Add the ability to check out a single file from a repo....

gclient_scm.py

 # Copyright (c) 2009 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 79 matching lines @@
     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 RunCommand(self, command, options, args, file_list=None):
     # file_list will have all files that are modified appended to it.
     if file_list is None:
       file_list = []
 
-    commands = ['cleanup', 'export', 'update', 'revert', 'revinfo',
-                'status', 'diff', 'pack', 'runhooks']
+    commands = ['cleanup', 'export', 'update', 'updatesingle', 'revert',
+                'revinfo', 'status', 'diff', 'pack', 'runhooks']
 
     if not command in commands:
       raise gclient_utils.Error('Unknown command %s' % command)
 
     if not command in dir(self):
       raise gclient_utils.Error('Command %s not implemented in %s wrapper' % (
           command, self.scm_name))
 
     return getattr(self, command)(options, args, file_list)
 
@@ skipping 627 matching lines @@
     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))
       return
 
     command = ["update", checkout_path]
     if revision:
       command.extend(['--revision', str(revision)])
     scm.SVN.RunAndGetFileList(options, 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 not os.path.exists(checkout_path):
+      # 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)
+      command = ["update", filename]
+      scm.SVN.RunAndGetFileList(options, 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)
+
   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.
     """
     __pychecker__ = 'unusednames=args'
     path = os.path.join(self._root_dir, self.relpath)
     if not os.path.isdir(path):
       # svn revert won't work if the directory doesn't exist. It needs to
@@ skipping 62 matching lines @@
       print("\n________ couldn't run \'%s\' in \'%s\':\nThe directory "
             "does not exist."
             % (' '.join(command), path))
       # There's no file list to retrieve.
     else:
       scm.SVN.RunAndGetFileList(options, 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