base.py

"""module with git command implementations of the basic interfaces
:note: we could add all implementations of the basic interfaces, its more efficient though
    to obtain them from the pure implementation"""
from git.exc import (
    GitCommandError,
    BadObject
)

from git.base import (
    OInfo,
    OStream
)

from git.util import (
    bin_to_hex,
    hex_to_bin,
    isfile,
    join_path,
    join,
    Actor,
    IterableList,
)
from git.db.interface import (
    FetchInfo,
    PushInfo,
    HighLevelRepository,
    TransportDB,
    RemoteProgress
)
from git.cmd import Git
from git.refs import (
    Reference,
    RemoteReference,
    SymbolicReference,
    TagReference
)
from git.objects.commit import Commit
from cStringIO import StringIO
import re
import os
import sys


__all__ = ('CmdTransportMixin', 'GitCommandMixin', 'CmdPushInfo', 'CmdFetchInfo',
           'CmdRemoteProgress', 'CmdObjectDBRMixin', 'CmdHighLevelRepository')


#{ Utilities

def touch(filename):
    fp = open(filename, "a")
    fp.close()


def digest_process_messages(fh, progress):
    """Read progress messages from file-like object fh, supplying the respective
    progress messages to the progress instance.

    :return: list(line, ...) list of lines without linebreaks that did 
        not contain progress information"""
    line_so_far = ''
    dropped_lines = list()
    while True:
        char = fh.read(1)
        if not char:
            break

        if char in ('\r', '\n'):
            dropped_lines.extend(progress._parse_progress_line(line_so_far))
            line_so_far = ''
        else:
            line_so_far += char
        # END process parsed line
    # END while file is not done reading
    return dropped_lines


def finalize_process(proc):
    """Wait for the process (fetch, pull or push) and handle its errors accordingly"""
    try:
        proc.wait()
    except GitCommandError, e:
        # if a push has rejected items, the command has non-zero return status
        # a return status of 128 indicates a connection error - reraise the previous one
        if proc.poll() == 128:
            raise
        pass
    # END exception handling


def get_fetch_info_from_stderr(repo, proc, progress):
    # skip first line as it is some remote info we are not interested in
    output = IterableList('name')

    # lines which are no progress are fetch info lines
    # this also waits for the command to finish
    # Skip some progress lines that don't provide relevant information
    fetch_info_lines = list()
    for line in digest_process_messages(proc.stderr, progress):
        if line.startswith('From') or line.startswith('remote: Total'):
            continue
        elif line.startswith('warning:'):
            print >> sys.stderr, line
            continue
        elif line.startswith('fatal:'):
            raise GitCommandError(("Error when fetching: %s" % line,), 2)
        # END handle special messages
        fetch_info_lines.append(line)
    # END for each line

    # read head information
    fp = open(join(repo.git_dir, 'FETCH_HEAD'), 'r')
    fetch_head_info = fp.readlines()
    fp.close()

    assert len(fetch_info_lines) == len(fetch_head_info)

    output.extend(CmdFetchInfo._from_line(repo, err_line, fetch_line)
                  for err_line, fetch_line in zip(fetch_info_lines, fetch_head_info))

    finalize_process(proc)
    return output


def get_push_info(repo, remotename_or_url, proc, progress):
    # read progress information from stderr
    # we hope stdout can hold all the data, it should ...
    # read the lines manually as it will use carriage returns between the messages
    # to override the previous one. This is why we read the bytes manually
    stdout, stderr = proc.communicate()
    digest_process_messages(StringIO(stderr), progress)

    output = IterableList('name')
    for line in stdout.splitlines():
        try:
            output.append(CmdPushInfo._from_line(repo, remotename_or_url, line))
        except ValueError:
            # if an error happens, additional info is given which we cannot parse
            pass
        # END exception handling
    # END for each line

    return output


def add_progress(kwargs, git, progress):
    """Add the --progress flag to the given kwargs dict if supported by the 
    git command. If the actual progress in the given progress instance is not 
    given, we do not request any progress
    :return: possibly altered kwargs"""
    if progress._progress is not None:
        v = git.version_info
        if v[0] > 1 or v[1] > 7 or v[2] > 0 or v[3] > 3:
            kwargs['progress'] = True
        # END handle --progress
    # END handle progress
    return kwargs

#} END utilities


class CmdRemoteProgress(RemoteProgress):

    """
    A Remote progress implementation taking a user derived progress to call the 
    respective methods on.
    """
    __slots__ = ("_seen_ops", '_progress')
    re_op_absolute = re.compile("(remote: )?([\w\s]+):\s+()(\d+)()(.*)")
    re_op_relative = re.compile("(remote: )?([\w\s]+):\s+(\d+)% \((\d+)/(\d+)\)(.*)")

    def __init__(self, progress_instance=None):
        self._seen_ops = list()
        if progress_instance is None:
            progress_instance = RemoteProgress()
        # END assure proper instance
        self._progress = progress_instance

    def _parse_progress_line(self, line):
        """Parse progress information from the given line as retrieved by git-push
        or git-fetch

        Call the own update(), __call__() and line_dropped() methods according 
        to the parsed result.

        :return: list(line, ...) list of lines that could not be processed"""
        # handle
        # Counting objects: 4, done.
        # Compressing objects:  50% (1/2)   \rCompressing objects: 100% (2/2)   \rCompressing objects: 100% (2/2), done.
        sub_lines = line.split('\r')
        failed_lines = list()
        for sline in sub_lines:
            # find esacpe characters and cut them away - regex will not work with
            # them as they are non-ascii. As git might expect a tty, it will send them
            last_valid_index = None
            for i, c in enumerate(reversed(sline)):
                if ord(c) < 32:
                    # its a slice index
                    last_valid_index = -i - 1
                # END character was non-ascii
            # END for each character in sline
            if last_valid_index is not None:
                sline = sline[:last_valid_index]
            # END cut away invalid part
            sline = sline.rstrip()

            cur_count, max_count = None, None
            match = self.re_op_relative.match(sline)
            if match is None:
                match = self.re_op_absolute.match(sline)

            if not match:
                self._progress.line_dropped(sline)
                failed_lines.append(sline)
                continue
            # END could not get match

            op_code = 0
            remote, op_name, percent, cur_count, max_count, message = match.groups()

            # get operation id
            if op_name == "Counting objects":
                op_code |= self.COUNTING
            elif op_name == "Compressing objects":
                op_code |= self.COMPRESSING
            elif op_name == "Writing objects":
                op_code |= self.WRITING
            elif op_name == "Receiving objects":
                op_code |= self.RECEIVING
            elif op_name == "Resolving deltas":
                op_code |= self.RESOLVING
            else:
                # Note: On windows it can happen that partial lines are sent
                # Hence we get something like "CompreReceiving objects", which is
                # a blend of "Compressing objects" and "Receiving objects".
                # This can't really be prevented, so we drop the line verbosely
                # to make sure we get informed in case the process spits out new
                # commands at some point.
                self.line_dropped(sline)
                sys.stderr.write("Operation name %r unknown - skipping line '%s'" % (op_name, sline))
                # Note: Don't add this line to the failed lines, as we have to silently
                # drop it
                return failed_lines
            # END handle opcode

            # figure out stage
            if op_code not in self._seen_ops:
                self._seen_ops.append(op_code)
                op_code |= self.BEGIN
            # END begin opcode

            if message is None:
                message = ''
            # END message handling

            message = message.strip()
            done_token = ', done.'
            if message.endswith(done_token):
                op_code |= self.END
                message = message[:-len(done_token)]
            # END end message handling

            self._progress.update(op_code, cur_count, max_count, message, line)
            self._progress(message, line)
        # END for each sub line
        return failed_lines


class CmdPushInfo(PushInfo):

    """
    Pure Python implementation of a PushInfo interface
    """
    __slots__ = ('local_ref', 'remote_ref_string', 'flags', 'old_commit_binsha',
                 '_remotename_or_url', 'repo', 'summary')

    _flag_map = {'X': PushInfo.NO_MATCH,
                 '-': PushInfo.DELETED, '*': 0,
                 '+': PushInfo.FORCED_UPDATE,
                 ' ': PushInfo.FAST_FORWARD,
                 '=': PushInfo.UP_TO_DATE,
                 '!': PushInfo.ERROR}

    def __init__(self, flags, local_ref, remote_ref_string, repo, remotename_or_url, old_commit_binsha=None,
                 summary=''):
        """ Initialize a new instance """
        self.flags = flags
        self.local_ref = local_ref
        self.repo = repo
        self.remote_ref_string = remote_ref_string
        self._remotename_or_url = remotename_or_url
        self.old_commit_binsha = old_commit_binsha
        self.summary = summary

    @property
    def remote_ref(self):
        """
        :return:
            Remote Reference or TagReference in the local repository corresponding 
            to the remote_ref_string kept in this instance."""
        # translate heads to a local remote, tags stay as they are
        if self.remote_ref_string.startswith("refs/tags"):
            return TagReference(self.repo, self.remote_ref_string)
        elif self.remote_ref_string.startswith("refs/heads"):
            remote_ref = Reference(self.repo, self.remote_ref_string)
            if '/' in self._remotename_or_url:
                sys.stderr.write(
                    "Cannot provide RemoteReference instance if it was created from a url instead of of a remote name: %s. Returning Reference instance instead" % sefl._remotename_or_url)
                return remote_ref
            # END assert correct input
            return RemoteReference(self.repo, "refs/remotes/%s/%s" % (str(self._remotename_or_url), remote_ref.name))
        else:
            raise ValueError("Could not handle remote ref: %r" % self.remote_ref_string)
        # END

    @classmethod
    def _from_line(cls, repo, remotename_or_url, line):
        """Create a new PushInfo instance as parsed from line which is expected to be like
            refs/heads/master:refs/heads/master 05d2687..1d0568e"""
        control_character, from_to, summary = line.split('\t', 3)
        flags = 0

        # control character handling
        try:
            flags |= cls._flag_map[control_character]
        except KeyError:
            raise ValueError("Control Character %r unknown as parsed from line %r" % (control_character, line))
        # END handle control character

        # from_to handling
        from_ref_string, to_ref_string = from_to.split(':')
        if flags & cls.DELETED:
            from_ref = None
        else:
            from_ref = Reference.from_path(repo, from_ref_string)

        # commit handling, could be message or commit info
        old_commit_binsha = None
        if summary.startswith('['):
            if "[rejected]" in summary:
                flags |= cls.REJECTED
            elif "[remote rejected]" in summary:
                flags |= cls.REMOTE_REJECTED
            elif "[remote failure]" in summary:
                flags |= cls.REMOTE_FAILURE
            elif "[no match]" in summary:
                flags |= cls.ERROR
            elif "[new tag]" in summary:
                flags |= cls.NEW_TAG
            elif "[new branch]" in summary:
                flags |= cls.NEW_HEAD
            # uptodate encoded in control character
        else:
            # fast-forward or forced update - was encoded in control character,
            # but we parse the old and new commit
            split_token = "..."
            if control_character == " ":
                split_token = ".."
            old_sha, new_sha = summary.split(' ')[0].split(split_token)
            old_commit_binsha = repo.resolve(old_sha)
        # END message handling

        return cls(flags, from_ref, to_ref_string, repo, remotename_or_url, old_commit_binsha, summary)


class CmdFetchInfo(FetchInfo):

    """
    Pure python implementation of a FetchInfo interface
    """
    __slots__ = ('ref', 'old_commit_binsha', 'flags', 'note')

    #                             %c    %-*s %-*s             -> %s       (%s)
    re_fetch_result = re.compile("^\s*(.) (\[?[\w\s\.]+\]?)\s+(.+) -> ([/\w_\+\.-]+)(    \(.*\)?$)?")

    _flag_map = {'!': FetchInfo.ERROR,
                 '+': FetchInfo.FORCED_UPDATE,
                 '-': FetchInfo.TAG_UPDATE,
                 '*': 0,
                 '=': FetchInfo.HEAD_UPTODATE,
                 ' ': FetchInfo.FAST_FORWARD}

    def __init__(self, ref, flags, note='', old_commit_binsha=None):
        """
        Initialize a new instance
        """
        self.ref = ref
        self.flags = flags
        self.note = note
        self.old_commit_binsha = old_commit_binsha

    def __str__(self):
        return self.name

    @property
    def name(self):
        """:return: Name of our remote ref"""
        return self.ref.name

    @property
    def commit(self):
        """:return: Commit of our remote ref"""
        return self.ref.commit

    @classmethod
    def _from_line(cls, repo, line, fetch_line):
        """Parse information from the given line as returned by git-fetch -v
        and return a new CmdFetchInfo object representing this information.

        We can handle a line as follows
        "%c %-*s %-*s -> %s%s"

        Where c is either ' ', !, +, -, *, or =
        ! means error
        + means success forcing update
        - means a tag was updated
        * means birth of new branch or tag
        = means the head was up to date ( and not moved )
        ' ' means a fast-forward

        fetch line is the corresponding line from FETCH_HEAD, like
        acb0fa8b94ef421ad60c8507b634759a472cd56c    not-for-merge   branch '0.1.7RC' of /tmp/tmpya0vairemote_repo"""
        match = cls.re_fetch_result.match(line)
        if match is None:
            raise ValueError("Failed to parse line: %r" % line)

        # parse lines
        control_character, operation, local_remote_ref, remote_local_ref, note = match.groups()
        try:
            new_hex_sha, fetch_operation, fetch_note = fetch_line.split("\t")
            ref_type_name, fetch_note = fetch_note.split(' ', 1)
        except ValueError:  # unpack error
            raise ValueError("Failed to parse FETCH__HEAD line: %r" % fetch_line)

        # handle FETCH_HEAD and figure out ref type
        # If we do not specify a target branch like master:refs/remotes/origin/master,
        # the fetch result is stored in FETCH_HEAD which destroys the rule we usually
        # have. In that case we use a symbolic reference which is detached
        ref_type = None
        if remote_local_ref == "FETCH_HEAD":
            ref_type = SymbolicReference
        elif ref_type_name in ("remote-tracking", "branch"):
            # note: remote-tracking is just the first part of the 'remote-tracking branch' token.
            # We don't parse it correctly, but its enough to know what to do, and its new in git 1.7something
            ref_type = RemoteReference
        elif ref_type_name == "tag":
            ref_type = TagReference
        else:
            raise TypeError("Cannot handle reference type: %r" % ref_type_name)
        # END handle ref type

        # create ref instance
        if ref_type is SymbolicReference:
            remote_local_ref = ref_type(repo, "FETCH_HEAD")
        else:
            # determine prefix. Tags are usually pulled into refs/tags, they may have subdirectories.
            # It is not clear sometimes where exactly the item is, unless we have an absolute path as indicated
            # by the 'ref/' prefix. Otherwise even a tag could be in refs/remotes, which is when it will have the
            # 'tags/' subdirectory in its path.
            # We don't want to test for actual existence, but try to figure everything out analytically.
            ref_path = None
            remote_local_ref = remote_local_ref.strip()
            if remote_local_ref.startswith(Reference._common_path_default + "/"):
                # always use actual type if we get absolute paths
                # Will always be the case if something is fetched outside of refs/remotes (if its not a tag)
                ref_path = remote_local_ref
                if ref_type is not TagReference and not remote_local_ref.startswith(RemoteReference._common_path_default + "/"):
                    ref_type = Reference
                # END downgrade remote reference
            elif ref_type is TagReference and 'tags/' in remote_local_ref:
                # even though its a tag, it is located in refs/remotes
                ref_path = join_path(RemoteReference._common_path_default, remote_local_ref)
            else:
                ref_path = join_path(ref_type._common_path_default, remote_local_ref)
            # END obtain refpath

            # even though the path could be within the git conventions, we make
            # sure we respect whatever the user wanted, and disabled path checking
            remote_local_ref = ref_type(repo, ref_path, check_path=False)
        # END create ref instance

        note = (note and note.strip()) or ''

        # parse flags from control_character
        flags = 0
        try:
            flags |= cls._flag_map[control_character]
        except KeyError:
            raise ValueError("Control character %r unknown as parsed from line %r" % (control_character, line))
        # END control char exception hanlding

        # parse operation string for more info - makes no sense for symbolic refs
        old_commit_binsha = None
        if isinstance(remote_local_ref, Reference):
            if 'rejected' in operation:
                flags |= cls.REJECTED
            if 'new tag' in operation:
                flags |= cls.NEW_TAG
            if 'new branch' in operation:
                flags |= cls.NEW_HEAD
            if '...' in operation or '..' in operation:
                split_token = '...'
                if control_character == ' ':
                    split_token = split_token[:-1]
                old_commit_binsha = repo.resolve(operation.split(split_token)[0])
            # END handle refspec
        # END reference flag handling

        return cls(remote_local_ref, flags, note, old_commit_binsha)


class GitCommandMixin(object):

    """A mixin to provide the git command object through the git property"""

    def __init__(self, *args, **kwargs):
        """Initialize this instance with the root and a git command"""
        super(GitCommandMixin, self).__init__(*args, **kwargs)
        self._git = Git(self.working_dir)

    @property
    def git(self):
        return self._git


class CmdObjectDBRMixin(object):

    """A mixing implementing object reading through a git command
    It will create objects only in the loose object database.
    :note: for now, we use the git command to do all the lookup, just until he 
        have packs and the other implementations
    """
    #{ ODB Interface
    # overrides from PureOdb Implementation, which is responsible only for writing
    # objects

    def info(self, sha):
        hexsha, typename, size = self._git.get_object_header(bin_to_hex(sha))
        return OInfo(hex_to_bin(hexsha), typename, size)

    def stream(self, sha):
        """For now, all lookup is done by git itself
        :note: As we don't know when the stream is actually read (and if it is 
            stored for later use) we read the data rigth away and cache it.
            This has HUGE performance implication, both for memory as for 
            reading/deserializing objects, but we have no other choice in order
            to make the database behaviour consistent with other implementations !"""

        hexsha, typename, size, data = self._git.get_object_data(bin_to_hex(sha))
        return OStream(hex_to_bin(hexsha), typename, size, StringIO(data))

    def partial_to_complete_sha_hex(self, partial_hexsha):
        """:return: Full binary 20 byte sha from the given partial hexsha
        :raise AmbiguousObjectName:
        :raise BadObject:
        :note: currently we only raise BadObject as git does not communicate 
            AmbiguousObjects separately"""
        try:
            hexsha, typename, size = self._git.get_object_header(partial_hexsha)
            return hex_to_bin(hexsha)
        except (GitCommandError, ValueError):
            raise BadObject(partial_hexsha)
        # END handle exceptions

    #} END odb interface


class CmdTransportMixin(TransportDB):

    """A mixin requiring the .git property as well as repository paths

    It will create objects only in the loose object database.
    :note: for now, we use the git command to do all the lookup, just until he 
        have packs and the other implementations
    """

    #{ Transport DB interface

    def push(self, url, refspecs=None, progress=None, **kwargs):
        """Push given refspecs using the git default implementation
        :param url: may be a remote name or a url
        :param refspecs: single string, RefSpec instance or list of such or None.
        :param progress: RemoteProgress derived instance or None
        :param **kwargs: Additional arguments to be passed to the git-push process"""
        progress = CmdRemoteProgress(progress)
        proc = self._git.push(
            url, refspecs, porcelain=True, as_process=True, **add_progress(kwargs, self.git, progress))
        return get_push_info(self, url, proc, progress)

    def pull(self, url, refspecs=None, progress=None, **kwargs):
        """Fetch and merge the given refspecs. 
        If not refspecs are given, the merge will only work properly if you 
        have setup upstream (tracking) branches.
        :param url: may be a remote name or a url
        :param refspecs: see push()
        :param progress: see push()"""
        progress = CmdRemoteProgress(progress)
        proc = self._git.pull(url, refspecs, with_extended_output=True, as_process=True,
                              v=True, **add_progress(kwargs, self.git, progress))
        return get_fetch_info_from_stderr(self, proc, progress)

    def fetch(self, url, refspecs=None, progress=None, **kwargs):
        """Fetch the latest changes
        :param url: may be a remote name or a url
        :param refspecs: see push()
        :param progress: see push()"""
        progress = CmdRemoteProgress(progress)
        proc = self._git.fetch(url, refspecs, with_extended_output=True, as_process=True,
                               v=True, **add_progress(kwargs, self.git, progress))
        return get_fetch_info_from_stderr(self, proc, progress)

    #} end transport db interface


class CmdHighLevelRepository(HighLevelRepository):

    """An intermediate interface carrying advanced git functionality that can be used
    in other comound repositories which do not implement this functionality themselves.

    The mixin must be used with repositories compatible to the GitCommandMixin.

    :note: at some point, methods provided here are supposed to be provided by custom interfaces"""
    DAEMON_EXPORT_FILE = 'git-daemon-export-ok'

    # precompiled regex
    re_whitespace = re.compile(r'\s+')
    re_hexsha_only = re.compile('^[0-9A-Fa-f]{40}$')
    re_hexsha_shortened = re.compile('^[0-9A-Fa-f]{4,40}$')
    re_author_committer_start = re.compile(r'^(author|committer)')
    re_tab_full_line = re.compile(r'^\t(.*)$')

    #{ Configuration
    CommitCls = Commit
    GitCls = Git
    #} END configuration

    def daemon_export():
        def _get_daemon_export(self):
            filename = join(self.git_dir, self.DAEMON_EXPORT_FILE)
            return os.path.exists(filename)

        def _set_daemon_export(self, value):
            filename = join(self.git_dir, self.DAEMON_EXPORT_FILE)
            fileexists = os.path.exists(filename)
            if value and not fileexists:
                touch(filename)
            elif not value and fileexists:
                os.unlink(filename)

        return property(_get_daemon_export, _set_daemon_export,
                        doc="If True, git-daemon may export this repository")

    daemon_export = daemon_export()

    def is_dirty(self, index=True, working_tree=True, untracked_files=False):
        if self._bare:
            # Bare repositories with no associated working directory are
            # always consired to be clean.
            return False

        # start from the one which is fastest to evaluate
        default_args = ('--abbrev=40', '--full-index', '--raw')
        if index:
            # diff index against HEAD
            if isfile(self.index.path) and \
                    len(self.git.diff('--cached', *default_args)):
                return True
        # END index handling
        if working_tree:
            # diff index against working tree
            if len(self.git.diff(*default_args)):
                return True
        # END working tree handling
        if untracked_files:
            if len(self.untracked_files):
                return True
        # END untracked files
        return False

    @property
    def untracked_files(self):
        # make sure we get all files, no only untracked directores
        proc = self.git.status(porcelain=True,
                               untracked_files=True,
                               as_process=True)
        # Untracked files preffix in porcelain mode
        prefix = "?? "

        untracked_files = list()
        for line in proc.stdout:
            if not line.startswith(prefix):
                continue
            filename = line[len(prefix):].rstrip('\n')
            # Special characters are escaped
            if filename[0] == filename[-1] == '"':
                filename = filename[1:-1].decode('string_escape')
            untracked_files.append(filename)
        return untracked_files

    def blame(self, rev, file):
        data = self.git.blame(rev, '--', file, p=True)
        commits = dict()
        blames = list()
        info = None

        for line in data.splitlines(False):
            parts = self.re_whitespace.split(line, 1)
            firstpart = parts[0]
            if self.re_hexsha_only.search(firstpart):
                # handles
                # 634396b2f541a9f2d58b00be1a07f0c358b999b3 1 1 7        - indicates blame-data start
                # 634396b2f541a9f2d58b00be1a07f0c358b999b3 2 2
                digits = parts[-1].split(" ")
                if len(digits) == 3:
                    info = {'id': firstpart}
                    blames.append([None, []])
                elif info['id'] != firstpart:
                    info = {'id': firstpart}
                    blames.append([commits.get(firstpart), []])
                # END blame data initialization
            else:
                m = self.re_author_committer_start.search(firstpart)
                if m:
                    # handles:
                    # author Tom Preston-Werner
                    # author-mail <tom@mojombo.com>
                    # author-time 1192271832
                    # author-tz -0700
                    # committer Tom Preston-Werner
                    # committer-mail <tom@mojombo.com>
                    # committer-time 1192271832
                    # committer-tz -0700  - IGNORED BY US
                    role = m.group(0)
                    if firstpart.endswith('-mail'):
                        info["%s_email" % role] = parts[-1]
                    elif firstpart.endswith('-time'):
                        info["%s_date" % role] = int(parts[-1])
                    elif role == firstpart:
                        info[role] = parts[-1]
                    # END distinguish mail,time,name
                else:
                    # handle
                    # filename lib/grit.rb
                    # summary add Blob
                    # <and rest>
                    if firstpart.startswith('filename'):
                        info['filename'] = parts[-1]
                    elif firstpart.startswith('summary'):
                        info['summary'] = parts[-1]
                    elif firstpart == '':
                        if info:
                            sha = info['id']
                            c = commits.get(sha)
                            if c is None:
                                c = self.CommitCls(self, hex_to_bin(sha),
                                                   author=Actor._from_string(
                                                       info['author'] + ' ' + info['author_email']),
                                                   authored_date=info['author_date'],
                                                   committer=Actor._from_string(
                                                       info['committer'] + ' ' + info['committer_email']),
                                                   committed_date=info['committer_date'],
                                                   message=info['summary'])
                                commits[sha] = c
                            # END if commit objects needs initial creation
                            m = self.re_tab_full_line.search(line)
                            text,  = m.groups()
                            blames[-1][0] = c
                            blames[-1][1].append(text)
                            info = {'id': sha}
                        # END if we collected commit info
                    # END distinguish filename,summary,rest
                # END distinguish author|committer vs filename,summary,rest
            # END distinguish hexsha vs other information
        return blames

    @classmethod
    def init(cls, path=None, mkdir=True, **kwargs):
        """
        :parm kwargs:
            keyword arguments serving as additional options to the git-init command

        For more information, see the respective docs of HighLevelRepository"""

        if mkdir and path and not os.path.exists(path):
            os.makedirs(path, 0755)

        # git command automatically chdir into the directory
        git = cls.GitCls(path)
        output = git.init(**kwargs)
        return cls(path)

    @classmethod
    def _clone(cls, git, url, path, progress, **kwargs):
        # special handling for windows for path at which the clone should be
        # created.
        # tilde '~' will be expanded to the HOME no matter where the ~ occours. Hence
        # we at least give a proper error instead of letting git fail
        prev_cwd = None
        prev_path = None
        if os.name == 'nt':
            if '~' in path:
                raise OSError("Git cannot handle the ~ character in path %r correctly" % path)

            # on windows, git will think paths like c: are relative and prepend the
            # current working dir ( before it fails ). We temporarily adjust the working
            # dir to make this actually work
            match = re.match("(\w:[/\\\])(.*)", path)
            if match:
                prev_cwd = os.getcwd()
                prev_path = path
                drive, rest_of_path = match.groups()
                os.chdir(drive)
                path = rest_of_path
                kwargs['with_keep_cwd'] = True
            # END cwd preparation
        # END windows handling

        try:
            proc = git.clone(url, path, with_extended_output=True, as_process=True,
                             v=True, **add_progress(kwargs, git, progress))
            if progress is not None:
                digest_process_messages(proc.stderr, progress)
            # END digest progress messages
            finalize_process(proc)
        finally:
            if prev_cwd is not None:
                os.chdir(prev_cwd)
                path = prev_path
            # END reset previous working dir
        # END bad windows handling

        # our git command could have a different working dir than our actual
        # environment, hence we prepend its working dir if required
        if not os.path.isabs(path) and git.working_dir:
            path = join(git._working_dir, path)

        # adjust remotes - there may be operating systems which use backslashes,
        # These might be given as initial paths, but when handling the config file
        # that contains the remote from which we were clones, git stops liking it
        # as it will escape the backslashes. Hence we undo the escaping just to be
        # sure
        repo = cls(os.path.abspath(path))
        if repo.remotes:
            repo.remotes[0].config_writer.set_value('url', repo.remotes[0].url.replace("\\\\", "\\").replace("\\", "/"))
        # END handle remote repo
        return repo

    def clone(self, path, progress=None, **kwargs):
        """
        :param kwargs:
            All remaining keyword arguments are given to the git-clone command

        For more information, see the respective method in HighLevelRepository"""
        return self._clone(self.git, self.git_dir, path, CmdRemoteProgress(progress), **kwargs)

    @classmethod
    def clone_from(cls, url, to_path, progress=None, **kwargs):
        """
        :param kwargs: see the ``clone`` method
        For more information, see the respective method in the HighLevelRepository"""
        return cls._clone(cls.GitCls(os.getcwd()), url, to_path, CmdRemoteProgress(progress), **kwargs)

    def archive(self, ostream, treeish=None, prefix=None,  **kwargs):
        """For all args see HighLevelRepository interface
        :parm kwargs:
            Additional arguments passed to git-archive
            NOTE: Use the 'format' argument to define the kind of format. Use 
            specialized ostreams to write any format supported by python

        :raise GitCommandError: in case something went wrong"""
        if treeish is None:
            treeish = self.head.commit
        if prefix and 'prefix' not in kwargs:
            kwargs['prefix'] = prefix
        kwargs['output_stream'] = ostream

        self.git.archive(treeish, **kwargs)
        return self