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

The syntax is:
deps {
  'path': File('http://svn..../path/file@42')
}

This will checkout a single file and use scm.update to
keep it up to date.

See https://bugs.webkit.org/show_bug.cgi?id=36578#c7 for a
description of why I want to add this.

Review URL: http://codereview.chromium.org/1356005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@43911 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -429,6 +429,29 @@ class GClient(object):
     def __str__(self):
       return 'From("%s")' % self.module_name
 
+  class FileImpl:
+    """Used to implement the File('') syntax which lets you sync a single file
+    from an SVN repo."""
+
+    def __init__(self, file_location):
+      self.file_location = file_location
+
+    def __str__(self):
+      return 'File("%s")' % self.file_location
+
+    def GetPath(self):
+      return os.path.split(self.file_location)[0]
+
+    def GetFilename(self):
+      rev_tokens = self.file_location.split('@')
+      return os.path.split(rev_tokens[0])[1]
+
+    def GetRevision(self):
+      rev_tokens = self.file_location.split('@')
+      if len(rev_tokens) > 1:
+        return rev_tokens[1]
+      return None
+
   class _VarImpl:
     def __init__(self, custom_vars, local_scope):
       self._custom_vars = custom_vars
@@ -461,7 +484,12 @@ class GClient(object):
     # Eval the content
     local_scope = {}
     var = self._VarImpl(custom_vars, local_scope)
-    global_scope = {"From": self.FromImpl, "Var": var.Lookup, "deps_os": {}}
+    global_scope = {
+      "File": self.FileImpl,
+      "From": self.FromImpl,
+      "Var": var.Lookup,
+      "deps_os": {},
+    }
     exec(solution_deps_content, global_scope, local_scope)
     deps = local_scope.get("deps", {})
 
@@ -560,14 +588,14 @@ class GClient(object):
           #
           # If multiple solutions all have the same From reference, then we
           # should only add one to our list of dependencies.
-          if type(url) != str:
+          if isinstance(url, self.FromImpl):
             if url.module_name in solution_urls:
               # Already parsed.
               continue
             if d in deps and type(deps[d]) != str:
               if url.module_name == deps[d].module_name:
                 continue
-          else:
+          elif isinstance(url, str):
             parsed_url = urlparse.urlparse(url)
             scheme = parsed_url[0]
             if not scheme:
@@ -728,12 +756,20 @@ class GClient(object):
           scm = gclient_scm.CreateSCM(url, self._root_dir, d)
           scm.RunCommand(command, self._options, args, file_list)
           self._options.revision = None
+      elif isinstance(deps[d], self.FileImpl):
+        file = deps[d]
+        self._options.revision = file.GetRevision()
+        if run_scm:
+          scm = gclient_scm.CreateSCM(file.GetPath(), self._root_dir, d)
+          scm.RunCommand("updatesingle", self._options,
+                         args + [file.GetFilename()], file_list)
+          
     if command == 'update' and not self._options.verbose:
       pm.end()
 
     # Second pass for inherited deps (via the From keyword)
     for d in deps_to_process:
-      if type(deps[d]) != str:
+      if isinstance(deps[d], self.FromImpl):
         filename = os.path.join(self._root_dir,
                                 deps[d].module_name,
                                 self._options.deps_file)
@@ -885,7 +921,7 @@ class GClient(object):
 
     # Second pass for inherited deps (via the From keyword)
     for d in deps_to_process:
-      if type(deps[d]) != str:
+      if isinstance(deps[d], self.FromImpl):
         deps_parent_url = entries[deps[d].module_name]
         if deps_parent_url.find("@") < 0:
           raise gclient_utils.Error("From %s missing revisioned url" %

gclient_scm.py

@@ -97,8 +97,8 @@ class SCMWrapper(object):
     if file_list is None:
       file_list = []
 
-    commands = ['cleanup', 'export', 'update', 'revert', 'revinfo',
+    commands = ['cleanup', 'export', 'update', 'updatesingle', 'revert',
-                'status', 'diff', 'pack', 'runhooks']
+                'revinfo', 'status', 'diff', 'pack', 'runhooks']
 
     if not command in commands:
       raise gclient_utils.Error('Unknown command %s' % command)
@@ -746,6 +746,20 @@ class SVNWrapper(SCMWrapper):
       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.
 

tests/gclient_scm_test.py

@@ -60,7 +60,8 @@ class SVNWrapperTestCase(BaseTestCase):
     members = [
         'FullUrlForRelativeUrl', 'RunCommand',
         'cleanup', 'diff', 'export', 'pack', 'relpath', 'revert',
-        'revinfo', 'runhooks', 'scm_name', 'status', 'update', 'url',
+        'revinfo', 'runhooks', 'scm_name', 'status', 'update',
+        'updatesingle', 'url',
     ]
 
     # If you add a member, be sure to add the relevant test!
@@ -266,6 +267,61 @@ class SVNWrapperTestCase(BaseTestCase):
                             relpath=self.relpath)
     scm.update(options, (), files_list)
 
+  def testUpdateSingleCheckout(self):
+    options = self.Options(verbose=True)
+    base_path = gclient_scm.os.path.join(self.root_dir, self.relpath)
+    file_info = {
+      'URL': self.url,
+      'Revision': 42,
+    }
+    # When checking out a single file, we issue an svn checkout and svn update.
+    gclient_scm.os.path.exists(base_path).AndReturn(False)
+    files_list = self.mox.CreateMockAnything()
+    gclient_scm.scm.SVN.Run(
+        ['checkout', '--depth', 'empty', self.url, base_path], self.root_dir)
+    gclient_scm.scm.SVN.RunAndGetFileList(options, ['update', 'DEPS'],
+        gclient_scm.os.path.join(self.root_dir, self.relpath), files_list)
+
+    # Now we fall back on scm.update().
+    gclient_scm.os.path.exists(gclient_scm.os.path.join(base_path, '.git')
+                               ).AndReturn(False)
+    gclient_scm.os.path.exists(base_path).AndReturn(True)
+    gclient_scm.scm.SVN.CaptureInfo(
+        gclient_scm.os.path.join(base_path, "."), '.'
+        ).AndReturn(file_info)
+    gclient_scm.scm.SVN.CaptureInfo(file_info['URL'], '.').AndReturn(file_info)
+    print("\n_____ %s at 42" % self.relpath)
+
+    self.mox.ReplayAll()
+    scm = self._scm_wrapper(url=self.url, root_dir=self.root_dir,
+                            relpath=self.relpath)
+    scm.updatesingle(options, ['DEPS'], files_list)
+
+  def testUpdateSingleUpdate(self):
+    options = self.Options(verbose=True)
+    base_path = gclient_scm.os.path.join(self.root_dir, self.relpath)
+    file_info = {
+      'URL': self.url,
+      'Revision': 42,
+    }
+    gclient_scm.os.path.exists(base_path).AndReturn(True)
+
+    # Now we fall back on scm.update().
+    files_list = self.mox.CreateMockAnything()
+    gclient_scm.os.path.exists(gclient_scm.os.path.join(base_path, '.git')
+                               ).AndReturn(False)
+    gclient_scm.os.path.exists(base_path).AndReturn(True)
+    gclient_scm.scm.SVN.CaptureInfo(
+        gclient_scm.os.path.join(base_path, "."), '.'
+        ).AndReturn(file_info)
+    gclient_scm.scm.SVN.CaptureInfo(file_info['URL'], '.').AndReturn(file_info)
+    print("\n_____ %s at 42" % self.relpath)
+
+    self.mox.ReplayAll()
+    scm = self._scm_wrapper(url=self.url, root_dir=self.root_dir,
+                            relpath=self.relpath)
+    scm.updatesingle(options, ['DEPS'], files_list)
+
   def testUpdateGit(self):
     options = self.Options(verbose=True)
     file_path = gclient_scm.os.path.join(self.root_dir, self.relpath, '.git')

tests/gclient_test.py

@@ -213,9 +213,6 @@ class TestDoRunHooks(GenericCommandTestCase):
 
 
 class TestDoUpdate(GenericCommandTestCase):
-  def Options(self, verbose=False, *args, **kwargs):
-    return self.OptionsObject(self, verbose=verbose, *args, **kwargs)
-
   def ReturnValue(self, command, function, return_value):
     options = self.Options()
     gclient.GClient.LoadCurrentConfig(options).AndReturn(gclient.GClient)
@@ -302,7 +299,7 @@ class TestDoRevert(GenericCommandTestCase):
 class GClientClassTestCase(GclientTestCase):
   def testDir(self):
     members = [
-      'ConfigContent', 'FromImpl', 'GetVar', 'LoadCurrentConfig',
+      'ConfigContent', 'FileImpl', 'FromImpl', 'GetVar', 'LoadCurrentConfig',
       'RunOnDeps', 'SaveConfig', 'SetConfig', 'SetDefaultConfig',
       'supported_commands', 'PrintRevInfo',
     ]
@@ -1033,6 +1030,48 @@ deps = {
     # TODO(maruel):  Test me!
     pass
 
+  def testFileImpl(self):
+    # Fake .gclient file.
+    name = "testFileImpl"
+    gclient_config = (
+        "solutions = [ { 'name': '%s',"
+        "'url': '%s', } ]" % (name, self.url)
+    )
+    # Fake DEPS file.
+    target = "chromium_deps"
+    deps_content = (
+        "deps = {"
+        "  '%s': File('%s/DEPS') }" % (target, self.url)
+    )
+
+    gclient.gclient_scm.CreateSCM(self.url, self.root_dir, name).AndReturn(
+        gclient.gclient_scm.CreateSCM)
+    options = self.Options()
+    gclient.gclient_scm.CreateSCM.RunCommand('update', options, self.args, [])
+    gclient.gclient_utils.FileRead(
+        gclient.os.path.join(self.root_dir, name, options.deps_file)
+        ).AndReturn(deps_content)
+    gclient.os.path.exists(
+        gclient.os.path.join(self.root_dir, name, '.git')
+        ).AndReturn(False)
+    gclient.os.path.exists(
+        gclient.os.path.join(self.root_dir, options.entries_filename)
+        ).AndReturn(False)
+
+    # This is where gclient tries to do the initial checkout.
+    gclient.gclient_scm.CreateSCM(self.url, self.root_dir, target).AndReturn(
+        gclient.gclient_scm.CreateSCM)
+    gclient.gclient_scm.CreateSCM.RunCommand('updatesingle', options,
+        self.args + ["DEPS"], [])
+    gclient.gclient_utils.FileWrite(
+        gclient.os.path.join(self.root_dir, options.entries_filename),
+        "entries = \\\n{'%s': '%s'}\n" % (name, self.url))
+
+    self.mox.ReplayAll()
+    client = self._gclient_gclient(self.root_dir, options)
+    client.SetConfig(gclient_config)
+    client.RunOnDeps('update', self.args)
+
   def test_PrintRevInfo(self):
     # TODO(aharper): no test yet for revinfo, lock it down once we've verified
     # implementation for Pulse plugin