*/
/*
- * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
+ * Copyright (C) 2012-2016 Eric Biggers
*
* This file is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
#include "wimlib/util.h"
/* Mapping: offset slot => first match offset that uses that offset slot.
- */
-const u32 lzx_offset_slot_base[LZX_MAX_OFFSET_SLOTS + 1] = {
- 0 , 1 , 2 , 3 , 4 , /* 0 --- 4 */
- 6 , 8 , 12 , 16 , 24 , /* 5 --- 9 */
- 32 , 48 , 64 , 96 , 128 , /* 10 --- 14 */
- 192 , 256 , 384 , 512 , 768 , /* 15 --- 19 */
- 1024 , 1536 , 2048 , 3072 , 4096 , /* 20 --- 24 */
- 6144 , 8192 , 12288 , 16384 , 24576 , /* 25 --- 29 */
- 32768 , 49152 , 65536 , 98304 , 131072 , /* 30 --- 34 */
- 196608 , 262144 , 393216 , 524288 , 655360 , /* 35 --- 39 */
- 786432 , 917504 , 1048576, 1179648, 1310720, /* 40 --- 44 */
- 1441792, 1572864, 1703936, 1835008, 1966080, /* 45 --- 49 */
- 2097152 /* extra */
+ * The offset slots for repeat offsets map to "fake" offsets < 1. */
+const s32 lzx_offset_slot_base[LZX_MAX_OFFSET_SLOTS + 1] = {
+ -2 , -1 , 0 , 1 , 2 , /* 0 --- 4 */
+ 4 , 6 , 10 , 14 , 22 , /* 5 --- 9 */
+ 30 , 46 , 62 , 94 , 126 , /* 10 --- 14 */
+ 190 , 254 , 382 , 510 , 766 , /* 15 --- 19 */
+ 1022 , 1534 , 2046 , 3070 , 4094 , /* 20 --- 24 */
+ 6142 , 8190 , 12286 , 16382 , 24574 , /* 25 --- 29 */
+ 32766 , 49150 , 65534 , 98302 , 131070 , /* 30 --- 34 */
+ 196606 , 262142 , 393214 , 524286 , 655358 , /* 35 --- 39 */
+ 786430 , 917502 , 1048574, 1179646, 1310718, /* 40 --- 44 */
+ 1441790, 1572862, 1703934, 1835006, 1966078, /* 45 --- 49 */
+ 2097150 /* extra */
};
/* Mapping: offset slot => how many extra bits must be read and added to the
unsigned
lzx_get_window_order(size_t max_bufsize)
{
- unsigned order;
-
if (max_bufsize == 0 || max_bufsize > LZX_MAX_WINDOW_SIZE)
return 0;
- order = fls32(max_bufsize);
-
- if (((u32)1 << order) != max_bufsize)
- order++;
-
- return max(order, LZX_MIN_WINDOW_ORDER);
+ return max(ilog2_ceil(max_bufsize), LZX_MIN_WINDOW_ORDER);
}
+/* Given a valid LZX window order, return the number of symbols that will exist
+ * in the main Huffman code. */
unsigned
-lzx_get_num_offset_slots(unsigned window_order)
+lzx_get_num_main_syms(unsigned window_order)
{
/* Note: one would expect that the maximum match offset would be
* 'window_size - LZX_MIN_MATCH_LEN', which would occur if the first two
* by 1. */
u32 window_size = (u32)1 << window_order;
u32 max_offset = window_size - LZX_MIN_MATCH_LEN - 1;
- return 1 + lzx_get_offset_slot(max_offset);
-}
+ unsigned num_offset_slots = 30;
+ while (max_offset >= lzx_offset_slot_base[num_offset_slots])
+ num_offset_slots++;
-/* Given a valid LZX window order, return the number of symbols that will exist
- * in the main Huffman code. */
-unsigned
-lzx_get_num_main_syms(unsigned window_order)
-{
- return LZX_NUM_CHARS + (lzx_get_num_offset_slots(window_order) *
- LZX_NUM_LEN_HEADERS);
+ return LZX_NUM_CHARS + (num_offset_slots * LZX_NUM_LEN_HEADERS);
}
static void
{
s32 abs_offset, rel_offset;
- rel_offset = get_unaligned_u32_le(target);
+ rel_offset = get_unaligned_le32(target);
if (rel_offset >= -input_pos && rel_offset < LZX_WIM_MAGIC_FILESIZE) {
if (rel_offset < LZX_WIM_MAGIC_FILESIZE - input_pos) {
/* "good translation" */
/* "compensating translation" */
abs_offset = rel_offset - LZX_WIM_MAGIC_FILESIZE;
}
- put_unaligned_u32_le(abs_offset, target);
+ put_unaligned_le32(abs_offset, target);
}
}
{
s32 abs_offset, rel_offset;
- abs_offset = get_unaligned_u32_le(target);
+ abs_offset = get_unaligned_le32(target);
if (abs_offset >= 0) {
if (abs_offset < LZX_WIM_MAGIC_FILESIZE) {
/* "good translation" */
rel_offset = abs_offset - input_pos;
- put_unaligned_u32_le(rel_offset, target);
+ put_unaligned_le32(rel_offset, target);
}
} else {
if (abs_offset >= -input_pos) {
/* "compensating translation" */
rel_offset = abs_offset + LZX_WIM_MAGIC_FILESIZE;
- put_unaligned_u32_le(rel_offset, target);
+ put_unaligned_le32(rel_offset, target);
}
}
}
* 'valid_mask' ensures we never process an E8 byte that
* was itself part of a translation target. */
while ((e8_mask &= valid_mask)) {
- unsigned bit = ffs32(e8_mask);
+ unsigned bit = bsf32(e8_mask);
(*process_target)(p + bit + 1, p + bit - data);
valid_mask &= ~((u64)0x1F << bit);
}
}
void
-lzx_do_e8_preprocessing(u8 *data, u32 size)
+lzx_preprocess(u8 *data, u32 size)
{
lzx_e8_filter(data, size, do_translate_target);
}
void
-lzx_undo_e8_preprocessing(u8 *data, u32 size)
+lzx_postprocess(u8 *data, u32 size)
{
lzx_e8_filter(data, size, undo_translate_target);
}