lbcd/blockchain
Dave Collins 1cba5c8fc0
blockchain: Remove exported CalcPastTimeMedian func.
This removes the exported CalcPastTimeMedian function from the
blockchain package as it is no longer needed since the information is
now available via the BestState snapshot.

Also, update the only known caller of this, which is the chain state in
block manager, to use the snapshot instead.  In reality, now that
everything the block manager chain state provides is available via the
blockchain BestState snapshot, the entire thing can be removed, however
that will be done in a separate to commit to keep the changes targeted.
2016-10-17 10:41:25 -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 blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -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.go blockchain: Remove exported CalcPastTimeMedian func. 2016-10-17 10:41:25 -05:00
chain_test.go blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -05:00
chainio.go blockchain: Add median time to state snapshot. 2016-08-23 01:29:11 -05:00
chainio_test.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 chaincfg/blockchain: Parameterize more chain consts. (#732) 2016-08-10 16:02:23 -05:00
compress.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
compress_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
difficulty.go chaincfg/blockchain: Parameterize more chain consts. (#732) 2016-08-10 16:02:23 -05:00
difficulty_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
doc.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
error_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
example_test.go blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -05:00
internal_test.go chaincfg/blockchain: Parameterize more chain consts. (#732) 2016-08-10 16:02:23 -05:00
log.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
mediantime_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
merkle_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
notifications.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
process.go blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -05:00
README.md docs: Make various README.md files consistent. 2015-10-23 14:51:36 -05:00
reorganization_test.go blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -05:00
scriptval.go chainhash: Abstract hash logic to new package. (#729) 2016-08-08 14:04:33 -05:00
scriptval_test.go blockchain: make scriptval_test fail more nicely 2016-09-16 15:44:27 -04:00
timesorter.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
timesorter_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
utxoviewpoint.go mempool: Add basic test harness infrastructure. 2016-08-24 10:04:40 -05:00
validate.go chaincfg/blockchain: Parameterize more chain consts. (#732) 2016-08-10 16:02:23 -05:00
validate_test.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.