AU: SplitWriter class for parsing our full update files.

src/platform/update_engine/decompressing_file_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_DECOMPRESSING_FILE_WRITER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_DECOMPRESSING_FILE_WRITER_H__
 
 #include <zlib.h>
 #include "base/basictypes.h"
 #include "update_engine/file_writer.h"
@@ skipping 18 matching lines @@
   virtual int Open(const char* path, int flags, mode_t mode) {
     return next_->Open(path, flags, mode);
   }
 
   // Write() calls into zlib to decompress the bytes passed in. It will not
   // necessarily write all the decompressed data associated with this set of
   // passed-in compressed data during this call, however for a valid gzip
   // stream, after the entire stream has been written to this object,
   // the entire decompressed stream will have been written to the
   // underlying FileWriter.
-  virtual int Write(const void* bytes, size_t count);
+  virtual ssize_t Write(const void* bytes, size_t count);
 
   virtual int Close() {
     return next_->Close();
   }
  private:
   // The FileWriter that we write all uncompressed data to
   FileWriter* next_;
 
   // The zlib state
   z_stream stream_;
 
   // This is for an optimization in Write(). We can keep this buffer around
   // in our class to avoid repeated calls to malloc().
   std::vector<char> buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(GzipDecompressingFileWriter);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DECOMPRESSING_FILE_WRITER_H__