gclient_scm: add support for .git

gclient_tests: add GitWrapper test cases

gclient_scm: make RunGit private and add url check

gclient_scm: add revert, run_hooks, and status

gclient_scm: add git implementations of cleanup, diff, and export

gclient_scm: implment GitSCM::update

gclient_scm: add a checks for unsupported scm and unimplemented method

Review URL: http://codereview.chromium.org/235005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@27241 0039d316-1c4b-4281-b951-d872f2087c98

PRESUBMIT.py

@@ -12,6 +12,7 @@ details on the presubmit API built into gcl.
 UNIT_TESTS = [
   'tests.gcl_unittest',
   'tests.gclient_test',
+  'tests.gclient_scm_test',
   'tests.presubmit_unittest',
   'tests.revert_unittest',
   'tests.trychange_unittest',

gclient_scm.py

@@ -34,7 +34,14 @@ def CreateSCM(url=None, root_dir=None, relpath=None, scm_name='svn'):
   # TODO(maruel): Deduce the SCM from the url.
   scm_map = {
     'svn' : SVNWrapper,
+    'git' : GitWrapper,
   }
+
+  if url and (url.startswith('git:') or
+              url.startswith('ssh:') or
+              url.endswith('.git')):
+    scm_name = 'git'
+
   if not scm_name in scm_map:
     raise gclient_utils.Error('Unsupported scm %s' % scm_name)
   return scm_map[scm_name](url, root_dir, relpath, scm_name)
@@ -58,6 +65,8 @@ class SCMWrapper(object):
     self.relpath = relpath
     if self.relpath:
       self.relpath = self.relpath.replace('/', os.sep)
+    if self.relpath and self._root_dir:
+      self.checkout_path = os.path.join(self._root_dir, self.relpath)
 
   def FullUrlForRelativeUrl(self, url):
     # Find the forth '/' and strip from there. A bit hackish.
@@ -81,6 +90,99 @@ class SCMWrapper(object):
     return getattr(self, command)(options, args, file_list)
 
 
+class GitWrapper(SCMWrapper):
+  """Wrapper for Git"""
+
+  def cleanup(self, options, args, file_list):
+    """Cleanup working copy."""
+    self._RunGit(['prune'])
+    self._RunGit(['fsck'])
+    self._RunGit(['gc'])
+
+  def diff(self, options, args, file_list):
+    # NOTE: This function does not currently modify file_list.
+    merge_base = self._RunGit(['merge-base', 'HEAD', 'origin'])
+    print self._RunGit(['diff', merge_base])
+
+  def export(self, options, args, file_list):
+    assert len(args) == 1
+    export_path = os.path.abspath(os.path.join(args[0], self.relpath))
+    if not os.path.exists(export_path):
+      os.makedirs(export_path)
+    self._RunGit(['checkout-index', '-a', '--prefix=%s/' % export_path])
+
+  def update(self, options, args, file_list):
+    """Runs git to update or transparently checkout the working copy.
+
+    All updated files will be appended to file_list.
+
+    Raises:
+      Error: if can't get URL for relative path.
+    """
+
+    if args:
+      raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
+
+    components = self.url.split("@")
+    url = components[0]
+    revision = None
+    if options.revision:
+      revision = options.revision
+    elif len(components) == 2:
+      revision = components[1]
+
+    if not os.path.exists(self.checkout_path):
+      self._RunGit(['clone', '-q', url, self.checkout_path], cwd=self._root_dir)
+      if revision:
+        self._RunGit(['reset', '--hard', revision])
+      files =  self._RunGit(['ls-files']).split()
+      file_list.extend([os.path.join(self.checkout_path, f) for f in files])
+      return
+
+    self._RunGit(['remote', 'update'])
+    new_base = 'origin'
+    if revision:
+      new_base = revision
+    files = self._RunGit(['diff', new_base, '--name-only']).split()
+    file_list.extend([os.path.join(self.checkout_path, f) for f in files])
+    self._RunGit(['rebase', new_base])
+
+  def revert(self, options, args, file_list):
+    """Reverts local modifications.
+
+    All reverted files will be appended to file_list.
+    """
+    merge_base = self._RunGit(['merge-base', 'HEAD', 'origin'])
+    files = self._RunGit(['diff', merge_base, '--name-only']).split()
+    print self._RunGit(['reset', '--hard', merge_base])
+    file_list.extend([os.path.join(self.checkout_path, f) for f in files])
+
+  def runhooks(self, options, args, file_list):
+    self.status(options, args, file_list)
+
+  def status(self, options, args, file_list):
+    """Display status information."""
+    if not os.path.isdir(self.checkout_path):
+      print('\n________ couldn\'t run status in %s:\nThe directory '
+            'does not exist.' % checkout_path)
+    else:
+      merge_base = self._RunGit(['merge-base', 'HEAD', 'origin'])
+      print self._RunGit(['diff', '--name-status', merge_base])
+      files = self._RunGit(['diff', '--name-only', merge_base]).split()
+      file_list.extend([os.path.join(self.checkout_path, f) for f in files])
+
+  def _RunGit(self, args, cwd=None, checkrc=True):
+    if cwd == None:
+      cwd = self.checkout_path
+    cmd = ['git']
+    cmd.extend(args)
+    sp = subprocess.Popen(cmd, cwd=cwd, stdout=subprocess.PIPE)
+    if checkrc and sp.returncode:
+      raise gclient_utils.Error('git command %s returned %d' %
+                                (args[0], sp.returncode))
+    return sp.communicate()[0].strip()
+
+
 class SVNWrapper(SCMWrapper):
   """ Wrapper for SVN """