Improve -m to be more efficient, only lookup the current rev if it is pinned.

gclient_scm.py

 # Copyright (c) 2010 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Gclient-specific SCM-specific operations."""
 
 import logging
 import os
 import posixpath
 import re
@@ skipping 707 matching lines @@
     # Only update if git is not controlling the directory.
     checkout_path = os.path.join(self._root_dir, self.relpath)
     git_path = os.path.join(self._root_dir, self.relpath, '.git')
     if os.path.exists(git_path):
       print("________ found .git directory; skipping %s" % self.relpath)
       return
 
     if args:
       raise gclient_utils.Error("Unsupported argument(s): %s" % ",".join(args))
 
+    # revision is the revision to match. It is None if no revision is specified,
+    # i.e. the 'deps ain't pinned'.
     url, revision = gclient_utils.SplitUrlRevision(self.url)
+    # Keep the original unpinned url for reference in case the repo is switched.
     base_url = url
-    forced_revision = False
-    rev_str = ""
     if options.revision:
       # Override the revision number.
       revision = str(options.revision)
     if revision:
       forced_revision = True
+      # Reconstruct the url.
       url = '%s@%s' % (url, revision)
       rev_str = ' at %s' % revision
+    else:
+      forced_revision = False
+      rev_str = ''
 
     if not os.path.exists(checkout_path):
       # We need to checkout.
       command = ['checkout', url, checkout_path]
-      command = self.AddAdditionalFlags(command, options, revision)
+      command = self._AddAdditionalUpdateFlags(command, options, revision)
       scm.SVN.RunAndGetFileList(options.verbose, command, self._root_dir,
           file_list)
       return
 
     # Get the existing scm url and the revision number of the current checkout.
     from_info = scm.SVN.CaptureInfo(os.path.join(checkout_path, '.'), '.')
     if not from_info:
-      raise gclient_utils.Error("Can't update/checkout %r if an unversioned "
-                                "directory is present. Delete the directory "
-                                "and try again." %
+      raise gclient_utils.Error(('Can\'t update/checkout %r if an unversioned '
+                                 'directory is present. Delete the directory '
+                                 'and try again.') %
                                 checkout_path)
 
     # Look for locked directories.
     dir_info = scm.SVN.CaptureStatus(os.path.join(checkout_path, '.'))
     if [True for d in dir_info if d[0][2] == 'L' and d[1] == checkout_path]:
       # The current directory is locked, clean it up.
       scm.SVN.Run(['cleanup'], checkout_path)
 
-    if options.manually_grab_svn_rev:
-      # Retrieve the current HEAD version because svn is slow at null updates.
-      if not revision:
-        from_info_live = scm.SVN.CaptureInfo(from_info['URL'], '.')
-        revision = str(from_info_live['Revision'])
-        rev_str = ' at %s' % revision
+    # Retrieve the current HEAD version because svn is slow at null updates.
+    if options.manually_grab_svn_rev and not revision:
+      from_info_live = scm.SVN.CaptureInfo(from_info['URL'], '.')
+      revision = str(from_info_live['Revision'])
+      rev_str = ' at %s' % revision
 
     if from_info['URL'] != base_url:
+      # The repository url changed, need to switch.
       to_info = scm.SVN.CaptureInfo(url, '.')
       if not to_info.get('Repository Root') or not to_info.get('UUID'):
         # The url is invalid or the server is not accessible, it's safer to bail
         # out right now.
         raise gclient_utils.Error('This url is unreachable: %s' % url)
       can_switch = ((from_info['Repository Root'] != to_info['Repository Root'])
                     and (from_info['UUID'] == to_info['UUID']))
       if can_switch:
-        print("\n_____ relocating %s to a new checkout" % self.relpath)
+        print('\n_____ relocating %s to a new checkout' % self.relpath)
         # We have different roots, so check if we can switch --relocate.
         # Subversion only permits this if the repository UUIDs match.
         # Perform the switch --relocate, then rewrite the from_url
         # to reflect where we "are now."  (This is the same way that
         # Subversion itself handles the metadata when switch --relocate
         # is used.)  This makes the checks below for whether we
         # can update to a revision or have to switch to a different
         # branch work as expected.
         # TODO(maruel):  TEST ME !
-        command = ["switch", "--relocate",
+        command = ['switch', '--relocate',
                    from_info['Repository Root'],
                    to_info['Repository Root'],
                    self.relpath]
         scm.SVN.Run(command, self._root_dir)
         from_info['URL'] = from_info['URL'].replace(
             from_info['Repository Root'],
             to_info['Repository Root'])
       else:
         if not options.force:
           # Look for local modifications but ignore unversioned files.
           for status in scm.SVN.CaptureStatus(checkout_path):
             if status[0] != '?':
               raise gclient_utils.Error(
                   ('Can\'t switch the checkout to %s; UUID don\'t match and '
                    'there is local changes in %s. Delete the directory and '
                    'try again.') % (url, checkout_path))
         # Ok delete it.
-        print("\n_____ switching %s to a new checkout" % self.relpath)
+        print('\n_____ switching %s to a new checkout' % self.relpath)
         gclient_utils.RemoveDirectory(checkout_path)
         # We need to checkout.
         command = ['checkout', url, checkout_path]
-        command = self.AddAdditionalFlags(command, options, revision)
+        command = self._AddAdditionalUpdateFlags(command, options, revision)
         scm.SVN.RunAndGetFileList(options.verbose, command, self._root_dir,
             file_list)
         return
 
-
     # If the provided url has a revision number that matches the revision
     # number of the existing directory, then we don't need to bother updating.
     if not options.force and str(from_info['Revision']) == revision:
       if options.verbose or not forced_revision:
-        print("\n_____ %s%s" % (self.relpath, rev_str))
+        print('\n_____ %s%s' % (self.relpath, rev_str))
       return
 
-    command = ["update", checkout_path]
-    command = self.AddAdditionalFlags(command, options, revision)
+    command = ['update', checkout_path]
+    command = self._AddAdditionalUpdateFlags(command, options, revision)
     scm.SVN.RunAndGetFileList(options.verbose, command, self._root_dir,
         file_list)
 
   def updatesingle(self, options, args, file_list):
     checkout_path = os.path.join(self._root_dir, self.relpath)
     filename = args.pop()
     if scm.SVN.AssertVersion("1.5")[0]:
       if not os.path.exists(os.path.join(checkout_path, '.svn')):
         # Create an empty checkout and then update the one file we want.  Future
         # operations will only apply to the one file we checked out.
         command = ["checkout", "--depth", "empty", self.url, checkout_path]
         scm.SVN.Run(command, self._root_dir)
         if os.path.exists(os.path.join(checkout_path, filename)):
           os.remove(os.path.join(checkout_path, filename))
         command = ["update", filename]
         scm.SVN.RunAndGetFileList(options.verbose, command, checkout_path,
             file_list)
       # After the initial checkout, we can use update as if it were any other
       # dep.
       self.update(options, args, file_list)
     else:
       # If the installed version of SVN doesn't support --depth, fallback to
       # just exporting the file.  This has the downside that revision
       # information is not stored next to the file, so we will have to
       # re-export the file every time we sync.
       if not os.path.exists(checkout_path):
         os.makedirs(checkout_path)
       command = ["export", os.path.join(self.url, filename),
                  os.path.join(checkout_path, filename)]
-      command = self.AddAdditionalFlags(command, options, options.revision)
+      command = self._AddAdditionalUpdateFlags(command, options,
+          options.revision)
       scm.SVN.Run(command, self._root_dir)
 
   def revert(self, options, args, file_list):
     """Reverts local modifications. Subversion specific.
 
     All reverted files will be appended to file_list, even if Subversion
     doesn't know about them.
     """
     path = os.path.join(self._root_dir, self.relpath)
     if not os.path.isdir(path):
@@ skipping 65 matching lines @@
             % (' '.join(command), path))
       # There's no file list to retrieve.
     else:
       scm.SVN.RunAndGetFileList(options.verbose, command, path, file_list)
 
   def FullUrlForRelativeUrl(self, url):
     # Find the forth '/' and strip from there. A bit hackish.
     return '/'.join(self.url.split('/')[:4]) + url
 
   @staticmethod
-  def AddAdditionalFlags(command, options, revision):
+  def _AddAdditionalUpdateFlags(command, options, revision):
     """Add additional flags to command depending on what options are set.
     command should be a list of strings that represents an svn command.
 
     This method returns a new list to be used as a command."""
     new_command = command[:]
     if revision:
       new_command.extend(['--revision', str(revision).strip()])
     # --force was added to 'svn update' in svn 1.5.
-    if options.force and scm.SVN.AssertVersion("1.5")[0]:
+    if ((options.force or options.manually_grab_svn_rev) and
+        scm.SVN.AssertVersion("1.5")[0]):
       new_command.append('--force')
     return new_command