xref: /external/chromium_org/sdch/open-vcdiff/src/google/format_extension_flags.h

// Copyright 2009 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_
#define OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_

namespace open_vcdiff {

// These flags are passed to the constructor of VCDiffStreamingEncoder
// to determine whether certain open-vcdiff format extensions
// (which are not part of the RFC 3284 draft standard for VCDIFF)
// are employed.
//
// Because these extensions are not part of the VCDIFF standard, if
// any of these flags except VCD_STANDARD_FORMAT is specified, then the caller
// must be certain that the receiver of the data will be using open-vcdiff
// to decode the delta file, or at least that the receiver can interpret
// these extensions.  The encoder will use an 'S' as the fourth character
// in the delta file to indicate that non-standard extensions are being used.
//
enum VCDiffFormatExtensionFlagValues {
  // No extensions: the encoded format will conform to the RFC
  // draft standard for VCDIFF.
  VCD_STANDARD_FORMAT = 0x00,
  // If this flag is specified, then the encoder writes each delta file
  // window by interleaving instructions and sizes with their corresponding
  // addresses and data, rather than placing these elements
  // into three separate sections.  This facilitates providing partially
  // decoded results when only a portion of a delta file window is received
  // (e.g. when HTTP over TCP is used as the transmission protocol.)
  VCD_FORMAT_INTERLEAVED = 0x01,
  // If this flag is specified, then an Adler32 checksum
  // of the target window data is included in the delta window.
  VCD_FORMAT_CHECKSUM = 0x02,
  // If this flag is specified, the encoder will output a JSON string
  // instead of the VCDIFF file format. If this flag is set, all other
  // flags have no effect.
  VCD_FORMAT_JSON = 0x04
};

typedef int VCDiffFormatExtensionFlags;

}  // namespace open_vcdiff

#endif  // OPEN_VCDIFF_FORMAT_EXTENSION_FLAGS_H_