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Diffstat (limited to 'source4/lib/compression/lzxpress.c')
| -rw-r--r-- | source4/lib/compression/lzxpress.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/source4/lib/compression/lzxpress.c b/source4/lib/compression/lzxpress.c new file mode 100644 index 0000000000..506305176f --- /dev/null +++ b/source4/lib/compression/lzxpress.c @@ -0,0 +1,144 @@ +/* + * 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); +} |