diff options
Diffstat (limited to 'src/inflate.c')
| -rw-r--r-- | src/inflate.c | 92 |
1 files changed, 89 insertions, 3 deletions
diff --git a/src/inflate.c b/src/inflate.c index 27dcc79..b536689 100644 --- a/src/inflate.c +++ b/src/inflate.c @@ -92,6 +92,11 @@ uint8_t deflate_hc_lengths[19]; */ uint8_t deflate_lld_lengths[318]; +#ifdef DEFLATE_WITH_LUT +uint16_t deflate_ll_codes[288]; +uint16_t deflate_d_codes[30]; +#endif + /* * Bit length counts and next code entries for Literal/Length alphabet. * Combined with the code lengths in deflate_lld_lengths, these make up the @@ -159,8 +164,14 @@ static uint16_t deflate_get_bits(uint8_t num_bits) return ret & deflate_bitmask(num_bits); } +#ifdef DEFLATE_WITH_LUT +static void deflate_build_alphabet(uint8_t * lengths, uint16_t size, + uint8_t * bl_count, uint16_t * next_code, + uint16_t * codes) +#else static void deflate_build_alphabet(uint8_t * lengths, uint16_t size, uint8_t * bl_count, uint16_t * next_code) +#endif { uint16_t i; uint16_t code = 0; @@ -178,12 +189,28 @@ static void deflate_build_alphabet(uint8_t * lengths, uint16_t size, } } - for (i = 1; i < max_len + 1; i++) { + for (i = 1; i <= max_len; i++) { code = (code + bl_count[i - 1]) << 1; next_code[i] = code; } + +#ifdef DEFLATE_WITH_LUT + uint8_t j = 0; + code = 0; + for (j = 1; j <= max_len; j++) { + for (i = 0; i < size; i++) { + if (lengths[i] == j) { + codes[code++] = i; + } + } + } +#endif } +#ifdef DEFLATE_WITH_LUT +static uint16_t deflate_huff(uint16_t * codes, + uint8_t * bl_count, uint16_t * next_code) +#else /* * This function trades speed for low memory requirements. Instead of building * an actual huffman tree (at a cost of about 650 Bytes of RAM), we iterate @@ -192,8 +219,12 @@ static void deflate_build_alphabet(uint8_t * lengths, uint16_t size, */ static uint16_t deflate_huff(uint8_t * lengths, uint16_t size, uint8_t * bl_count, uint16_t * next_code) +#endif { uint16_t next_word = deflate_get_word(); +#ifdef DEFLATE_WITH_LUT + uint16_t code = 0; +#endif for (uint8_t num_bits = 1; num_bits < 16; num_bits++) { uint16_t next_bits = deflate_rev_word(next_word, num_bits); if (bl_count[num_bits] && next_bits >= next_code[num_bits] @@ -203,9 +234,11 @@ static uint16_t deflate_huff(uint8_t * lengths, uint16_t size, deflate_input_now++; deflate_bit_offset -= 8; } +#ifdef DEFLATE_WITH_LUT + return codes[code + (next_bits - next_code[num_bits])]; +#else uint8_t len_pos = next_bits; uint8_t cur_pos = next_code[num_bits]; - // This is slow, but memory-efficient for (uint16_t i = 0; i < size; i++) { if (lengths[i] == num_bits) { if (cur_pos == len_pos) { @@ -214,20 +247,35 @@ static uint16_t deflate_huff(uint8_t * lengths, uint16_t size, cur_pos++; } } +#endif + } else { +#ifdef DEFLATE_WITH_LUT + code += bl_count[num_bits]; +#endif } } return 65535; } +#ifdef DEFLATE_WITH_LUT +static int8_t deflate_huffman(uint16_t * ll_codes, uint16_t * d_codes) +#else static int8_t deflate_huffman(uint8_t * ll_lengths, uint16_t ll_size, uint8_t * d_lengths, uint8_t d_size) +#endif { uint16_t code; uint16_t dcode; while (1) { +#ifdef DEFLATE_WITH_LUT + code = + deflate_huff(ll_codes, deflate_bl_count_ll, + deflate_next_code_ll); +#else code = deflate_huff(ll_lengths, ll_size, deflate_bl_count_ll, deflate_next_code_ll); +#endif if (code < 256) { if (deflate_output_now == deflate_output_end) { return DEFLATE_ERR_OUTPUT_LENGTH; @@ -244,10 +292,17 @@ static int8_t deflate_huffman(uint8_t * ll_lengths, uint16_t ll_size, if (extra_bits) { len_val += deflate_get_bits(extra_bits); } +#ifdef DEFLATE_WITH_LUT + dcode = + deflate_huff(d_codes, + deflate_bl_count_d, + deflate_next_code_d); +#else dcode = deflate_huff(d_lengths, d_size, deflate_bl_count_d, deflate_next_code_d); +#endif uint16_t dist_val = deflate_distance_offsets[dcode]; extra_bits = deflate_distance_bits[dcode]; if (extra_bits) { @@ -313,12 +368,21 @@ static int8_t deflate_static_huffman() deflate_lld_lengths[i] = 5; } +#ifdef DEFLATE_WITH_LUT + deflate_build_alphabet(deflate_lld_lengths, 288, deflate_bl_count_ll, + deflate_next_code_ll, deflate_ll_codes); + deflate_build_alphabet(deflate_lld_lengths + 288, 29, + deflate_bl_count_d, deflate_next_code_d, + deflate_d_codes); + return deflate_huffman(deflate_ll_codes, deflate_d_codes); +#else deflate_build_alphabet(deflate_lld_lengths, 288, deflate_bl_count_ll, deflate_next_code_ll); deflate_build_alphabet(deflate_lld_lengths + 288, 29, deflate_bl_count_d, deflate_next_code_d); return deflate_huffman(deflate_lld_lengths, 288, deflate_lld_lengths + 288, 29); +#endif } static int8_t deflate_dynamic_huffman() @@ -336,16 +400,29 @@ static int8_t deflate_dynamic_huffman() deflate_hc_lengths[deflate_hclen_index[i]] = 0; } +#ifdef DEFLATE_WITH_LUT + deflate_build_alphabet(deflate_hc_lengths, + sizeof(deflate_hc_lengths), + deflate_bl_count_ll, deflate_next_code_ll, + deflate_ll_codes); +#else deflate_build_alphabet(deflate_hc_lengths, sizeof(deflate_hc_lengths), deflate_bl_count_ll, deflate_next_code_ll); +#endif uint16_t items_processed = 0; while (items_processed < hlit + hdist) { +#ifdef DEFLATE_WITH_LUT + uint8_t code = deflate_huff(deflate_ll_codes, + deflate_bl_count_ll, + deflate_next_code_ll); +#else uint8_t code = deflate_huff(deflate_hc_lengths, sizeof(deflate_hc_lengths), deflate_bl_count_ll, deflate_next_code_ll); +#endif if (code == 16) { uint8_t copy_count = 3 + deflate_get_bits(2); for (uint8_t i = 0; i < copy_count; i++) { @@ -371,13 +448,22 @@ static int8_t deflate_dynamic_huffman() } } +#ifdef DEFLATE_WITH_LUT + deflate_build_alphabet(deflate_lld_lengths, hlit, + deflate_bl_count_ll, deflate_next_code_ll, + deflate_ll_codes); + deflate_build_alphabet(deflate_lld_lengths + hlit, hdist, + deflate_bl_count_d, deflate_next_code_d, + deflate_d_codes); + return deflate_huffman(deflate_ll_codes, deflate_d_codes); +#else deflate_build_alphabet(deflate_lld_lengths, hlit, deflate_bl_count_ll, deflate_next_code_ll); deflate_build_alphabet(deflate_lld_lengths + hlit, hdist, deflate_bl_count_d, deflate_next_code_d); - return deflate_huffman(deflate_lld_lengths, hlit, deflate_lld_lengths + hlit, hdist); +#endif } int16_t inflate(unsigned char *input_buf, uint16_t input_len, |