diff options
Diffstat (limited to 'modules/brotli/dec/huffman.h')
| -rw-r--r-- | modules/brotli/dec/huffman.h | 85 |
1 files changed, 72 insertions, 13 deletions
diff --git a/modules/brotli/dec/huffman.h b/modules/brotli/dec/huffman.h index fc880810c..b9f0716c1 100644 --- a/modules/brotli/dec/huffman.h +++ b/modules/brotli/dec/huffman.h @@ -9,8 +9,8 @@ #ifndef BROTLI_DEC_HUFFMAN_H_ #define BROTLI_DEC_HUFFMAN_H_ -#include "./types.h" -#include "./port.h" +#include "../common/platform.h" +#include <brotli/types.h> #if defined(__cplusplus) || defined(c_plusplus) extern "C" { @@ -18,46 +18,105 @@ extern "C" { #define BROTLI_HUFFMAN_MAX_CODE_LENGTH 15 -/* For current format this constant equals to kNumInsertAndCopyCodes */ -#define BROTLI_HUFFMAN_MAX_CODE_LENGTHS_SIZE 704 - /* Maximum possible Huffman table size for an alphabet size of (index * 32), - * max code length 15 and root table bits 8. */ + max code length 15 and root table bits 8. */ static const uint16_t kMaxHuffmanTableSize[] = { 256, 402, 436, 468, 500, 534, 566, 598, 630, 662, 694, 726, 758, 790, 822, - 854, 886, 920, 952, 984, 1016, 1048, 1080}; + 854, 886, 920, 952, 984, 1016, 1048, 1080, 1112, 1144, 1176, 1208, 1240, 1272, + 1304, 1336, 1368, 1400, 1432, 1464, 1496, 1528}; +/* BROTLI_NUM_BLOCK_LEN_SYMBOLS == 26 */ #define BROTLI_HUFFMAN_MAX_SIZE_26 396 +/* BROTLI_MAX_BLOCK_TYPE_SYMBOLS == 258 */ #define BROTLI_HUFFMAN_MAX_SIZE_258 632 +/* BROTLI_MAX_CONTEXT_MAP_SYMBOLS == 272 */ #define BROTLI_HUFFMAN_MAX_SIZE_272 646 #define BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH 5 +#if ((defined(BROTLI_TARGET_ARMV7) || defined(BROTLI_TARGET_ARMV8_32)) && \ + BROTLI_GNUC_HAS_ATTRIBUTE(aligned, 2, 7, 0)) +#define BROTLI_HUFFMAN_CODE_FAST_LOAD +#endif + +#if !defined(BROTLI_HUFFMAN_CODE_FAST_LOAD) +/* Do not create this struct directly - use the ConstructHuffmanCode + * constructor below! */ typedef struct { uint8_t bits; /* number of bits used for this symbol */ uint16_t value; /* symbol value or table offset */ } HuffmanCode; +static BROTLI_INLINE HuffmanCode ConstructHuffmanCode(const uint8_t bits, + const uint16_t value) { + HuffmanCode h; + h.bits = bits; + h.value = value; + return h; +} + +/* Please use the following macros to optimize HuffmanCode accesses in hot + * paths. + * + * For example, assuming |table| contains a HuffmanCode pointer: + * + * BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(table); + * BROTLI_HC_ADJUST_TABLE_INDEX(table, index_into_table); + * *bits = BROTLI_HC_GET_BITS(table); + * *value = BROTLI_HC_GET_VALUE(table); + * BROTLI_HC_ADJUST_TABLE_INDEX(table, offset); + * *bits2 = BROTLI_HC_GET_BITS(table); + * *value2 = BROTLI_HC_GET_VALUE(table); + * + */ + +#define BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(H) +#define BROTLI_HC_ADJUST_TABLE_INDEX(H, V) H += (V) + +/* These must be given a HuffmanCode pointer! */ +#define BROTLI_HC_FAST_LOAD_BITS(H) (H->bits) +#define BROTLI_HC_FAST_LOAD_VALUE(H) (H->value) + +#else /* BROTLI_HUFFMAN_CODE_FAST_LOAD */ + +typedef BROTLI_ALIGNED(4) uint32_t HuffmanCode; + +static BROTLI_INLINE HuffmanCode ConstructHuffmanCode(const uint8_t bits, + const uint16_t value) { + return ((value & 0xFFFF) << 16) | (bits & 0xFF); +} + +#define BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(H) uint32_t __fastload_##H = (*H) +#define BROTLI_HC_ADJUST_TABLE_INDEX(H, V) H += (V); __fastload_##H = (*H) + +/* These must be given a HuffmanCode pointer! */ +#define BROTLI_HC_FAST_LOAD_BITS(H) ((__fastload_##H) & 0xFF) +#define BROTLI_HC_FAST_LOAD_VALUE(H) ((__fastload_##H) >> 16) +#endif /* BROTLI_HUFFMAN_CODE_FAST_LOAD */ + /* Builds Huffman lookup table assuming code lengths are in symbol order. */ BROTLI_INTERNAL void BrotliBuildCodeLengthsHuffmanTable(HuffmanCode* root_table, const uint8_t* const code_lengths, uint16_t* count); -/* Builds Huffman lookup table assuming code lengths are in symbol order. */ -/* Returns size of resulting table. */ +/* Builds Huffman lookup table assuming code lengths are in symbol order. + Returns size of resulting table. */ BROTLI_INTERNAL uint32_t BrotliBuildHuffmanTable(HuffmanCode* root_table, int root_bits, const uint16_t* const symbol_lists, uint16_t* count_arg); -/* Builds a simple Huffman table. The num_symbols parameter is to be */ -/* interpreted as follows: 0 means 1 symbol, 1 means 2 symbols, 2 means 3 */ -/* symbols, 3 means 4 symbols with lengths 2,2,2,2, 4 means 4 symbols with */ -/* lengths 1,2,3,3. */ +/* Builds a simple Huffman table. The |num_symbols| parameter is to be + interpreted as follows: 0 means 1 symbol, 1 means 2 symbols, + 2 means 3 symbols, 3 means 4 symbols with lengths [2, 2, 2, 2], + 4 means 4 symbols with lengths [1, 2, 3, 3]. */ BROTLI_INTERNAL uint32_t BrotliBuildSimpleHuffmanTable(HuffmanCode* table, int root_bits, uint16_t* symbols, uint32_t num_symbols); /* Contains a collection of Huffman trees with the same alphabet size. */ +/* max_symbol is needed due to simple codes since log2(alphabet_size) could be + greater than log2(max_symbol). */ typedef struct { HuffmanCode** htrees; HuffmanCode* codes; uint16_t alphabet_size; + uint16_t max_symbol; uint16_t num_htrees; } HuffmanTreeGroup; |