Mercurial > hg
view tests/fakedirstatewritetime.py @ 44363:f7459da77f23
nodemap: introduce an option to use mmap to read the nodemap mapping
The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.
This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).
Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:
Before:
* do not use the persistent nodemap
* use the CPython implementation of the index for nodemap
* use mmapping of the changelog index
After:
* use the MixedIndex Rust code, with the NodeTree object for nodemap access
(still in review)
* use the persistent nodemap data from disk
* access the persistent nodemap data through mmap
* use mmapping of the changelog index
The persistent nodemap greatly speed up most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.
Here are some numbers (in seconds) for the reference copy of mozilla-try:
Revset Before After abs-change speedup
-10000: 0.004622 0.005532 0.000910 × 0.83
-10: 0.000050 0.000132 0.000082 × 0.37
tip 0.000052 0.000085 0.000033 × 0.61
0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29
0 0.023521 0.000084 -0.023437 × 280.01
(-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37
(-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79
(-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55
:99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84
:9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68
:9 0.316450 0.000143 -0.316307 ×2212.93
On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.
Here are some numbers (in seconds) for the reference copy of mercurial:
Revset Before After abs-change speedup
-10: 0.000065 0.000097 0.000032 × 0.67
tip 0.000063 0.000078 0.000015 × 0.80
0 0.000561 0.000079 -0.000482 × 7.10
-10000: 0.004609 0.003648 -0.000961 × 1.26
0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35
(-10:) + :9 0.002187 0.000108 -0.002079 ×20.25
(-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68
(-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71
:9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96
:9 0.003854 0.000099 -0.003755 ×38.92
:99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02
Differential Revision: https://phab.mercurial-scm.org/D7894
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Tue, 11 Feb 2020 11:18:52 +0100 |
parents | 9f70512ae2cf |
children | 89a2afe31e82 |
line wrap: on
line source
# extension to emulate invoking 'dirstate.write()' at the time # specified by '[fakedirstatewritetime] fakenow', only when # 'dirstate.write()' is invoked via functions below: # # - 'workingctx._poststatusfixup()' (= 'repo.status()') # - 'committablectx.markcommitted()' from __future__ import absolute_import from mercurial import ( context, dirstate, extensions, policy, registrar, ) from mercurial.utils import dateutil try: from mercurial import rustext rustext.__name__ # force actual import (see hgdemandimport) except ImportError: rustext = None configtable = {} configitem = registrar.configitem(configtable) configitem( b'fakedirstatewritetime', b'fakenow', default=None, ) parsers = policy.importmod('parsers') rustmod = policy.importrust('parsers') def pack_dirstate(fakenow, orig, dmap, copymap, pl, now): # execute what original parsers.pack_dirstate should do actually # for consistency actualnow = int(now) for f, e in dmap.items(): if e[0] == 'n' and e[3] == actualnow: e = parsers.dirstatetuple(e[0], e[1], e[2], -1) dmap[f] = e return orig(dmap, copymap, pl, fakenow) def fakewrite(ui, func): # fake "now" of 'pack_dirstate' only if it is invoked while 'func' fakenow = ui.config(b'fakedirstatewritetime', b'fakenow') if not fakenow: # Execute original one, if fakenow isn't configured. This is # useful to prevent subrepos from executing replaced one, # because replacing 'parsers.pack_dirstate' is also effective # in subrepos. return func() # parsing 'fakenow' in YYYYmmddHHMM format makes comparison between # 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy fakenow = dateutil.parsedate(fakenow, [b'%Y%m%d%H%M'])[0] if rustmod is not None: # The Rust implementation does not use public parse/pack dirstate # to prevent conversion round-trips orig_dirstatemap_write = dirstate.dirstatemap.write wrapper = lambda self, st, now: orig_dirstatemap_write( self, st, fakenow ) dirstate.dirstatemap.write = wrapper orig_dirstate_getfsnow = dirstate._getfsnow wrapper = lambda *args: pack_dirstate(fakenow, orig_pack_dirstate, *args) orig_module = parsers orig_pack_dirstate = parsers.pack_dirstate orig_module.pack_dirstate = wrapper dirstate._getfsnow = lambda *args: fakenow try: return func() finally: orig_module.pack_dirstate = orig_pack_dirstate dirstate._getfsnow = orig_dirstate_getfsnow if rustmod is not None: dirstate.dirstatemap.write = orig_dirstatemap_write def _poststatusfixup(orig, workingctx, status, fixup): ui = workingctx.repo().ui return fakewrite(ui, lambda: orig(workingctx, status, fixup)) def markcommitted(orig, committablectx, node): ui = committablectx.repo().ui return fakewrite(ui, lambda: orig(committablectx, node)) def extsetup(ui): extensions.wrapfunction( context.workingctx, '_poststatusfixup', _poststatusfixup ) extensions.wrapfunction(context.workingctx, 'markcommitted', markcommitted)