OFDeflateStream.h

/*
 * Copyright (c) 2008-2026 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

@interface OFDeflateStream: OFStream <OFReadyForReadingObserving>
{
    OFStream *_stream;
    unsigned char *_Nullable _slidingWindow;
    uint16_t _slidingWindowIndex;
    struct OFInflateContext {
        unsigned char buffer[OFInflateStreamBufferSize];
        uint16_t bufferIndex, bufferLength;
        uint8_t byte;
        uint8_t bitIndex, savedBitsLength;
        uint16_t savedBits;
        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;
        } ctx;
        bool inLastBlock;
    } *_Nullable _inflateCtx;
    bool _atEndOfStream;
    OF_RESERVE_IVARS(OFDeflateStream, 4)
}

@property (retain, nonatomic) OFStream *underlyingStream;

+ (instancetype)streamWithStream: (OFStream *)stream
    OF_DEPRECATED(ObjFW, 1, 5, "Use +[streamWithStream:mode:] instead");

+ (instancetype)streamWithStream: (OFStream *)stream mode: (OFString *)mode;
 
- (instancetype)init OF_UNAVAILABLE;

- (instancetype)initWithStream: (OFStream *)stream
    OF_DEPRECATED(ObjFW, 1, 5, "Use -[initWithStream:mode:] instead!");

- (instancetype)initWithStream: (OFStream *)stream
              mode: (OFString *)mode OF_DESIGNATED_INITIALIZER;
@end
 
OF_ASSUME_NONNULL_END