lbcd/blockchain
Dave Collins 9f0e66ee3f
blockchain: Correct invalid assertion.
This corrects the assertion in the decodeSpentTxOut function so it does
not improperly cause a panic when unwinding transactions during a reorg
under certain circumstances.  In particular, the provided transaction
version that is passed when a stxo entry does not exist is now -1 in
order to properly distinguish it from the zero value.

It also updates the tests accordingly.

This was discovered by the reorg on testnet from block
00000000000018c58c2d2816f03dac327d975a18af6edf1a369df67ecddaf816 to
0000000000001c1161a367156465cc6226e9f862d9c585f94db5779fdf5455ff.
2017-07-01 02:25:41 -05:00
..
fullblocktests multi: Update markdown files for GFM changes. 2017-05-25 12:06:16 -05:00
indexers multi: Update markdown files for GFM changes. 2017-05-25 12:06:16 -05:00
testdata blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
accept.go blockchain: Refactor main block index logic. 2017-02-01 13:14:41 -06:00
bench_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
blockindex.go blockchain: Use hash values in structs. 2017-02-03 11:36:33 -06:00
blocklocator.go blockchain: Use hash values in structs. 2017-02-03 11:36:33 -06:00
chain.go multi: Simplify code per gosimple linter. 2017-07-01 02:25:10 -05:00
chain_test.go rpctest: Make subpackage of integration. 2017-05-11 15:17:29 -05:00
chainio.go blockchain: Correct invalid assertion. 2017-07-01 02:25:41 -05:00
chainio_test.go blockchain: Correct invalid assertion. 2017-07-01 02:25:41 -05:00
checkpoints.go multi: Improvements to configurable checkpoints. 2017-01-23 12:07:54 -06:00
common_test.go blockchain: Allow adding additional checkpoints 2017-01-18 23:56:43 +01:00
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 blockchain: Refactor main block index logic. 2017-02-01 13:14:41 -06:00
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 Implement infrastructure for BIP0009. 2016-11-30 13:51:59 -06:00
error_test.go Implement infrastructure for BIP0009. 2016-11-30 13:51:59 -06:00
example_test.go blockchain: Expose main chain flag on ProcessBlock. 2016-10-13 16:47:50 -05:00
fullblocks_test.go blockchain: Use hash values in structs. 2017-02-03 11:36:33 -06:00
internal_test.go blockchain: Use int64 timestamps in block nodes. 2017-01-31 17:51:29 -06:00
log.go all: Remove seelog logger. 2017-06-19 16:46:50 -04:00
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: Ignore side chains in exists check. 2017-02-03 11:02:35 -06:00
README.md multi: Update markdown files for GFM changes. 2017-05-25 12:06:16 -05:00
reorganization_test.go multi: Simplify code per gosimple linter. 2017-07-01 02:25:10 -05:00
scriptval.go multi: Simplify code per gosimple linter. 2016-11-03 13:00:35 -05:00
scriptval_test.go blockchain: make scriptval_test fail more nicely 2016-09-16 15:44:27 -04:00
thresholdstate.go Fix a ton of typos accumulated over time 2017-05-30 16:59:51 +02:00
thresholdstate_test.go blockchain: Use hash values in structs. 2017-02-03 11:36:33 -06:00
timesorter.go blockchain: Use int64 timestamps in block nodes. 2017-01-31 17:51:29 -06:00
timesorter_test.go blockchain: Use int64 timestamps in block nodes. 2017-01-31 17:51:29 -06:00
utxoviewpoint.go multi: Simplify code per gosimple linter. 2017-07-01 02:25:10 -05:00
validate.go Fix a ton of typos accumulated over time 2017-05-30 16:59:51 +02:00
validate_test.go wire: Make NewMsgTx accept the tx version. 2016-10-27 14:09:29 -05:00
versionbits.go blockchain: Refactor main block index logic. 2017-02-01 13:14:41 -06:00

blockchain

Build Status ISC License GoDoc

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
    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
    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
    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_NAME is a placeholder for the specific tag:

    git tag -v TAG_NAME
    

License

Package blockchain is licensed under the copyfree ISC License.