ObjFW  Check-in [1b5d3ac8af]

 *
 * 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"
#import "OFKernelEventObserver.h"

OF_ASSUME_NONNULL_BEGIN

#define OF_INFLATE64_STREAM_BUFFER_SIZE 4096

/*!
 * @class OFInflate64Stream OFInflate64Stream.h ObjFW/OFInflate64Stream.h
 *
 * @note This class only conforms to OFReadyForReadingObserving if the
 *	 underlying stream does so, too.
 *
 * @brief A class that handles Deflate decompression transparently for an
 *	  underlying stream.
 */
@interface OFInflate64Stream: OFStream <OFReadyForReadingObserving>
{
#ifdef OF_INFLATE64_STREAM_M
@public
#endif
	OF_KINDOF(OFStream *) _stream;
	unsigned char _buffer[OF_INFLATE64_STREAM_BUFFER_SIZE];
	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 of_huffman_tree *_Nullable litLenTree;
			struct of_huffman_tree *_Nullable distTree;
			struct of_huffman_tree *_Nullable codeLenTree;
			struct of_huffman_tree *_Nullable treeIter;
			uint8_t *_Nullable lengths;
			uint16_t receivedCount;
			uint8_t value, litLenCodesCount, distCodesCount;
			uint8_t codeLenCodesCount;
		} huffmanTree;
		struct {
			struct of_huffman_tree *_Nullable litLenTree;
			struct of_huffman_tree *_Nullable distTree;
			struct of_huffman_tree *_Nullable treeIter;
			int state;
			uint16_t value, length, distance, extraBits;
		} huffman;
	} _context;
	bool _inLastBlock, _atEndOfStream;
}

/*!
 * @brief Creates a new OFInflate64Stream 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 OFInflate64Stream
 */
+ (instancetype)streamWithStream: (OFStream *)stream;

- (instancetype)init OF_UNAVAILABLE;

/*!
 * @brief Initializes an already allocated OFInflate64Stream 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 OFInflate64Stream
 */
- (instancetype)initWithStream: (OFStream *)stream OF_DESIGNATED_INITIALIZER;
@end

OF_ASSUME_NONNULL_END

 *
 * 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.
 */

#define OF_INFLATE64_STREAM_M
#include "OFInflateStream.m"

#include "config.h"

#include <stdlib.h>
#include <string.h>

#include <assert.h>

#ifndef OF_INFLATE64_STREAM_M
# import "OFInflateStream.h"
#else
# import "OFInflate64Stream.h"
# define OFInflateStream OFInflate64Stream
#endif

#import "huffman_tree.h"

#import "OFInitializationFailedException.h"
#import "OFInvalidFormatException.h"
#import "OFNotOpenException.h"
#import "OFOutOfMemoryException.h"

#ifndef OF_INFLATE64_STREAM_M
# define BUFFER_SIZE OF_INFLATE_STREAM_BUFFER_SIZE
#else
# define BUFFER_SIZE OF_INFLATE64_STREAM_BUFFER_SIZE
#endif

enum state {
	BLOCK_HEADER,
	UNCOMPRESSED_BLOCK_HEADER,
	UNCOMPRESSED_BLOCK,
	HUFFMAN_TREE,
	HUFFMAN_BLOCK
};

enum huffman_state {
	WRITE_VALUE,
	AWAIT_CODE,
	AWAIT_LENGTH_EXTRA_BITS,
	AWAIT_DISTANCE,
	AWAIT_DISTANCE_EXTRA_BITS,
	PROCESS_PAIR
};

#ifndef OF_INFLATE64_STREAM_M
static const uint8_t numDistanceCodes = 30;
static const uint8_t lengthCodes[29] = {
	/* indices are -257, values -3 */
	0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
	64, 80, 96, 112, 128, 160, 192, 224, 255
};
static const uint8_t lengthExtraBits[29] = {

	for (uint16_t i = 0; i <= 31; i++)
		lengths[i] = 5;

	fixedDistTree = of_huffman_tree_construct(lengths, 32);
}


+ (instancetype)streamWithStream: (OFStream *)stream
{
	return [[[self alloc] initWithStream: stream] autorelease];
}

- (instancetype)init
{
	OF_INVALID_INIT_METHOD
}

- (instancetype)initWithStream: (OFStream *)stream
{
	self = [super init];

	@try {
		_stream = [stream retain];

		/* 0-7 address the bit, 8 means fetch next byte */
		_bitIndex = 8;

#ifdef OF_INFLATE64_STREAM_M
		_slidingWindowMask = 0xFFFF;
#else
		_slidingWindowMask = 0x7FFF;
#endif
		_slidingWindow = [self allocZeroedMemoryWithSize:
		    _slidingWindowMask + 1];
	} @catch (id e) {

			of_huffman_tree_release(_context.huffman.litLenTree);
		if (_context.huffman.distTree != fixedDistTree)
			of_huffman_tree_release(_context.huffman.distTree);
	}

	[super dealloc];
}


- (size_t)lowlevelReadIntoBuffer: (void *)buffer_
			  length: (size_t)length
{
	unsigned char *buffer = buffer_;
	uint16_t bits, tmp, value;
	size_t bytesWritten = 0;

		break;
#undef CTX
	}

	OF_UNREACHABLE
}


- (bool)lowlevelIsAtEndOfStream
{
	if (_stream == nil)
		@throw [OFNotOpenException exceptionWithObject: self];

	return _atEndOfStream;
}

- (int)fileDescriptorForReading
{
	return [_stream fileDescriptorForReading];
}

- (bool)hasDataInReadBuffer
{
	return ([super hasDataInReadBuffer] || [_stream hasDataInReadBuffer]);
}


- (void)close
{
	/* Give back our buffer to the stream, in case it's shared */
	[_stream unreadFromBuffer: _buffer + _bufferIndex
			   length: _bufferLength - _bufferIndex];
	_bufferIndex = _bufferLength = 0;