Commit Graph

12 Commits

Author SHA1 Message Date
Alexander Block
241f76f9bf Collection of minor performance optimizations (#2855)
* Merge #13176: Improve CRollingBloomFilter performance: replace modulus with FastMod

9aac9f90d5e56752cc6cbfac48063ad29a01143c replace modulus with FastMod (Martin Ankerl)

Pull request description:

  Not sure if this is optimization is necessary, but anyway I have some spare time so here it is. This replaces the slow modulo operation with a much faster 64bit multiplication & shift. This works when the hash is uniformly distributed between 0 and 2^32-1. This speeds up the benchmark by a factor of about 1.3:

  ```
  RollingBloom, 5, 1500000, 3.73733, 4.97569e-07, 4.99002e-07, 4.98372e-07 # before
  RollingBloom, 5, 1500000, 2.86842, 3.81630e-07, 3.83730e-07, 3.82473e-07 # FastMod
  ```

  Be aware that this changes the internal data of the filter, so this should probably
  not be used for CBloomFilter because of interoperability problems.

Tree-SHA512: 04104f3fb09f56c9d14458a6aad919aeb0a5af944e8ee6a31f00e93c753e22004648c1cd65bf36752b6addec528d19fb665c27b955ce1666a85a928e17afa47a

* Use unordered_map in CSporkManager

In one of my profiling sessions with many InstantSend transactions
happening, calls into CSporkManager added up to about 1% of total CPU time.
This is easily avoidable by using unordered maps.

* Use std::unordered_map instead of std::map in limitedmap

* Use unordered_set for CNode::setAskFor

* Add serialization support for unordered maps and sets

* Use unordered_map for mapArgs and mapMultiArgs

* Let limitedmap prune in batches and use unordered_multimap

Due to the batched pruning, there is no need to maintain an ordered map
of values anymore. Only when nPruneAfterSize, there is a need to create
a temporary ordered vector of values to figure out what can be removed.

* Instead of using a multimap for mapAskFor, use a vector which we sort on demand

CNode::AskFor will now push entries into an initially unordered vector
instead of an ordered multimap. Only when we later want to use vecAskFor in
SendMessages, we sort the vector.

The vector will actually be mostly sorted in most cases as insertion order
usually mimics the desired ordering. Only the last few entries might need
some shuffling around. Doing the sort on-demand should be less wasteful
then trying to maintain correct order all the time.

* Fix compilation of tests

* Fix limitedmap tests

* Rename limitedmap to unordered_limitedmap to ensure backports conflict

This ensures that future backports that depends on limitedmap's ordering
conflict so that we are made aware of needed action.

* Fix compilation error on Travis
2019-04-11 15:42:14 +03:00
Wladimir J. van der Laan
6ba688b1c6 Merge #8353: Trivial: tiny c++11 refactors
c784086 use std::map::emplace() instead of std::map::insert() (whythat)
5e187e7 use c++11 std::unique_ptr instead of boost::shared_ptr (whythat)
947913f use std::map::erase(const_iterator, const_iterator) to get non-constant iterator (whythat)
2018-01-08 18:04:55 +01:00
MarcoFalke
333e1eaeea
Bump copyright headers to 2015
- Bump copyright headers to 2015
- [devtools] Rewrite fix-copyright-headers.py
- [devtools] Use git pretty-format for year parsing

Github-Pull: #7205
Rebased-From: fa6ad855e9 fa24439ff3 fa71669452
2016-01-05 14:13:33 +01:00
Casey Rodarmor
8b06894194 Disallow unlimited limited maps 2015-08-17 12:15:32 -04:00
Casey Rodarmor
fd2d862fbc Make limited map actually respect max size 2015-08-17 12:15:32 -04:00
sandakersmann
f914f1a746
Added "Core" to copyright headers
Github-Pull: #5494
Rebased-From: 15de949bb9277e442302bdd8dee299a8d6deee60
2014-12-19 19:55:32 +01:00
Philip Kaufmann
2e5361b9c2 remove code below asserts in limitedmap.h (fixes a ToDo) 2014-09-22 09:35:40 +02:00
Pieter Wuille
20e01b1a03 Apply clang-format on some infrequently-updated files 2014-09-19 19:21:46 +02:00
Philip Kaufmann
093303a887 add missing header end comments
- ensures a consistent usage in header files
- also add a blank line after the copyright header where missing
- also remove orphan new-lines at the end of some files
2014-08-28 22:25:21 +02:00
Brandon Dahler
51ed9ec971 Cleanup code using forward declarations.
Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.
2013-11-10 09:36:28 -06:00
Gavin Andresen
319b11607f Refactor: CTxMempool class to its own txmempool.{cpp,h} 2013-11-04 11:27:02 +10:00
Matt Corallo
5ffc299404 Add a limitedmap class similar to mruset 2013-04-01 11:56:22 -04:00