164 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			164 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| ///////////////////////////////////////////////////////////////////////////////
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| //
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| /// \file       alone_decoder.c
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| /// \brief      Decoder for LZMA_Alone files
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| //
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| //  Author:     Lasse Collin
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| //
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| //  This file has been put into the public domain.
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| //  You can do whatever you want with this file.
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| //
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| ///////////////////////////////////////////////////////////////////////////////
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| 
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| #include "common.h"
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| #include "lzma_encoder.h"
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| 
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| 
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| #define ALONE_HEADER_SIZE (1 + 4 + 8)
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| 
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| 
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| typedef struct {
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| 	lzma_next_coder next;
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| 
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| 	enum {
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| 		SEQ_HEADER,
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| 		SEQ_CODE,
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| 	} sequence;
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| 
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| 	size_t header_pos;
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| 	uint8_t header[ALONE_HEADER_SIZE];
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| } lzma_alone_coder;
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| 
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| 
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| static lzma_ret
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| alone_encode(void *coder_ptr,
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| 		const lzma_allocator *allocator lzma_attribute((__unused__)),
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| 		const uint8_t *restrict in, size_t *restrict in_pos,
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| 		size_t in_size, uint8_t *restrict out,
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| 		size_t *restrict out_pos, size_t out_size,
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| 		lzma_action action)
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| {
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| 	lzma_alone_coder *coder = coder_ptr;
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| 
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| 	while (*out_pos < out_size)
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| 	switch (coder->sequence) {
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| 	case SEQ_HEADER:
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| 		lzma_bufcpy(coder->header, &coder->header_pos,
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| 				ALONE_HEADER_SIZE,
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| 				out, out_pos, out_size);
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| 		if (coder->header_pos < ALONE_HEADER_SIZE)
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| 			return LZMA_OK;
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| 
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| 		coder->sequence = SEQ_CODE;
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| 		break;
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| 
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| 	case SEQ_CODE:
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| 		return coder->next.code(coder->next.coder,
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| 				allocator, in, in_pos, in_size,
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| 				out, out_pos, out_size, action);
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| 
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| 	default:
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| 		assert(0);
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| 		return LZMA_PROG_ERROR;
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| 	}
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| 
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| 	return LZMA_OK;
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| }
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| 
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| 
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| static void
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| alone_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
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| {
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| 	lzma_alone_coder *coder = coder_ptr;
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| 	lzma_next_end(&coder->next, allocator);
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| 	lzma_free(coder, allocator);
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| 	return;
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| }
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| 
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| 
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| // At least for now, this is not used by any internal function.
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| static lzma_ret
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| alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
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| 		const lzma_options_lzma *options)
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| {
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| 	lzma_next_coder_init(&alone_encoder_init, next, allocator);
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| 
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| 	lzma_alone_coder *coder = next->coder;
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| 
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| 	if (coder == NULL) {
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| 		coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
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| 		if (coder == NULL)
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| 			return LZMA_MEM_ERROR;
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| 
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| 		next->coder = coder;
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| 		next->code = &alone_encode;
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| 		next->end = &alone_encoder_end;
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| 		coder->next = LZMA_NEXT_CODER_INIT;
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| 	}
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| 
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| 	// Basic initializations
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| 	coder->sequence = SEQ_HEADER;
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| 	coder->header_pos = 0;
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| 
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| 	// Encode the header:
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| 	// - Properties (1 byte)
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| 	if (lzma_lzma_lclppb_encode(options, coder->header))
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| 		return LZMA_OPTIONS_ERROR;
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| 
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| 	// - Dictionary size (4 bytes)
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| 	if (options->dict_size < LZMA_DICT_SIZE_MIN)
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| 		return LZMA_OPTIONS_ERROR;
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| 
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| 	// Round up to the next 2^n or 2^n + 2^(n - 1) depending on which
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| 	// one is the next unless it is UINT32_MAX. While the header would
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| 	// allow any 32-bit integer, we do this to keep the decoder of liblzma
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| 	// accepting the resulting files.
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| 	uint32_t d = options->dict_size - 1;
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| 	d |= d >> 2;
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| 	d |= d >> 3;
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| 	d |= d >> 4;
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| 	d |= d >> 8;
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| 	d |= d >> 16;
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| 	if (d != UINT32_MAX)
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| 		++d;
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| 
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| 	unaligned_write32le(coder->header + 1, d);
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| 
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| 	// - Uncompressed size (always unknown and using EOPM)
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| 	memset(coder->header + 1 + 4, 0xFF, 8);
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| 
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| 	// Initialize the LZMA encoder.
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| 	const lzma_filter_info filters[2] = {
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| 		{
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| 			.init = &lzma_lzma_encoder_init,
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| 			.options = (void *)(options),
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| 		}, {
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| 			.init = NULL,
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| 		}
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| 	};
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| 
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| 	return lzma_next_filter_init(&coder->next, allocator, filters);
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| }
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| 
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| 
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| /*
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| extern lzma_ret
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| lzma_alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
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| 		const lzma_options_alone *options)
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| {
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| 	lzma_next_coder_init(&alone_encoder_init, next, allocator, options);
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| }
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| */
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| 
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| 
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| extern LZMA_API(lzma_ret)
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| lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
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| {
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| 	lzma_next_strm_init(alone_encoder_init, strm, options);
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| 
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| 	strm->internal->supported_actions[LZMA_RUN] = true;
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| 	strm->internal->supported_actions[LZMA_FINISH] = true;
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| 
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| 	return LZMA_OK;
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| }
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