struct lzms_huffman_decoder delta_power_decoder;
struct lzms_huffman_decoder delta_offset_decoder;
- /* LRU (least-recently-used) queue of LZ match offsets. */
- u64 recent_lz_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match powers. */
- u32 recent_delta_powers[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match offsets. */
- u32 recent_delta_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* These variables are used to delay updates to the LRU queues by one
- * decoded item. */
- u32 prev_lz_offset;
- u32 prev_delta_power;
- u32 prev_delta_offset;
- u32 upcoming_lz_offset;
- u32 upcoming_delta_power;
- u32 upcoming_delta_offset;
+ /* LRU (least-recently-used) queues for match information. */
+ struct lzms_lru_queues lru;
/* Used for postprocessing. */
s32 last_target_usages[65536];
static void
lzms_rebuild_adaptive_huffman_code(struct lzms_huffman_decoder *dec)
{
- int ret;
/* XXX: This implementation makes use of code already implemented for
* the XPRESS and LZX compression formats. However, since for the
dec->num_syms);
make_canonical_huffman_code(dec->num_syms, LZMS_MAX_CODEWORD_LEN,
dec->sym_freqs, dec->lens, dec->codewords);
- ret = make_huffman_decode_table(dec->decode_table, dec->num_syms,
- LZMS_DECODE_TABLE_BITS, dec->lens,
- LZMS_MAX_CODEWORD_LEN);
+#if defined(ENABLE_LZMS_DEBUG)
+ int ret =
+#endif
+ make_huffman_decode_table(dec->decode_table, dec->num_syms,
+ LZMS_DECODE_TABLE_BITS, dec->lens,
+ LZMS_MAX_CODEWORD_LEN);
LZMS_ASSERT(ret == 0);
}
if (!lzms_range_decode_bit(&ctx->lz_repeat_match_range_decoders[i]))
break;
- offset = ctx->recent_lz_offsets[i];
+ offset = ctx->lru.lz.recent_offsets[i];
for (; i < LZMS_NUM_RECENT_OFFSETS; i++)
- ctx->recent_lz_offsets[i] = ctx->recent_lz_offsets[i + 1];
+ ctx->lru.lz.recent_offsets[i] = ctx->lru.lz.recent_offsets[i + 1];
}
/* Decode match length, which is always given explicitly (there is no
* LRU queue for repeat lengths). */
length = lzms_decode_value(&ctx->length_decoder);
- ctx->upcoming_lz_offset = offset;
+ ctx->lru.lz.upcoming_offset = offset;
LZMS_DEBUG("Decoded %s LZ match: length=%u, offset=%u",
(bit ? "repeat" : "explicit"), length, offset);
if (!lzms_range_decode_bit(&ctx->delta_repeat_match_range_decoders[i]))
break;
- power = ctx->recent_delta_powers[i];
- raw_offset = ctx->recent_delta_offsets[i];
+ power = ctx->lru.delta.recent_powers[i];
+ raw_offset = ctx->lru.delta.recent_offsets[i];
for (; i < LZMS_NUM_RECENT_OFFSETS; i++) {
- ctx->recent_delta_powers[i] = ctx->recent_delta_powers[i + 1];
- ctx->recent_delta_offsets[i] = ctx->recent_delta_offsets[i + 1];
+ ctx->lru.delta.recent_powers[i] = ctx->lru.delta.recent_powers[i + 1];
+ ctx->lru.delta.recent_offsets[i] = ctx->lru.delta.recent_offsets[i + 1];
}
}
length = lzms_decode_value(&ctx->length_decoder);
- ctx->upcoming_delta_power = power;
- ctx->upcoming_delta_offset = raw_offset;
+ ctx->lru.delta.upcoming_power = power;
+ ctx->lru.delta.upcoming_offset = raw_offset;
LZMS_DEBUG("Decoded %s delta match: length=%u, power=%u, raw_offset=%u",
(bit ? "repeat" : "explicit"), length, power, raw_offset);
{
int ret;
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_power = 0;
+ ctx->lru.lz.upcoming_offset = 0;
+ ctx->lru.delta.upcoming_power = 0;
+ ctx->lru.delta.upcoming_offset = 0;
if (lzms_range_decode_bit(&ctx->main_range_decoder))
ret = lzms_decode_match(ctx);
return ret;
/* Update LRU queues */
- if (ctx->prev_lz_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--)
- ctx->recent_lz_offsets[i + 1] = ctx->recent_lz_offsets[i];
- ctx->recent_lz_offsets[0] = ctx->prev_lz_offset;
- }
-
- if (ctx->prev_delta_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--) {
- ctx->recent_delta_powers[i + 1] = ctx->recent_delta_powers[i];
- ctx->recent_delta_offsets[i + 1] = ctx->recent_delta_offsets[i];
- }
- ctx->recent_delta_powers[0] = ctx->prev_delta_power;
- ctx->recent_delta_offsets[0] = ctx->prev_delta_offset;
- }
-
- ctx->prev_lz_offset = ctx->upcoming_lz_offset;
- ctx->prev_delta_offset = ctx->upcoming_delta_offset;
- ctx->prev_delta_power = ctx->upcoming_delta_power;
+ lzms_update_lru_queues(&ctx->lru);
return 0;
}
lzms_init_range_decoder(&ctx->delta_repeat_match_range_decoders[i],
&ctx->rd, LZMS_NUM_DELTA_REPEAT_MATCH_STATES);
- /* Initialize the LRU queue for recent match offsets. */
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++)
- ctx->recent_lz_offsets[i] = i + 1;
-
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++) {
- ctx->recent_delta_powers[i] = 0;
- ctx->recent_delta_offsets[i] = i + 1;
- }
- ctx->prev_lz_offset = 0;
- ctx->prev_delta_offset = 0;
- ctx->prev_delta_power = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_delta_power = 0;
+ /* Initialize LRU match information. */
+ lzms_init_lru_queues(&ctx->lru);
LZMS_DEBUG("Decompressor successfully initialized");
}