courgette/third_party/bsdiff.h

   1 /*-
   2  * Copyright 2003,2004 Colin Percival
   3  * All rights reserved
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted providing that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * Changelog:
  27  * 2005-04-26 - Define the header as a C structure, add a CRC32 checksum to
  28  *              the header, and make all the types 32-bit.
  29  *                --Benjamin Smedberg <benjamin@smedbergs.us>
  30  * 2009-03-31 - Change to use Streams.  Move CRC code to crc.{h,cc}
  31  *              Changed status to an enum, removed unused status codes.
  32  *                --Stephen Adams <sra@chromium.org>
  33  * 2013-04-10 - Added wrapper to apply a patch directly to files.
  34  *                --Joshua Pawlicki <waffles@chromium.org>
  35  */
  36
  37 #ifndef COURGETTE_BSDIFF_H_
  38 #define COURGETTE_BSDIFF_H_
  39
  40 #include "base/basictypes.h"
  41 #include "base/files/file_util.h"
  42
  43 namespace courgette {
  44
  45 enum BSDiffStatus {
  46   OK = 0,
  47   MEM_ERROR = 1,
  48   CRC_ERROR = 2,
  49   READ_ERROR = 3,
  50   UNEXPECTED_ERROR = 4,
  51   WRITE_ERROR = 5
  52 };
  53
  54 class SourceStream;
  55 class SinkStream;
  56
  57 // Creates a binary patch.
  58 //
  59 BSDiffStatus CreateBinaryPatch(SourceStream* old_stream,
  60                                SourceStream* new_stream,
  61                                SinkStream* patch_stream);
  62
  63 // Applies the given patch file to a given source file. This method validates
  64 // the CRC of the original file stored in the patch file, before applying the
  65 // patch to it.
  66 //
  67 BSDiffStatus ApplyBinaryPatch(SourceStream* old_stream,
  68                               SourceStream* patch_stream,
  69                               SinkStream* new_stream);
  70
  71 // As above, but simply takes the file paths.
  72 BSDiffStatus ApplyBinaryPatch(const base::FilePath& old_stream,
  73                               const base::FilePath& patch_stream,
  74                               const base::FilePath& new_stream);
  75
  76 // The following declarations are common to the patch-creation and
  77 // patch-application code.
  78
  79 // The patch stream starts with a MBSPatchHeader.
  80 typedef struct MBSPatchHeader_ {
  81   char tag[8];       // Contains MBS_PATCH_HEADER_TAG
  82   uint32 slen;       // Length of the file to be patched.
  83   uint32 scrc32;     // CRC32 of the file to be patched.
  84   uint32 dlen;       // Length of the result file.
  85 } MBSPatchHeader;
  86
  87 // This is the value for the tag field.  Must match length exactly, not counting
  88 // null at end of string.
  89 #define MBS_PATCH_HEADER_TAG "GBSDIF42"
  90
  91 }  // namespace
  92 #endif  // COURGETTE_BSDIFF_H_