forked from mirrors/gecko-dev
2bd348aaf4
Differential Revision: https://phabricator.services.mozilla.com/D69656 --HG-- extra : moz-landing-system : lando
80 lines
2.7 KiB
C++
80 lines
2.7 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef mozilla_SnappyFrameUtils_h__
|
|
#define mozilla_SnappyFrameUtils_h__
|
|
|
|
#include <cstddef>
|
|
|
|
#include "mozilla/Attributes.h"
|
|
#include "nsError.h"
|
|
|
|
namespace mozilla {
|
|
namespace detail {
|
|
|
|
//
|
|
// Utility class providing primitives necessary to build streams based
|
|
// on the snappy compressor. This essentially abstracts the framing format
|
|
// defined in:
|
|
//
|
|
// other-licences/snappy/src/framing_format.txt
|
|
//
|
|
// NOTE: Currently only the StreamIdentifier and CompressedData chunks are
|
|
// supported.
|
|
//
|
|
class SnappyFrameUtils {
|
|
public:
|
|
enum ChunkType {
|
|
Unknown,
|
|
StreamIdentifier,
|
|
CompressedData,
|
|
UncompressedData,
|
|
Padding,
|
|
Reserved,
|
|
ChunkTypeCount
|
|
};
|
|
|
|
static const size_t kChunkTypeLength = 1;
|
|
static const size_t kChunkLengthLength = 3;
|
|
static const size_t kHeaderLength = kChunkTypeLength + kChunkLengthLength;
|
|
static const size_t kStreamIdentifierDataLength = 6;
|
|
static const size_t kCRCLength = 4;
|
|
|
|
static nsresult WriteStreamIdentifier(char* aDest, size_t aDestLength,
|
|
size_t* aBytesWrittenOut);
|
|
|
|
static nsresult WriteCompressedData(char* aDest, size_t aDestLength,
|
|
const char* aData, size_t aDataLength,
|
|
size_t* aBytesWrittenOut);
|
|
|
|
static nsresult ParseHeader(const char* aSource, size_t aSourceLength,
|
|
ChunkType* aTypeOut, size_t* aDataLengthOut);
|
|
|
|
static nsresult ParseData(char* aDest, size_t aDestLength, ChunkType aType,
|
|
const char* aData, size_t aDataLength,
|
|
size_t* aBytesWrittenOut, size_t* aBytesReadOut);
|
|
|
|
static nsresult ParseStreamIdentifier(char* aDest, size_t aDestLength,
|
|
const char* aData, size_t aDataLength,
|
|
size_t* aBytesWrittenOut,
|
|
size_t* aBytesReadOut);
|
|
|
|
static nsresult ParseCompressedData(char* aDest, size_t aDestLength,
|
|
const char* aData, size_t aDataLength,
|
|
size_t* aBytesWrittenOut,
|
|
size_t* aBytesReadOut);
|
|
|
|
static size_t MaxCompressedBufferLength(size_t aSourceLength);
|
|
|
|
protected:
|
|
SnappyFrameUtils() = default;
|
|
virtual ~SnappyFrameUtils() = default;
|
|
};
|
|
|
|
} // namespace detail
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_SnappyFrameUtils_h__
|