/*
* Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
* Jonathan Schleifer <js@heap.zone>
*
* All rights reserved.
*
* This file is part of ObjFW. It may be distributed under the terms of the
* Q Public License 1.0, which can be found in the file LICENSE.QPL included in
* the packaging of this file.
*
* Alternatively, it may be distributed under the terms of the GNU General
* Public License, either version 2 or 3, which can be found in the file
* LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
* file.
*/
#import "OFStream.h"
OF_ASSUME_NONNULL_BEGIN
#define OF_INFLATE_STREAM_BUFFER_SIZE 4096
/*!
* @class OFDeflateStream OFDeflateStream.h ObjFW/OFDeflateStream.h
*
* @brief A class that handles Deflate decompression transparently for an
* underlying stream.
*/
@interface OFDeflateStream: OFStream
{
#ifdef OF_INFLATE_STREAM_M
@public
#endif
OFStream *_stream;
struct of_deflate_stream_decompression_ivars {
uint8_t buffer[OF_INFLATE_STREAM_BUFFER_SIZE];
uint16_t bufferIndex, bufferLength;
uint8_t byte;
uint8_t bitIndex, savedBitsLength;
uint16_t savedBits;
uint8_t *slidingWindow;
uint16_t slidingWindowIndex, slidingWindowMask;
int state;
union {
struct {
uint8_t position;
uint8_t length[4];
} uncompressedHeader;
struct {
uint16_t position, length;
} uncompressed;
struct {
struct huffman_tree *litLenTree, *distTree;
struct huffman_tree *codeLenTree, *treeIter;
uint8_t *lengths;
uint16_t receivedCount;
uint8_t value, litLenCodesCount, distCodesCount;
uint8_t codeLenCodesCount;
} huffmanTree;
struct {
struct huffman_tree *litLenTree, *distTree;
struct huffman_tree *treeIter;
int state;
uint16_t value, length, distance;
uint16_t extraBits;
} huffman;
} context;
bool inLastBlock, atEndOfStream;
} *_decompression;
}
/*!
* @brief Creates a new OFDeflateStream with the specified underlying stream.
*
* @param stream The underlying stream to which compressed data is written or
* from which compressed data is read
* @return A new, autoreleased OFDeflateStream
*/
+ (instancetype)streamWithStream: (OFStream*)stream;
/*!
* @brief Initializes an already allocated OFDeflateStream with the specified
* underlying stream.
*
* @param stream The underlying stream to which compressed data is written or
* from which compressed data is read
* @return A initialized OFDeflateStream
*/
- initWithStream: (OFStream*)stream;
@end
OF_ASSUME_NONNULL_END