Use Amount type for TxOut value field

yancyribbens · yancyribbens · commit d57ec019d527 · 2023-05-04T17:09:08.000+02:00
diff --git a/bitcoin/examples/ecdsa-psbt.rs b/bitcoin/examples/ecdsa-psbt.rs
@@ -192,11 +192,8 @@ impl WatchOnly {
                 witness: Witness::default(),
             }],
             output: vec![
-                TxOut { value: to_amount.to_sat(), script_pubkey: to_address.script_pubkey() },
-                TxOut {
-                    value: change_amount.to_sat(),
-                    script_pubkey: change_address.script_pubkey(),
-                },
+                TxOut { value: to_amount, script_pubkey: to_address.script_pubkey() },
+                TxOut { value: change_amount, script_pubkey: change_address.script_pubkey() },
             ],
         };
 
@@ -282,7 +279,7 @@ fn previous_output() -> TxOut {
         .expect("failed to parse input utxo scriptPubkey");
     let amount = Amount::from_str(INPUT_UTXO_VALUE).expect("failed to parse input utxo value");
 
-    TxOut { value: amount.to_sat(), script_pubkey }
+    TxOut { value: amount, script_pubkey }
 }
 
 struct Error(Box<dyn std::error::Error>);
diff --git a/bitcoin/examples/taproot-psbt.rs b/bitcoin/examples/taproot-psbt.rs
@@ -40,7 +40,7 @@ const UTXO_SCRIPT_PUBKEY: &str =
     "5120be27fa8b1f5278faf82cab8da23e8761f8f9bd5d5ebebbb37e0e12a70d92dd16";
 const UTXO_PUBKEY: &str = "a6ac32163539c16b6b5dbbca01b725b8e8acaa5f821ba42c80e7940062140d19";
 const UTXO_MASTER_FINGERPRINT: &str = "e61b318f";
-const ABSOLUTE_FEES_IN_SATS: u64 = 1000;
+const ABSOLUTE_FEES_IN_SATS: Amount = Amount::from_sat(1_000);
 
 // UTXO_1 will be used for spending example 1
 const UTXO_1: P2trUtxo = P2trUtxo {
@@ -49,7 +49,7 @@ const UTXO_1: P2trUtxo = P2trUtxo {
     script_pubkey: UTXO_SCRIPT_PUBKEY,
     pubkey: UTXO_PUBKEY,
     master_fingerprint: UTXO_MASTER_FINGERPRINT,
-    amount_in_sats: 50 * COIN_VALUE, // 50 BTC
+    amount_in_sats: Amount::from_sat(50 * 100_000_000), // 50 BTC
     derivation_path: BIP86_DERIVATION_PATH,
 };
 
@@ -60,7 +60,7 @@ const UTXO_2: P2trUtxo = P2trUtxo {
     script_pubkey: UTXO_SCRIPT_PUBKEY,
     pubkey: UTXO_PUBKEY,
     master_fingerprint: UTXO_MASTER_FINGERPRINT,
-    amount_in_sats: 50 * COIN_VALUE,
+    amount_in_sats: Amount::from_sat(50 * 100_000_000), // 50 BTC
     derivation_path: BIP86_DERIVATION_PATH,
 };
 
@@ -71,7 +71,7 @@ const UTXO_3: P2trUtxo = P2trUtxo {
     script_pubkey: UTXO_SCRIPT_PUBKEY,
     pubkey: UTXO_PUBKEY,
     master_fingerprint: UTXO_MASTER_FINGERPRINT,
-    amount_in_sats: 50 * COIN_VALUE,
+    amount_in_sats: Amount::from_sat(50 * 100_000_000), // 50 BTC
     derivation_path: BIP86_DERIVATION_PATH,
 };
 
@@ -80,7 +80,6 @@ use std::str::FromStr;
 
 use bitcoin::bip32::{ChildNumber, DerivationPath, ExtendedPrivKey, ExtendedPubKey, Fingerprint};
 use bitcoin::consensus::encode;
-use bitcoin::constants::COIN_VALUE;
 use bitcoin::key::{TapTweak, XOnlyPublicKey};
 use bitcoin::opcodes::all::{OP_CHECKSIG, OP_CLTV, OP_DROP};
 use bitcoin::psbt::{self, Input, Output, Psbt, PsbtSighashType};
@@ -105,7 +104,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let change_address =
         Address::from_str("bcrt1pz449kexzydh2kaypatup5ultru3ej284t6eguhnkn6wkhswt0l7q3a7j76")?
             .require_network(Network::Regtest)?;
-    let amount_to_send_in_sats = COIN_VALUE;
+    let amount_to_send_in_sats = Amount::ONE_BTC;
     let change_amount = UTXO_1
         .amount_in_sats
         .checked_sub(amount_to_send_in_sats)
@@ -216,7 +215,7 @@ struct P2trUtxo<'a> {
     script_pubkey: &'a str,
     pubkey: &'a str,
     master_fingerprint: &'a str,
-    amount_in_sats: u64,
+    amount_in_sats: Amount,
     derivation_path: &'a str,
 }
 
@@ -259,9 +258,7 @@ fn generate_bip86_key_spend_tx(
         witness_utxo: {
             let script_pubkey = ScriptBuf::from_hex(input_utxo.script_pubkey)
                 .expect("failed to parse input utxo scriptPubkey");
-            let amount = Amount::from_sat(from_amount);
-
-            Some(TxOut { value: amount.to_sat(), script_pubkey })
+            Some(TxOut { value: from_amount, script_pubkey })
         },
         tap_key_origins: origins,
         ..Default::default()
@@ -448,9 +445,7 @@ impl BenefactorWallet {
         let input = Input {
             witness_utxo: {
                 let script_pubkey = script_pubkey;
-                let amount = Amount::from_sat(value);
-
-                Some(TxOut { value: amount.to_sat(), script_pubkey })
+                Some(TxOut { value, script_pubkey })
             },
             tap_key_origins: origins,
             tap_merkle_root: taproot_spend_info.merkle_root(),
@@ -594,9 +589,9 @@ impl BenefactorWallet {
             let input = Input {
                 witness_utxo: {
                     let script_pubkey = output_script_pubkey;
-                    let amount = Amount::from_sat(output_value);
+                    let amount = output_value;
 
-                    Some(TxOut { value: amount.to_sat(), script_pubkey })
+                    Some(TxOut { value: amount, script_pubkey })
                 },
                 tap_key_origins: origins,
                 tap_merkle_root: taproot_spend_info.merkle_root(),
diff --git a/bitcoin/src/amount.rs b/bitcoin/src/amount.rs
@@ -11,6 +11,8 @@ use core::fmt::{self, Write};
 use core::str::FromStr;
 use core::{default, ops};
 
+use crate::consensus::encode::{self, Decodable, Encodable};
+use crate::io;
 use crate::prelude::*;
 
 /// A set of denominations in which amounts can be expressed.
@@ -483,6 +485,8 @@ fn fmt_satoshi_in(
 /// the checked arithmetic methods.
 ///
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "serde", serde(crate = "actual_serde"))]
 pub struct Amount(u64);
 
 impl Amount {
@@ -660,6 +664,20 @@ impl Amount {
     }
 }
 
+impl Decodable for Amount {
+    #[inline]
+    fn consensus_decode<R: io::Read + ?Sized>(r: &mut R) -> Result<Self, encode::Error> {
+        Ok(Amount(Decodable::consensus_decode(r)?))
+    }
+}
+
+impl Encodable for Amount {
+    #[inline]
+    fn consensus_encode<W: io::Write + ?Sized>(&self, w: &mut W) -> Result<usize, io::Error> {
+        self.0.consensus_encode(w)
+    }
+}
+
 impl default::Default for Amount {
     fn default() -> Self { Amount::ZERO }
 }
diff --git a/bitcoin/src/bip152.rs b/bitcoin/src/bip152.rs
@@ -378,7 +378,8 @@ mod test {
     use crate::consensus::encode::{deserialize, serialize};
     use crate::hash_types::TxMerkleNode;
     use crate::{
-        CompactTarget, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut, Txid, Witness,
+        Amount, CompactTarget, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut, Txid,
+        Witness,
     };
 
     fn dummy_tx(nonce: &[u8]) -> Transaction {
@@ -391,7 +392,7 @@ mod test {
                 sequence: Sequence(1),
                 witness: Witness::new(),
             }],
-            output: vec![TxOut { value: 1, script_pubkey: ScriptBuf::new() }],
+            output: vec![TxOut { value: Amount::ONE_SAT, script_pubkey: ScriptBuf::new() }],
         }
     }
 
diff --git a/bitcoin/src/blockdata/constants.rs b/bitcoin/src/blockdata/constants.rs
@@ -22,9 +22,8 @@ use crate::blockdata::witness::Witness;
 use crate::internal_macros::impl_bytes_newtype;
 use crate::network::constants::Network;
 use crate::pow::CompactTarget;
+use crate::Amount;
 
-/// How many satoshis are in "one bitcoin".
-pub const COIN_VALUE: u64 = 100_000_000;
 /// How many seconds between blocks we expect on average.
 pub const TARGET_BLOCK_SPACING: u32 = 600;
 /// How many blocks between diffchanges.
@@ -61,11 +60,6 @@ pub const MAX_SCRIPTNUM_VALUE: u32 = 0x80000000; // 2^31
 /// Number of blocks needed for an output from a coinbase transaction to be spendable.
 pub const COINBASE_MATURITY: u32 = 100;
 
-/// The maximum value allowed in an output (useful for sanity checking,
-/// since keeping everything below this value should prevent overflows
-/// if you are doing anything remotely sane with monetary values).
-pub const MAX_MONEY: u64 = 21_000_000 * COIN_VALUE;
-
 /// Constructs and returns the coinbase (and only) transaction of the Bitcoin genesis block.
 fn bitcoin_genesis_tx() -> Transaction {
     // Base
@@ -93,7 +87,7 @@ fn bitcoin_genesis_tx() -> Transaction {
     let script_bytes = hex!("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f");
     let out_script =
         script::Builder::new().push_slice(script_bytes).push_opcode(OP_CHECKSIG).into_script();
-    ret.output.push(TxOut { value: 50 * COIN_VALUE, script_pubkey: out_script });
+    ret.output.push(TxOut { value: Amount::from_sat(50 * 100_000_000), script_pubkey: out_script });
 
     // end
     ret
@@ -198,6 +192,8 @@ impl ChainHash {
 
 #[cfg(test)]
 mod test {
+    use core::str::FromStr;
+
     use super::*;
     use crate::blockdata::locktime::absolute;
     use crate::consensus::encode::serialize;
@@ -219,7 +215,7 @@ mod test {
         assert_eq!(gen.output.len(), 1);
         assert_eq!(serialize(&gen.output[0].script_pubkey),
                    hex!("434104678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5fac"));
-        assert_eq!(gen.output[0].value, 50 * COIN_VALUE);
+        assert_eq!(gen.output[0].value, Amount::from_str("50 BTC").unwrap());
         assert_eq!(gen.lock_time, absolute::LockTime::ZERO);
 
         assert_eq!(
diff --git a/bitcoin/src/blockdata/transaction.rs b/bitcoin/src/blockdata/transaction.rs
@@ -35,7 +35,7 @@ use crate::prelude::*;
 #[cfg(doc)]
 use crate::sighash::{EcdsaSighashType, TapSighashType};
 use crate::string::FromHexStr;
-use crate::{io, VarInt};
+use crate::{io, Amount, VarInt};
 
 /// A reference to a transaction output.
 ///
@@ -478,7 +478,7 @@ impl_parse_str_from_int_infallible!(Sequence, u32, from_consensus);
 #[cfg_attr(feature = "serde", serde(crate = "actual_serde"))]
 pub struct TxOut {
     /// The value of the output, in satoshis.
-    pub value: u64,
+    pub value: Amount,
     /// The script which must be satisfied for the output to be spent.
     pub script_pubkey: ScriptBuf,
 }
@@ -512,15 +512,17 @@ impl TxOut {
         let dust_amount = (len as u64) * 3;
 
         TxOut {
-            value: dust_amount + 1, // minimal non-dust amount is one higher than dust amount
+            value: Amount::from_sat(dust_amount + 1), // minimal non-dust amount is one higher than dust amount
             script_pubkey,
         }
     }
 }
 
 // This is used as a "null txout" in consensus signing code.
 impl Default for TxOut {
-    fn default() -> TxOut { TxOut { value: 0xffffffffffffffff, script_pubkey: ScriptBuf::new() } }
+    fn default() -> TxOut {
+        TxOut { value: Amount::from_sat(0xffffffffffffffff), script_pubkey: ScriptBuf::new() }
+    }
 }
 
 /// Result of [`Transaction::encode_signing_data_to`].
@@ -962,12 +964,7 @@ impl Transaction {
         let flags: u32 = flags.into();
         for (idx, input) in self.input.iter().enumerate() {
             if let Some(output) = spent(&input.previous_output) {
-                output.script_pubkey.verify_with_flags(
-                    idx,
-                    crate::Amount::from_sat(output.value),
-                    tx.as_slice(),
-                    flags,
-                )?;
+                output.script_pubkey.verify_with_flags(idx, output.value, tx.as_slice(), flags)?;
             } else {
                 return Err(script::Error::UnknownSpentOutput(input.previous_output));
             }
diff --git a/bitcoin/src/crypto/sighash.rs b/bitcoin/src/crypto/sighash.rs
@@ -22,7 +22,7 @@ use crate::consensus::{encode, Encodable};
 use crate::error::impl_std_error;
 use crate::prelude::*;
 use crate::taproot::{LeafVersion, TapLeafHash, TAPROOT_ANNEX_PREFIX};
-use crate::{io, Script, ScriptBuf, Sequence, Transaction, TxIn, TxOut};
+use crate::{io, Amount, Script, ScriptBuf, Sequence, Transaction, TxIn, TxOut};
 
 /// Used for signature hash for invalid use of SIGHASH_SINGLE.
 #[rustfmt::skip]
@@ -751,7 +751,7 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
         mut writer: Write,
         input_index: usize,
         script_code: &Script,
-        value: u64,
+        value: Amount,
         sighash_type: EcdsaSighashType,
     ) -> Result<(), Error> {
         let zero_hash = sha256d::Hash::all_zeros();
@@ -810,7 +810,7 @@ impl<R: Borrow<Transaction>> SighashCache<R> {
         &mut self,
         input_index: usize,
         script_code: &Script,
-        value: u64,
+        value: Amount,
         sighash_type: EcdsaSighashType,
     ) -> Result<SegwitV0Sighash, Error> {
         let mut enc = SegwitV0Sighash::engine();
@@ -1062,7 +1062,7 @@ impl<R: BorrowMut<Transaction>> SighashCache<R> {
     ///
     /// This allows in-line signing such as
     /// ```
-    /// use bitcoin::{absolute, Transaction, Script};
+    /// use bitcoin::{absolute, Amount, Transaction, Script};
     /// use bitcoin::sighash::{EcdsaSighashType, SighashCache};
     ///
     /// let mut tx_to_sign = Transaction { version: 2, lock_time: absolute::LockTime::ZERO, input: Vec::new(), output: Vec::new() };
@@ -1071,7 +1071,7 @@ impl<R: BorrowMut<Transaction>> SighashCache<R> {
     /// let mut sig_hasher = SighashCache::new(&mut tx_to_sign);
     /// for inp in 0..input_count {
     ///     let prevout_script = Script::empty();
-    ///     let _sighash = sig_hasher.segwit_signature_hash(inp, prevout_script, 42, EcdsaSighashType::All);
+    ///     let _sighash = sig_hasher.segwit_signature_hash(inp, prevout_script, Amount::ONE_SAT, EcdsaSighashType::All);
     ///     // ... sign the sighash
     ///     sig_hasher.witness_mut(inp).unwrap().push(&Vec::new());
     /// }
@@ -1468,7 +1468,7 @@ mod tests {
             #[serde(rename = "scriptPubKey")]
             script_pubkey: ScriptBuf,
             #[serde(rename = "amountSats")]
-            value: u64,
+            value: Amount,
         }
 
         #[derive(serde::Deserialize)]
@@ -1685,7 +1685,7 @@ mod tests {
 
         let witness_script =
             p2pkh_hex("025476c2e83188368da1ff3e292e7acafcdb3566bb0ad253f62fc70f07aeee6357");
-        let value = 600_000_000;
+        let value = Amount::from_sat(600_000_000);
 
         let mut cache = SighashCache::new(&tx);
         assert_eq!(
@@ -1726,7 +1726,7 @@ mod tests {
 
         let witness_script =
             p2pkh_hex("03ad1d8e89212f0b92c74d23bb710c00662ad1470198ac48c43f7d6f93a2a26873");
-        let value = 1_000_000_000;
+        let value = Amount::from_sat(1_000_000_000);
 
         let mut cache = SighashCache::new(&tx);
         assert_eq!(
@@ -1773,7 +1773,7 @@ mod tests {
              56ae",
         )
         .unwrap();
-        let value = 987654321;
+        let value = Amount::from_sat(987_654_321);
 
         let mut cache = SighashCache::new(&tx);
         assert_eq!(
diff --git a/bitcoin/src/psbt/mod.rs b/bitcoin/src/psbt/mod.rs
diff --git a/bitcoin/tests/psbt.rs b/bitcoin/tests/psbt.rs
diff --git a/bitcoin/tests/serde.rs b/bitcoin/tests/serde.rs
