OFInflateStream.h

/*
 * Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
 *
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3.0 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
 * version 3.0 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3.0 along with this program. If not, see
 * <https://www.gnu.org/licenses/>.
 */
 
#import "OFStream.h"
#import "OFKernelEventObserver.h"
 
OF_ASSUME_NONNULL_BEGIN
 
#define OFInflateStreamBufferSize 4096
 
OF_SUBCLASSING_RESTRICTED
@interface OFInflateStream: OFStream <OFReadyForReadingObserving>
{
    OFStream *_stream;
    unsigned char _buffer[OFInflateStreamBufferSize];
    uint16_t _bufferIndex, _bufferLength;
    uint8_t _byte;
    uint8_t _bitIndex, _savedBitsLength;
    uint16_t _savedBits;
    unsigned char *_Nullable _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 _OFHuffmanTree *_Nullable litLenTree;
            struct _OFHuffmanTree *_Nullable distTree;
            struct _OFHuffmanTree *_Nullable codeLenTree;
            struct _OFHuffmanTree *_Nullable treeIter;
            uint8_t *_Nullable lengths;
            uint16_t receivedCount;
            uint8_t value, litLenCodesCount, distCodesCount;
            uint8_t codeLenCodesCount;
        } huffmanTree;
        struct {
            struct _OFHuffmanTree *_Nullable litLenTree;
            struct _OFHuffmanTree *_Nullable distTree;
            struct _OFHuffmanTree *_Nullable treeIter;
            int state;
            uint16_t value, length, distance, extraBits;
        } huffman;
    } _context;
    bool _inLastBlock, _atEndOfStream;
}
 
@property (retain, nonatomic) OFStream *underlyingStream;
 
+ (instancetype)streamWithStream: (OFStream *)stream;
 
- (instancetype)init OF_UNAVAILABLE;
 
- (instancetype)initWithStream: (OFStream *)stream OF_DESIGNATED_INITIALIZER;
@end
 
OF_ASSUME_NONNULL_END