AU: Beginnings of delta support

src/platform/update_engine/action.h

 // Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef UPDATE_ENGINE_ACTION_H__
-#define UPDATE_ENGINE_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__
 
 #include <stdio.h>
 #include <tr1/memory>
 #include <iostream>
-
 #include "base/basictypes.h"
-#include <base/logging.h>
-
+#include "chromeos/obsolete_logging.h"
 #include "update_engine/action_processor.h"
+#include "update_engine/action_pipe.h"
 
 // The structure of these classes (Action, ActionPipe, ActionProcessor, etc.)
 // is based on the KSAction* classes from the Google Update Engine code at
 // http://code.google.com/p/update-engine/ . The author of this file sends
 // a big thanks to that team for their high quality design, implementation,
 // and documentation.
 //
 // Readers may want to consult this wiki page from the Update Engine site:
 // http://code.google.com/p/update-engine/wiki/ActionProcessor
 // Although it's referring to the Objective-C KSAction* classes, much
@@ skipping 124 matching lines @@
   // of object that this class expects.
   // This is generally called by ActionPipe::Bond()
   void set_out_pipe(
       // this type is a fancy way of saying: a shared_ptr to an
       // ActionPipe<OutputObjectType>.
       const shared_ptr<ActionPipe<
           typename ActionTraits<SubClass>::OutputObjectType> >&
           out_pipe) {
     out_pipe_ = out_pipe;
   }
- protected:
+
   // Returns true iff there is an associated input pipe. If there's an input
   // pipe, there's an input object, but it may have been constructed with the
   // default ctor if the previous action didn't call SetOutputObject().
   bool HasInputObject() const { return in_pipe_.get(); }
 
   // returns a const reference to the object in the input pipe.
   const typename ActionTraits<SubClass>::InputObjectType& GetInputObject()
       const {
     CHECK(HasInputObject());
     return in_pipe_->contents();
   }
 
   // Returns true iff there's an output pipe.
   bool HasOutputPipe() const {
     return out_pipe_.get();
   }
 
   // Copies the object passed into the output pipe. It will be accessible to
   // the next Action via that action's input pipe (which is the same as this
   // Action's output pipe).
   void SetOutputObject(
       const typename ActionTraits<SubClass>::OutputObjectType& out_obj) {
     CHECK(HasOutputPipe());
     out_pipe_->set_contents(out_obj);
   }
 
+  // Returns a reference to the object sitting in the output pipe.
+  const typename ActionTraits<SubClass>::OutputObjectType& GetOutputObject() {
+    CHECK(HasOutputPipe());
+    return out_pipe_->contents();
+  }
+
+protected:
   // We use a shared_ptr to the pipe. shared_ptr objects destroy what they
   // point to when the last such shared_ptr object dies. We consider the
   // Actions on either end of a pipe to "own" the pipe. When the last Action
   // of the two dies, the ActionPipe will die, too.
   shared_ptr<ActionPipe<typename ActionTraits<SubClass>::InputObjectType> >
       in_pipe_;
   shared_ptr<ActionPipe<typename ActionTraits<SubClass>::OutputObjectType> >
       out_pipe_;
 };
 
 };  // namespace chromeos_update_engine
 
-#endif  // UPDATE_ENGINE_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__