localrepo: add branchtip() method for faster single-branch lookups
For the PyPy repo with 744 branches and 843 branch heads, this brings
hg log -r default over NFS from:
CallCount Recursive Total(ms) Inline(ms) module:lineno(function)
3249 0 1.3222 1.3222 <open>
3244 0 0.6211 0.6211 <method 'close' of 'file' objects>
3243 0 0.0800 0.0800 <method 'read' of 'file' objects>
3241 0 0.0660 0.0660 <method 'seek' of 'file' objects>
3905 0 0.0476 0.0476 <zlib.decompress>
3281 0 2.6756 0.0472 mercurial.changelog:182(read)
+3281 0 2.5256 0.0453 +mercurial.revlog:881(revision)
+3276 0 0.0389 0.0196 +mercurial.changelog:28(decodeextra)
+6562 0 0.0123 0.0123 +<method 'split' of 'str' objects>
+6562 0 0.0408 0.0073 +mercurial.encoding:61(tolocal)
+3281 0 0.0054 0.0054 +<method 'index' of 'str' objects>
3241 0 2.2464 0.0456 mercurial.revlog:818(_loadchunk)
+3241 0 0.6205 0.6205 +<method 'close' of 'file' objects>
+3241 0 0.0765 0.0765 +<method 'read' of 'file' objects>
+3241 0 0.0660 0.0660 +<method 'seek' of 'file' objects>
+3241 0 1.4209 0.0135 +mercurial.store:374(__call__)
+3241 0 0.0122 0.0107 +mercurial.revlog:810(_addchunk)
3281 0 2.5256 0.0453 mercurial.revlog:881(revision)
+3280 0 0.0175 0.0175 +mercurial.revlog:305(rev)
+3281 0 2.2819 0.0119 +mercurial.revlog:847(_chunkraw)
+3281 0 0.0603 0.0083 +mercurial.revlog:945(_checkhash)
+3281 0 0.0051 0.0051 +mercurial.revlog:349(flags)
+3281 0 0.0040 0.0040 +<mercurial.mpatch.patches>
13682 0 0.0479 0.0248 <method 'decode' of 'str' objects>
+7418 0 0.0228 0.0076 +encodings.utf_8:15(decode)
+1 0 0.0003 0.0000 +encodings:71(search_function)
3248 0 1.3995 0.0246 mercurial.scmutil:218(__call__)
+3248 0 1.3222 1.3222 +<open>
+3248 0 0.0235 0.0184 +os.path:80(split)
+3248 0 0.0084 0.0068 +mercurial.scmutil:92(__call__)
Time: real 2.750 secs (user 0.680+0.000 sys 0.360+0.000)
down to:
CallCount Recursive Total(ms) Inline(ms) module:lineno(function)
55 31 0.0197 0.0163 <__import__>
+1 0 0.0006 0.0002 +mercurial.context:8(<module>)
+1 0 0.0042 0.0001 +mercurial.revlog:12(<module>)
+1 0 0.0002 0.0001 +mercurial.match:8(<module>)
+1 0 0.0003 0.0001 +mercurial.dirstate:7(<module>)
+1 0 0.0057 0.0001 +mercurial.changelog:8(<module>)
1 0 0.0117 0.0032 mercurial.localrepo:525(_readbranchcache)
+844 0 0.0015 0.0015 +<binascii.unhexlify>
+845 0 0.0010 0.0010 +<method 'split' of 'str' objects>
+843 0 0.0045 0.0009 +mercurial.encoding:61(tolocal)
+843 0 0.0004 0.0004 +<method 'setdefault' of 'dict' objects>
+1 0 0.0003 0.0003 +<method 'close' of 'file' objects>
3 0 0.0029 0.0029 <method 'read' of 'file' objects>
9 0 0.0018 0.0018 <open>
990 0 0.0017 0.0017 <binascii.unhexlify>
53 0 0.0016 0.0016 mercurial.demandimport:43(__init__)
862 0 0.0015 0.0015 <_codecs.utf_8_decode>
862 0 0.0037 0.0014 <method 'decode' of 'str' objects>
+862 0 0.0023 0.0008 +encodings.utf_8:15(decode)
981 0 0.0011 0.0011 <method 'split' of 'str' objects>
861 0 0.0046 0.0009 mercurial.encoding:61(tolocal)
+861 0 0.0037 0.0014 +<method 'decode' of 'str' objects>
862 0 0.0023 0.0008 encodings.utf_8:15(decode)
+862 0 0.0015 0.0015 +<_codecs.utf_8_decode>
4 0 0.0008 0.0008 <method 'close' of 'file' objects>
179 154 0.0202 0.0004 mercurial.demandimport:83(__getattribute__)
+36 11 0.0199 0.0003 +mercurial.demandimport:55(_load)
+72 0 0.0001 0.0001 +mercurial.demandimport:83(__getattribute__)
+36 0 0.0000 0.0000 +<getattr>
1 0 0.0015 0.0004 mercurial.tags:148(_readtagcache)
Time: real 0.060 secs (user 0.030+0.000 sys 0.010+0.000)
$ hg init
$ cat > .hg/hgrc <<EOF
> [extensions]
> prefixfilter = prefix.py
> [encode]
> *.txt = stripprefix: Copyright 2046, The Masters
> [decode]
> *.txt = insertprefix: Copyright 2046, The Masters
> EOF
$ cat > prefix.py <<EOF
> from mercurial import util
> def stripprefix(s, cmd, filename, **kwargs):
> header = '%s\n' % cmd
> if s[:len(header)] != header:
> raise util.Abort('missing header "%s" in %s' % (cmd, filename))
> return s[len(header):]
> def insertprefix(s, cmd):
> return '%s\n%s' % (cmd, s)
> def reposetup(ui, repo):
> repo.adddatafilter('stripprefix:', stripprefix)
> repo.adddatafilter('insertprefix:', insertprefix)
> EOF
$ cat > .hgignore <<EOF
> .hgignore
> prefix.py
> prefix.pyc
> EOF
$ cat > stuff.txt <<EOF
> Copyright 2046, The Masters
> Some stuff to ponder very carefully.
> EOF
$ hg add stuff.txt
$ hg ci -m stuff
Repository data:
$ hg cat stuff.txt
Some stuff to ponder very carefully.
Fresh checkout:
$ rm stuff.txt
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat stuff.txt
Copyright 2046, The Masters
Some stuff to ponder very carefully.
$ echo "Very very carefully." >> stuff.txt
$ hg stat
M stuff.txt
$ echo "Unauthorized material subject to destruction." > morestuff.txt
Problem encoding:
$ hg add morestuff.txt
$ hg ci -m morestuff
abort: missing header "Copyright 2046, The Masters" in morestuff.txt
[255]
$ hg stat
M stuff.txt
A morestuff.txt