mercurial/filelog.py

util._matcher: speed up regexp matching.

In 4babaa52badf, Benoit made a change that substantially slows matching
when a big .hgignore file is in play, because it calls into the regexp
matching engine potentially hundreds of times per file to be matched.

I've partly rolled back his change, so that we only call into the matcher
once per file, but preserved the ability to report a meaningful error
message if there's a syntax error in the regexp.

# filelog.py - file history class for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from revlog import *
import os

class filelog(revlog):
    def __init__(self, opener, path):
        revlog.__init__(self, opener,
                        "/".join(("data", self.encodedir(path + ".i"))))

    # This avoids a collision between a file named foo and a dir named
    # foo.i or foo.d
    def encodedir(self, path):
        return (path
                .replace(".hg/", ".hg.hg/")
                .replace(".i/", ".i.hg/")
                .replace(".d/", ".d.hg/"))

    def decodedir(self, path):
        return (path
                .replace(".d.hg/", ".d/")
                .replace(".i.hg/", ".i/")
                .replace(".hg.hg/", ".hg/"))

    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 = ""
            if meta:
                mt = [ "%s: %s\n" % (k, v) for k,v in meta.items() ]
            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] != nullid:
            return False
        m = self._readmeta(node)
        if m and m.has_key("copy"):
            return (m["copy"], 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))

        return revlog.size(self, rev)

    def cmp(self, node, text):
        """compare text with a given file revision"""

        # for renames, we have to go the slow way
        if self.renamed(node):
            t2 = self.read(node)
            return t2 != text

        return revlog.cmp(self, node, text)