Add a Transaction.get_weight() method, check it in fuzzing

This commit is contained in:
Matt Corallo 2018-03-26 11:33:08 -04:00
parent f859dc8b26
commit 3793b2859a
2 changed files with 59 additions and 2 deletions

View File

@ -1,7 +1,19 @@
extern crate bitcoin; extern crate bitcoin;
type BResult = Result<bitcoin::blockdata::transaction::Transaction, bitcoin::util::Error>; type BResult = Result<bitcoin::blockdata::transaction::Transaction, bitcoin::util::Error>;
fn do_test(data: &[u8]) { fn do_test(data: &[u8]) {
let _: BResult = bitcoin::network::serialize::deserialize(data); let tx_result: BResult = bitcoin::network::serialize::deserialize(data);
match tx_result {
Err(_) => {},
Ok(mut tx) => {
let len = bitcoin::network::serialize::serialize(&tx).unwrap().len() as u64;
let calculated_weight = tx.get_weight();
for input in &mut tx.input {
input.witness = vec![];
}
let no_witness_len = bitcoin::network::serialize::serialize(&tx).unwrap().len() as u64;
assert_eq!(no_witness_len * 3 + len, calculated_weight);
},
}
} }
#[cfg(feature = "afl")] #[cfg(feature = "afl")]

View File

@ -33,7 +33,7 @@ use util::hash::Sha256dHash;
#[cfg(feature="bitcoinconsensus")] use blockdata::script; #[cfg(feature="bitcoinconsensus")] use blockdata::script;
use blockdata::script::Script; use blockdata::script::Script;
use network::serialize::{serialize, BitcoinHash, SimpleEncoder, SimpleDecoder}; use network::serialize::{serialize, BitcoinHash, SimpleEncoder, SimpleDecoder};
use network::encodable::{ConsensusEncodable, ConsensusDecodable}; use network::encodable::{ConsensusEncodable, ConsensusDecodable, VarInt};
/// A reference to a transaction output /// A reference to a transaction output
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)] #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
@ -209,6 +209,48 @@ impl Transaction {
Sha256dHash::from_data(&raw_vec) Sha256dHash::from_data(&raw_vec)
} }
/// Gets the "weight" of this transaction, as defined by BIP141. For transactions with an empty
/// witness, this is simply the consensus-serialized size times 4. For transactions with a
/// witness, this is the non-witness consensus-serialized size multiplied by 3 plus the
/// with-witness consensus-serialized size.
#[inline]
pub fn get_weight(&self) -> u64 {
let mut input_weight = 0;
let mut inputs_with_witnesses = 0;
for input in &self.input {
input_weight += 4*(32 + 4 + 4 + // outpoint (32+4) + nSequence
VarInt(input.script_sig.len() as u64).encoded_length() +
input.script_sig.len() as u64);
if !input.witness.is_empty() {
inputs_with_witnesses += 1;
input_weight += VarInt(input.witness.len() as u64).encoded_length();
for elem in &input.witness {
input_weight += VarInt(elem.len() as u64).encoded_length() + elem.len() as u64;
}
}
}
let mut output_size = 0;
for output in &self.output {
output_size += 8 + // value
VarInt(output.script_pubkey.len() as u64).encoded_length() +
output.script_pubkey.len() as u64;
}
let non_input_size =
// version:
4 +
// count varints:
VarInt(self.input.len() as u64).encoded_length() +
VarInt(self.output.len() as u64).encoded_length() +
output_size +
// lock_time
4;
if inputs_with_witnesses == 0 {
non_input_size * 4 + input_weight
} else {
non_input_size * 4 + input_weight + self.input.len() as u64 - inputs_with_witnesses + 2
}
}
#[cfg(feature="bitcoinconsensus")] #[cfg(feature="bitcoinconsensus")]
/// Verify that this transaction is able to spend some outputs of spent transactions /// Verify that this transaction is able to spend some outputs of spent transactions
pub fn verify (&self, spent : &HashMap<Sha256dHash, Transaction>) -> Result<(), script::Error> { pub fn verify (&self, spent : &HashMap<Sha256dHash, Transaction>) -> Result<(), script::Error> {
@ -431,6 +473,7 @@ mod tests {
assert_eq!(realtx.bitcoin_hash().be_hex_string(), assert_eq!(realtx.bitcoin_hash().be_hex_string(),
"a6eab3c14ab5272a58a5ba91505ba1a4b6d7a3a9fcbd187b6cd99a7b6d548cb7".to_string()); "a6eab3c14ab5272a58a5ba91505ba1a4b6d7a3a9fcbd187b6cd99a7b6d548cb7".to_string());
assert_eq!(realtx.get_weight(), 193*4);
} }
#[test] #[test]
@ -485,6 +528,7 @@ mod tests {
assert_eq!(tx.bitcoin_hash().be_hex_string(), "d6ac4a5e61657c4c604dcde855a1db74ec6b3e54f32695d72c5e11c7761ea1b4"); assert_eq!(tx.bitcoin_hash().be_hex_string(), "d6ac4a5e61657c4c604dcde855a1db74ec6b3e54f32695d72c5e11c7761ea1b4");
assert_eq!(tx.txid().be_hex_string(), "9652aa62b0e748caeec40c4cb7bc17c6792435cc3dfe447dd1ca24f912a1c6ec"); assert_eq!(tx.txid().be_hex_string(), "9652aa62b0e748caeec40c4cb7bc17c6792435cc3dfe447dd1ca24f912a1c6ec");
assert_eq!(tx.get_weight(), 2718);
// non-segwit tx from my mempool // non-segwit tx from my mempool
let hex_tx = hex_bytes( let hex_tx = hex_bytes(
@ -528,6 +572,7 @@ mod tests {
fn test_segwit_tx_decode() { fn test_segwit_tx_decode() {
let hex_tx = hex_bytes("010000000001010000000000000000000000000000000000000000000000000000000000000000ffffffff3603da1b0e00045503bd5704c7dd8a0d0ced13bb5785010800000000000a636b706f6f6c122f4e696e6a61506f6f6c2f5345475749542fffffffff02b4e5a212000000001976a914876fbb82ec05caa6af7a3b5e5a983aae6c6cc6d688ac0000000000000000266a24aa21a9edf91c46b49eb8a29089980f02ee6b57e7d63d33b18b4fddac2bcd7db2a39837040120000000000000000000000000000000000000000000000000000000000000000000000000").unwrap(); let hex_tx = hex_bytes("010000000001010000000000000000000000000000000000000000000000000000000000000000ffffffff3603da1b0e00045503bd5704c7dd8a0d0ced13bb5785010800000000000a636b706f6f6c122f4e696e6a61506f6f6c2f5345475749542fffffffff02b4e5a212000000001976a914876fbb82ec05caa6af7a3b5e5a983aae6c6cc6d688ac0000000000000000266a24aa21a9edf91c46b49eb8a29089980f02ee6b57e7d63d33b18b4fddac2bcd7db2a39837040120000000000000000000000000000000000000000000000000000000000000000000000000").unwrap();
let tx: Transaction = deserialize(&hex_tx).unwrap(); let tx: Transaction = deserialize(&hex_tx).unwrap();
assert_eq!(tx.get_weight(), 780);
let encoded = strason::from_serialize(&tx).unwrap(); let encoded = strason::from_serialize(&tx).unwrap();
let decoded = encoded.into_deserialize().unwrap(); let decoded = encoded.into_deserialize().unwrap();