X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Flzx-decompress.c;h=16b46cb253a264fc8b32b20a744e01176401acee;hb=4075b6ec704b03f387af8044762f228b60ffb2d6;hp=2405b9493ad9710f0476af9e2745fe8c59490b2f;hpb=883833a4b3dabec325edf1ca938000f91d587c00;p=wimlib diff --git a/src/lzx-decompress.c b/src/lzx-decompress.c index 2405b949..16b46cb2 100644 --- a/src/lzx-decompress.c +++ b/src/lzx-decompress.c @@ -7,7 +7,7 @@ */ /* - * Copyright (C) 2012, 2013 Eric Biggers + * Copyright (C) 2012, 2013, 2014 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * @@ -26,7 +26,7 @@ */ /* - * LZX is a LZ77 and Huffman-code based compression format that has many + * LZX is an LZ77 and Huffman-code based compression format that has many * similarities to the DEFLATE format used in zlib. The compression ratio is as * good or better than DEFLATE. * @@ -38,12 +38,12 @@ * last decompress to a fixed number of bytes, by default 32768. This is quite * similar to the cabinet (.cab) file format, but they are not the same. * According to the cabinet format documentation, the LZX block size is - * independent from the CFDATA blocks, and a LZX block may span several CFDATA + * independent from the CFDATA blocks, and an LZX block may span several CFDATA * blocks. However, in WIMs, LZX blocks do not appear to ever span multiple WIM * chunks. Note that this means any WIM chunk may be decompressed or compressed * independently from any other chunk, which allows random access. * - * A LZX compressed WIM chunk contains one or more LZX blocks of the aligned, + * An LZX compressed WIM chunk contains one or more LZX blocks of the aligned, * verbatim, or uncompressed block types. For aligned and verbatim blocks, the * size of the block in uncompressed bytes is specified by a bit following the 3 * bits that specify the block type, possibly followed by an additional 16 bits. @@ -107,9 +107,9 @@ # include "config.h" #endif -#include "wimlib.h" #include "wimlib/decompressor_ops.h" #include "wimlib/decompress_common.h" +#include "wimlib/error.h" #include "wimlib/lzx.h" #include "wimlib/util.h" @@ -145,50 +145,39 @@ struct lzx_decompressor { /* * Reads a Huffman-encoded symbol using the pre-tree. */ -static inline int +static inline u16 read_huffsym_using_pretree(struct input_bitstream *istream, - const u16 pretree_decode_table[], - const u8 pretree_lens[], unsigned *n) + const u16 pretree_decode_table[]) { - return read_huffsym(istream, pretree_decode_table, pretree_lens, - LZX_PRECODE_NUM_SYMBOLS, LZX_PRECODE_TABLEBITS, n, - LZX_MAX_PRE_CODEWORD_LEN); + return read_huffsym(istream, pretree_decode_table, + LZX_PRECODE_TABLEBITS, LZX_MAX_PRE_CODEWORD_LEN); } /* Reads a Huffman-encoded symbol using the main tree. */ -static inline int +static inline u16 read_huffsym_using_maintree(struct input_bitstream *istream, - const struct lzx_tables *tables, - unsigned *n, - unsigned num_main_syms) + const struct lzx_tables *tables) { return read_huffsym(istream, tables->maintree_decode_table, - tables->maintree_lens, num_main_syms, - LZX_MAINCODE_TABLEBITS, n, LZX_MAX_MAIN_CODEWORD_LEN); + LZX_MAINCODE_TABLEBITS, LZX_MAX_MAIN_CODEWORD_LEN); } /* Reads a Huffman-encoded symbol using the length tree. */ -static inline int +static inline u16 read_huffsym_using_lentree(struct input_bitstream *istream, - const struct lzx_tables *tables, - unsigned *n) + const struct lzx_tables *tables) { return read_huffsym(istream, tables->lentree_decode_table, - tables->lentree_lens, LZX_LENCODE_NUM_SYMBOLS, - LZX_LENCODE_TABLEBITS, n, LZX_MAX_LEN_CODEWORD_LEN); + LZX_LENCODE_TABLEBITS, LZX_MAX_LEN_CODEWORD_LEN); } /* Reads a Huffman-encoded symbol using the aligned offset tree. */ -static inline int +static inline u16 read_huffsym_using_alignedtree(struct input_bitstream *istream, - const struct lzx_tables *tables, - unsigned *n) + const struct lzx_tables *tables) { return read_huffsym(istream, tables->alignedtree_decode_table, - tables->alignedtree_lens, - LZX_ALIGNEDCODE_NUM_SYMBOLS, - LZX_ALIGNEDCODE_TABLEBITS, n, - LZX_MAX_ALIGNED_CODEWORD_LEN); + LZX_ALIGNEDCODE_TABLEBITS, LZX_MAX_ALIGNED_CODEWORD_LEN); } /* @@ -213,17 +202,13 @@ lzx_read_code_lens(struct input_bitstream *istream, u8 lens[], _aligned_attribute(DECODE_TABLE_ALIGNMENT); u8 pretree_lens[LZX_PRECODE_NUM_SYMBOLS]; unsigned i; - u32 len; int ret; /* Read the code lengths of the pretree codes. There are 20 lengths of * 4 bits each. */ for (i = 0; i < LZX_PRECODE_NUM_SYMBOLS; i++) { - ret = bitstream_read_bits(istream, LZX_PRECODE_ELEMENT_SIZE, - &len); - if (ret) - return ret; - pretree_lens[i] = len; + pretree_lens[i] = bitstream_read_bits(istream, + LZX_PRECODE_ELEMENT_SIZE); } /* Make the decoding table for the pretree. */ @@ -252,15 +237,11 @@ lzx_read_code_lens(struct input_bitstream *istream, u8 lens[], u32 num_same; signed char value; - ret = read_huffsym_using_pretree(istream, pretree_decode_table, - pretree_lens, &tree_code); - if (ret) - return ret; + tree_code = read_huffsym_using_pretree(istream, + pretree_decode_table); switch (tree_code) { case 17: /* Run of 0's */ - ret = bitstream_read_bits(istream, 4, &num_zeroes); - if (ret) - return ret; + num_zeroes = bitstream_read_bits(istream, 4); num_zeroes += 4; while (num_zeroes--) { *lens = 0; @@ -269,9 +250,7 @@ lzx_read_code_lens(struct input_bitstream *istream, u8 lens[], } break; case 18: /* Longer run of 0's */ - ret = bitstream_read_bits(istream, 5, &num_zeroes); - if (ret) - return ret; + num_zeroes = bitstream_read_bits(istream, 5); num_zeroes += 20; while (num_zeroes--) { *lens = 0; @@ -280,16 +259,10 @@ lzx_read_code_lens(struct input_bitstream *istream, u8 lens[], } break; case 19: /* Run of identical lengths */ - ret = bitstream_read_bits(istream, 1, &num_same); - if (ret) - return ret; + num_same = bitstream_read_bits(istream, 1); num_same += 4; - ret = read_huffsym_using_pretree(istream, - pretree_decode_table, - pretree_lens, - &code); - if (ret) - return ret; + code = read_huffsym_using_pretree(istream, + pretree_decode_table); value = (signed char)*lens - (signed char)code; if (value < 0) value += 17; @@ -319,7 +292,7 @@ lzx_read_code_lens(struct input_bitstream *istream, u8 lens[], * in bytes, will be returned. * @block_type_ret: A pointer to an int into which the type of the block * (LZX_BLOCKTYPE_*) will be returned. - * @tables: A pointer to a lzx_tables structure in which the + * @tables: A pointer to an lzx_tables structure in which the * main tree, the length tree, and possibly the * aligned offset tree will be constructed. * @queue: A pointer to the least-recently-used queue into which @@ -339,38 +312,29 @@ lzx_read_block_header(struct input_bitstream *istream, unsigned block_type; unsigned block_size; - ret = bitstream_ensure_bits(istream, 4); - if (ret) - return ret; + bitstream_ensure_bits(istream, 4); /* The first three bits tell us what kind of block it is, and are one * of the LZX_BLOCKTYPE_* values. */ - block_type = bitstream_read_bits_nocheck(istream, 3); + block_type = bitstream_pop_bits(istream, 3); /* Read the block size. This mirrors the behavior * lzx_write_compressed_block() in lzx-compress.c; see that for more * details. */ - if (bitstream_read_bits_nocheck(istream, 1)) { + if (bitstream_pop_bits(istream, 1)) { block_size = LZX_DEFAULT_BLOCK_SIZE; } else { u32 tmp; block_size = 0; - ret = bitstream_read_bits(istream, 8, &tmp); - if (ret) - return ret; + tmp = bitstream_read_bits(istream, 8); block_size |= tmp; - - ret = bitstream_read_bits(istream, 8, &tmp); - if (ret) - return ret; + tmp = bitstream_read_bits(istream, 8); block_size <<= 8; block_size |= tmp; if (max_window_size >= 65536) { - ret = bitstream_read_bits(istream, 8, &tmp); - if (ret) - return ret; + tmp = bitstream_read_bits(istream, 8); block_size <<= 8; block_size |= tmp; } @@ -382,14 +346,9 @@ lzx_read_block_header(struct input_bitstream *istream, * then build it. */ for (unsigned i = 0; i < LZX_ALIGNEDCODE_NUM_SYMBOLS; i++) { - u32 len; - - ret = bitstream_read_bits(istream, - LZX_ALIGNEDCODE_ELEMENT_SIZE, - &len); - if (ret) - return ret; - tables->alignedtree_lens[i] = len; + tables->alignedtree_lens[i] = + bitstream_read_bits(istream, + LZX_ALIGNEDCODE_ELEMENT_SIZE); } LZX_DEBUG("Building the aligned tree."); @@ -561,14 +520,9 @@ lzx_decode_match(unsigned main_element, int block_type, unsigned position_slot; unsigned match_len; unsigned match_offset; - unsigned additional_len; unsigned num_extra_bits; u32 verbatim_bits; u32 aligned_bits; - unsigned i; - int ret; - u8 *match_dest; - u8 *match_src; /* The main element is offset by 256 because values under 256 indicate a * literal value. */ @@ -585,34 +539,21 @@ lzx_decode_match(unsigned main_element, int block_type, * the length tree, offset by 9 (LZX_MIN_MATCH_LEN + * LZX_NUM_PRIMARY_LENS) */ match_len = LZX_MIN_MATCH_LEN + length_header; - if (length_header == LZX_NUM_PRIMARY_LENS) { - ret = read_huffsym_using_lentree(istream, tables, - &additional_len); - if (ret) - return ret; - match_len += additional_len; - } - + if (length_header == LZX_NUM_PRIMARY_LENS) + match_len += read_huffsym_using_lentree(istream, tables); /* If the position_slot is 0, 1, or 2, the match offset is retrieved * from the LRU queue. Otherwise, the match offset is not in the LRU * queue. */ - switch (position_slot) { - case 0: - match_offset = queue->R[0]; - break; - case 1: - match_offset = queue->R[1]; - swap(queue->R[0], queue->R[1]); - break; - case 2: - /* The queue doesn't work quite the same as a real LRU queue, - * since using the R2 offset doesn't bump the R1 offset down to - * R2. */ - match_offset = queue->R[2]; - swap(queue->R[0], queue->R[2]); - break; - default: + if (position_slot <= 2) { + /* Note: This isn't a real LRU queue, since using the R2 offset + * doesn't bump the R1 offset down to R2. This quirk allows all + * 3 recent offsets to be handled by the same code. (For R0, + * the swap is a no-op.) */ + match_offset = queue->R[position_slot]; + queue->R[position_slot] = queue->R[0]; + queue->R[0] = match_offset; + } else { /* Otherwise, the offset was not encoded as one the offsets in * the queue. Depending on the position slot, there is a * certain number of extra bits that need to be read to fully @@ -635,27 +576,17 @@ lzx_decode_match(unsigned main_element, int block_type, * equal to 3. (Note that in the case with * num_extra_bits == 3, the assignment to verbatim_bits * will just set it to 0. ) */ - ret = bitstream_read_bits(istream, num_extra_bits - 3, - &verbatim_bits); - if (ret) - return ret; - + verbatim_bits = bitstream_read_bits(istream, + num_extra_bits - 3); verbatim_bits <<= 3; - - ret = read_huffsym_using_alignedtree(istream, tables, - &aligned_bits); - if (ret) - return ret; + aligned_bits = read_huffsym_using_alignedtree(istream, + tables); } else { /* For non-aligned blocks, or for aligned blocks with * less than 3 extra bits, the extra bits are added * directly to the match offset, and the correction for * the alignment is taken to be 0. */ - ret = bitstream_read_bits(istream, num_extra_bits, - &verbatim_bits); - if (ret) - return ret; - + verbatim_bits = bitstream_read_bits(istream, num_extra_bits); aligned_bits = 0; } @@ -667,20 +598,19 @@ lzx_decode_match(unsigned main_element, int block_type, queue->R[2] = queue->R[1]; queue->R[1] = queue->R[0]; queue->R[0] = match_offset; - break; } /* Verify that the match is in the bounds of the part of the window * currently in use, then copy the source of the match to the current * position. */ - if (match_len > bytes_remaining) { + if (unlikely(match_len > bytes_remaining)) { LZX_DEBUG("Match of length %u bytes overflows " "uncompressed block size", match_len); return -1; } - if (match_offset > window_pos) { + if (unlikely(match_offset > window_pos)) { LZX_DEBUG("Match of length %u bytes references " "data before window (match_offset = %u, " "window_pos = %u)", @@ -688,91 +618,19 @@ lzx_decode_match(unsigned main_element, int block_type, return -1; } - match_dest = window + window_pos; - match_src = match_dest - match_offset; - -#if 0 - printf("Match: src %u, dst %u, len %u\n", match_src - window, - match_dest - window, - match_len); - putchar('|'); - for (i = 0; i < match_len; i++) { - match_dest[i] = match_src[i]; - putchar(match_src[i]); - } - putchar('|'); - putchar('\n'); -#else - for (i = 0; i < match_len; i++) - match_dest[i] = match_src[i]; -#endif + lz_copy(&window[window_pos], match_len, match_offset, + &window[window_pos + bytes_remaining]); return match_len; } -static void -undo_call_insn_translation(u32 *call_insn_target, s32 input_pos, - s32 file_size) -{ - s32 abs_offset; - s32 rel_offset; - - abs_offset = le32_to_cpu(*call_insn_target); - if (abs_offset >= -input_pos && abs_offset < file_size) { - if (abs_offset >= 0) { - /* "good translation" */ - rel_offset = abs_offset - input_pos; - } else { - /* "compensating translation" */ - rel_offset = abs_offset + file_size; - } - *call_insn_target = cpu_to_le32(rel_offset); - } -} - -/* Undo the 'E8' preprocessing, where the targets of x86 CALL instructions were - * changed from relative offsets to absolute offsets. - * - * Note that this call instruction preprocessing can and will be used on any - * data even if it is not actually x86 machine code. In fact, this type of - * preprocessing appears to always be used in LZX-compressed resources in WIM - * files; there is no bit to indicate whether it is used or not, unlike in the - * LZX compressed format as used in cabinet files, where a bit is reserved for - * that purpose. - * - * Call instruction preprocessing is disabled in the last 6 bytes of the - * uncompressed data, which really means the 5-byte call instruction cannot - * start in the last 10 bytes of the uncompressed data. This is one of the - * errors in the LZX documentation. - * - * Call instruction preprocessing does not appear to be disabled after the - * 32768th chunk of a WIM stream, which is apparently is yet another difference - * from the LZX compression used in cabinet files. - * - * Call instruction processing is supposed to take the file size as a parameter, - * as it is used in calculating the translated jump targets. But in WIM files, - * this file size is always the same (LZX_WIM_MAGIC_FILESIZE == 12000000).*/ -static void -undo_call_insn_preprocessing(u8 *uncompressed_data, s32 uncompressed_size) -{ - for (s32 i = 0; i < uncompressed_size - 10; i++) { - if (uncompressed_data[i] == 0xe8) { - undo_call_insn_translation((u32*)&uncompressed_data[i + 1], - i, - LZX_WIM_MAGIC_FILESIZE); - i += 4; - } - } -} - /* - * Decompresses a LZX-compressed block of data from which the header has already + * Decompresses an LZX-compressed block of data from which the header has already * been read. * * @block_type: The type of the block (LZX_BLOCKTYPE_VERBATIM or * LZX_BLOCKTYPE_ALIGNED) * @block_size: The size of the block, in bytes. - * @num_main_syms: Number of symbols in the main alphabet. * @window: Pointer to the decompression window. * @window_pos: The current position in the window. Will be 0 for the first * block. @@ -783,7 +641,6 @@ undo_call_insn_preprocessing(u8 *uncompressed_data, s32 uncompressed_size) */ static int lzx_decompress_block(int block_type, unsigned block_size, - unsigned num_main_syms, u8 *window, unsigned window_pos, const struct lzx_tables *tables, @@ -792,17 +649,11 @@ lzx_decompress_block(int block_type, unsigned block_size, { unsigned main_element; unsigned end; - int ret; int match_len; end = window_pos + block_size; while (window_pos < end) { - ret = read_huffsym_using_maintree(istream, tables, - &main_element, - num_main_syms); - if (ret) - return ret; - + main_element = read_huffsym_using_maintree(istream, tables); if (main_element < LZX_NUM_CHARS) { /* literal: 0 to LZX_NUM_CHARS - 1 */ window[window_pos++] = main_element; @@ -816,7 +667,7 @@ lzx_decompress_block(int block_type, unsigned block_size, tables, queue, istream); - if (match_len < 0) + if (unlikely(match_len < 0)) return match_len; window_pos += match_len; } @@ -895,7 +746,6 @@ lzx_decompress(const void *compressed_data, size_t compressed_size, LZX_DEBUG("LZX_BLOCKTYPE_ALIGNED"); ret = lzx_decompress_block(block_type, block_size, - ctx->num_main_syms, uncompressed_data, window_pos, &ctx->tables, @@ -931,7 +781,7 @@ lzx_decompress(const void *compressed_data, size_t compressed_size, } } if (e8_preprocessing_done) - undo_call_insn_preprocessing(uncompressed_data, uncompressed_size); + lzx_undo_e8_preprocessing(uncompressed_data, uncompressed_size); return 0; } @@ -940,20 +790,19 @@ lzx_free_decompressor(void *_ctx) { struct lzx_decompressor *ctx = _ctx; - FREE(ctx); + ALIGNED_FREE(ctx); } static int -lzx_create_decompressor(size_t max_window_size, - const struct wimlib_decompressor_params_header *params, - void **ctx_ret) +lzx_create_decompressor(size_t max_window_size, void **ctx_ret) { struct lzx_decompressor *ctx; if (!lzx_window_size_valid(max_window_size)) return WIMLIB_ERR_INVALID_PARAM; - ctx = MALLOC(sizeof(struct lzx_decompressor)); + ctx = ALIGNED_MALLOC(sizeof(struct lzx_decompressor), + DECODE_TABLE_ALIGNMENT); if (ctx == NULL) return WIMLIB_ERR_NOMEM;