bf57746c3b
This existing code for calculating treasury spend window values, namely CalculateTSpendWindowStart and CalculateTSpendWindowEnd, has a couple of footguns: - The starting value calculation returns totally invalid values without an error when provided with a expiry that is prior to the first voting window - Expiry values that are invalid for the start calc are valid for the end calc even though they should not be As a result, the code for handling the error paths in the rpc server and mining code produces error messages that don't make sense in some cases because they blindly print the start value without checking the error. To remove the aforementioned footguns and also address the incorrect error messages, the following overview of changes are made: - Replaces the CalculateTSpendWindowStart and CalculateTSpendWindowEnd functions with a single combined CalcTSpendWindow function that properly checks for expiries before the first possible voting interval - Modifies the returned errors to match the new reality - Shortens the prefix to Calc to match the rest of the function names in the package - Updates the incorrect error handling paths to avoid reporting the values that are not guaranteed to be meaningful and modifies the error messages to be more consistent - Adds a comprehensive set of tests for the new function Note that in addition to addressing the aforementioned issues, this approach has at least a couple of other benefits: - It is more efficient to have a single function with a single bounds check - Almost all callers outside of the tests need both the start and end value anyway, so it allows more compact code Finally, this updates all callers in the repository accordingly. |
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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 | ||
| treasury_test.go | ||
| treasury.go | ||
| upgrade_test.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.