if not is_git(environ):

            return self.application(environ, start_response)

        ipaddr = self._get_ip_addr(environ)

        username = None

        self._git_first_op = False

        # skip passing error to error controller

        environ['pylons.status_code_redirect'] = True

        #======================================================================

        # EXTRACT REPOSITORY NAME FROM ENV

        #======================================================================

        try:

            repo_name = self.__get_repository(environ)

            log.debug('Extracted repo name is %s' % repo_name)

        except:

            return HTTPInternalServerError()(environ, start_response)

        # quick check if that dir exists...

        if is_valid_repo(repo_name, self.basepath) is False:

            return HTTPNotFound()(environ, start_response)

        #======================================================================

        # GET ACTION PULL or PUSH

        #======================================================================

        action = self.__get_action(environ)

        #======================================================================

        # CHECK ANONYMOUS PERMISSION

        #======================================================================

        if action in ['pull', 'push']:

            anonymous_user = self.__get_user('default')

            username = anonymous_user.username

            anonymous_perm = self._check_permission(action, anonymous_user,

                                                    repo_name)

            if anonymous_perm is not True or anonymous_user.active is False:

                if anonymous_perm is not True:

                    log.debug('Not enough credentials to access this '

                              'repository as anonymous user')

                if anonymous_user.active is False:

                    log.debug('Anonymous access is disabled, running '

                              'authentication')

                #==============================================================

                # DEFAULT PERM FAILED OR ANONYMOUS ACCESS IS DISABLED SO WE

                # NEED TO AUTHENTICATE AND ASK FOR AUTH USER PERMISSIONS

                #==============================================================

                # Attempting to retrieve username from the container

                username = get_container_username(environ, self.config)

                # If not authenticated by the container, running basic auth

                if not username:

                    self.authenticate.realm = \

                        safe_str(self.config['rhodecode_realm'])

                    result = self.authenticate(environ)

                    if isinstance(result, str):

                        AUTH_TYPE.update(environ, 'basic')

                        REMOTE_USER.update(environ, result)

                        username = result

                    else:

                        return result.wsgi_application(environ, start_response)

                #==============================================================

                # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME

                #==============================================================

                if action in ['pull', 'push']:

                    try:

                        user = self.__get_user(username)

                        if user is None or not user.active:

                            return HTTPForbidden()(environ, start_response)

                        username = user.username

                    except:

                        log.error(traceback.format_exc())

                        return HTTPInternalServerError()(environ,

                                                         start_response)

                    #check permissions for this repository

                    perm = self._check_permission(action, user, repo_name)

                    if perm is not True:

                        return HTTPForbidden()(environ, start_response)

        extras = {

            'ip': ipaddr,

            'username': username,

            'action': action,

            'repository': repo_name,

            'scm': 'git',

        }

        #===================================================================

        # GIT REQUEST HANDLING

        #===================================================================

        repo_path = os.path.join(safe_str(self.basepath), safe_str(repo_name))

        log.debug('Repository path is %s' % repo_path)

        baseui = make_ui('db')

        try:

            # invalidate cache on push

            if action == 'push':

                self._invalidate_cache(repo_name)

            self._handle_githooks(action, baseui, environ)

            log.info('%s action on GIT repo "%s"' % (action, repo_name))

            app = self.__make_app(repo_name, repo_path)

            return app(environ, start_response)

        except Exception:

            log.error(traceback.format_exc())

            return HTTPInternalServerError()(environ, start_response)

    def __make_app(self, repo_name, repo_path):

        """

        Make an wsgi application using dulserver

        :param repo_name: name of the repository

        :param repo_path: full path to the repository

        """

        _d = {'/' + repo_name: Repo(repo_path)}

        backend = dulserver.DictBackend(_d)

        gitserve = make_wsgi_chain(backend)

        return gitserve

    def __get_repository(self, environ):

        """

        Get's repository name out of PATH_INFO header

        :param environ: environ where PATH_INFO is stored

        """

        try:

            environ['PATH_INFO'] = self._get_by_id(environ['PATH_INFO'])

            repo_name = GIT_PROTO_PAT.match(environ['PATH_INFO']).group(1)

        except:

            log.error(traceback.format_exc())

            raise

        return repo_name

    def __get_user(self, username):

        return User.get_by_username(username)

    def __get_action(self, environ):

        """

        Maps git request commands into a pull or push command.

        :param environ:

        """

        service = environ['QUERY_STRING'].split('=')

        if len(service) > 1:

            service_cmd = service[1]

            mapping = {

                'git-receive-pack': 'push',

                'git-upload-pack': 'pull',

            }

            op = mapping[service_cmd]

            self._git_stored_op = op

            return op

        else:

            # try to fallback to stored variable as we don't know if the last

            # operation is pull/push

            op = getattr(self, '_git_stored_op', 'pull')

        return op

    def _handle_githooks(self, action, baseui, environ):

        from rhodecode.lib.hooks import log_pull_action, log_push_action

        service = environ['QUERY_STRING'].split('=')

        if len(service) < 2:

            return

        push_hook = 'pretxnchangegroup.push_logger'

        pull_hook = 'preoutgoing.pull_logger'

        _hooks = dict(baseui.configitems('hooks')) or {}

        if action == 'push' and _hooks.get(push_hook):

        elif action == 'pull' and _hooks.get(pull_hook):

# -*- coding: utf-8 -*-

"""

    vcs.backends.git

    ~~~~~~~~~~~~~~~~

    Git backend implementation.

    :created_on: Apr 8, 2010

    :copyright: (c) 2010-2011 by Marcin Kuzminski, Lukasz Balcerzak.

"""

import os

import re

import time

import posixpath

from dulwich.repo import Repo, NotGitRepository

#from dulwich.config import ConfigFile

from string import Template

from subprocess import Popen, PIPE

from rhodecode.lib.vcs.backends.base import BaseRepository

from rhodecode.lib.vcs.exceptions import BranchDoesNotExistError

from rhodecode.lib.vcs.exceptions import ChangesetDoesNotExistError

from rhodecode.lib.vcs.exceptions import EmptyRepositoryError

from rhodecode.lib.vcs.exceptions import RepositoryError

from rhodecode.lib.vcs.exceptions import TagAlreadyExistError

from rhodecode.lib.vcs.exceptions import TagDoesNotExistError

from rhodecode.lib.vcs.utils import safe_unicode, makedate, date_fromtimestamp

from rhodecode.lib.vcs.utils.lazy import LazyProperty

from rhodecode.lib.vcs.utils.ordered_dict import OrderedDict

from rhodecode.lib.vcs.utils.paths import abspath

from rhodecode.lib.vcs.utils.paths import get_user_home

from .workdir import GitWorkdir

from .changeset import GitChangeset

from .inmemory import GitInMemoryChangeset

from .config import ConfigFile

class GitRepository(BaseRepository):

    """

    Git repository backend.

    """

    DEFAULT_BRANCH_NAME = 'master'

    scm = 'git'

    def __init__(self, repo_path, create=False, src_url=None,

                 update_after_clone=False, bare=False):

        self.path = abspath(repo_path)

        self._repo = self._get_repo(create, src_url, update_after_clone, bare)

        try:

            self.head = self._repo.head()

        except KeyError:

            self.head = None

        self._config_files = [

            bare and abspath(self.path, 'config') or abspath(self.path, '.git',

                'config'),

            abspath(get_user_home(), '.gitconfig'),

        ]

    @LazyProperty

    def revisions(self):

        """

        Returns list of revisions' ids, in ascending order.  Being lazy

        attribute allows external tools to inject shas from cache.

        """

        return self._get_all_revisions()

    def run_git_command(self, cmd):

        """

        Runs given ``cmd`` as git command and returns tuple

        (returncode, stdout, stderr).

        .. note::

           This method exists only until log/blame functionality is implemented

           at Dulwich (see https://bugs.launchpad.net/bugs/645142). Parsing

           os command's output is road to hell...

        :param cmd: git command to be executed

        """

        _copts = ['-c', 'core.quotepath=false', ]

        _str_cmd = False

        if isinstance(cmd, basestring):

            cmd = [cmd]

            _str_cmd = True

        cmd = ['GIT_CONFIG_NOGLOBAL=1', 'git'] + _copts + cmd

        if _str_cmd:

            cmd = ' '.join(cmd)

        try:

            opts = dict(

                shell=isinstance(cmd, basestring),

                stdout=PIPE,

                stderr=PIPE)

            if os.path.isdir(self.path):

                opts['cwd'] = self.path

            p = Popen(cmd, **opts)

        except OSError, err:

            raise RepositoryError("Couldn't run git command (%s).\n"

                "Original error was:%s" % (cmd, err))

        so, se = p.communicate()

        if not se.startswith("fatal: bad default revision 'HEAD'") and \

            p.returncode != 0:

            raise RepositoryError("Couldn't run git command (%s).\n"

                "stderr:\n%s" % (cmd, se))

        return so, se

    def _check_url(self, url):

        """

        Functon will check given url and try to verify if it's a valid

        link. Sometimes it may happened that mercurial will issue basic

        auth request that can cause whole API to hang when used from python

        or other external calls.

        On failures it'll raise urllib2.HTTPError

        """

        #TODO: implement this

        pass

    def _get_repo(self, create, src_url=None, update_after_clone=False,

            bare=False):

        if create and os.path.exists(self.path):

            raise RepositoryError("Location already exist")

        if src_url and not create:

            raise RepositoryError("Create should be set to True if src_url is "

                                  "given (clone operation creates repository)")

        try:

            if create and src_url:

                self._check_url(src_url)

                self.clone(src_url, update_after_clone, bare)

                return Repo(self.path)

            elif create:

                os.mkdir(self.path)

                if bare:

                    return Repo.init_bare(self.path)

                else:

                    return Repo.init(self.path)

            else:

                return Repo(self.path)

        except (NotGitRepository, OSError), err:

            raise RepositoryError(err)

    def _get_all_revisions(self):

        if start:

            _start = self._get_revision(start)

            try:

                start_pos = revs.index(_start)

            except ValueError:

                pass

        if end is not None:

            _end = self._get_revision(end)

            try:

                end_pos = revs.index(_end)

            except ValueError:

                pass

        if None not in [start, end] and start_pos > end_pos:

            raise RepositoryError('start cannot be after end')

        if end_pos is not None:

            end_pos += 1

        revs = revs[start_pos:end_pos]

        if reverse:

            revs = reversed(revs)

        for rev in revs:

            yield self.get_changeset(rev)

    def get_diff(self, rev1, rev2, path=None, ignore_whitespace=False,

            context=3):

        """

        Returns (git like) *diff*, as plain text. Shows changes introduced by

        ``rev2`` since ``rev1``.

        :param rev1: Entry point from which diff is shown. Can be

          ``self.EMPTY_CHANGESET`` - in this case, patch showing all

          the changes since empty state of the repository until ``rev2``

        :param rev2: Until which revision changes should be shown.

        :param ignore_whitespace: If set to ``True``, would not show whitespace

          changes. Defaults to ``False``.

        :param context: How many lines before/after changed lines should be

          shown. Defaults to ``3``.

        """

        flags = ['-U%s' % context]

        if ignore_whitespace:

            flags.append('-w')

        if rev1 == self.EMPTY_CHANGESET:

            rev2 = self.get_changeset(rev2).raw_id

            cmd = ' '.join(['show'] + flags + [rev2])

        else:

            rev1 = self.get_changeset(rev1).raw_id

            rev2 = self.get_changeset(rev2).raw_id

            cmd = ' '.join(['diff'] + flags + [rev1, rev2])

        if path:

            cmd += ' -- "%s"' % path

        stdout, stderr = self.run_git_command(cmd)

        # If we used 'show' command, strip first few lines (until actual diff

        # starts)

        if rev1 == self.EMPTY_CHANGESET:

            lines = stdout.splitlines()

            x = 0

            for line in lines:

                if line.startswith('diff'):

                    break

                x += 1

            # Append new line just like 'diff' command do

            stdout = '\n'.join(lines[x:]) + '\n'

        return stdout

    @LazyProperty

    def in_memory_changeset(self):

        """

        Returns ``GitInMemoryChangeset`` object for this repository.

        """

        return GitInMemoryChangeset(self)

    def clone(self, url, update_after_clone=True, bare=False):

        """

        Tries to clone changes from external location.

        :param update_after_clone: If set to ``False``, git won't checkout

          working directory

        :param bare: If set to ``True``, repository would be cloned into

          *bare* git repository (no working directory at all).

        """

        url = self._get_url(url)

        cmd = ['clone']

        if bare:

            cmd.append('--bare')

        elif not update_after_clone:

            cmd.append('--no-checkout')

        cmd += ['--', '"%s"' % url, '"%s"' % self.path]

        cmd = ' '.join(cmd)

        # If error occurs run_git_command raises RepositoryError already

        self.run_git_command(cmd)

    @LazyProperty

    def workdir(self):

        """

        Returns ``Workdir`` instance for this repository.

        """

        return GitWorkdir(self)

    def get_config_value(self, section, name, config_file=None):

        """

        Returns configuration value for a given [``section``] and ``name``.

        :param section: Section we want to retrieve value from

        :param name: Name of configuration we want to retrieve

        :param config_file: A path to file which should be used to retrieve

          configuration from (might also be a list of file paths)

        """

        if config_file is None:

            config_file = []

        elif isinstance(config_file, basestring):

            config_file = [config_file]

        def gen_configs():

            for path in config_file + self._config_files:

                try:

                    yield ConfigFile.from_path(path)

                except (IOError, OSError, ValueError):

                    continue

        for config in gen_configs():

            try:

                return config.get(section, name)

            except KeyError:

                continue

        return None

    def get_user_name(self, config_file=None):

        """

        Returns user's name from global configuration file.

        :param config_file: A path to file which should be used to retrieve

          configuration from (might also be a list of file paths)

        """

        return self.get_config_value('user', 'name', config_file)

    def get_user_email(self, config_file=None):

        """

        Returns user's email from global configuration file.

        :param config_file: A path to file which should be used to retrieve

          configuration from (might also be a list of file paths)

        """

        return self.get_config_value('user', 'email', config_file)

                return

            except:

                log.error(traceback.format_exc())

                raise

        try:

            f = UserFollowing()

            f.user_id = user_id

            f.follows_repo_id = follow_repo_id

            self.sa.add(f)

            action_logger(UserTemp(user_id),

                          'started_following_repo',

                          RepoTemp(follow_repo_id))

        except:

            log.error(traceback.format_exc())

            raise

    def toggle_following_user(self, follow_user_id, user_id):

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_user_id == follow_user_id)\

            .filter(UserFollowing.user_id == user_id).scalar()

        if f is not None:

            try:

                self.sa.delete(f)

                return

            except:

                log.error(traceback.format_exc())

                raise

        try:

            f = UserFollowing()

            f.user_id = user_id

            f.follows_user_id = follow_user_id

            self.sa.add(f)

        except:

            log.error(traceback.format_exc())

            raise

    def is_following_repo(self, repo_name, user_id, cache=False):

        r = self.sa.query(Repository)\

            .filter(Repository.repo_name == repo_name).scalar()

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_repository == r)\

            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def is_following_user(self, username, user_id, cache=False):

        u = User.get_by_username(username)

        f = self.sa.query(UserFollowing)\

            .filter(UserFollowing.follows_user == u)\

            .filter(UserFollowing.user_id == user_id).scalar()

        return f is not None

    def get_followers(self, repo_id):

        if not isinstance(repo_id, int):

            repo_id = getattr(Repository.get_by_repo_name(repo_id), 'repo_id')

        return self.sa.query(UserFollowing)\

                .filter(UserFollowing.follows_repo_id == repo_id).count()

    def get_forks(self, repo_id):

        if not isinstance(repo_id, int):

            repo_id = getattr(Repository.get_by_repo_name(repo_id), 'repo_id')

        return self.sa.query(Repository)\

                .filter(Repository.fork_id == repo_id).count()

    def mark_as_fork(self, repo, fork, user):

        repo = self.__get_repo(repo)

        fork = self.__get_repo(fork)

        repo.fork = fork

        self.sa.add(repo)

        return repo

    def pull_changes(self, repo_name, username):

        dbrepo = Repository.get_by_repo_name(repo_name)

        clone_uri = dbrepo.clone_uri

        if not clone_uri:

            raise Exception("This repository doesn't have a clone uri")

        repo = dbrepo.scm_instance

        try:

            extras = {

                'ip': '',

                'username': username,

                'action': 'push_remote',

                'repository': repo_name,

                'scm': repo.alias,

            }

            for k, v in extras.items():

                repo._repo.ui.setconfig('rhodecode_extras', k, v)

            repo.pull(clone_uri)

            self.mark_for_invalidation(repo_name)

        except:

            log.error(traceback.format_exc())

            raise

    def commit_change(self, repo, repo_name, cs, user, author, message,

                      content, f_path):

        if repo.alias == 'hg':

            from rhodecode.lib.vcs.backends.hg import \

                MercurialInMemoryChangeset as IMC

        elif repo.alias == 'git':

            from rhodecode.lib.vcs.backends.git import \

                GitInMemoryChangeset as IMC

        # decoding here will force that we have proper encoded values

        # in any other case this will throw exceptions and deny commit

        content = safe_str(content)

        path = safe_str(f_path)

        # message and author needs to be unicode

        # proper backend should then translate that into required type

        message = safe_unicode(message)

        author = safe_unicode(author)

        m = IMC(repo)

        m.change(FileNode(path, content))

        tip = m.commit(message=message,

                       author=author,

                       parents=[cs], branch=cs.branch)

        new_cs = tip.short_id

        action = 'push_local:%s' % new_cs

        action_logger(user, action, repo_name)

        self.mark_for_invalidation(repo_name)

    def create_node(self, repo, repo_name, cs, user, author, message, content,

                      f_path):

        if repo.alias == 'hg':

            from rhodecode.lib.vcs.backends.hg import MercurialInMemoryChangeset as IMC

        elif repo.alias == 'git':

            from rhodecode.lib.vcs.backends.git import GitInMemoryChangeset as IMC

        # decoding here will force that we have proper encoded values

        # in any other case this will throw exceptions and deny commit

        if isinstance(content, (basestring,)):

            content = safe_str(content)

        elif isinstance(content, (file, cStringIO.OutputType,)):

            content = content.read()

        else:

            raise Exception('Content is of unrecognized type %s' % (

                type(content)

            ))

        message = safe_unicode(message)

        author = safe_unicode(author)

        path = safe_str(f_path)

        m = IMC(repo)

        if isinstance(cs, EmptyChangeset):

            # EmptyChangeset means we we're editing empty repository

            parents = None

        else:

            parents = [cs]

        m.add(FileNode(path, content=content))

        tip = m.commit(message=message,

                       author=author,

                       parents=parents, branch=cs.branch)

        new_cs = tip.short_id

        action = 'push_local:%s' % new_cs

        action_logger(user, action, repo_name)

        self.mark_for_invalidation(repo_name)

    def get_nodes(self, repo_name, revision, root_path='/', flat=True):

        """

        recursive walk in root dir and return a set of all path in that dir

        based on repository walk function

        :param repo_name: name of repository

        :param revision: revision for which to list nodes

        :param root_path: root path to list

        :param flat: return as a list, if False returns a dict with decription

        """

        _files = list()

        _dirs = list()

        try:

            _repo = self.__get_repo(repo_name)

            changeset = _repo.scm_instance.get_changeset(revision)