6c6da6df18
Part of adding nodes to the block index involves updating the current chain tip in order to be able to efficiently keep track of all known chain tips. Since there can be multiple tips at a given height, the current code uses a slice for each height to track them. However, this is wasteful since it is extremely rare for there to be more than one chain tip at the same height. It is particularly notable at startup since the block index has to load up hundreds of thousands of nodes. Given that, this modifies the chain tip tracking logic to avoid creating a slice unless it is actually needed by making use of an entry with a static field for the normal case and a dynamic slice for the case when more than 1 tip for the height actually exists. It also keeps a running sum of the total number of known chips for use as a hint to further reduce allocations when serving up related data and updates the chain tip tests to ensure 100% branch coverage is maintained. The end result is that this reduces the total number of allocs at startup by around 1%, which results in faster startup, and also reduces the overall memory usage by a few MB for nodes that have a long running history of side chains. |
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| .. | ||
| chaingen | ||
| fullblocktests | ||
| indexers | ||
| internal/progresslog | ||
| stake | ||
| standalone | ||
| testdata | ||
| accept.go | ||
| agendas_test.go | ||
| bench_test.go | ||
| blockindex_test.go | ||
| blockindex.go | ||
| chain_test.go | ||
| chain.go | ||
| chainio_test.go | ||
| chainio.go | ||
| chainquery.go | ||
| chainview_test.go | ||
| chainview.go | ||
| checkpoints.go | ||
| common_test.go | ||
| compress_test.go | ||
| compress.go | ||
| difficulty_test.go | ||
| difficulty.go | ||
| doc.go | ||
| error_test.go | ||
| error.go | ||
| example_test.go | ||
| fullblocks_test.go | ||
| fullblocksstakeversion_test.go | ||
| go.mod | ||
| go.sum | ||
| headercmt_test.go | ||
| headercmt.go | ||
| log.go | ||
| mediantime_test.go | ||
| mediantime.go | ||
| notifications.go | ||
| process_test.go | ||
| process.go | ||
| prune.go | ||
| README.md | ||
| scriptval.go | ||
| sequencelock_test.go | ||
| sequencelock.go | ||
| stakeext.go | ||
| stakenode.go | ||
| stakeversion_test.go | ||
| stakeversion.go | ||
| subsidy.go | ||
| thresholdstate_test.go | ||
| thresholdstate.go | ||
| timesorter_test.go | ||
| timesorter.go | ||
| upgrade.go | ||
| utxoviewpoint_test.go | ||
| utxoviewpoint.go | ||
| validate_test.go | ||
| validate.go | ||
| votebits_test.go | ||
| votebits.go | ||
blockchain
Package blockchain implements Decred 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 decred block chain.
Installation and Updating
$ go get -u github.com/decred/dcrd/blockchain
Decred 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
- 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 add a block to the chain. This example intentionally attempts to insert a duplicate genesis block to illustrate how an invalid block is handled.
License
Package blockchain is licensed under the copyfree ISC License.