Previously Bitcoin would send 1/4 of transactions out to all peers instantly. This causes high overhead because it makes >80% of INVs size 1. Doing so harms privacy, because it limits the amount of source obscurity a transaction can receive. These randomized broadcasts also disobeyed transaction dependencies and required use of the orphan pool. Because the orphan pool is so small this leads to poor propagation for dependent transactions. When the bypass wasn't in effect, transactions were sent in the order they were received. This avoided creating orphans but undermines privacy fairly significantly. This commit: Eliminates the bypass. The bypass is replaced by halving the average delay for outbound peers. Sorts candidate transactions for INV by their topological depth then by their feerate (then hash); removing the information leakage and providing priority service to higher fee transactions. Limits the amount of transactions sent in a single INV to 7tx/sec (and twice that for outbound); this limits the harm of low fee transaction floods, gives faster relay service to higher fee transactions. The 7 sounds lower than it really is because received advertisements need not be sent, and because the aggregate rate is multipled by the number of peers. |
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.tx | ||
build-aux/m4 | ||
contrib | ||
depends | ||
doc | ||
qa | ||
share | ||
src | ||
.gitattributes | ||
.gitignore | ||
.travis.yml | ||
CONTRIBUTING.md | ||
COPYING | ||
INSTALL | ||
Makefile.am | ||
README.md | ||
autogen.sh | ||
configure.ac | ||
libbitcoinconsensus.pc.in |
README.md
Bitcoin Core integration/staging tree
What is Bitcoin?
Bitcoin is an experimental new digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information, as well as an immediately useable, binary version of the Bitcoin Core software, see https://bitcoin.org/en/download, or read the original whitepaper.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master
branch is regularly built and tested, but is not guaranteed to be
completely stable. Tags are created
regularly to indicate new official, stable release versions of Bitcoin Core.
The contribution workflow is described in CONTRIBUTING.md.
The developer mailing list should be used to discuss complicated or controversial changes before working on a patch set.
Developer IRC can be found on Freenode at #bitcoin-core-dev.
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 in configure) with: make check
There are also regression and integration tests of the RPC interface, written
in Python, that are run automatically on the build server.
These tests can be run (if the test dependencies are installed) with: qa/pull-tester/rpc-tests.py
The Travis CI system makes sure that every pull request is built for Windows and Linux, OS X, and that unit and sanity tests are automatically run.
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.
Translators should also subscribe to the mailing list.