mirror of
https://github.com/aaru-dps/Aaru.Compression.Native.git
synced 2026-05-06 20:36:22 +00:00
Natalia Portillo
ba39191e07
- Implemented range coder in `rangecoder.c` and `rangecoder.h` for efficient encoding/decoding. - Added RLE90 decoding in `rle90.c` for handling StuffIt method 1. - Introduced `stuffit.h` and `stuffit_internal.h` to define compression methods and internal structures. - Implemented x86 address transformation in `x86.c` for StuffIt X preprocessing. - Updated CMakeLists to include new test data files for various StuffIt methods. - Created comprehensive tests in `stuffit.cpp` for validating decompression of multiple StuffIt formats. - Added binary test data for StuffIt methods including compress, method 13, arsenic, and StuffIt X variants.
119 lines
3.8 KiB
C
119 lines
3.8 KiB
C
/*
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* This file is part of the Aaru Data Preservation Suite.
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* Copyright (c) 2019-2026 Natalia Portillo.
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2.1 of the
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* License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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/* StuffIt X preprocessor 2: x86 executable address transformation */
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#include <string.h>
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#include "stuffit.h"
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#include "stuffit_internal.h"
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int stuffitx_x86_decode_buffer(uint8_t *dst, size_t *dst_size, const uint8_t *src, size_t src_size)
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{
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size_t limit = *dst_size;
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size_t si = 0;
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size_t di = 0;
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int lasthit = -6;
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uint32_t bitfield = 0;
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static const int table[8] = {1, 1, 1, 0, 1, 0, 0, 0};
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static const int shifts[8] = {24, 16, 8, 8, 0, 0, 0, 0};
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while(si < src_size && di < limit)
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{
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uint8_t b = src[si++];
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if(b == 0xe8 || b == 0xe9)
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{
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int dist = (int)di - lasthit;
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lasthit = (int)di;
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if(dist > 5)
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bitfield = 0;
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else
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for(int i = 0; i < dist; i++) bitfield = (bitfield & 0x77) << 1;
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dst[di++] = b;
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/* Check if we have 4 bytes to read */
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if(si + 4 > src_size)
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{
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/* Not enough data for offset, just copy remaining */
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while(si < src_size && di < limit) dst[di++] = src[si++];
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break;
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}
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uint8_t offset_buf[4];
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memcpy(offset_buf, src + si, 4);
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if(offset_buf[3] == 0x00 || offset_buf[3] == 0xff)
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{
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if(table[(bitfield >> 1) & 0x07] && (bitfield >> 1) <= 0x0f)
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{
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int32_t absaddr = stuffit_read_le32(offset_buf);
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int32_t reladdr;
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for(;;)
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{
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reladdr = absaddr - (int32_t)di - 6 + 1;
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if(bitfield == 0) break;
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int shift = shifts[bitfield >> 1];
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int something = (reladdr >> shift) & 0xff;
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if(something != 0 && something != 0xff) break;
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absaddr = reladdr ^ ((1 << (shift + 8)) - 1);
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}
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reladdr &= 0x1ffffff;
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if(reladdr >= 0x1000000) reladdr |= (int32_t)0xff000000;
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stuffit_write_le32(offset_buf, reladdr);
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si += 4;
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if(di + 4 <= limit)
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{
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memcpy(dst + di, offset_buf, 4);
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di += 4;
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}
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bitfield = 0;
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}
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else
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{
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bitfield |= 0x11;
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}
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}
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else
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{
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bitfield |= 0x01;
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}
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/* If we didn't consume the offset bytes above, they pass through normally */
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if(si < src_size && di < limit && !(offset_buf[3] == 0x00 || offset_buf[3] == 0xff) ||
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!table[(bitfield >> 1) & 0x07])
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{
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/* Already handled or will be handled in next iteration */
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}
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}
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else
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{
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dst[di++] = b;
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}
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}
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*dst_size = di;
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return 0;
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}
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