btcd/blockchain
Dave Collins bd4e64d1d4 chainhash: Abstract hash logic to new package. (#729)
This is mostly a backport of some of the same modifications made in
Decred along with a few additional things cleaned up.  In particular,
this updates the code to make use of the new chainhash package.

Also, since this required API changes anyways and the hash algorithm is
no longer tied specifically to SHA, all other functions throughout the
code base which had "Sha" in their name have been changed to Hash so
they are not incorrectly implying the hash algorithm.

The following is an overview of the changes:

- Remove the wire.ShaHash type
- Update all references to wire.ShaHash to the new chainhash.Hash type
- Rename the following functions and update all references:
  - wire.BlockHeader.BlockSha -> BlockHash
  - wire.MsgBlock.BlockSha -> BlockHash
  - wire.MsgBlock.TxShas -> TxHashes
  - wire.MsgTx.TxSha -> TxHash
  - blockchain.ShaHashToBig -> HashToBig
  - peer.ShaFunc -> peer.HashFunc
- Rename all variables that included sha in their name to include hash
  instead
- Update for function name changes in other dependent packages such as
  btcutil
- Update copyright dates on all modified files
- Update glide.lock file to use the required version of btcutil
2016-08-08 14:04:33 -05:00
..
indexers chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
testdata blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
accept.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
bench_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
blocklocator.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
chain_test.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
chain.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
chainio_test.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
chainio.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
checkpoints.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
common_test.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
compress_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
compress.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
difficulty_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
difficulty.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
doc.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
error_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
error.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
example_test.go blockchain: Associate time src with chain instance. 2016-07-14 13:10:47 -05:00
internal_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
log.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
mediantime_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
mediantime.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
merkle_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
merkle.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
notifications.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
process.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
README.md docs: Make various README.md files consistent. 2015-10-23 14:51:36 -05:00
reorganization_test.go blockchain: Associate time src with chain instance. 2016-07-14 13:10:47 -05:00
scriptval_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
scriptval.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
timesorter_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
timesorter.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
utxoviewpoint.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
validate_test.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
validate.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00

blockchain

[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/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

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 blockchain is licensed under the copyfree ISC License.