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)