Reapply r104938 "Make svn update not prompt during a sync."

scm.py

 # Copyright (c) 2011 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.
 
 """SCM-specific utility classes."""
 
 import cStringIO
 import glob
 import logging
 import os
@@ skipping 68 matching lines @@
       subprocess2.check_call(
           ['git', 'rev-parse', '--show-cdup'],
           stdout=subprocess2.VOID,
           stderr=subprocess2.VOID,
           cwd=root)
       return 'git'
     except (OSError, subprocess2.CalledProcessError):
       return None
 
 
+def only_int(val):
+  if val.isdigit():
+    return int(val)
+  else:
+    return 0
+
+
 class GIT(object):
+  current_version = None
+
   @staticmethod
   def Capture(args, **kwargs):
     return subprocess2.check_output(
         ['git'] + args, stderr=subprocess2.PIPE, **kwargs)
 
   @staticmethod
   def CaptureStatus(files, upstream_branch=None):
     """Returns git status.
 
     @files can be a string (one file) or a list of files.
@@ skipping 263 matching lines @@
     short_sha = GIT.Capture(['rev-parse', '--short=4', 'HEAD'], cwd=cwd).strip()
     return "%s#%s" % (GIT.GetBranch(cwd), short_sha)
 
   @staticmethod
   def GetCheckoutRoot(cwd):
     """Returns the top level directory of a git checkout as an absolute path.
     """
     root = GIT.Capture(['rev-parse', '--show-cdup'], cwd=cwd).strip()
     return os.path.abspath(os.path.join(cwd, root))
 
-  @staticmethod
-  def AssertVersion(min_version):
+  @classmethod
+  def AssertVersion(cls, min_version):
     """Asserts git's version is at least min_version."""
-    def only_int(val):
-      if val.isdigit():
-        return int(val)
-      else:
-        return 0
-    current_version =  GIT.Capture(['--version']).split()[-1]
-    current_version_list = map(only_int, current_version.split('.'))
+    if cls.current_version is None:
+      cls.current_version = cls.Capture(['--version']).split()[-1]
+    current_version_list = map(only_int, cls.current_version.split('.'))
     for min_ver in map(int, min_version.split('.')):
       ver = current_version_list.pop(0)
       if ver < min_ver:
-        return (False, current_version)
+        return (False, cls.current_version)
       elif ver > min_ver:
-        return (True, current_version)
-    return (True, current_version)
+        return (True, cls.current_version)
+    return (True, cls.current_version)
 
 
 class SVN(object):
   current_version = None
 
   @staticmethod
   def Capture(args, **kwargs):
     """Always redirect stderr.
 
     Throws an exception if non-0 is returned.
@@ skipping 517 matching lines @@
         info = SVN.CaptureInfo(parent)
         if (info['Repository Root'] != cur_dir_repo_root or
             info['URL'] != os.path.dirname(url)):
           break
         url = info['URL']
       except subprocess2.CalledProcessError:
         break
       directory = parent
     return GetCasedPath(directory)
 
-  @staticmethod
-  def AssertVersion(min_version):
+  @classmethod
+  def AssertVersion(cls, min_version):
     """Asserts svn's version is at least min_version."""
-    def only_int(val):
-      if val.isdigit():
-        return int(val)
-      else:
-        return 0
-    if not SVN.current_version:
-      SVN.current_version = SVN.Capture(['--version']).split()[2]
-    current_version_list = map(only_int, SVN.current_version.split('.'))
+    if cls.current_version is None:
+      cls.current_version = cls.Capture(['--version']).split()[2]
+    current_version_list = map(only_int, cls.current_version.split('.'))
     for min_ver in map(int, min_version.split('.')):
       ver = current_version_list.pop(0)
       if ver < min_ver:
-        return (False, SVN.current_version)
+        return (False, cls.current_version)
       elif ver > min_ver:
-        return (True, SVN.current_version)
-    return (True, SVN.current_version)
+        return (True, cls.current_version)
+    return (True, cls.current_version)
 
   @staticmethod
   def Revert(repo_root, callback=None, ignore_externals=False):
     """Reverts all svn modifications in repo_root, including properties.
 
     Deletes any modified files or directory.
 
     A "svn update --revision BASE" call is required after to revive deleted
     files.
     """
@@ skipping 29 matching lines @@
       if (file_status[0][0] in ('D', 'A', '!') or
           not file_status[0][1:].isspace()):
         # Added, deleted file requires manual intervention and require calling
         # revert, like for properties.
         try:
           SVN.Capture(['revert', file_status[1]], cwd=repo_root)
         except subprocess2.CalledProcessError:
           if not os.path.exists(file_path):
             continue
           raise