hgext/convert/git.py

dirstate: skip step 3 in walk if nothing new will match

nothing will ever match on match.never
nothing new will match on match.exact (all found in step 1)
nothing new will match on match.match when
  there is no pattern and
  there is no direcory in pats

# git.py - git support for the convert extension
#
#  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.

import os
from mercurial import util

from common import NoRepo, commit, converter_source, checktool

class convert_git(converter_source):
    # Windows does not support GIT_DIR= construct while other systems
    # cannot remove environment variable. Just assume none have
    # both issues.
    if hasattr(os, 'unsetenv'):
        def gitcmd(self, s):
            prevgitdir = os.environ.get('GIT_DIR')
            os.environ['GIT_DIR'] = self.path
            try:
                return util.popen(s, 'rb')
            finally:
                if prevgitdir is None:
                    del os.environ['GIT_DIR']
                else:
                    os.environ['GIT_DIR'] = prevgitdir
    else:
        def gitcmd(self, s):
            return util.popen('GIT_DIR=%s %s' % (self.path, s), 'rb')

    def __init__(self, ui, path, rev=None):
        super(convert_git, self).__init__(ui, path, rev=rev)

        if os.path.isdir(path + "/.git"):
            path += "/.git"
        if not os.path.exists(path + "/objects"):
            raise NoRepo("%s does not look like a Git repo" % path)

        checktool('git', 'git')

        self.path = path

    def getheads(self):
        if not self.rev:
            return self.gitcmd('git rev-parse --branches --remotes').read().splitlines()
        else:
            fh = self.gitcmd("git rev-parse --verify %s" % self.rev)
            return [fh.read()[:-1]]

    def catfile(self, rev, type):
        if rev == "0" * 40: raise IOError()
        fh = self.gitcmd("git cat-file %s %s" % (type, rev))
        return fh.read()

    def getfile(self, name, rev):
        return self.catfile(rev, "blob")

    def getmode(self, name, rev):
        return self.modecache[(name, rev)]

    def getchanges(self, version):
        self.modecache = {}
        fh = self.gitcmd("git diff-tree -z --root -m -r %s" % version)
        changes = []
        seen = set()
        entry = None
        for l in fh.read().split('\x00'):
            if not entry:
                if not l.startswith(':'):
                    continue
                entry = l
                continue
            f = l
            if f not in seen:
                seen.add(f)
                entry = entry.split()
                h = entry[3]
                p = (entry[1] == "100755")
                s = (entry[1] == "120000")
                self.modecache[(f, h)] = (p and "x") or (s and "l") or ""
                changes.append((f, h))
            entry = None
        return (changes, {})

    def getcommit(self, version):
        c = self.catfile(version, "commit") # read the commit hash
        end = c.find("\n\n")
        message = c[end+2:]
        message = self.recode(message)
        l = c[:end].splitlines()
        parents = []
        author = committer = None
        for e in l[1:]:
            n, v = e.split(" ", 1)
            if n == "author":
                p = v.split()
                tm, tz = p[-2:]
                author = " ".join(p[:-2])
                if author[0] == "<": author = author[1:-1]
                author = self.recode(author)
            if n == "committer":
                p = v.split()
                tm, tz = p[-2:]
                committer = " ".join(p[:-2])
                if committer[0] == "<": committer = committer[1:-1]
                committer = self.recode(committer)
            if n == "parent": parents.append(v)

        if committer and committer != author:
            message += "\ncommitter: %s\n" % committer
        tzs, tzh, tzm = tz[-5:-4] + "1", tz[-4:-2], tz[-2:]
        tz = -int(tzs) * (int(tzh) * 3600 + int(tzm))
        date = tm + " " + str(tz)

        c = commit(parents=parents, date=date, author=author, desc=message,
                   rev=version)
        return c

    def gettags(self):
        tags = {}
        fh = self.gitcmd('git ls-remote --tags "%s"' % self.path)
        prefix = 'refs/tags/'
        for line in fh:
            line = line.strip()
            if not line.endswith("^{}"):
                continue
            node, tag = line.split(None, 1)
            if not tag.startswith(prefix):
                continue
            tag = tag[len(prefix):-3]
            tags[tag] = node

        return tags

    def getchangedfiles(self, version, i):
        changes = []
        if i is None:
            fh = self.gitcmd("git diff-tree --root -m -r %s" % version)
            for l in fh:
                if "\t" not in l:
                    continue
                m, f = l[:-1].split("\t")
                changes.append(f)
            fh.close()
        else:
            fh = self.gitcmd('git diff-tree --name-only --root -r %s "%s^%s" --'
                             % (version, version, i+1))
            changes = [f.rstrip('\n') for f in fh]
            fh.close()

        return changes