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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/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_
93