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/*
* Copyright (C) Matthieu Suiche 2008
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include "includes.h"
#include "replace.h"
#include "lzxpress.h"
#define __BUF_POS_CONST(buf,ofs)(((const uint8_t *)buf)+(ofs))
#define __PULL_BYTE(buf,ofs) \
((uint8_t)((*__BUF_POS_CONST(buf,ofs)) & 0xFF))
#ifndef PULL_LE_UINT16
#define PULL_LE_UINT16(buf,ofs) ((uint16_t)( \
((uint16_t)(((uint16_t)(__PULL_BYTE(buf,(ofs)+0))) << 0)) | \
((uint16_t)(((uint16_t)(__PULL_BYTE(buf,(ofs)+1))) << 8)) \
))
#endif
#ifndef PULL_LE_UINT32
#define PULL_LE_UINT32(buf,ofs) ((uint32_t)( \
((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+0))) << 0)) | \
((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+1))) << 8)) | \
((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+2))) << 16)) | \
((uint32_t)(((uint32_t)(__PULL_BYTE(buf,(ofs)+3))) << 24)) \
))
#endif
static uint32_t xpress_decompress(uint8_t *input,
uint32_t input_size,
uint8_t *output,
uint32_t output_size)
{
uint32_t output_index, input_index;
uint32_t indicator, indicator_bit;
uint32_t length;
uint32_t offset;
uint32_t nibble_index;
output_index = 0;
input_index = 0;
indicator = 0;
indicator_bit = 0;
length = 0;
offset = 0;
nibble_index = 0;
do {
if (indicator_bit == 0) {
indicator = PULL_LE_UINT32(input, input_index);
input_index += sizeof(uint32_t);
indicator_bit = 32;
}
indicator_bit--;
/*
* check whether the bit specified by indicator_bit is set or not
* set in indicator. For example, if indicator_bit has value 4
* check whether the 4th bit of the value in indicator is set
*/
if (((indicator >> indicator_bit) & 1) == 0) {
output[output_index] = input[input_index];
input_index += sizeof(uint8_t);
output_index += sizeof(uint8_t);
} else {
length = PULL_LE_UINT16(input, input_index);
input_index += sizeof(uint16_t);
offset = length / 8;
length = length % 8;
if (length == 7) {
if (nibble_index == 0) {
nibble_index = input_index;
length = input[input_index] % 16;
input_index += sizeof(uint8_t);
} else {
length = input[nibble_index] / 16;
nibble_index = 0;
}
if (length == 15) {
length = input[input_index];
input_index += sizeof(uint8_t);
if (length == 255) {
length = PULL_LE_UINT16(input, input_index);
input_index += sizeof(uint16_t);
length -= (15 + 7);
}
length += 15;
}
length += 7;
}
length += 3;
do {
if (output_index >= output_size) break;
output[output_index] = output[output_index - offset - 1];
output_index += sizeof(uint8_t);
length -= sizeof(uint8_t);
} while (length != 0);
}
} while ((output_index < output_size) && (input_index < input_size));
return output_index;
}
uint32_t lzxpress_decompress(DATA_BLOB *inbuf,
DATA_BLOB *outbuf)
{
return xpress_decompress(inbuf->data, inbuf->length, outbuf->data, outbuf->length);
}
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