Replace u64 with Amount type in TxOut

Some places, most prominently TxOut, were still using u64s for amounts (in sat). This PR replaces these with the Amount newtype and also implements the consensus encode traits for Amount to make it all work.
rust-bitcoin · Apr 30, 2021 · c3eb51f · c3eb51f
1 parent 4db4e60
commit c3eb51f
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Showing 6 changed files with 41 additions and 22 deletions.
diff --git a/src/blockdata/constants.rs b/src/blockdata/constants.rs
@@ -29,6 +29,7 @@ use blockdata::transaction::{OutPoint, Transaction, TxOut, TxIn};
 use blockdata::block::{Block, BlockHeader};
 use network::constants::Network;
 use util::uint::Uint256;
+use Amount;
 
 /// The maximum allowable sequence number
 pub const MAX_SEQUENCE: u32 = 0xFFFFFFFF;
@@ -88,7 +89,7 @@ fn bitcoin_genesis_tx() -> Transaction {
         .push_opcode(opcodes::all::OP_CHECKSIG)
         .into_script();
     ret.output.push(TxOut {
-        value: 50 * COIN_VALUE,
+        value: Amount::from_sat(50 * COIN_VALUE),
         script_pubkey: out_script
     });
 
@@ -166,6 +167,7 @@ mod test {
     use consensus::encode::serialize;
     use blockdata::constants::{genesis_block, bitcoin_genesis_tx};
     use blockdata::constants::{MAX_SEQUENCE, COIN_VALUE};
+    use Amount;
 
     #[test]
     fn bitcoin_genesis_first_transaction() {
@@ -182,7 +184,7 @@ mod test {
         assert_eq!(gen.output.len(), 1);
         assert_eq!(serialize(&gen.output[0].script_pubkey),
                    Vec::from_hex("434104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac").unwrap());
-        assert_eq!(gen.output[0].value, 50 * COIN_VALUE);
+        assert_eq!(gen.output[0].value, Amount::from_sat(50 * COIN_VALUE));
         assert_eq!(gen.lock_time, 0);
 
         assert_eq!(format!("{:x}", gen.wtxid()),

diff --git a/src/blockdata/script.rs b/src/blockdata/script.rs
@@ -454,8 +454,8 @@ impl Script {
     ///  * index - the input index in spending which is spending this transaction
     ///  * amount - the amount this script guards
     ///  * spending - the transaction that attempts to spend the output holding this script
-    pub fn verify (&self, index: usize, amount: u64, spending: &[u8]) -> Result<(), Error> {
-        Ok(bitcoinconsensus::verify (&self.0[..], amount, spending, index)?)
+    pub fn verify (&self, index: usize, amount: Amount, spending: &[u8]) -> Result<(), Error> {
+        Ok(bitcoinconsensus::verify (&self.0[..], amount.as_sat(), spending, index)?)
     }
 
     /// Write the assembly decoding of the script bytes to the formatter.

diff --git a/src/blockdata/transaction.rs b/src/blockdata/transaction.rs
@@ -35,7 +35,7 @@ use blockdata::constants::WITNESS_SCALE_FACTOR;
 use blockdata::script::Script;
 use consensus::{encode, Decodable, Encodable};
 use hash_types::{SigHash, Txid, Wtxid};
-use VarInt;
+use ::{VarInt, Amount};
 
 /// A reference to a transaction output
 #[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
@@ -210,15 +210,16 @@ impl Default for TxIn {
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct TxOut {
     /// The value of the output, in satoshis
-    pub value: u64,
+    #[cfg_attr(feature = "serde", serde(with="crate::util::amount::serde::as_sat"))]
+    pub value: Amount,
     /// The script which must satisfy for the output to be spent
     pub script_pubkey: Script
 }
 
 // This is used as a "null txout" in consensus signing code
 impl Default for TxOut {
     fn default() -> TxOut {
-        TxOut { value: 0xffffffffffffffff, script_pubkey: Script::new() }
+        TxOut { value: Amount::from_sat(0xffffffffffffffff), script_pubkey: Script::new() }
     }
 }
 

diff --git a/src/util/amount.rs b/src/util/amount.rs
@@ -20,6 +20,7 @@ use std::fmt::{self, Write};
 use std::ops;
 use std::str::FromStr;
 use std::cmp::Ordering;
+use consensus::{Encodable, Decodable, encode};
 
 /// A set of denominations in which amounts can be expressed.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
@@ -446,6 +447,18 @@ impl fmt::Display for Amount {
     }
 }
 
+impl Encodable for Amount {
+    fn consensus_encode<W: std::io::Write>(&self, writer: W) -> Result<usize, std::io::Error> {
+        self.0.consensus_encode(writer)
+    }
+}
+
+impl Decodable for Amount {
+    fn consensus_decode<D: std::io::Read>(d: D) -> Result<Self, encode::Error> {
+        Ok(Amount(u64::consensus_decode(d)?))
+    }
+}
+
 impl ops::Add for Amount {
     type Output = Amount;
 

diff --git a/src/util/bip143.rs b/src/util/bip143.rs
@@ -27,6 +27,7 @@ use consensus::{encode, Encodable};
 
 use std::io;
 use std::ops::{Deref, DerefMut};
+use Amount;
 
 /// Parts of a sighash which are common across inputs or signatures, and which are
 /// sufficient (in conjunction with a private key) to sign the transaction
@@ -176,7 +177,7 @@ impl<R: Deref<Target=Transaction>> SigHashCache<R> {
         mut writer: Write,
         input_index: usize,
         script_code: &Script,
-        value: u64,
+        value: Amount,
         sighash_type: SigHashType,
     ) -> Result<(), encode::Error> {
         let zero_hash = sha256d::Hash::default();
@@ -229,7 +230,7 @@ impl<R: Deref<Target=Transaction>> SigHashCache<R> {
         &mut self,
         input_index: usize,
         script_code: &Script,
-        value: u64,
+        value: Amount,
         sighash_type: SigHashType
     ) -> SigHash {
         let mut enc = SigHash::engine();
@@ -247,15 +248,15 @@ impl<R: DerefMut<Target=Transaction>> SigHashCache<R> {
     /// ```
     /// use bitcoin::blockdata::transaction::{Transaction, SigHashType};
     /// use bitcoin::util::bip143::SigHashCache;
-    /// use bitcoin::Script;
+    /// use bitcoin::{Script, Amount};
     ///
     /// let mut tx_to_sign = Transaction { version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
     /// let input_count = tx_to_sign.input.len();
     ///
     /// let mut sig_hasher = SigHashCache::new(&mut tx_to_sign);
     /// for inp in 0..input_count {
     ///     let prevout_script = Script::new();
-    ///     let _sighash = sig_hasher.signature_hash(inp, &prevout_script, 42, SigHashType::All);
+    ///     let _sighash = sig_hasher.signature_hash(inp, &prevout_script, Amount::from_sat(42), SigHashType::All);
     ///     // ... sign the sighash
     ///     sig_hasher.access_witness(inp).push(Vec::new());
     /// }
@@ -293,7 +294,7 @@ mod tests {
         let expected_result = SigHash::from_slice(&raw_expected[..]).unwrap();
         let mut cache = SigHashCache::new(&tx);
         let sighash_type = SigHashType::from_u32_consensus(hash_type);
-        let actual_result = cache.signature_hash(input_index, &script, value, sighash_type);
+        let actual_result = cache.signature_hash(input_index, &script, Amount::from_sat(value), sighash_type);
         assert_eq!(actual_result, expected_result);
     }
 

diff --git a/src/util/psbt/mod.rs b/src/util/psbt/mod.rs
@@ -228,6 +228,7 @@ mod tests {
 
     use super::PartiallySignedTransaction;
     use util::psbt::raw::ProprietaryKey;
+    use Amount;
 
     #[test]
     fn trivial_psbt() {
@@ -316,13 +317,13 @@ mod tests {
                 }],
                 output: vec![
                     TxOut {
-                        value: 99999699,
+                        value: Amount::from_sat(99999699),
                         script_pubkey: hex_script!(
                             "76a914d0c59903c5bac2868760e90fd521a4665aa7652088ac"
                         ),
                     },
                     TxOut {
-                        value: 100000000,
+                        value: Amount::from_sat(100000000),
                         script_pubkey: hex_script!(
                             "a9143545e6e33b832c47050f24d3eeb93c9c03948bc787"
                         ),
@@ -475,6 +476,7 @@ mod tests {
         use util::psbt::map::{Map, Global, Input, Output};
         use util::psbt::raw;
         use util::psbt::{PartiallySignedTransaction, Error};
+        use Amount;
 
         #[test]
         #[should_panic(expected = "InvalidMagic")]
@@ -572,11 +574,11 @@ mod tests {
                         }],
                         output: vec![
                             TxOut {
-                                value: 99999699,
+                                value: Amount::from_sat(99999699),
                                 script_pubkey: hex_script!("76a914d0c59903c5bac2868760e90fd521a4665aa7652088ac"),
                             },
                             TxOut {
-                                value: 100000000,
+                                value: Amount::from_sat(100000000),
                                 script_pubkey: hex_script!("a9143545e6e33b832c47050f24d3eeb93c9c03948bc787"),
                             },
                         ],
@@ -620,11 +622,11 @@ mod tests {
                         }],
                         output: vec![
                             TxOut {
-                                value: 200000000,
+                                value: Amount::from_sat(200000000),
                                 script_pubkey: hex_script!("76a91485cff1097fd9e008bb34af709c62197b38978a4888ac"),
                             },
                             TxOut {
-                                value: 190303501938,
+                                value: Amount::from_sat(190303501938),
                                 script_pubkey: hex_script!("a914339725ba21efd62ac753a9bcd067d6c7a6a39d0587"),
                             },
                         ],
@@ -805,11 +807,11 @@ mod tests {
                     }],
                     output: vec![
                         TxOut {
-                            value: 99999699,
+                            value: Amount::from_sat(99999699),
                             script_pubkey: hex_script!("76a914d0c59903c5bac2868760e90fd521a4665aa7652088ac"),
                         },
                         TxOut {
-                            value: 100000000,
+                            value: Amount::from_sat(100000000),
                             script_pubkey: hex_script!("a9143545e6e33b832c47050f24d3eeb93c9c03948bc787"),
                         },
                     ],
@@ -853,11 +855,11 @@ mod tests {
                     }],
                     output: vec![
                         TxOut {
-                            value: 200000000,
+                            value: Amount::from_sat(200000000),
                             script_pubkey: hex_script!("76a91485cff1097fd9e008bb34af709c62197b38978a4888ac"),
                         },
                         TxOut {
-                            value: 190303501938,
+                            value: Amount::from_sat(190303501938),
                             script_pubkey: hex_script!("a914339725ba21efd62ac753a9bcd067d6c7a6a39d0587"),
                         },
                     ],