btcd/blockchain
Dave Collins 7c174620f7 indexers: Implement optional tx/address indexes.
This introduces a new indexing infrastructure for supporting optional
indexes using the new database and blockchain infrastructure along with
two concrete indexer implementations which provide both a
transaction-by-hash and a transaction-by-address index.

The new infrastructure is mostly separated into a package named indexers
which is housed under the blockchain package.  In order to support this,
a new interface named IndexManager has been introduced in the blockchain
package which provides methods to be notified when the chain has been
initialized and when blocks are connected and disconnected from the main
chain.  A concrete implementation of an index manager is provided by the
new indexers package.

The new indexers package also provides a new interface named Indexer
which allows the index manager to manage concrete index implementations
which conform to the interface.

The following is high level overview of the main index infrastructure
changes:

- Define a new IndexManager interface in the blockchain package and
  modify the package to make use of the interface when specified
- Create a new indexers package
  - Provides an Index interface which allows concrete indexes to plugin
    to an index manager
  - Provides a concrete IndexManager implementation
    - Handles the lifecycle of all indexes it manages
    - Tracks the index tips
    - Handles catching up disabled indexes that have been reenabled
    - Handles reorgs while the index was disabled
    - Invokes the appropriate methods for all managed indexes to allow
      them to index and deindex the blocks and transactions
  - Implement a transaction-by-hash index
    - Makes use of internal block IDs to save a significant amount of
      space and indexing costs over the old transaction index format
  - Implement a transaction-by-address index
    - Makes use of a leveling scheme in order to provide a good tradeoff
      between space required and indexing costs
- Supports enabling and disabling indexes at will
- Support the ability to drop indexes if they are no longer desired

The following is an overview of the btcd changes:

- Add a new index logging subsystem
- Add new options --txindex and --addrindex in order to enable the
  optional indexes
  - NOTE: The transaction index will automatically be enabled when the
    address index is enabled because it depends on it
- Add new options --droptxindex and --dropaddrindex to allow the indexes
  to be removed
  - NOTE: The address index will also be removed when the transaction
    index is dropped because it depends on it
- Update getrawtransactions RPC to make use of the transaction index
- Reimplement the searchrawtransaction RPC that makes use of the address
  index
- Update sample-btcd.conf to include sample usage for the new optional
  index flags
2016-04-11 17:16:42 -05:00
..
indexers indexers: Implement optional tx/address indexes. 2016-04-11 17:16:42 -05:00
testdata blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
accept.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
bench_test.go Relicense to the btcsuite developers. 2015-05-01 12:00:56 -05:00
blocklocator.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
chain_test.go multi: Fix several misspellings in the comments. 2016-02-25 11:17:12 -06:00
chain.go indexers: Implement optional tx/address indexes. 2016-04-11 17:16:42 -05:00
chainio_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
chainio.go indexers: Implement optional tx/address indexes. 2016-04-11 17:16:42 -05:00
checkpoints.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
common_test.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
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 blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -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: Rework to use new db interface. 2016-04-11 16:47:27 -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 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: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
README.md docs: Make various README.md files consistent. 2015-10-23 14:51:36 -05:00
reorganization_test.go multi: Update with result of gofmt -s. 2016-02-25 13:02:54 -06:00
scriptval_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
scriptval.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -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 blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
validate_test.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -05:00
validate.go blockchain: Rework to use new db interface. 2016-04-11 16:47:27 -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.