318c4760c0
This modifies the code to only enforce the fairly expensive BIP0030 (duplicate transcactions) checks when the chain has not yet reached the BIP0034 activation height (and is not one of the 2 special historical blocks that break the rule and prompted BIP0034 to being with) since that BIP made it impossible to create duplicate coinbases and thus removed the possibility of creating transactions that overwrite older ones. This is a rather large optimization because the check is expensive due to involving a ton of cache misses in the utxoset. For example, the following are times it took to perform the BIP0030 check on blocks 425490 - 425502 and a system with a relatively old Hitachi spinner HDD: block 425490: 674.5857ms block 425491: 726.5923ms block 425492: 827.6051ms block 425493: 680.0863ms block 425494: 722.0917ms block 425495: 700.0889ms block 425496: 647.5823ms block 425497: 445.0565ms block 425498: 602.5765ms block 425499: 375.0476ms block 425500: 771.0979ms block 425501: 461.5586ms block 425502: 603.0766ms As can be seen from these numbers, this reduces the block validation time by an average of just over half a second for the given representative data set and hardware. Signed-off-by: Dave Collins <davec@conformal.com> |
||
|---|---|---|
| .. | ||
| fullblocktests | ||
| indexers | ||
| testdata | ||
| accept.go | ||
| bench_test.go | ||
| blocklocator.go | ||
| chain.go | ||
| chain_test.go | ||
| chainio.go | ||
| chainio_test.go | ||
| checkpoints.go | ||
| common_test.go | ||
| compress.go | ||
| compress_test.go | ||
| difficulty.go | ||
| difficulty_test.go | ||
| doc.go | ||
| error.go | ||
| error_test.go | ||
| example_test.go | ||
| fullblocks_test.go | ||
| internal_test.go | ||
| log.go | ||
| mediantime.go | ||
| mediantime_test.go | ||
| merkle.go | ||
| merkle_test.go | ||
| notifications.go | ||
| process.go | ||
| README.md | ||
| reorganization_test.go | ||
| scriptval.go | ||
| scriptval_test.go | ||
| thresholdstate.go | ||
| thresholdstate_test.go | ||
| timesorter.go | ||
| timesorter_test.go | ||
| utxoviewpoint.go | ||
| validate.go | ||
| validate_test.go | ||
| versionbits.go | ||
blockchain
[
]
(https://travis-ci.org/btcsuite/btcd) ![ISC License]
(http://img.shields.io/badge/license-ISC-blue.svg)
[
]
(http://godoc.org/github.com/btcsuite/btcd/blockchain)
Package blockchain implements bitcoin block handling and chain selection rules.
The test coverage is currently only around 60%, but will be increasing over
time. See test_coverage.txt for the gocov coverage report. Alternatively, if
you are running a POSIX OS, you can run the cov_report.sh script for a
real-time report. Package blockchain is licensed under the liberal ISC license.
There is an associated blog post about the release of this package here.
This package has intentionally been designed so it can be used as a standalone package for any projects needing to handle processing of blocks into the bitcoin block chain.
Installation and Updating
$ go get -u github.com/btcsuite/btcd/blockchain
Bitcoin Chain Processing Overview
Before a block is allowed into the block chain, it must go through an intensive series of validation rules. The following list serves as a general outline of those rules to provide some intuition into what is going on under the hood, but is by no means exhaustive:
- Reject duplicate blocks
- Perform a series of sanity checks on the block and its transactions such as verifying proof of work, timestamps, number and character of transactions, transaction amounts, script complexity, and merkle root calculations
- Compare the block against predetermined checkpoints for expected timestamps and difficulty based on elapsed time since the checkpoint
- Save the most recent orphan blocks for a limited time in case their parent blocks become available
- Stop processing if the block is an orphan as the rest of the processing depends on the block's position within the block chain
- Perform a series of more thorough checks that depend on the block's position within the block chain such as verifying block difficulties adhere to difficulty retarget rules, timestamps are after the median of the last several blocks, all transactions are finalized, checkpoint blocks match, and block versions are in line with the previous blocks
- Determine how the block fits into the chain and perform different actions accordingly in order to ensure any side chains which have higher difficulty than the main chain become the new main chain
- When a block is being connected to the main chain (either through reorganization of a side chain to the main chain or just extending the main chain), perform further checks on the block's transactions such as verifying transaction duplicates, script complexity for the combination of connected scripts, coinbase maturity, double spends, and connected transaction values
- Run the transaction scripts to verify the spender is allowed to spend the coins
- Insert the block into the block database
Examples
-
[ProcessBlock Example] (http://godoc.org/github.com/btcsuite/btcd/blockchain#example-BlockChain-ProcessBlock)
Demonstrates how to create a new chain instance and use ProcessBlock to attempt to attempt add a block to the chain. This example intentionally attempts to insert a duplicate genesis block to illustrate how an invalid block is handled. -
[CompactToBig Example] (http://godoc.org/github.com/btcsuite/btcd/blockchain#example-CompactToBig)
Demonstrates how to convert the compact "bits" in a block header which represent the target difficulty to a big integer and display it using the typical hex notation. -
[BigToCompact Example] (http://godoc.org/github.com/btcsuite/btcd/blockchain#example-BigToCompact)
Demonstrates how to convert how to convert a target difficulty into the compact "bits" in a block header which represent that target difficulty.
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 blockchain is licensed under the copyfree ISC License.