view hgext/convert/subversion.py @ 5854:8b95f598097c

convert: separate trunk detection from branch layout detection

In some subversion repositories, trunk is present but no branches
are used. The current code is assuming that both trunk and branches
must exist before adding trunk's head to the heads list.

It's just better to separate the branch layout stuff from the trunk one.

# Subversion 1.4/1.5 Python API backend
#
# Copyright(C) 2007 Daniel Holth et al
#
# Configuration options:
#
# convert.svn.trunk
#   Relative path to the trunk (default: "trunk")
# convert.svn.branches
#   Relative path to tree of branches (default: "branches")
# convert.svn.tags
#   Relative path to tree of tags (default: "tags")
#
# Set these in a hgrc, or on the command line as follows:
#
#   hg convert --config convert.svn.trunk=wackoname [...]

import locale
import os
import re
import sys
import cPickle as pickle
import tempfile

from mercurial import strutil, util
from mercurial.i18n import _

# Subversion stuff. Works best with very recent Python SVN bindings
# e.g. SVN 1.5 or backports. Thanks to the bzr folks for enhancing
# these bindings.

from cStringIO import StringIO

from common import NoRepo, commit, converter_source, encodeargs, decodeargs
from common import commandline, converter_sink, mapfile

try:
    from svn.core import SubversionException, Pool
    import svn
    import svn.client
    import svn.core
    import svn.ra
    import svn.delta
    import transport
except ImportError:
    pass

def geturl(path):
    try:
        return svn.client.url_from_path(svn.core.svn_path_canonicalize(path))
    except SubversionException:
        pass
    if os.path.isdir(path):
        path = os.path.normpath(os.path.abspath(path))
        if os.name == 'nt':
            path = '/' + util.normpath(path)
        return 'file://%s' % path
    return path

def optrev(number):
    optrev = svn.core.svn_opt_revision_t()
    optrev.kind = svn.core.svn_opt_revision_number
    optrev.value.number = number
    return optrev

class changedpath(object):
    def __init__(self, p):
        self.copyfrom_path = p.copyfrom_path
        self.copyfrom_rev = p.copyfrom_rev
        self.action = p.action

def get_log_child(fp, url, paths, start, end, limit=0, discover_changed_paths=True,
                    strict_node_history=False):
    protocol = -1
    def receiver(orig_paths, revnum, author, date, message, pool):
        if orig_paths is not None:
            for k, v in orig_paths.iteritems():
                orig_paths[k] = changedpath(v)
        pickle.dump((orig_paths, revnum, author, date, message),
                    fp, protocol)

    try:
        # Use an ra of our own so that our parent can consume
        # our results without confusing the server.
        t = transport.SvnRaTransport(url=url)
        svn.ra.get_log(t.ra, paths, start, end, limit,
                       discover_changed_paths,
                       strict_node_history,
                       receiver)
    except SubversionException, (inst, num):
        pickle.dump(num, fp, protocol)
    else:
        pickle.dump(None, fp, protocol)
    fp.close()

def debugsvnlog(ui, **opts):
    """Fetch SVN log in a subprocess and channel them back to parent to
    avoid memory collection issues.
    """
    util.set_binary(sys.stdin)
    util.set_binary(sys.stdout)
    args = decodeargs(sys.stdin.read())
    get_log_child(sys.stdout, *args)

# SVN conversion code stolen from bzr-svn and tailor
class svn_source(converter_source):
    def __init__(self, ui, url, rev=None):
        super(svn_source, self).__init__(ui, url, rev=rev)

        try:
            SubversionException
        except NameError:
            raise NoRepo('Subversion python bindings could not be loaded')

        self.encoding = locale.getpreferredencoding()
        self.lastrevs = {}

        latest = None
        try:
            # Support file://path@rev syntax. Useful e.g. to convert
            # deleted branches.
            at = url.rfind('@')
            if at >= 0:
                latest = int(url[at+1:])
                url = url[:at]
        except ValueError, e:
            pass
        self.url = geturl(url)
        self.encoding = 'UTF-8' # Subversion is always nominal UTF-8
        try:
            self.transport = transport.SvnRaTransport(url=self.url)
            self.ra = self.transport.ra
            self.ctx = self.transport.client
            self.base = svn.ra.get_repos_root(self.ra)
            self.module = self.url[len(self.base):]
            self.modulemap = {} # revision, module
            self.commits = {}
            self.paths = {}
            self.uuid = svn.ra.get_uuid(self.ra).decode(self.encoding)
        except SubversionException, e:
            ui.print_exc()
            raise NoRepo("%s does not look like a Subversion repo" % self.url)

        if rev:
            try:
                latest = int(rev)
            except ValueError:
                raise util.Abort('svn: revision %s is not an integer' % rev)

        try:
            self.get_blacklist()
        except IOError, e:
            pass

        self.last_changed = self.latest(self.module, latest)

        self.head = self.revid(self.last_changed)
        self._changescache = None

        if os.path.exists(os.path.join(url, '.svn/entries')):
            self.wc = url
        else:
            self.wc = None
        self.convertfp = None

    def setrevmap(self, revmap):
        lastrevs = {}
        for revid in revmap.iterkeys():
            uuid, module, revnum = self.revsplit(revid)
            lastrevnum = lastrevs.setdefault(module, revnum)
            if revnum > lastrevnum:
                lastrevs[module] = revnum
        self.lastrevs = lastrevs

    def exists(self, path, optrev):
        try:
            svn.client.ls(self.url.rstrip('/') + '/' + path,
                                 optrev, False, self.ctx)
            return True
        except SubversionException, err:
            return False

    def getheads(self):

        def getcfgpath(name, rev):
            cfgpath = self.ui.config('convert', 'svn.' + name)
            path = (cfgpath or name).strip('/')
            if not self.exists(path, rev):
                if cfgpath:
                    raise util.Abort(_('expected %s to be at %r, but not found')
                                 % (name, path))
                return None
            self.ui.note(_('found %s at %r\n') % (name, path))
            return path

        rev = optrev(self.last_changed)
        oldmodule = ''
        trunk = getcfgpath('trunk', rev)
        tags = getcfgpath('tags', rev)
        branches = getcfgpath('branches', rev)

        # If the project has a trunk or branches, we will extract heads
        # from them. We keep the project root otherwise.
        if trunk:
            oldmodule = self.module or ''
            self.module += '/' + trunk
            lt = self.latest(self.module, self.last_changed)
            self.head = self.revid(lt)

        # First head in the list is the module's head
        self.heads = [self.head]
        self.tags = '%s/%s' % (oldmodule , (tags or 'tags'))

        # Check if branches bring a few more heads to the list
        if branches:
            rpath = self.url.strip('/')
            branchnames = svn.client.ls(rpath + '/' + branches, rev, False,
                                        self.ctx)
            for branch in branchnames.keys():
                module = '%s/%s/%s' % (oldmodule, branches, branch)
                brevnum = self.latest(module, self.last_changed)
                brev = self.revid(brevnum, module)
                self.ui.note('found branch %s at %d\n' % (branch, brevnum))
                self.heads.append(brev)

        return self.heads

    def getfile(self, file, rev):
        data, mode = self._getfile(file, rev)
        self.modecache[(file, rev)] = mode
        return data

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

    def getchanges(self, rev):
        if self._changescache and self._changescache[0] == rev:
            return self._changescache[1]
        self._changescache = None
        self.modecache = {}
        (paths, parents) = self.paths[rev]
        files, copies = self.expandpaths(rev, paths, parents)
        files.sort()
        files = zip(files, [rev] * len(files))

        # caller caches the result, so free it here to release memory
        del self.paths[rev]
        return (files, copies)

    def getchangedfiles(self, rev, i):
        changes = self.getchanges(rev)
        self._changescache = (rev, changes)
        return [f[0] for f in changes[0]]

    def getcommit(self, rev):
        if rev not in self.commits:
            uuid, module, revnum = self.revsplit(rev)
            self.module = module
            self.reparent(module)
            stop = self.lastrevs.get(module, 0)
            self._fetch_revisions(from_revnum=revnum, to_revnum=stop)
        commit = self.commits[rev]
        # caller caches the result, so free it here to release memory
        del self.commits[rev]
        return commit

    def get_log(self, paths, start, end, limit=0, discover_changed_paths=True,
                strict_node_history=False):

        def parent(fp):
            while True:
                entry = pickle.load(fp)
                try:
                    orig_paths, revnum, author, date, message = entry
                except:
                    if entry is None:
                        break
                    raise SubversionException("child raised exception", entry)
                yield entry

        args = [self.url, paths, start, end, limit, discover_changed_paths,
                strict_node_history]
        arg = encodeargs(args)
        hgexe = util.hgexecutable()
        cmd = '%s debugsvnlog' % util.shellquote(hgexe)
        stdin, stdout = os.popen2(cmd, 'b')

        stdin.write(arg)
        stdin.close()

        for p in parent(stdout):
            yield p

    def gettags(self):
        tags = {}
        start = self.revnum(self.head)
        try:
            for entry in self.get_log([self.tags], 0, start):
                orig_paths, revnum, author, date, message = entry
                for path in orig_paths:
                    if not path.startswith(self.tags+'/'):
                        continue
                    ent = orig_paths[path]
                    source = ent.copyfrom_path
                    rev = ent.copyfrom_rev
                    tag = path.split('/')[-1]
                    tags[tag] = self.revid(rev, module=source)
        except SubversionException, (inst, num):
            self.ui.note('no tags found at revision %d\n' % start)
        return tags

    def converted(self, rev, destrev):
        if not self.wc:
            return
        if self.convertfp is None:
            self.convertfp = open(os.path.join(self.wc, '.svn', 'hg-shamap'),
                                  'a')
        self.convertfp.write('%s %d\n' % (destrev, self.revnum(rev)))
        self.convertfp.flush()

    # -- helper functions --

    def revid(self, revnum, module=None):
        if not module:
            module = self.module
        return u"svn:%s%s@%s" % (self.uuid, module.decode(self.encoding),
                                 revnum)

    def revnum(self, rev):
        return int(rev.split('@')[-1])

    def revsplit(self, rev):
        url, revnum = rev.encode(self.encoding).split('@', 1)
        revnum = int(revnum)
        parts = url.split('/', 1)
        uuid = parts.pop(0)[4:]
        mod = ''
        if parts:
            mod = '/' + parts[0]
        return uuid, mod, revnum

    def latest(self, path, stop=0):
        'find the latest revision affecting path, up to stop'
        if not stop:
            stop = svn.ra.get_latest_revnum(self.ra)
        try:
            self.reparent('')
            dirent = svn.ra.stat(self.ra, path.strip('/'), stop)
            self.reparent(self.module)
        except SubversionException:
            dirent = None
        if not dirent:
            raise util.Abort('%s not found up to revision %d' % (path, stop))

        return dirent.created_rev

    def get_blacklist(self):
        """Avoid certain revision numbers.
        It is not uncommon for two nearby revisions to cancel each other
        out, e.g. 'I copied trunk into a subdirectory of itself instead
        of making a branch'. The converted repository is significantly
        smaller if we ignore such revisions."""
        self.blacklist = util.set()
        blacklist = self.blacklist
        for line in file("blacklist.txt", "r"):
            if not line.startswith("#"):
                try:
                    svn_rev = int(line.strip())
                    blacklist.add(svn_rev)
                except ValueError, e:
                    pass # not an integer or a comment

    def is_blacklisted(self, svn_rev):
        return svn_rev in self.blacklist

    def reparent(self, module):
        svn_url = self.base + module
        self.ui.debug("reparent to %s\n" % svn_url.encode(self.encoding))
        svn.ra.reparent(self.ra, svn_url.encode(self.encoding))

    def expandpaths(self, rev, paths, parents):
        def get_entry_from_path(path, module=self.module):
            # Given the repository url of this wc, say
            #   "http://server/plone/CMFPlone/branches/Plone-2_0-branch"
            # extract the "entry" portion (a relative path) from what
            # svn log --xml says, ie
            #   "/CMFPlone/branches/Plone-2_0-branch/tests/PloneTestCase.py"
            # that is to say "tests/PloneTestCase.py"
            if path.startswith(module):
                relative = path[len(module):]
                if relative.startswith('/'):
                    return relative[1:]
                else:
                    return relative

            # The path is outside our tracked tree...
            self.ui.debug('%r is not under %r, ignoring\n' % (path, module))
            return None

        entries = []
        copyfrom = {} # Map of entrypath, revision for finding source of deleted revisions.
        copies = {}
        revnum = self.revnum(rev)

        if revnum in self.modulemap:
            new_module = self.modulemap[revnum]
            if new_module != self.module:
                self.module = new_module
                self.reparent(self.module)

        for path, ent in paths:
            entrypath = get_entry_from_path(path, module=self.module)
            entry = entrypath.decode(self.encoding)

            kind = svn.ra.check_path(self.ra, entrypath, revnum)
            if kind == svn.core.svn_node_file:
                if ent.copyfrom_path:
                    copyfrom_path = get_entry_from_path(ent.copyfrom_path)
                    if copyfrom_path:
                        self.ui.debug("Copied to %s from %s@%s\n" %
                                      (entrypath, copyfrom_path,
                                       ent.copyfrom_rev))
                        # It's probably important for hg that the source
                        # exists in the revision's parent, not just the
                        # ent.copyfrom_rev
                        fromkind = svn.ra.check_path(self.ra, copyfrom_path, ent.copyfrom_rev)
                        if fromkind != 0:
                            copies[self.recode(entry)] = self.recode(copyfrom_path)
                entries.append(self.recode(entry))
            elif kind == 0: # gone, but had better be a deleted *file*
                self.ui.debug("gone from %s\n" % ent.copyfrom_rev)

                # if a branch is created but entries are removed in the same
                # changeset, get the right fromrev
                if parents:
                    uuid, old_module, fromrev = self.revsplit(parents[0])
                else:
                    fromrev = revnum - 1
                    # might always need to be revnum - 1 in these 3 lines?
                    old_module = self.modulemap.get(fromrev, self.module)

                basepath = old_module + "/" + get_entry_from_path(path, module=self.module)
                entrypath = old_module + "/" + get_entry_from_path(path, module=self.module)

                def lookup_parts(p):
                    rc = None
                    parts = p.split("/")
                    for i in range(len(parts)):
                        part = "/".join(parts[:i])
                        info = part, copyfrom.get(part, None)
                        if info[1] is not None:
                            self.ui.debug("Found parent directory %s\n" % info[1])
                            rc = info
                    return rc

                self.ui.debug("base, entry %s %s\n" % (basepath, entrypath))

                frompath, froment = lookup_parts(entrypath) or (None, revnum - 1)

                # need to remove fragment from lookup_parts and replace with copyfrom_path
                if frompath is not None:
                    self.ui.debug("munge-o-matic\n")
                    self.ui.debug(entrypath + '\n')
                    self.ui.debug(entrypath[len(frompath):] + '\n')
                    entrypath = froment.copyfrom_path + entrypath[len(frompath):]
                    fromrev = froment.copyfrom_rev
                    self.ui.debug("Info: %s %s %s %s\n" % (frompath, froment, ent, entrypath))

                fromkind = svn.ra.check_path(self.ra, entrypath, fromrev)
                if fromkind == svn.core.svn_node_file:   # a deleted file
                    entries.append(self.recode(entry))
                elif fromkind == svn.core.svn_node_dir:
                    # print "Deleted/moved non-file:", revnum, path, ent
                    # children = self._find_children(path, revnum - 1)
                    # print "find children %s@%d from %d action %s" % (path, revnum, ent.copyfrom_rev, ent.action)
                    # Sometimes this is tricky. For example: in
                    # The Subversion Repository revision 6940 a dir
                    # was copied and one of its files was deleted
                    # from the new location in the same commit. This
                    # code can't deal with that yet.
                    if ent.action == 'C':
                        children = self._find_children(path, fromrev)
                    else:
                        oroot = entrypath.strip('/')
                        nroot = path.strip('/')
                        children = self._find_children(oroot, fromrev)
                        children = [s.replace(oroot,nroot) for s in children]
                    # Mark all [files, not directories] as deleted.
                    for child in children:
                        # Can we move a child directory and its
                        # parent in the same commit? (probably can). Could
                        # cause problems if instead of revnum -1,
                        # we have to look in (copyfrom_path, revnum - 1)
                        entrypath = get_entry_from_path("/" + child, module=old_module)
                        if entrypath:
                            entry = self.recode(entrypath.decode(self.encoding))
                            if entry in copies:
                                # deleted file within a copy
                                del copies[entry]
                            else:
                                entries.append(entry)
                else:
                    self.ui.debug('unknown path in revision %d: %s\n' % \
                                  (revnum, path))
            elif kind == svn.core.svn_node_dir:
                # Should probably synthesize normal file entries
                # and handle as above to clean up copy/rename handling.

                # If the directory just had a prop change,
                # then we shouldn't need to look for its children.
                # Also this could create duplicate entries. Not sure
                # whether this will matter. Maybe should make entries a set.
                # print "Changed directory", revnum, path, ent.action, ent.copyfrom_path, ent.copyfrom_rev
                # This will fail if a directory was copied
                # from another branch and then some of its files
                # were deleted in the same transaction.
                children = self._find_children(path, revnum)
                children.sort()
                for child in children:
                    # Can we move a child directory and its
                    # parent in the same commit? (probably can). Could
                    # cause problems if instead of revnum -1,
                    # we have to look in (copyfrom_path, revnum - 1)
                    entrypath = get_entry_from_path("/" + child, module=self.module)
                    # print child, self.module, entrypath
                    if entrypath:
                        # Need to filter out directories here...
                        kind = svn.ra.check_path(self.ra, entrypath, revnum)
                        if kind != svn.core.svn_node_dir:
                            entries.append(self.recode(entrypath))

                # Copies here (must copy all from source)
                # Probably not a real problem for us if
                # source does not exist

                # Can do this with the copy command "hg copy"
                # if ent.copyfrom_path:
                #     copyfrom_entry = get_entry_from_path(ent.copyfrom_path.decode(self.encoding),
                #             module=self.module)
                #     copyto_entry = entrypath
                #
                #     print "copy directory", copyfrom_entry, 'to', copyto_entry
                #
                #     copies.append((copyfrom_entry, copyto_entry))

                if ent.copyfrom_path:
                    copyfrom_path = ent.copyfrom_path.decode(self.encoding)
                    copyfrom_entry = get_entry_from_path(copyfrom_path, module=self.module)
                    if copyfrom_entry:
                        copyfrom[path] = ent
                        self.ui.debug("mark %s came from %s\n" % (path, copyfrom[path]))

                        # Good, /probably/ a regular copy. Really should check
                        # to see whether the parent revision actually contains
                        # the directory in question.
                        children = self._find_children(self.recode(copyfrom_path), ent.copyfrom_rev)
                        children.sort()
                        for child in children:
                            entrypath = get_entry_from_path("/" + child, module=self.module)
                            if entrypath:
                                entry = entrypath.decode(self.encoding)
                                # print "COPY COPY From", copyfrom_entry, entry
                                copyto_path = path + entry[len(copyfrom_entry):]
                                copyto_entry =  get_entry_from_path(copyto_path, module=self.module)
                                # print "COPY", entry, "COPY To", copyto_entry
                                copies[self.recode(copyto_entry)] = self.recode(entry)
                                # copy from quux splort/quuxfile

        return (entries, copies)

    def _fetch_revisions(self, from_revnum = 0, to_revnum = 347):
        self.child_cset = None
        def parselogentry(orig_paths, revnum, author, date, message):
            self.ui.debug("parsing revision %d (%d changes)\n" %
                          (revnum, len(orig_paths)))

            if revnum in self.modulemap:
                new_module = self.modulemap[revnum]
                if new_module != self.module:
                    self.module = new_module
                    self.reparent(self.module)

            rev = self.revid(revnum)
            # branch log might return entries for a parent we already have
            if (rev in self.commits or
                (revnum < self.lastrevs.get(self.module, 0))):
                return

            parents = []
            # check whether this revision is the start of a branch
            if self.module in orig_paths:
                ent = orig_paths[self.module]
                if ent.copyfrom_path:
                    # ent.copyfrom_rev may not be the actual last revision
                    prev = self.latest(ent.copyfrom_path, ent.copyfrom_rev)
                    self.modulemap[prev] = ent.copyfrom_path
                    parents = [self.revid(prev, ent.copyfrom_path)]
                    self.ui.note('found parent of branch %s at %d: %s\n' % \
                                     (self.module, prev, ent.copyfrom_path))
                else:
                    self.ui.debug("No copyfrom path, don't know what to do.\n")

            self.modulemap[revnum] = self.module # track backwards in time

            orig_paths = orig_paths.items()
            orig_paths.sort()
            paths = []
            # filter out unrelated paths
            for path, ent in orig_paths:
                if not path.startswith(self.module):
                    self.ui.debug("boring@%s: %s\n" % (revnum, path))
                    continue
                paths.append((path, ent))

            self.paths[rev] = (paths, parents)

            # Example SVN datetime. Includes microseconds.
            # ISO-8601 conformant
            # '2007-01-04T17:35:00.902377Z'
            date = util.parsedate(date[:19] + " UTC", ["%Y-%m-%dT%H:%M:%S"])

            log = message and self.recode(message)
            author = author and self.recode(author) or ''
            try:
                branch = self.module.split("/")[-1]
                if branch == 'trunk':
                    branch = ''
            except IndexError:
                branch = None

            cset = commit(author=author,
                          date=util.datestr(date),
                          desc=log,
                          parents=parents,
                          branch=branch,
                          rev=rev.encode('utf-8'))

            self.commits[rev] = cset
            if self.child_cset and not self.child_cset.parents:
                self.child_cset.parents = [rev]
            self.child_cset = cset

        self.ui.note('fetching revision log for "%s" from %d to %d\n' %
                     (self.module, from_revnum, to_revnum))

        try:
            for entry in self.get_log([self.module], from_revnum, to_revnum):
                orig_paths, revnum, author, date, message = entry
                if self.is_blacklisted(revnum):
                    self.ui.note('skipping blacklisted revision %d\n' % revnum)
                    continue
                if orig_paths is None:
                    self.ui.debug('revision %d has no entries\n' % revnum)
                    continue
                parselogentry(orig_paths, revnum, author, date, message)
        except SubversionException, (inst, num):
            if num == svn.core.SVN_ERR_FS_NO_SUCH_REVISION:
                raise NoSuchRevision(branch=self,
                    revision="Revision number %d" % to_revnum)
            raise

    def _getfile(self, file, rev):
        io = StringIO()
        # TODO: ra.get_file transmits the whole file instead of diffs.
        mode = ''
        try:
            revnum = self.revnum(rev)
            if self.module != self.modulemap[revnum]:
                self.module = self.modulemap[revnum]
                self.reparent(self.module)
            info = svn.ra.get_file(self.ra, file, revnum, io)
            if isinstance(info, list):
                info = info[-1]
            mode = ("svn:executable" in info) and 'x' or ''
            mode = ("svn:special" in info) and 'l' or mode
        except SubversionException, e:
            notfound = (svn.core.SVN_ERR_FS_NOT_FOUND,
                svn.core.SVN_ERR_RA_DAV_PATH_NOT_FOUND)
            if e.apr_err in notfound: # File not found
                raise IOError()
            raise
        data = io.getvalue()
        if mode == 'l':
            link_prefix = "link "
            if data.startswith(link_prefix):
                data = data[len(link_prefix):]
        return data, mode

    def _find_children(self, path, revnum):
        path = path.strip('/')
        pool = Pool()
        rpath = '/'.join([self.base, path]).strip('/')
        return ['%s/%s' % (path, x) for x in svn.client.ls(rpath, optrev(revnum), True, self.ctx, pool).keys()]

pre_revprop_change = '''#!/bin/sh

REPOS="$1"
REV="$2"
USER="$3"
PROPNAME="$4"
ACTION="$5"

if [ "$ACTION" = "M" -a "$PROPNAME" = "svn:log" ]; then exit 0; fi
if [ "$ACTION" = "A" -a "$PROPNAME" = "hg:convert-branch" ]; then exit 0; fi
if [ "$ACTION" = "A" -a "$PROPNAME" = "hg:convert-rev" ]; then exit 0; fi

echo "Changing prohibited revision property" >&2
exit 1
'''

class svn_sink(converter_sink, commandline):
    commit_re = re.compile(r'Committed revision (\d+).', re.M)

    def prerun(self):
        if self.wc:
            os.chdir(self.wc)

    def postrun(self):
        if self.wc:
            os.chdir(self.cwd)

    def join(self, name):
        return os.path.join(self.wc, '.svn', name)

    def revmapfile(self):
        return self.join('hg-shamap')

    def authorfile(self):
        return self.join('hg-authormap')

    def __init__(self, ui, path):
        converter_sink.__init__(self, ui, path)
        commandline.__init__(self, ui, 'svn')
        self.delete = []
        self.setexec = []
        self.delexec = []
        self.copies = []
        self.wc = None
        self.cwd = os.getcwd()

        path = os.path.realpath(path)

        created = False
        if os.path.isfile(os.path.join(path, '.svn', 'entries')):
            self.wc = path
            self.run0('update')
        else:
            wcpath = os.path.join(os.getcwd(), os.path.basename(path) + '-wc')

            if os.path.isdir(os.path.dirname(path)):
                if not os.path.exists(os.path.join(path, 'db', 'fs-type')):
                    ui.status(_('initializing svn repo %r\n') %
                              os.path.basename(path))
                    commandline(ui, 'svnadmin').run0('create', path)
                    created = path
                path = util.normpath(path)
                if not path.startswith('/'):
                    path = '/' + path
                path = 'file://' + path

            ui.status(_('initializing svn wc %r\n') % os.path.basename(wcpath))
            self.run0('checkout', path, wcpath)

            self.wc = wcpath
        self.opener = util.opener(self.wc)
        self.wopener = util.opener(self.wc)
        self.childmap = mapfile(ui, self.join('hg-childmap'))
        self.is_exec = util.checkexec(self.wc) and util.is_exec or None

        if created:
            hook = os.path.join(created, 'hooks', 'pre-revprop-change')
            fp = open(hook, 'w')
            fp.write(pre_revprop_change)
            fp.close()
            util.set_flags(hook, "x")

        xport = transport.SvnRaTransport(url=geturl(path))
        self.uuid = svn.ra.get_uuid(xport.ra)

    def wjoin(self, *names):
        return os.path.join(self.wc, *names)

    def putfile(self, filename, flags, data):
        if 'l' in flags:
            self.wopener.symlink(data, filename)
        else:
            try:
                if os.path.islink(self.wjoin(filename)):
                    os.unlink(filename)
            except OSError:
                pass
            self.wopener(filename, 'w').write(data)

            if self.is_exec:
                was_exec = self.is_exec(self.wjoin(filename))
            else:
                # On filesystems not supporting execute-bit, there is no way
                # to know if it is set but asking subversion. Setting it
                # systematically is just as expensive and much simpler.
                was_exec = 'x' not in flags

            util.set_flags(self.wjoin(filename), flags)
            if was_exec:
                if 'x' not in flags:
                    self.delexec.append(filename)
            else:
                if 'x' in flags:
                    self.setexec.append(filename)

    def delfile(self, name):
        self.delete.append(name)

    def copyfile(self, source, dest):
        self.copies.append([source, dest])

    def _copyfile(self, source, dest):
        # SVN's copy command pukes if the destination file exists, but
        # our copyfile method expects to record a copy that has
        # already occurred.  Cross the semantic gap.
        wdest = self.wjoin(dest)
        exists = os.path.exists(wdest)
        if exists:
            fd, tempname = tempfile.mkstemp(
                prefix='hg-copy-', dir=os.path.dirname(wdest))
            os.close(fd)
            os.unlink(tempname)
            os.rename(wdest, tempname)
        try:
            self.run0('copy', source, dest)
        finally:
            if exists:
                try:
                    os.unlink(wdest)
                except OSError:
                    pass
                os.rename(tempname, wdest)

    def dirs_of(self, files):
        dirs = set()
        for f in files:
            if os.path.isdir(self.wjoin(f)):
                dirs.add(f)
            for i in strutil.rfindall(f, '/'):
                dirs.add(f[:i])
        return dirs

    def add_dirs(self, files):
        add_dirs = [d for d in self.dirs_of(files)
                    if not os.path.exists(self.wjoin(d, '.svn', 'entries'))]
        if add_dirs:
            add_dirs.sort()
            self.xargs(add_dirs, 'add', non_recursive=True, quiet=True)
        return add_dirs

    def add_files(self, files):
        if files:
            self.xargs(files, 'add', quiet=True)
        return files

    def tidy_dirs(self, names):
        dirs = list(self.dirs_of(names))
        dirs.sort(reverse=True)
        deleted = []
        for d in dirs:
            wd = self.wjoin(d)
            if os.listdir(wd) == '.svn':
                self.run0('delete', d)
                deleted.append(d)
        return deleted

    def addchild(self, parent, child):
        self.childmap[parent] = child

    def revid(self, rev):
        return u"svn:%s@%s" % (self.uuid, rev)

    def putcommit(self, files, parents, commit):
        for parent in parents:
            try:
                return self.revid(self.childmap[parent])
            except KeyError:
                pass
        entries = set(self.delete)
        files = util.frozenset(files)
        entries.update(self.add_dirs(files.difference(entries)))
        if self.copies:
            for s, d in self.copies:
                self._copyfile(s, d)
            self.copies = []
        if self.delete:
            self.xargs(self.delete, 'delete')
            self.delete = []
        entries.update(self.add_files(files.difference(entries)))
        entries.update(self.tidy_dirs(entries))
        if self.delexec:
            self.xargs(self.delexec, 'propdel', 'svn:executable')
            self.delexec = []
        if self.setexec:
            self.xargs(self.setexec, 'propset', 'svn:executable', '*')
            self.setexec = []

        fd, messagefile = tempfile.mkstemp(prefix='hg-convert-')
        fp = os.fdopen(fd, 'w')
        fp.write(commit.desc)
        fp.close()
        try:
            output = self.run0('commit',
                               username=util.shortuser(commit.author),
                               file=messagefile,
                               encoding='utf-8')
            try:
                rev = self.commit_re.search(output).group(1)
            except AttributeError:
                self.ui.warn(_('unexpected svn output:\n'))
                self.ui.warn(output)
                raise util.Abort(_('unable to cope with svn output'))
            if commit.rev:
                self.run('propset', 'hg:convert-rev', commit.rev,
                         revprop=True, revision=rev)
            if commit.branch and commit.branch != 'default':
                self.run('propset', 'hg:convert-branch', commit.branch,
                         revprop=True, revision=rev)
            for parent in parents:
                self.addchild(parent, rev)
            return self.revid(rev)
        finally:
            os.unlink(messagefile)

    def puttags(self, tags):
        self.ui.warn(_('XXX TAGS NOT IMPLEMENTED YET\n'))