AU: Class to perform delta updates.

src/platform/update_engine/extent_writer.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 CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__
 
 #include <vector>
 #include "chromeos/obsolete_logging.h"
 #include "update_engine/update_metadata.pb.h"
 #include "update_engine/utils.h"
 
 // ExtentWriter is an abstract class which synchronously writes to a given
 // file descriptor at the extents given.
 
 namespace chromeos_update_engine {
 
-// When an extent's start block is kSparseHole, that data written for that
-// extent will be dropped rather than written to the unerlying fd.
-const uint64 kSparseHole = kuint64max;
-
 class ExtentWriter {
  public:
   ExtentWriter() : end_called_(false) {}
   virtual ~ExtentWriter() {
     LOG_IF(ERROR, !end_called_) << "End() not called on ExtentWriter.";
   }
 
   // Returns true on success.
   virtual bool Init(int fd,
                     const std::vector<Extent>& extents,
@@ skipping 34 matching lines @@
   bool Write(const void* bytes, size_t count);
   bool EndImpl() {
     return true;
   }
 
  private:
   int fd_;
   
   size_t block_size_;
   // Bytes written into next_extent_index_ thus far
-  uint64 extent_bytes_written_;
+  uint64_t extent_bytes_written_;
   std::vector<Extent> extents_;
   // The next call to write should correspond to extents_[next_extent_index_]
   std::vector<Extent>::size_type next_extent_index_;
 };
 
 // Takes an underlying ExtentWriter to which all operations are delegated.
 // When End() is called, ZeroPadExtentWriter ensures that the total number
 // of bytes written is a multiple of block_size_. If not, it writes zeros
 // to pad as needed.
 
@@ skipping 29 matching lines @@
 
  private:
   ExtentWriter* underlying_extent_writer_;  // The underlying ExtentWriter.
   size_t block_size_;
   size_t bytes_written_mod_block_size_;
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__