lbcd/txscript
Olaoluwa Osuntokun 3b39edcaa1 txscript: optimize sigcache lookup (#598)
Profiles discovered that lookups into the signature cache included an
expensive comparison to the stored `sigInfo` struct. This lookup had the
potential to be more expensive than directly verifying the signature
itself!

In addition, evictions were rather expensive because they involved
reading from /dev/urandom, or equivalent, for each eviction once the
signature cache was full as well as potentially iterating over every
item in the cache in the worst-case.

To remedy this poor performance several changes have been made:
* Change the lookup key to the fixed sized 32-byte signature hash
* Perform a full equality check only if there is a cache hit which
    results in a significant  speed up for both insertions and existence
checks
* Override entries in the case of a colliding hash on insert Add an
* .IsEqual() method to the Signature and PublicKey types in the
  btcec package to facilitate easy equivalence testing
* Allocate the signature cache map with the max number of entries in
  order to avoid unnecessary map re-sizes/allocations
* Optimize evictions from the signature cache Delete the first entry
* seen which is safe from manipulation due to
    the pre image resistance of the hash function
* Double the default maximum number of entries within the signature
  cache due to the reduction in the size of a cache entry
  * With this eviction scheme, removals are effectively O(1)

Fixes #575.
2016-04-13 21:56:10 -05:00
..
data txscript: sync Bitcoin Core script tests 2015-12-30 09:38:16 -05:00
consensus.go Revert "Move IsFinalizedTransaction to txscript." 2015-06-29 11:12:35 -04:00
doc.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
engine.go txscript: Correct comments on alt stack methods. (#657) 2016-04-11 14:22:25 -05:00
engine_test.go Integrate a valid ECDSA signature cache into btcd 2015-10-08 17:31:42 -07:00
error.go multi: Fix several misspellings in the comments. 2016-02-25 11:17:12 -06:00
example_test.go Integrate a valid ECDSA signature cache into btcd 2015-10-08 17:31:42 -07:00
internal_test.go Add signature hash calculation tests from Bitcoin Core. 2015-11-15 16:39:00 -05:00
log.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
log_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
opcode.go txscript: Comment improvements and fixes 2016-02-11 21:43:32 -06:00
opcode_test.go txscript: Implement CheckLockTimeVerify (BIP0065) 2015-10-14 13:19:49 -04:00
README.md txscript: Fix typo in README 2016-01-29 12:39:11 -08:00
reference_test.go txscript: optimize sigcache lookup (#598) 2016-04-13 21:56:10 -05:00
script.go multi: Fix several misspellings in the comments. 2016-02-25 11:17:12 -06:00
script_test.go txscript: New function IsUnspendable 2015-08-03 10:10:23 -04:00
scriptbuilder.go multi: Fix several misspellings in the comments. 2016-02-25 11:17:12 -06:00
scriptbuilder_test.go txscript: Test consistency and cleanup. 2015-05-04 16:04:29 -05:00
scriptnum.go txscript: Change makeScriptNum to take a length argument 2015-10-05 19:48:55 -04:00
scriptnum_test.go txscript: Change makeScriptNum to take a length argument 2015-10-05 19:48:55 -04:00
sigcache.go txscript: optimize sigcache lookup (#598) 2016-04-13 21:56:10 -05:00
sigcache_test.go Review and fix typos in SigCache code. 2015-12-30 11:57:15 -07:00
sign.go multi: Fix several misspellings in the comments. 2016-02-25 11:17:12 -06:00
sign_test.go multi: Update with result of gofmt -s. 2016-02-25 13:02:54 -06:00
stack.go txscript: Change makeScriptNum to take a length argument 2015-10-05 19:48:55 -04:00
stack_test.go Remove duplicate stack tests. 2016-02-09 11:17:04 -06:00
standard.go txscript: fix isMultiSig bug. 2015-10-22 15:55:34 -04:00
standard_test.go txscript: fix isMultiSig bug. 2015-10-22 15:55:34 -04:00

txscript

[Build Status] (https://travis-ci.org/btcsuite/btcd) ![ISC License] (http://img.shields.io/badge/license-ISC-blue.svg) [GoDoc] (http://godoc.org/github.com/btcsuite/btcd/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

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_NAME is a placeholder for the specific tag:

    git tag -v TAG_NAME
    

License

Package txscript is licensed under the copyfree ISC License.