hgext/convert/git.py

localrepo: make invalidate avoid invalidating store inside transaction (API)

Before this patch, invalidate() discards in-memory fncache changes,
even inside transaction scope.

Such changes should be written out at closing transaction. Otherwise,
fncache might overlook newly added files. A file overlooked by
fncache isn't accessible via store vfs, even if it actually exists in
store.

On the other hand, a non-existing file in fncache is less harmful,
because fncachestore always examines whether a file actually exists or
not before access. Therefore, discarding in-memory changes can be
safely omitted.

It is typical case that repo.invalidate() in streamclone is executed
inside nested transaction.

This patch makes invalidate() avoid invalidating store inside
transaction.

This patch focuses on describing only how invalidate() changes own
behavior according to activity of transaction. Describing other detail
of invalidate() in docstr will be done in another series, which
refactors invalidate*() functions.

# 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 or any later version.
from __future__ import absolute_import

import os

from mercurial.i18n import _
from mercurial import (
    config,
    error,
    node as nodemod,
)

from . import (
    common,
)

class submodule(object):
    def __init__(self, path, node, url):
        self.path = path
        self.node = node
        self.url = url

    def hgsub(self):
        return "%s = [git]%s" % (self.path, self.url)

    def hgsubstate(self):
        return "%s %s" % (self.node, self.path)

class convert_git(common.converter_source, common.commandline):
    # Windows does not support GIT_DIR= construct while other systems
    # cannot remove environment variable. Just assume none have
    # both issues.

    def _gitcmd(self, cmd, *args, **kwargs):
        return cmd('--git-dir=%s' % self.path, *args, **kwargs)

    def gitrun0(self, *args, **kwargs):
        return self._gitcmd(self.run0, *args, **kwargs)

    def gitrun(self, *args, **kwargs):
        return self._gitcmd(self.run, *args, **kwargs)

    def gitrunlines0(self, *args, **kwargs):
        return self._gitcmd(self.runlines0, *args, **kwargs)

    def gitrunlines(self, *args, **kwargs):
        return self._gitcmd(self.runlines, *args, **kwargs)

    def gitpipe(self, *args, **kwargs):
        return self._gitcmd(self._run3, *args, **kwargs)

    def __init__(self, ui, path, revs=None):
        super(convert_git, self).__init__(ui, path, revs=revs)
        common.commandline.__init__(self, ui, 'git')

        # Pass an absolute path to git to prevent from ever being interpreted
        # as a URL
        path = os.path.abspath(path)

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

        # The default value (50) is based on the default for 'git diff'.
        similarity = ui.configint('convert', 'git.similarity', default=50)
        if similarity < 0 or similarity > 100:
            raise error.Abort(_('similarity must be between 0 and 100'))
        if similarity > 0:
            self.simopt = ['-C%d%%' % similarity]
            findcopiesharder = ui.configbool('convert', 'git.findcopiesharder',
                                             False)
            if findcopiesharder:
                self.simopt.append('--find-copies-harder')
        else:
            self.simopt = []

        common.checktool('git', 'git')

        self.path = path
        self.submodules = []

        self.catfilepipe = self.gitpipe('cat-file', '--batch')

    def after(self):
        for f in self.catfilepipe:
            f.close()

    def getheads(self):
        if not self.revs:
            output, status = self.gitrun('rev-parse', '--branches', '--remotes')
            heads = output.splitlines()
            if status:
                raise error.Abort(_('cannot retrieve git heads'))
        else:
            heads = []
            for rev in self.revs:
                rawhead, ret = self.gitrun('rev-parse', '--verify', rev)
                heads.append(rawhead[:-1])
                if ret:
                    raise error.Abort(_('cannot retrieve git head "%s"') % rev)
        return heads

    def catfile(self, rev, type):
        if rev == nodemod.nullhex:
            raise IOError
        self.catfilepipe[0].write(rev+'\n')
        self.catfilepipe[0].flush()
        info = self.catfilepipe[1].readline().split()
        if info[1] != type:
            raise error.Abort(_('cannot read %r object at %s') % (type, rev))
        size = int(info[2])
        data = self.catfilepipe[1].read(size)
        if len(data) < size:
            raise error.Abort(_('cannot read %r object at %s: unexpected size')
                             % (type, rev))
        # read the trailing newline
        self.catfilepipe[1].read(1)
        return data

    def getfile(self, name, rev):
        if rev == nodemod.nullhex:
            return None, None
        if name == '.hgsub':
            data = '\n'.join([m.hgsub() for m in self.submoditer()])
            mode = ''
        elif name == '.hgsubstate':
            data = '\n'.join([m.hgsubstate() for m in self.submoditer()])
            mode = ''
        else:
            data = self.catfile(rev, "blob")
            mode = self.modecache[(name, rev)]
        return data, mode

    def submoditer(self):
        null = nodemod.nullhex
        for m in sorted(self.submodules, key=lambda p: p.path):
            if m.node != null:
                yield m

    def parsegitmodules(self, content):
        """Parse the formatted .gitmodules file, example file format:
        [submodule "sub"]\n
        \tpath = sub\n
        \turl = git://giturl\n
        """
        self.submodules = []
        c = config.config()
        # Each item in .gitmodules starts with whitespace that cant be parsed
        c.parse('.gitmodules', '\n'.join(line.strip() for line in
                               content.split('\n')))
        for sec in c.sections():
            s = c[sec]
            if 'url' in s and 'path' in s:
                self.submodules.append(submodule(s['path'], '', s['url']))

    def retrievegitmodules(self, version):
        modules, ret = self.gitrun('show', '%s:%s' % (version, '.gitmodules'))
        if ret:
            # This can happen if a file is in the repo that has permissions
            # 160000, but there is no .gitmodules file.
            self.ui.warn(_("warning: cannot read submodules config file in "
                           "%s\n") % version)
            return

        try:
            self.parsegitmodules(modules)
        except error.ParseError:
            self.ui.warn(_("warning: unable to parse .gitmodules in %s\n")
                         % version)
            return

        for m in self.submodules:
            node, ret = self.gitrun('rev-parse', '%s:%s' % (version, m.path))
            if ret:
                continue
            m.node = node.strip()

    def getchanges(self, version, full):
        if full:
            raise error.Abort(_("convert from git does not support --full"))
        self.modecache = {}
        cmd = ['diff-tree','-z', '--root', '-m', '-r'] + self.simopt + [version]
        output, status = self.gitrun(*cmd)
        if status:
            raise error.Abort(_('cannot read changes in %s') % version)
        changes = []
        copies = {}
        seen = set()
        entry = None
        subexists = [False]
        subdeleted = [False]
        difftree = output.split('\x00')
        lcount = len(difftree)
        i = 0

        skipsubmodules = self.ui.configbool('convert', 'git.skipsubmodules',
                                            False)
        def add(entry, f, isdest):
            seen.add(f)
            h = entry[3]
            p = (entry[1] == "100755")
            s = (entry[1] == "120000")
            renamesource = (not isdest and entry[4][0] == 'R')

            if f == '.gitmodules':
                if skipsubmodules:
                    return

                subexists[0] = True
                if entry[4] == 'D' or renamesource:
                    subdeleted[0] = True
                    changes.append(('.hgsub', nodemod.nullhex))
                else:
                    changes.append(('.hgsub', ''))
            elif entry[1] == '160000' or entry[0] == ':160000':
                if not skipsubmodules:
                    subexists[0] = True
            else:
                if renamesource:
                    h = nodemod.nullhex
                self.modecache[(f, h)] = (p and "x") or (s and "l") or ""
                changes.append((f, h))

        while i < lcount:
            l = difftree[i]
            i += 1
            if not entry:
                if not l.startswith(':'):
                    continue
                entry = l.split()
                continue
            f = l
            if entry[4][0] == 'C':
                copysrc = f
                copydest = difftree[i]
                i += 1
                f = copydest
                copies[copydest] = copysrc
            if f not in seen:
                add(entry, f, False)
            # A file can be copied multiple times, or modified and copied
            # simultaneously. So f can be repeated even if fdest isn't.
            if entry[4][0] == 'R':
                # rename: next line is the destination
                fdest = difftree[i]
                i += 1
                if fdest not in seen:
                    add(entry, fdest, True)
                    # .gitmodules isn't imported at all, so it being copied to
                    # and fro doesn't really make sense
                    if f != '.gitmodules' and fdest != '.gitmodules':
                        copies[fdest] = f
            entry = None

        if subexists[0]:
            if subdeleted[0]:
                changes.append(('.hgsubstate', nodemod.nullhex))
            else:
                self.retrievegitmodules(version)
                changes.append(('.hgsubstate', ''))
        return (changes, copies, set())

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

    def numcommits(self):
        output, ret = self.gitrunlines('rev-list', '--all')
        if ret:
            raise error.Abort(_('cannot retrieve number of commits in %s') \
                              % self.path)
        return len(output)

    def gettags(self):
        tags = {}
        alltags = {}
        output, status = self.gitrunlines('ls-remote', '--tags', self.path)

        if status:
            raise error.Abort(_('cannot read tags from %s') % self.path)
        prefix = 'refs/tags/'

        # Build complete list of tags, both annotated and bare ones
        for line in output:
            line = line.strip()
            if line.startswith("error:") or line.startswith("fatal:"):
                raise error.Abort(_('cannot read tags from %s') % self.path)
            node, tag = line.split(None, 1)
            if not tag.startswith(prefix):
                continue
            alltags[tag[len(prefix):]] = node

        # Filter out tag objects for annotated tag refs
        for tag in alltags:
            if tag.endswith('^{}'):
                tags[tag[:-3]] = alltags[tag]
            else:
                if tag + '^{}' in alltags:
                    continue
                else:
                    tags[tag] = alltags[tag]

        return tags

    def getchangedfiles(self, version, i):
        changes = []
        if i is None:
            output, status = self.gitrunlines('diff-tree', '--root', '-m',
                                              '-r', version)
            if status:
                raise error.Abort(_('cannot read changes in %s') % version)
            for l in output:
                if "\t" not in l:
                    continue
                m, f = l[:-1].split("\t")
                changes.append(f)
        else:
            output, status = self.gitrunlines('diff-tree', '--name-only',
                                              '--root', '-r', version,
                                              '%s^%s' % (version, i + 1), '--')
            if status:
                raise error.Abort(_('cannot read changes in %s') % version)
            changes = [f.rstrip('\n') for f in output]

        return changes

    def getbookmarks(self):
        bookmarks = {}

        # Handle local and remote branches
        remoteprefix = self.ui.config('convert', 'git.remoteprefix', 'remote')
        reftypes = [
            # (git prefix, hg prefix)
            ('refs/remotes/origin/', remoteprefix + '/'),
            ('refs/heads/', '')
        ]

        exclude = set([
            'refs/remotes/origin/HEAD',
        ])

        try:
            output, status = self.gitrunlines('show-ref')
            for line in output:
                line = line.strip()
                rev, name = line.split(None, 1)
                # Process each type of branch
                for gitprefix, hgprefix in reftypes:
                    if not name.startswith(gitprefix) or name in exclude:
                        continue
                    name = '%s%s' % (hgprefix, name[len(gitprefix):])
                    bookmarks[name] = rev
        except Exception:
            pass

        return bookmarks

    def checkrevformat(self, revstr, mapname='splicemap'):
        """ git revision string is a 40 byte hex """
        self.checkhexformat(revstr, mapname)