c134b1a4bc
6f113cb184txgraph: use fallback order to sort chunks (feature) (Pieter Wuille)0a3351947etxgraph: use fallback order when linearizing (feature) (Pieter Wuille)fba004a3dftxgraph: pass fallback_order to TxGraph (preparation) (Pieter Wuille)941c432a46txgraph test: subclass TxGraph::Ref like mempool does (preparation) (Pieter Wuille)39d0052cbfclusterlin: make optimal linearizations deterministic (feature) (Pieter Wuille)8bfbba3207txgraph: sort distinct-cluster chunks by equal-feerate-prefix size (feature) (Pieter Wuille)e0bc73ba92clusterlin: sort tx in chunk by feerate and size (feature) (Pieter Wuille)6c1bcb2c7ctxgraph: clear cluster's chunk index in ~Ref (preparation) (Pieter Wuille)7427c7d098txgraph: update chunk index on Compact (preparation) (Pieter Wuille)3ddafceb9atxgraph: initialize Ref in AddTransaction (preparation) (Pieter Wuille) Pull request description: Part of #30289. TxGraph's fundamental responsibility is deciding the order of transactions in the mempool. It relies on the `cluster_linearize.h` code to optimize it, but there can and often will be many different orderings that are essentially equivalent from a quality perspective, so we have to pick one. At a high level, the solution will involve one or more of: * Deciding based on **internal identifiers** (`Cluster::m_sequence`, `DepGraphIndex`). This is very simple, but risks leaking information about transaction receive order. * Deciding **randomly**, which is private, but may interfere with relay expectations, block propagation, and ability to monitor network behavior. * Deciding **based on txid**, which is private and deterministic, but risks incentivizing grinding to get an edge (though we haven't really seen such behavior). * Deciding **based on size** (e.g. prefer smaller transactions), which is somewhat related to quality, but not unconditionally (depending on mempool layout, the ideal ordering might call for smaller transactions first, last, or anywhere in between). It's also not a strong ordering as there can be many identically-sized transactions. However, if it were to encourage grinding behavior, incentivizing smaller transactions is probably not a bad thing. As of #32545, the current behavior is primarily picking randomly, though inconsistently, as some code paths also use internal identifiers and size. #33335 sought to change it to use random (preferring size in a few places), with the downsides listed above. This PR is an alternative to that, which changes the order to tie-break based on size everywhere possible, and use lowest-txid-first as final fallback. This is fully deterministic: for any given set of mempool transactions, if all linearized optimally, the transaction order exposed by TxGraph is deterministic. The transactions within a chunk are sorted according to: 1. `PostLinearize` (which improves sub-chunk order), using an initial linearization created using the rules 2-5 below. 2. Topology (parents before children). 3. Individual transaction feerate (high to low) 4. Individual transaction weight (small to large) 5. Txid (low to high txid) The chunks within a cluster are sorted according to: 1. Topology (chunks after their dependencies) 2. Chunk feerate (high to low) 3. Chunk weight (small to large) 4. Max-txid (chunk with lowest maximum-txid first) The chunks across clusters are sorted according to: 1. Feerate (high to low) 2. Equal-feerate-chunk-prefix weight (small to large) 3. Max-txid (chunk with lowest maximum-txid first) The equal-feerate-chunk-prefix weight of a chunk C is defined as the sum of the weights of all chunks in the same cluster as C, with the same feerate as C, up to and including C itself, in linearization order (but excluding such chunks that appear after C). This is a well-defined approximation of sorting chunks from small to large across clusters, while remaining consistent with intra-cluster linearization order. ACKs for top commit: ajtowns: reACK6f113cb184it was good before and now it's better instagibbs: ACK6f113cb184marcofleon: light crACK6f113cb184Tree-SHA512: 16dc43c62b7e83c81db1ee14c01e068ae2f06c1ffaa0898837d87271fa7179dd98baeb74abc9fe79220e01fdba6876defe60022c2b72badc21d770644a0fe0ac
Bitcoin Core integration/staging tree
For an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/.
What is Bitcoin Core?
Bitcoin Core connects to the Bitcoin peer-to-peer network to download and fully validate blocks and transactions. It also includes a wallet and graphical user interface, which can be optionally built.
Further information about Bitcoin Core is available in the doc folder.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/license/MIT.
Development Process
The master branch is regularly built (see doc/build-*.md for instructions) and tested, but it is not guaranteed to be
completely stable. Tags are created
regularly from release branches to indicate new official, stable release versions of Bitcoin Core.
The https://github.com/bitcoin-core/gui repository is used exclusively for the development of the GUI. Its master branch is identical in all monotree repositories. Release branches and tags do not exist, so please do not fork that repository unless it is for development reasons.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled during the generation of the build system) with: ctest. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python.
These tests can be run (if the test dependencies are installed) with: build/test/functional/test_runner.py
(assuming build is your build directory).
The CI (Continuous Integration) systems make sure that every pull request is tested on Windows, Linux, and macOS. The CI must pass on all commits before merge to avoid unrelated CI failures on new pull requests.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.