Tools/Scripts/webkitpy/common/checkout/scm/detection.py

# Copyright (c) 2009, 2010, 2011 Google Inc. All rights reserved.
# Copyright (c) 2009 Apple Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
#     * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import logging

from webkitpy.common.system.filesystem import FileSystem
from webkitpy.common.system.executive import Executive

from webkitpy.common.checkout.scm.svn import SVN
from webkitpy.common.checkout.scm.git import Git
from webkitpy.common.checkout.scm.stub_repository import StubRepository

_log = logging.getLogger(__name__)


class SCMDetector(object):
    def __init__(self, filesystem, executive):
        self._filesystem = filesystem
        self._executive = executive

    def default_scm(self, patch_directories=None):
        """Return the default SCM object as determined by the CWD and running code.

        Returns the default SCM object for the current working directory; if the
        CWD is not in a checkout, then we attempt to figure out if the SCM module
        itself is part of a checkout, and return that one. If neither is part of
        a checkout, None is returned.
        """
        cwd = self._filesystem.getcwd()
        scm_system = self.detect_scm_system(cwd, patch_directories)
        if not scm_system:
            script_directory = self._filesystem.dirname(self._filesystem.path_to_module(self.__module__))
            scm_system = self.detect_scm_system(script_directory, patch_directories)
            if scm_system:
                _log.info("The current directory (%s) is not a WebKit checkout, using %s" % (cwd, scm_system.checkout_root))
            else:
                raise Exception("FATAL: Failed to determine the SCM system for either %s or %s" % (cwd, script_directory))
        return scm_system

    def detect_scm_system(self, path, patch_directories=None):
        real_path = self._filesystem.realpath(path)

        if patch_directories == []:
            patch_directories = None

        if SVN.in_working_directory(real_path, executive=self._executive):
            return SVN(cwd=real_path, patch_directories=patch_directories, filesystem=self._filesystem, executive=self._executive)

        if Git.in_working_directory(real_path, executive=self._executive):
            return Git(cwd=real_path, patch_directories=patch_directories, filesystem=self._filesystem, executive=self._executive)

        if StubRepository.in_working_directory(real_path, filesystem=self._filesystem):
            return StubRepository(cwd=real_path, patch_directories=patch_directories, filesystem=self._filesystem, executive=self._executive)

        return None


# FIXME: These free functions are all deprecated:

def detect_scm_system(path, patch_directories=None):
    return SCMDetector(FileSystem(), Executive()).detect_scm_system(path, patch_directories)