/*-
 * Copyright 2003,2004 Colin Percival
 * All rights reserved
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted providing that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Changelog:
 * 2005-04-26 - Define the header as a C structure, add a CRC32 checksum to
 *              the header, and make all the types 32-bit.
 *                --Benjamin Smedberg <benjamin@smedbergs.us>
 * 2009-03-31 - Change to use Streams.  Move CRC code to crc.{h,cc}
 *              Changed status to an enum, removed unused status codes.
 *                --Stephen Adams <sra@chromium.org>
 * 2013-04-10 - Added wrapper to apply a patch directly to files.
 *                --Joshua Pawlicki <waffles@chromium.org>
 */

#ifndef COURGETTE_BSDIFF_H_
#define COURGETTE_BSDIFF_H_

#include "base/basictypes.h"
#include "base/files/file_util.h"

namespace courgette {

enum BSDiffStatus {
  OK = 0,
  MEM_ERROR = 1,
  CRC_ERROR = 2,
  READ_ERROR = 3,
  UNEXPECTED_ERROR = 4,
  WRITE_ERROR = 5
};

class SourceStream;
class SinkStream;

// Creates a binary patch.
//
BSDiffStatus CreateBinaryPatch(SourceStream* old_stream,
                               SourceStream* new_stream,
                               SinkStream* patch_stream);

// Applies the given patch file to a given source file. This method validates
// the CRC of the original file stored in the patch file, before applying the
// patch to it.
//
BSDiffStatus ApplyBinaryPatch(SourceStream* old_stream,
                              SourceStream* patch_stream,
                              SinkStream* new_stream);

// As above, but simply takes the file paths.
BSDiffStatus ApplyBinaryPatch(const base::FilePath& old_stream,
                              const base::FilePath& patch_stream,
                              const base::FilePath& new_stream);

// The following declarations are common to the patch-creation and
// patch-application code.

// The patch stream starts with a MBSPatchHeader.
typedef struct MBSPatchHeader_ {
  char tag[8];       // Contains MBS_PATCH_HEADER_TAG
  uint32 slen;       // Length of the file to be patched.
  uint32 scrc32;     // CRC32 of the file to be patched.
  uint32 dlen;       // Length of the result file.
} MBSPatchHeader;

// This is the value for the tag field.  Must match length exactly, not counting
// null at end of string.
#define MBS_PATCH_HEADER_TAG "GBSDIF42"

}  // namespace
#endif  // COURGETTE_BSDIFF_H_