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)
revset: add 'l' flag to formatspec for args
This makes it easy to calculate a revset with lists:
good = [1, 2, 3]
bad = [10, 11, 12]
between = repo.set('%ld::%ld', good, bad)
bisect: add some bisection examples, and some log revset.bisect() examples
Add a few examples on how to use bisect:
- a few bisection examples
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
revset.bisect: add new 'untested' set to the bisect keyword
The 'untested' set is made of changesets that are in the bisection range
but for which the status is still unknown, and that can later be used to
further decide on the bisection outcome.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
revset.bisect: add new 'pruned' set to the bisect keyword
The 'pruned' set is made of changesets that did participate to
the bisection. They are made of
- all good changesets
- all bad changsets
- all skipped changesets, provided they are in the bisection range
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
revset.bisect: add new 'range' set to the bisect keyword
The 'range' set is made of all changesets that make the bisection
range, that is
- csets that are ancestors of bad csets and descendants of good csets
or
- csets that are ancestors of good csets and descendants of bad csets
That is, roughly equivalent of:
bisect(good)::bisect(bad) | bisect(bad)::bisect(good)
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
revset.bisect: move bisect() code to hbisect.py
Computing the ranges of csets in the bisection belongs to the hbisect
code. This allows for reusing the status computation from many places,
not only the revset code, but also to later display the bisection status
of a cset...
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>