dcrd/txscript
Dave Collins 9f2f038842
txscript: Optimize IsPayToScriptHash.
This converts the IsPayToScriptHash function to analyze the raw script
instead of using 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 extractScriptHash and works with the raw script bytes to
simultaneously determine if the script is a p2sh script, and in the case
it is, extract and return the hash.  The second new function is named
isScriptHashScript and is defined in terms of the former.

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.

Finally, this also deprecates the isScriptHash function that requires
opcodes in favor of the new functions and modifies the comment on
IsPayToScriptHash to explicitly call out the script version semantics.

The following is a before and after comparison of analyzing a large
script that is not a p2sh script:

benchmark                    old ns/op    new ns/op    delta
---------------------------------------------------------------
BenchmarkIsPayToScriptHash   139961       0.66         -100.00%

benchmark                    old allocs   new allocs   delta
---------------------------------------------------------------
BenchmarkIsPayToScriptHash   1            0            -100.00%

benchmark                    old bytes    new bytes    delta
---------------------------------------------------------------
BenchmarkIsPayToScriptHash   466944       0            -100.00%
2019-03-26 14:51:02 -05:00
..
data txscript: Add remove signature reference test. 2019-02-14 14:10:12 -06:00
bench_test.go txscript: Add benchmark for IsPayToScriptHash. 2019-03-26 14:51:01 -05:00
consensus_test.go multi: Break coinbase dep on standardness rules. 2018-05-08 12:49:40 -05:00
consensus.go txscript: Significantly improve errors. 2018-07-01 15:04:59 -05:00
doc.go txscript: Significantly improve errors. 2018-07-01 15:04:59 -05:00
engine_test.go txscript: Remove DER signature verification flag. 2018-07-02 12:02:28 -05:00
engine.go txscript: Tighten standardness pubkey checks. 2019-03-11 19:33:27 -05:00
error_test.go txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00
error.go txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00
example_test.go txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00
go.mod multi: Add go 1.11 directive to all modules. 2019-03-18 02:02:35 -05:00
go.sum multi: Remove non-root module replacements. 2019-02-08 18:01:43 -06:00
log.go multi: deprecate DisableLog 2019-03-18 11:16:35 -05:00
opcode_test.go multi: cleanup linter warnings 2019-02-13 08:38:25 -05:00
opcode.go txscript: Optimize script disasm. 2019-03-26 14:50:57 -05:00
README.md txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00
reference_test.go txscript: Convert sighash calc tests. 2019-03-26 14:50:59 -05:00
script_test.go txscript: Introduce raw script sighash calc func. 2019-03-26 14:50:57 -05:00
script.go txscript: Optimize IsPayToScriptHash. 2019-03-26 14:51:02 -05:00
scriptbuilder_test.go txscript: Significantly improve errors. 2018-07-01 15:04:59 -05:00
scriptbuilder.go txscript: code cleanup 2019-02-08 09:18:53 -05:00
scriptnum_test.go txscript: Remove script num require minimal flag. 2018-07-02 12:14:15 -05:00
scriptnum.go txscript: Introduce constant for max CSV bytes. 2019-03-12 10:26:04 -05:00
sigcache_test.go multi: Remove unused secp256k1 sig parse parameter. 2018-07-04 12:27:34 -05:00
sigcache.go multi: release the mutex earlier 2018-02-13 13:55:02 -06:00
sighash_test.go txscript: Decouple and optimize sighash calc. 2018-05-01 08:51:41 -05:00
sighash.go txscript: Optimize CalcSignatureHash. 2019-03-26 14:50:58 -05:00
sign_test.go txscript: code cleanup 2019-02-08 09:18:53 -05:00
sign.go txscript: code cleanup 2019-02-08 09:18:53 -05:00
stack_test.go txscript: Make PeekInt consistent with PopInt. 2018-07-02 12:14:37 -05:00
stack.go txscript: code cleanup 2019-02-08 09:18:53 -05:00
standard_test.go txscript: Tighten standardness pubkey checks. 2019-03-11 19:33:27 -05:00
standard.go txscript: Make isStakeOpcode accept raw opcode. 2019-03-26 14:51:01 -05:00
tokenizer_test.go txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00
tokenizer.go txscript: Introduce zero-alloc script tokenizer. 2019-03-26 14:50:56 -05:00

txscript

Build Status ISC License GoDoc

Package txscript implements the Decred 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 Decred transaction scripts.

Decred Scripts

Decred provides a stack-based, FORTH-like language for the scripts in the Decred transactions. This language is not turing complete although it is still fairly powerful.

Installation and Updating

$ go get -u github.com/decred/dcrd/txscript

Examples

License

Package txscript is licensed under the copyfree ISC License.