67e2cbe374
This converts the IsMultisigScript function to make use of the new tokenizer instead of the far less efficient parseScript thereby significantly optimizing the function. In order to accomplish this, it introduces two new functions. The first one is named extractMultisigScriptDetails and works with the raw script bytes to simultaneously determine if the script is a multisignature script, and in the case it is, extract and return the relevant details. The second new function is named isMultisigScript and is defined in terms of the former. The extract function accepts the script version, raw script bytes, and a flag to determine whether or not the public keys should also be extracted. The flag is provided because extracting pubkeys results in an allocation that the caller might wish to avoid. The extract function approach was chosen because it is common for callers to want to only extract relevant details from a script if the script is of the specific type. Extracting those details requires performing the exact same checks to ensure the script is of the correct type, so it is more efficient to combine the two into one and define the type determination in terms of the result so long as the extraction does not require allocations. It is important to note that this new implementation intentionally has a semantic difference from the existing implementation in that it will now correctly identify a multisig script with zero pubkeys whereas previously it incorrectly required at least one pubkey. This change is acceptable because the function only deals with standardness rather than consensus rules. Finally, this also deprecates the isMultiSig function that requires opcodes in favor of the new functions and deprecates the error return on the export IsMultisigScript function since it really does not make sense given the purpose of the function. The following is a before and after comparison of analyzing both a large script that is not a multisig script and a 1-of-2 multisig public key script: benchmark old ns/op new ns/op delta BenchmarkIsMultisigScriptLarge-8 64166 5.52 -99.99% BenchmarkIsMultisigScript-8 630 59.4 -90.57% benchmark old allocs new allocs delta BenchmarkIsMultisigScriptLarge-8 1 0 -100.00% BenchmarkIsMultisigScript-8 1 0 -100.00% benchmark old bytes new bytes delta BenchmarkIsMultisigScriptLarge-8 311299 0 -100.00% BenchmarkIsMultisigScript-8 2304 0 -100.00% |
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|---|---|---|
| .. | ||
| data | ||
| bench_test.go | ||
| consensus.go | ||
| doc.go | ||
| engine.go | ||
| engine_test.go | ||
| error.go | ||
| error_test.go | ||
| example_test.go | ||
| hashcache.go | ||
| hashcache_test.go | ||
| log.go | ||
| opcode.go | ||
| opcode_test.go | ||
| pkscript.go | ||
| pkscript_test.go | ||
| README.md | ||
| reference_test.go | ||
| script.go | ||
| script_test.go | ||
| scriptbuilder.go | ||
| scriptbuilder_test.go | ||
| scriptnum.go | ||
| scriptnum_test.go | ||
| sigcache.go | ||
| sigcache_test.go | ||
| sign.go | ||
| sign_test.go | ||
| stack.go | ||
| stack_test.go | ||
| standard.go | ||
| standard_test.go | ||
| tokenizer.go | ||
| tokenizer_test.go | ||
txscript
Package txscript implements the bitcoin transaction script language. There is a comprehensive test suite.
This package has intentionally been designed so it can be used as a standalone package for any projects needing to use or validate bitcoin transaction scripts.
Bitcoin Scripts
Bitcoin provides a stack-based, FORTH-like language for the scripts in the bitcoin transactions. This language is not turing complete although it is still fairly powerful. A description of the language can be found at https://en.bitcoin.it/wiki/Script
Installation and Updating
$ go get -u github.com/btcsuite/btcd/txscript
Examples
-
Standard Pay-to-pubkey-hash Script
Demonstrates creating a script which pays to a bitcoin address. It also prints the created script hex and uses the DisasmString function to display the disassembled script. -
Extracting Details from Standard Scripts
Demonstrates extracting information from a standard public key script. -
Manually Signing a Transaction Output
Demonstrates manually creating and signing a redeem transaction. -
Counting Opcodes in Scripts
Demonstrates creating a script tokenizer instance and using it to count the number of opcodes a script contains.
GPG Verification Key
All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:
-
Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt
-
Import the public key into your GPG keyring:
gpg --import GIT-GPG-KEY-conformal.txt -
Verify the release tag with the following command where
TAG_NAMEis a placeholder for the specific tag:git tag -v TAG_NAME
License
Package txscript is licensed under the copyfree ISC License.