• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Copyright 2009 Google Inc.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #ifndef OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_
16 #define OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_
17 
18 namespace open_vcdiff {
19 
20 // These flags are passed to the constructor of VCDiffStreamingEncoder
21 // to determine whether certain open-vcdiff format extensions
22 // (which are not part of the RFC 3284 draft standard for VCDIFF)
23 // are employed.
24 //
25 // Because these extensions are not part of the VCDIFF standard, if
26 // any of these flags except VCD_STANDARD_FORMAT is specified, then the caller
27 // must be certain that the receiver of the data will be using open-vcdiff
28 // to decode the delta file, or at least that the receiver can interpret
29 // these extensions.  The encoder will use an 'S' as the fourth character
30 // in the delta file to indicate that non-standard extensions are being used.
31 //
32 enum VCDiffFormatExtensionFlagValues {
33   // No extensions: the encoded format will conform to the RFC
34   // draft standard for VCDIFF.
35   VCD_STANDARD_FORMAT = 0x00,
36   // If this flag is specified, then the encoder writes each delta file
37   // window by interleaving instructions and sizes with their corresponding
38   // addresses and data, rather than placing these elements
39   // into three separate sections.  This facilitates providing partially
40   // decoded results when only a portion of a delta file window is received
41   // (e.g. when HTTP over TCP is used as the transmission protocol.)
42   VCD_FORMAT_INTERLEAVED = 0x01,
43   // If this flag is specified, then an Adler32 checksum
44   // of the target window data is included in the delta window.
45   VCD_FORMAT_CHECKSUM = 0x02,
46   // If this flag is specified, the encoder will output a JSON string
47   // instead of the VCDIFF file format. If this flag is set, all other
48   // flags have no effect.
49   VCD_FORMAT_JSON = 0x04
50 };
51 
52 typedef int VCDiffFormatExtensionFlags;
53 
54 }  // namespace open_vcdiff
55 
56 #endif  // OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_
57