/* These values are chosen for fast decompression. */
#define LZX_MAINCODE_TABLEBITS 11
-#define LZX_LENCODE_TABLEBITS 10
+#define LZX_LENCODE_TABLEBITS 9
#define LZX_PRECODE_TABLEBITS 6
#define LZX_ALIGNEDCODE_TABLEBITS 7
struct lzx_decompressor {
- u16 maincode_decode_table[(1 << LZX_MAINCODE_TABLEBITS) +
- (LZX_MAINCODE_MAX_NUM_SYMBOLS * 2)]
- _aligned_attribute(DECODE_TABLE_ALIGNMENT);
+ DECODE_TABLE(maincode_decode_table, LZX_MAINCODE_MAX_NUM_SYMBOLS,
+ LZX_MAINCODE_TABLEBITS, LZX_MAX_MAIN_CODEWORD_LEN);
u8 maincode_lens[LZX_MAINCODE_MAX_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN];
-
- u16 lencode_decode_table[(1 << LZX_LENCODE_TABLEBITS) +
- (LZX_LENCODE_NUM_SYMBOLS * 2)]
- _aligned_attribute(DECODE_TABLE_ALIGNMENT);
+ DECODE_TABLE(lencode_decode_table, LZX_LENCODE_NUM_SYMBOLS,
+ LZX_LENCODE_TABLEBITS, LZX_MAX_LEN_CODEWORD_LEN);
u8 lencode_lens[LZX_LENCODE_NUM_SYMBOLS + LZX_READ_LENS_MAX_OVERRUN];
union {
- u16 alignedcode_decode_table[(1 << LZX_ALIGNEDCODE_TABLEBITS) +
- (LZX_ALIGNEDCODE_NUM_SYMBOLS * 2)]
- _aligned_attribute(DECODE_TABLE_ALIGNMENT);
+ DECODE_TABLE(alignedcode_decode_table, LZX_ALIGNEDCODE_NUM_SYMBOLS,
+ LZX_ALIGNEDCODE_TABLEBITS, LZX_MAX_ALIGNED_CODEWORD_LEN);
u8 alignedcode_lens[LZX_ALIGNEDCODE_NUM_SYMBOLS];
};
union {
- u16 precode_decode_table[(1 << LZX_PRECODE_TABLEBITS) +
- (LZX_PRECODE_NUM_SYMBOLS * 2)]
- _aligned_attribute(DECODE_TABLE_ALIGNMENT);
+ DECODE_TABLE(precode_decode_table, LZX_PRECODE_NUM_SYMBOLS,
+ LZX_PRECODE_TABLEBITS, LZX_MAX_PRE_CODEWORD_LEN);
u8 precode_lens[LZX_PRECODE_NUM_SYMBOLS];
+ u8 extra_offset_bits[LZX_MAX_OFFSET_SLOTS];
+ };
+
+ union {
+ DECODE_TABLE_WORKING_SPACE(maincode_working_space,
+ LZX_MAINCODE_MAX_NUM_SYMBOLS,
+ LZX_MAX_MAIN_CODEWORD_LEN);
+ DECODE_TABLE_WORKING_SPACE(lencode_working_space,
+ LZX_LENCODE_NUM_SYMBOLS,
+ LZX_MAX_LEN_CODEWORD_LEN);
+ DECODE_TABLE_WORKING_SPACE(alignedcode_working_space,
+ LZX_ALIGNEDCODE_NUM_SYMBOLS,
+ LZX_MAX_ALIGNED_CODEWORD_LEN);
+ DECODE_TABLE_WORKING_SPACE(precode_working_space,
+ LZX_PRECODE_NUM_SYMBOLS,
+ LZX_MAX_PRE_CODEWORD_LEN);
};
unsigned window_order;
unsigned num_main_syms;
+
+ /* Like lzx_extra_offset_bits[], but does not include the entropy-coded
+ * bits of aligned offset blocks */
+ u8 extra_offset_bits_minus_aligned[LZX_MAX_OFFSET_SLOTS];
+
} _aligned_attribute(DECODE_TABLE_ALIGNMENT);
/* Read a Huffman-encoded symbol using the precode. */
LZX_PRECODE_NUM_SYMBOLS,
LZX_PRECODE_TABLEBITS,
d->precode_lens,
- LZX_MAX_PRE_CODEWORD_LEN))
+ LZX_MAX_PRE_CODEWORD_LEN,
+ d->precode_working_space))
return -1;
/* Decode the codeword lengths. */
d->num_main_syms,
LZX_MAINCODE_TABLEBITS,
d->maincode_lens,
- LZX_MAX_MAIN_CODEWORD_LEN))
+ LZX_MAX_MAIN_CODEWORD_LEN,
+ d->maincode_working_space))
return -1;
if (make_huffman_decode_table(d->lencode_decode_table,
LZX_LENCODE_NUM_SYMBOLS,
LZX_LENCODE_TABLEBITS,
d->lencode_lens,
- LZX_MAX_LEN_CODEWORD_LEN))
+ LZX_MAX_LEN_CODEWORD_LEN,
+ d->lencode_working_space))
return -1;
if (block_type == LZX_BLOCKTYPE_ALIGNED) {
LZX_ALIGNEDCODE_NUM_SYMBOLS,
LZX_ALIGNEDCODE_TABLEBITS,
d->alignedcode_lens,
- LZX_MAX_ALIGNED_CODEWORD_LEN))
+ LZX_MAX_ALIGNED_CODEWORD_LEN,
+ d->alignedcode_working_space))
return -1;
- min_aligned_offset_slot = 8;
+ min_aligned_offset_slot = LZX_MIN_ALIGNED_OFFSET_SLOT;
+ memcpy(d->extra_offset_bits, d->extra_offset_bits_minus_aligned,
+ sizeof(lzx_extra_offset_bits));
} else {
min_aligned_offset_slot = LZX_MAX_OFFSET_SLOTS;
+ memcpy(d->extra_offset_bits, lzx_extra_offset_bits,
+ sizeof(lzx_extra_offset_bits));
}
/* Decode the literals and matches. */
unsigned length;
u32 offset;
unsigned offset_slot;
- unsigned num_extra_bits;
mainsym = read_mainsym(d, is);
if (mainsym < LZX_NUM_CHARS) {
recent_offsets[offset_slot] = recent_offsets[0];
} else {
/* Explicit offset */
-
- /* Look up the number of extra bits that need to be read
- * to decode offsets with this offset slot. */
- num_extra_bits = lzx_extra_offset_bits[offset_slot];
-
- /* Start with the offset slot base value. */
- offset = lzx_offset_slot_base[offset_slot];
-
- /* In aligned offset blocks, the low-order 3 bits of
- * each offset are encoded using the aligned offset
- * code. Otherwise, all the extra bits are literal. */
-
+ offset = bitstream_read_bits(is, d->extra_offset_bits[offset_slot]);
if (offset_slot >= min_aligned_offset_slot) {
- offset +=
- bitstream_read_bits(is,
- num_extra_bits -
- LZX_NUM_ALIGNED_OFFSET_BITS)
- << LZX_NUM_ALIGNED_OFFSET_BITS;
- offset += read_alignedsym(d, is);
- } else {
- offset += bitstream_read_bits(is, num_extra_bits);
+ offset = (offset << LZX_NUM_ALIGNED_OFFSET_BITS) |
+ read_alignedsym(d, is);
}
+ offset += lzx_offset_slot_base[offset_slot];
/* Update the match offset LRU queue. */
STATIC_ASSERT(LZX_NUM_RECENT_OFFSETS == 3);
}
recent_offsets[0] = offset;
- /* Validate the match, then copy it to the current position. */
-
- if (unlikely(length > block_end - out_next))
+ /* Validate the match and copy it to the current position. */
+ if (unlikely(lz_copy(length, offset, out_begin,
+ out_next, block_end, LZX_MIN_MATCH_LEN)))
return -1;
-
- if (unlikely(offset > out_next - out_begin))
- return -1;
-
- lz_copy(out_next, length, offset, block_end, LZX_MIN_MATCH_LEN);
-
out_next += length;
-
} while (out_next != block_end);
return 0;
d->window_order = window_order;
d->num_main_syms = lzx_get_num_main_syms(window_order);
+ /* Initialize 'd->extra_offset_bits_minus_aligned'. */
+ STATIC_ASSERT(sizeof(d->extra_offset_bits_minus_aligned) ==
+ sizeof(lzx_extra_offset_bits));
+ STATIC_ASSERT(sizeof(d->extra_offset_bits) ==
+ sizeof(lzx_extra_offset_bits));
+ memcpy(d->extra_offset_bits_minus_aligned, lzx_extra_offset_bits,
+ sizeof(lzx_extra_offset_bits));
+ for (unsigned offset_slot = LZX_MIN_ALIGNED_OFFSET_SLOT;
+ offset_slot < LZX_MAX_OFFSET_SLOTS; offset_slot++)
+ {
+ d->extra_offset_bits_minus_aligned[offset_slot] -=
+ LZX_NUM_ALIGNED_OFFSET_BITS;
+ }
+
*d_ret = d;
return 0;
}
git://wimlib.net / wimlib / blobdiff