Mercurial > hg
view mercurial/filelog.py @ 12709:4147a292c508
filectx: use ctx.size comparisons to speed up ctx.cmp
Comparing sizes is cheaper than comparing file contents, as it does not
involve reading the file on disk or from the filelog.
It is however not always possible: some extensions, or encode filters,
change data when extracting it to the working directory.
author | Nicolas Dumazet <nicdumz.commits@gmail.com> |
---|---|
date | Tue, 27 Jul 2010 23:07:30 +0900 |
parents | ab9fa7a85dd9 |
children | e5060aa22043 |
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# filelog.py - file history class for mercurial # # Copyright 2005-2007 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. import revlog class filelog(revlog.revlog): def __init__(self, opener, path): revlog.revlog.__init__(self, opener, "/".join(("data", path + ".i"))) def read(self, node): t = self.revision(node) if not t.startswith('\1\n'): return t s = t.index('\1\n', 2) return t[s + 2:] def _readmeta(self, node): t = self.revision(node) if not t.startswith('\1\n'): return {} s = t.index('\1\n', 2) mt = t[2:s] m = {} for l in mt.splitlines(): k, v = l.split(": ", 1) m[k] = v return m def add(self, text, meta, transaction, link, p1=None, p2=None): if meta or text.startswith('\1\n'): mt = ["%s: %s\n" % (k, v) for k, v in sorted(meta.iteritems())] text = "\1\n%s\1\n%s" % ("".join(mt), text) return self.addrevision(text, transaction, link, p1, p2) def renamed(self, node): if self.parents(node)[0] != revlog.nullid: return False m = self._readmeta(node) if m and "copy" in m: return (m["copy"], revlog.bin(m["copyrev"])) return False def size(self, rev): """return the size of a given revision""" # for revisions with renames, we have to go the slow way node = self.node(rev) if self.renamed(node): return len(self.read(node)) # XXX if self.read(node).startswith("\1\n"), this returns (size+4) return revlog.revlog.size(self, rev) def cmp(self, node, text): """compare text with a given file revision returns True if text is different than what is stored. """ t = text if text.startswith('\1\n'): t = '\1\n\1\n' + text samehashes = not revlog.revlog.cmp(self, node, t) if samehashes: return False # renaming a file produces a different hash, even if the data # remains unchanged. Check if it's the case (slow): if self.renamed(node): t2 = self.read(node) return t2 != text return True