impl Decodable for Transaction {
 }
 
 impl From<Transaction> for Txid {
-    fn from(tx: Transaction) -> Txid { tx.txid() }
+    fn from(tx: Transaction) -> Txid { tx.compute_txid() }
 }
 
 impl From<&Transaction> for Txid {
-    fn from(tx: &Transaction) -> Txid { tx.txid() }
+    fn from(tx: &Transaction) -> Txid { tx.compute_txid() }
 }
 
 impl From<Transaction> for Wtxid {
@@ -1732,7 +1742,7 @@ mod tests {
         assert_eq!(realtx.lock_time, absolute::LockTime::ZERO);
 
         assert_eq!(
-            format!("{:x}", realtx.txid()),
+            format!("{:x}", realtx.compute_txid()),
             "a6eab3c14ab5272a58a5ba91505ba1a4b6d7a3a9fcbd187b6cd99a7b6d548cb7".to_string()
         );
         assert_eq!(
@@ -1783,7 +1793,7 @@ mod tests {
         assert_eq!(realtx.lock_time, absolute::LockTime::ZERO);
 
         assert_eq!(
-            format!("{:x}", realtx.txid()),
+            format!("{:x}", realtx.compute_txid()),
             "f5864806e3565c34d1b41e716f72609d00b55ea5eac5b924c9719a842ef42206".to_string()
         );
         assert_eq!(
@@ -1911,7 +1921,7 @@ mod tests {
             "d6ac4a5e61657c4c604dcde855a1db74ec6b3e54f32695d72c5e11c7761ea1b4"
         );
         assert_eq!(
-            format!("{:x}", tx.txid()),
+            format!("{:x}", tx.compute_txid()),
             "9652aa62b0e748caeec40c4cb7bc17c6792435cc3dfe447dd1ca24f912a1c6ec"
         );
         assert_eq!(tx.weight(), Weight::from_wu(2718));
@@ -1932,7 +1942,7 @@ mod tests {
             "971ed48a62c143bbd9c87f4bafa2ef213cfa106c6e140f111931d0be307468dd"
         );
         assert_eq!(
-            format!("{:x}", tx.txid()),
+            format!("{:x}", tx.compute_txid()),
             "971ed48a62c143bbd9c87f4bafa2ef213cfa106c6e140f111931d0be307468dd"
         );
     }
@@ -2017,9 +2027,9 @@ mod tests {
             .as_slice()).unwrap();
 
         let mut spent = HashMap::new();
-        spent.insert(spent1.txid(), spent1);
+        spent.insert(spent1.compute_txid(), spent1);
-        spent.insert(spent2.txid(), spent2);
+        spent.insert(spent2.compute_txid(), spent2);
-        spent.insert(spent3.txid(), spent3);
+        spent.insert(spent3.compute_txid(), spent3);
         let mut spent2 = spent.clone();
         let mut spent3 = spent.clone();
 

bitcoin/src/merkle_tree/block.rs

@@ -103,7 +103,7 @@ impl MerkleBlock {
     where
         F: Fn(&Txid) -> bool,
     {
-        let block_txids: Vec<_> = block.txdata.iter().map(Transaction::txid).collect();
+        let block_txids: Vec<_> = block.txdata.iter().map(Transaction::compute_txid).collect();
         Self::from_header_txids_with_predicate(&block.header, &block_txids, match_txids)
     }
 

bitcoin/src/merkle_tree/mod.rs

@@ -125,7 +125,7 @@ mod tests {
         let block: Block = deserialize(&segwit_block[..]).expect("Failed to deserialize block");
         assert!(block.check_merkle_root()); // Sanity check.
 
-        let hashes_iter = block.txdata.iter().map(|obj| obj.txid().to_raw_hash());
+        let hashes_iter = block.txdata.iter().map(|obj| obj.compute_txid().to_raw_hash());
 
         let mut hashes_array: [sha256d::Hash; 15] = [Hash::all_zeros(); 15];
         for (i, hash) in hashes_iter.clone().enumerate() {

bitcoin/src/psbt/error.rs

@@ -127,8 +127,8 @@ impl fmt::Display for Error {
             UnexpectedUnsignedTx { expected: ref e, actual: ref a } => write!(
                 f,
                 "different unsigned transaction: expected {}, actual {}",
-                e.txid(),
+                e.compute_txid(),
-                a.txid()
+                a.compute_txid()
             ),
             NonStandardSighashType(ref sht) => write!(f, "non-standard sighash type: {}", sht),
             InvalidHash(ref e) => write_err!(f, "invalid hash when parsing slice"; e),

bitcoin/src/psbt/mod.rs

@@ -1597,7 +1597,7 @@ mod tests {
             let tx_input = &psbt.unsigned_tx.input[0];
             let psbt_non_witness_utxo = psbt.inputs[0].non_witness_utxo.as_ref().unwrap();
 
-            assert_eq!(tx_input.previous_output.txid, psbt_non_witness_utxo.txid());
+            assert_eq!(tx_input.previous_output.txid, psbt_non_witness_utxo.compute_txid());
             assert!(psbt_non_witness_utxo.output[tx_input.previous_output.vout as usize]
                 .script_pubkey
                 .is_p2pkh());
@@ -1664,7 +1664,7 @@ mod tests {
 
             let tx = &psbt.unsigned_tx;
             assert_eq!(
-                tx.txid(),
+                tx.compute_txid(),
                 "75c5c9665a570569ad77dd1279e6fd4628a093c4dcbf8d41532614044c14c115".parse().unwrap(),
             );