Mercurial > hg-stable
view tests/test-filecache.py @ 15141:16dc9a32ca04
mdiff: speed up showfunc for large diffs
This addresses the following issues with showfunc:
- Silly usage of regular expressions.
- Doing str.rstrip() needlessly in an inner loop.
- Doing catastrophic backtracking when trying to find a function line.
Finding function text is now at worst O(n lines in the old file), and
at best close to O(n hunks).
Given a diff like this[1]:
src/main/antlr3/uk/ac/cam/ch/wwmm/pregenerated/ChemicalChunker.g | 4 +-
src/main/java/uk/ac/cam/ch/wwmm/pregenerated/ChemicalChunkerLexer.java | 2 +-
src/main/java/uk/ac/cam/ch/wwmm/pregenerated/ChemicalChunkerParser.java | 29189 +++++----
3 files changed, 14741 insertions(+), 14454 deletions(-)
[1]: https://bitbucket.org/wwmm/chemicaltagger/changeset/d2bfbaecd4fc/raw
Without this change, hg log --stat --config diff.showfunc=1 takes an
absurdly long time to complete:
CallCount Recursive Total(ms) Inline(ms) module:lineno(function)
32813 0 80.3546 40.6086 mercurial.mdiff:160(yieldhunk)
+65062746 0 25.7227 25.7227 +<method 'match' of '_sre.SRE_Pattern' objects>
+65062746 0 14.0221 14.0221 +<method 'rstrip' of 'str' objects>
+1809 0 0.0009 0.0009 +mercurial.mdiff:148(contextend)
+1809 0 0.0003 0.0003 +<len>
65062746 0 25.7227 25.7227 <method 'match' of '_sre.SRE_Pattern' objects>
65062763 0 14.0221 14.0221 <method 'rstrip' of 'str' objects>
543 0 0.1631 0.1631 <zlib.decompress>
3 0 0.0505 0.0505 <mercurial.bdiff.blocks>
31007 0 80.4564 0.0477 mercurial.mdiff:147(_unidiff)
+32813 0 80.3546 40.6086 +mercurial.mdiff:160(yieldhunk)
+3 0 0.0505 0.0505 +<mercurial.bdiff.blocks>
+3618 0 0.0022 0.0022 +mercurial.mdiff:154(contextstart)
+5427 0 0.0013 0.0013 +<len>
+3 0 0.0001 0.0000 +re:188(compile)
1 0 80.8381 0.0322 mercurial.patch:1777(diffstatdata)
+107499 0 0.0235 0.0235 +<method 'startswith' of 'str' objects>
+31014 0 80.7820 0.0071 +mercurial.util:1284(iterlines)
+3 0 0.0000 0.0000 +<method 'search' of '_sre.SRE_Pattern' objects>
+4 0 0.0000 0.0000 +mercurial.patch:1783(addresult)
+3 0 0.0000 0.0000 +<method 'group' of '_sre.SRE_Match' objects>
6 0 0.0444 0.0283 mercurial.mdiff:12(splitnewlines)
+6 0 0.0160 0.0160 +<method 'split' of 'str' objects>
32 0 0.0246 0.0246 <method 'update' of '_hashlib.HASH' objects>
11 0 0.0236 0.0236 <method 'read' of 'file' objects>
Time: real 80.880 secs (user 80.200+0.000 sys 0.380+0.000)
With this change, it's almost as fast as not using showfunc at all:
CallCount Recursive Total(ms) Inline(ms) module:lineno(function)
543 0 0.1699 0.1699 <zlib.decompress>
3 0 0.0501 0.0501 <mercurial.bdiff.blocks>
32813 0 0.0415 0.0348 mercurial.mdiff:161(yieldhunk)
+70837 0 0.0058 0.0058 +<method 'isalnum' of 'str' objects>
+1809 0 0.0006 0.0006 +mercurial.mdiff:148(contextend)
+1809 0 0.0002 0.0002 +<len>
1 0 0.4879 0.0310 mercurial.patch:1777(diffstatdata)
+107499 0 0.0230 0.0230 +<method 'startswith' of 'str' objects>
+31014 0 0.4335 0.0065 +mercurial.util:1284(iterlines)
+3 0 0.0000 0.0000 +<method 'search' of '_sre.SRE_Pattern' objects>
+4 0 0.0000 0.0000 +mercurial.patch:1783(addresult)
+1 0 0.0004 0.0000 +re:188(compile)
32 0 0.0293 0.0293 <method 'update' of '_hashlib.HASH' objects>
6 0 0.0427 0.0279 mercurial.mdiff:12(splitnewlines)
+6 0 0.0147 0.0147 +<method 'split' of 'str' objects>
31007 0 0.1169 0.0235 mercurial.mdiff:147(_unidiff)
+3 0 0.0501 0.0501 +<mercurial.bdiff.blocks>
+32813 0 0.0415 0.0348 +mercurial.mdiff:161(yieldhunk)
+3618 0 0.0012 0.0012 +mercurial.mdiff:154(contextstart)
+5427 0 0.0006 0.0006 +<len>
107597 0 0.0230 0.0230 <method 'startswith' of 'str' objects>
16 0 0.0213 0.0213 <mercurial.mpatch.patches>
194 0 0.0149 0.0149 <method 'split' of 'str' objects>
Time: real 0.530 secs (user 0.450+0.000 sys 0.070+0.000)
author | Brodie Rao <brodie@bitheap.org> |
---|---|
date | Mon, 19 Sep 2011 15:58:03 -0700 |
parents | 774da7121fc9 |
children | d01e08ea459d |
line wrap: on
line source
import sys, os, subprocess if subprocess.call(['%s/hghave' % os.environ['TESTDIR'], 'cacheable']): sys.exit(80) from mercurial import util, scmutil, extensions filecache = scmutil.filecache class fakerepo(object): def __init__(self): self._filecache = {} def join(self, p): return p def sjoin(self, p): return p @filecache('x') def cached(self): print 'creating' def invalidate(self): for k in self._filecache: try: delattr(self, k) except AttributeError: pass def basic(repo): # file doesn't exist, calls function repo.cached repo.invalidate() # file still doesn't exist, uses cache repo.cached # create empty file f = open('x', 'w') f.close() repo.invalidate() # should recreate the object repo.cached f = open('x', 'w') f.write('a') f.close() repo.invalidate() # should recreate the object repo.cached repo.invalidate() # stats file again, nothing changed, reuses object repo.cached # atomic replace file, size doesn't change # hopefully st_mtime doesn't change as well so this doesn't use the cache # because of inode change f = scmutil.opener('.')('x', 'w', atomictemp=True) f.write('b') f.close() repo.invalidate() repo.cached def fakeuncacheable(): def wrapcacheable(orig, *args, **kwargs): return False def wrapinit(orig, *args, **kwargs): pass originit = extensions.wrapfunction(util.cachestat, '__init__', wrapinit) origcacheable = extensions.wrapfunction(util.cachestat, 'cacheable', wrapcacheable) try: os.remove('x') except: pass basic(fakerepo()) util.cachestat.cacheable = origcacheable util.cachestat.__init__ = originit print 'basic:' print basic(fakerepo()) print print 'fakeuncacheable:' print fakeuncacheable()