Mercurial > hg
view mercurial/parser.py @ 20182:04036798ebed
branches: avoid unnecessary changectx.branch() calls
This requires reading from the changelog, which can be costly over NFS.
Note that this does not totally remove reading from the changelog; we
still do that when calling changectx.closesbranch(). That call will be
removed in a later patch.
Running hg branches on the PyPy repo (with 996) over a busy NFS server,
before this change:
$ time hg --profile branches > /dev/null
CallCount Recursive Total(s) Inline(s) module:lineno(function)
2042 0 2.2827 2.2827 <open>
2036 0 0.9840 0.9840 <method 'close' of 'file' objects>
2036 0 0.0464 0.0464 <method 'read' of 'file' objects>
5233 0 0.1985 0.0453 mercurial.repoview:161(changelog)
10462 0 0.0791 0.0314 mercurial.changelog:133(tip)
5233 0 0.0388 0.0176 mercurial.localrepo:26(__get__)
10462 0 0.0250 0.0126 <len>
5233 0 0.0059 0.0039 mercurial.repoview:112(filterrevs)
10462 0 0.0029 0.0029 <hash>
2034 0 0.0444 0.0444 <method 'seek' of 'file' objects>
5340 0 0.0390 0.0390 mercurial.revlog:296(rev)
2582 0 0.0371 0.0371 <zlib.decompress>
3155 0 0.1963 0.0366 mercurial.context:202(__init__)
3155 0 0.1238 0.0306 mercurial.repoview:161(changelog)
3155 0 0.0261 0.0080 mercurial.changelog:183(rev)
9465 0 0.0061 0.0061 <isinstance>
1096 0 0.0023 0.0023 <binascii.unhexlify>
4251 0 0.0014 0.0014 <len>
2059 0 3.7341 0.0332 mercurial.changelog:270(read)
2059 0 3.6304 0.0307 mercurial.revlog:907(revision)
2057 0 0.0262 0.0137 mercurial.changelog:28(decodeextra)
4118 0 0.0094 0.0094 <method 'split' of 'str' objects>
4118 0 0.0270 0.0048 mercurial.encoding:61(tolocal)
2059 0 0.0040 0.0040 <method 'index' of 'str' objects>
10462 0 0.0791 0.0314 mercurial.changelog:133(tip)
10462 0 0.0289 0.0207 mercurial.changelog:190(node)
10462 0 0.0188 0.0091 <len>
52433 20932 0.0478 0.0310 <len>
20932 0 0.0221 0.0168 mercurial.revlog:262(__len__)
2059 0 3.6304 0.0307 mercurial.revlog:907(revision)
real 0m4.361s
user 0m0.986s
sys 0m0.237s
After this change:
$ time hg --profile branches > /dev/null
CallCount Recursive Total(s) Inline(s) module:lineno(function)
1069 0 1.1098 1.1098 <open>
1063 0 0.4865 0.4865 <method 'close' of 'file' objects>
4122 0 0.1811 0.0404 mercurial.repoview:161(changelog)
8240 0 0.0712 0.0272 mercurial.changelog:133(tip)
4122 0 0.0378 0.0177 mercurial.localrepo:26(__get__)
8240 0 0.0221 0.0115 <len>
4122 0 0.0057 0.0033 mercurial.repoview:112(filterrevs)
8240 0 0.0025 0.0025 <hash>
3029 0 0.1979 0.0371 mercurial.context:202(__init__)
3029 0 0.1278 0.0310 mercurial.repoview:161(changelog)
3029 0 0.0230 0.0081 mercurial.changelog:183(rev)
9087 0 0.0061 0.0061 <isinstance>
1096 0 0.0026 0.0026 <binascii.unhexlify>
4125 0 0.0014 0.0014 <len>
4229 0 0.0337 0.0337 mercurial.revlog:296(rev)
1061 0 0.0296 0.0296 <method 'seek' of 'file' objects>
1063 0 0.0292 0.0292 <method 'read' of 'file' objects>
8240 0 0.0712 0.0272 mercurial.changelog:133(tip)
8240 0 0.0271 0.0196 mercurial.changelog:190(node)
8240 0 0.0169 0.0083 <len>
40476 16488 0.0422 0.0271 <len>
16488 0 0.0193 0.0152 mercurial.revlog:262(__len__)
1342 0 0.0241 0.0241 <zlib.decompress>
9445 0 0.0336 0.0224 mercurial.changelog:190(node)
9445 0 0.0112 0.0112 mercurial.revlog:317(node)
1074 0 1.9102 0.0224 mercurial.changelog:270(read)
1074 0 1.8397 0.0202 mercurial.revlog:907(revision)
1073 0 0.0187 0.0099 mercurial.changelog:28(decodeextra)
2148 0 0.0061 0.0061 <method 'split' of 'str' objects>
2148 0 0.0184 0.0034 mercurial.encoding:61(tolocal)
real 0m2.402s
user 0m0.735s
sys 0m0.177s
author | Brodie Rao <brodie@sf.io> |
---|---|
date | Fri, 15 Nov 2013 23:18:08 -0500 |
parents | 8ac8db8dc346 |
children | 7c4778bc29f0 |
line wrap: on
line source
# parser.py - simple top-down operator precedence parser for mercurial # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # see http://effbot.org/zone/simple-top-down-parsing.htm and # http://eli.thegreenplace.net/2010/01/02/top-down-operator-precedence-parsing/ # for background # takes a tokenizer and elements # tokenizer is an iterator that returns type, value pairs # elements is a mapping of types to binding strength, prefix and infix actions # an action is a tree node name, a tree label, and an optional match # __call__(program) parses program into a labeled tree import error from i18n import _ class parser(object): def __init__(self, tokenizer, elements, methods=None): self._tokenizer = tokenizer self._elements = elements self._methods = methods self.current = None def _advance(self): 'advance the tokenizer' t = self.current try: self.current = self._iter.next() except StopIteration: pass return t def _match(self, m, pos): 'make sure the tokenizer matches an end condition' if self.current[0] != m: raise error.ParseError(_("unexpected token: %s") % self.current[0], self.current[2]) self._advance() def _parse(self, bind=0): token, value, pos = self._advance() # handle prefix rules on current token prefix = self._elements[token][1] if not prefix: raise error.ParseError(_("not a prefix: %s") % token, pos) if len(prefix) == 1: expr = (prefix[0], value) else: if len(prefix) > 2 and prefix[2] == self.current[0]: self._match(prefix[2], pos) expr = (prefix[0], None) else: expr = (prefix[0], self._parse(prefix[1])) if len(prefix) > 2: self._match(prefix[2], pos) # gather tokens until we meet a lower binding strength while bind < self._elements[self.current[0]][0]: token, value, pos = self._advance() e = self._elements[token] # check for suffix - next token isn't a valid prefix if len(e) == 4 and not self._elements[self.current[0]][1]: suffix = e[3] expr = (suffix[0], expr) else: # handle infix rules if len(e) < 3 or not e[2]: raise error.ParseError(_("not an infix: %s") % token, pos) infix = e[2] if len(infix) == 3 and infix[2] == self.current[0]: self._match(infix[2], pos) expr = (infix[0], expr, (None)) else: expr = (infix[0], expr, self._parse(infix[1])) if len(infix) == 3: self._match(infix[2], pos) return expr def parse(self, message): 'generate a parse tree from a message' self._iter = self._tokenizer(message) self._advance() res = self._parse() token, value, pos = self.current return res, pos def eval(self, tree): 'recursively evaluate a parse tree using node methods' if not isinstance(tree, tuple): return tree return self._methods[tree[0]](*[self.eval(t) for t in tree[1:]]) def __call__(self, message): 'parse a message into a parse tree and evaluate if methods given' t = self.parse(message) if self._methods: return self.eval(t) return t