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Wladimir J. van der Laan 6b9405e319
Merge #16957: 9% less memory: make SaltedOutpointHasher noexcept
67d99900b0 make SaltedOutpointHasher noexcept (Martin Ankerl)

Pull request description:

  If the hash is not `noexcept`, `unorderd_map` has to assume that it can throw an exception. Thus when rehashing care needs to be taken. libstdc++ solves this by simply caching the hash value, which increases memory of each node by 8 bytes. Adding `noexcept` prevents this caching. In my experiments with `-reindex-chainstate -stopatheight=594000`, memory usage (maximum resident set size) has decreased by 9.4% while runtime has increased by 1.6% due to additional hashing. Additionally, memusage::DynamicUsage() is now more accurate and does not underestimate.

  |                                       | runtime h:mm:ss | max RSS kbyte |
  |---------------------------------------|-----------------|--------------|
  | master                                |         4:13:59 |      7696728 |
  | 2019-09-SaltedOutpointHasher-noexcept |         4:18:11 |      6971412 |
  | change                                |          +1.65% |       -9,42% |

  Comparison of progress masters vs. 2019-09-SaltedOutpointHasher-noexcept
  ![out](https://user-images.githubusercontent.com/14386/65541887-69424e00-df0e-11e9-8644-b3a068ed8c3f.png)

ACKs for top commit:
  jamesob:
    Tested ACK 67d99900b0

Tree-SHA512: 9c44e3cca993b5a564dd61ebd2926b9c4a238609ea4d283514c018236f977d935e35a384dd4696486fd3d78781dd2ba190bb72596e20a5e931042fa465872a0b
2019-09-30 09:47:28 +02:00
.github doc: Add issue templates for bug and feature request 2019-09-08 15:39:54 +02:00
.tx gui: Update transifex slug for 0.19 2019-09-02 13:40:01 +02:00
build-aux/m4 Merge #16870: build: update boost macros to latest upstream for improved error reporting 2019-09-21 10:00:28 +08:00
build_msvc Added libbitcoin_qt and bitcoin-qt to the msbuild configuration. 2019-09-08 14:13:05 +02:00
ci Merge #16961: test: Remove python dead code linter 2019-09-25 13:14:22 -04:00
contrib doc: Fix whitespace errs in .md files, bitcoin.conf, Info.plist.in, and find_bdb48.m4 2019-09-17 03:21:22 -04:00
depends Merge #16837: depends: qt: Fix {C{,XX},LD}FLAGS pickup 2019-09-26 13:19:20 +02:00
doc build: Factor out qt translations from build system 2019-09-29 14:24:54 +02:00
share doc: Fix whitespace errs in .md files, bitcoin.conf, Info.plist.in, and find_bdb48.m4 2019-09-17 03:21:22 -04:00
src Merge #16957: 9% less memory: make SaltedOutpointHasher noexcept 2019-09-30 09:47:28 +02:00
test Merge #16953: doc: Improve test READMEs 2019-09-30 09:27:35 +02:00
.appveyor.yml Added libbitcoin_qt and bitcoin-qt to the msbuild configuration. 2019-09-08 14:13:05 +02:00
.cirrus.yml test: Make PORT_MIN in test runner configurable 2019-09-19 12:03:40 -04:00
.gitattributes Separate protocol versioning from clientversion 2014-10-29 00:24:40 -04:00
.gitignore Merge #16371: build: ignore macOS make deploy artefacts & add them to clean-local 2019-08-21 08:02:20 +08:00
.python-version .python-version: Specify full version 3.5.6 2019-03-02 12:06:26 -05:00
.style.yapf test: .style.yapf: Set column_limit=160 2019-03-04 18:28:13 -05:00
.travis.yml travis: Disable feature_block in tsan run 2019-09-23 11:36:03 -04:00
autogen.sh Enable ShellCheck rules 2019-07-04 19:35:25 +03:00
configure.ac Merge #15146: Solve SmartOS FD_ZERO build issue 2019-09-18 16:33:23 +02:00
CONTRIBUTING.md doc: Update labels in CONTRIBUTING.md 2019-08-26 11:48:58 +03:00
COPYING [Trivial] Update license year range to 2019 2018-12-31 04:27:59 +01:00
INSTALL.md Update INSTALL landing redirection notice for build instructions. 2016-10-06 12:27:23 +13:00
libbitcoinconsensus.pc.in Unify package name to as few places as possible without major changes 2015-12-14 02:11:10 +00:00
Makefile.am build: ignore macOS make deploy artefacts & add them to clean-local 2019-08-14 08:07:12 +08:00
README.md doc: Remove travis badge from readme 2019-06-19 11:39:27 -04:00
SECURITY.md doc: Remove explicit mention of version from SECURITY.md 2019-06-14 06:39:17 -04:00

Bitcoin Core integration/staging tree

https://bitcoincore.org

What is Bitcoin?

Bitcoin is an experimental 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://bitcoincore.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 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 in configure) with: make check. 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, that are run automatically on the build server. These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py

The Travis CI system makes sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.

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.