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brotli/c/enc/static_dict.c
Evgenii Kliuchnikov 3ebb2d30ab Move serialized dictionary feature behind the flag. 
BROTLI_SHARED_DICTIONARY_SERIALIZED enum value is a part of API,
but it should not be used (will cause failures).
Changing how serialized dictionaries work won't be considered as an API change, until this feature is enabled.
Enabling this feature in the future will be considered as a "compatible" change.

PiperOrigin-RevId: 558091676
2023-08-18 02:55:33 -07:00

543 lines
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/* Copyright 2013 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
#include "static_dict.h"
#include "../common/dictionary.h"
#include "../common/platform.h"
#include "../common/transform.h"
#include "encoder_dict.h"
#include "find_match_length.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
static BROTLI_INLINE uint32_t Hash(const uint8_t* data) {
uint32_t h = BROTLI_UNALIGNED_LOAD32LE(data) * kDictHashMul32;
/* The higher bits contain more mixture from the multiplication,
so we take our results from there. */
return h >> (32 - kDictNumBits);
}
static BROTLI_INLINE void AddMatch(size_t distance, size_t len, size_t len_code,
uint32_t* matches) {
uint32_t match = (uint32_t)((distance << 5) + len_code);
matches[len] = BROTLI_MIN(uint32_t, matches[len], match);
}
static BROTLI_INLINE size_t DictMatchLength(const BrotliDictionary* dictionary,
const uint8_t* data,
size_t id,
size_t len,
size_t maxlen) {
const size_t offset = dictionary->offsets_by_length[len] + len * id;
return FindMatchLengthWithLimit(&dictionary->data[offset], data,
BROTLI_MIN(size_t, len, maxlen));
}
static BROTLI_INLINE BROTLI_BOOL IsMatch(const BrotliDictionary* dictionary,
DictWord w, const uint8_t* data, size_t max_length) {
if (w.len > max_length) {
return BROTLI_FALSE;
} else {
const size_t offset = dictionary->offsets_by_length[w.len] +
(size_t)w.len * (size_t)w.idx;
const uint8_t* dict = &dictionary->data[offset];
if (w.transform == 0) {
/* Match against base dictionary word. */
return
TO_BROTLI_BOOL(FindMatchLengthWithLimit(dict, data, w.len) == w.len);
} else if (w.transform == 10) {
/* Match against uppercase first transform.
Note that there are only ASCII uppercase words in the lookup table. */
return TO_BROTLI_BOOL(dict[0] >= 'a' && dict[0] <= 'z' &&
(dict[0] ^ 32) == data[0] &&
FindMatchLengthWithLimit(&dict[1], &data[1], w.len - 1u) ==
w.len - 1u);
} else {
/* Match against uppercase all transform.
Note that there are only ASCII uppercase words in the lookup table. */
size_t i;
for (i = 0; i < w.len; ++i) {
if (dict[i] >= 'a' && dict[i] <= 'z') {
if ((dict[i] ^ 32) != data[i]) return BROTLI_FALSE;
} else {
if (dict[i] != data[i]) return BROTLI_FALSE;
}
}
return BROTLI_TRUE;
}
}
}
/* Finds matches for a single static dictionary */
static BROTLI_BOOL BrotliFindAllStaticDictionaryMatchesFor(
const BrotliEncoderDictionary* dictionary, const uint8_t* data,
size_t min_length, size_t max_length, uint32_t* matches) {
BROTLI_BOOL has_found_match = BROTLI_FALSE;
#if defined(BROTLI_EXPERIMENTAL)
if (dictionary->has_words_heavy) {
const BrotliTrieNode* node = &dictionary->trie.root;
size_t l = 0;
while (node && l < max_length) {
uint8_t c;
if (l >= min_length && node->len_) {
AddMatch(node->idx_, l, node->len_, matches);
has_found_match = BROTLI_TRUE;
}
c = data[l++];
node = BrotliTrieSub(&dictionary->trie, node, c);
}
return has_found_match;
}
#endif /* BROTLI_EXPERIMENTAL */
{
size_t offset = dictionary->buckets[Hash(data)];
BROTLI_BOOL end = !offset;
while (!end) {
DictWord w = dictionary->dict_words[offset++];
const size_t l = w.len & 0x1F;
const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
const size_t id = w.idx;
end = !!(w.len & 0x80);
w.len = (uint8_t)l;
if (w.transform == 0) {
const size_t matchlen =
DictMatchLength(dictionary->words, data, id, l, max_length);
const uint8_t* s;
size_t minlen;
size_t maxlen;
size_t len;
/* Transform "" + BROTLI_TRANSFORM_IDENTITY + "" */
if (matchlen == l) {
AddMatch(id, l, l, matches);
has_found_match = BROTLI_TRUE;
}
/* Transforms "" + BROTLI_TRANSFORM_OMIT_LAST_1 + "" and
"" + BROTLI_TRANSFORM_OMIT_LAST_1 + "ing " */
if (matchlen >= l - 1) {
AddMatch(id + 12 * n, l - 1, l, matches);
if (l + 2 < max_length &&
data[l - 1] == 'i' && data[l] == 'n' && data[l + 1] == 'g' &&
data[l + 2] == ' ') {
AddMatch(id + 49 * n, l + 3, l, matches);
}
has_found_match = BROTLI_TRUE;
}
/* Transform "" + BROTLI_TRANSFORM_OMIT_LAST_# + "" (# = 2 .. 9) */
minlen = min_length;
if (l > 9) minlen = BROTLI_MAX(size_t, minlen, l - 9);
maxlen = BROTLI_MIN(size_t, matchlen, l - 2);
for (len = minlen; len <= maxlen; ++len) {
size_t cut = l - len;
size_t transform_id = (cut << 2) +
(size_t)((dictionary->cutoffTransforms >> (cut * 6)) & 0x3F);
AddMatch(id + transform_id * n, len, l, matches);
has_found_match = BROTLI_TRUE;
}
if (matchlen < l || l + 6 >= max_length) {
continue;
}
s = &data[l];
/* Transforms "" + BROTLI_TRANSFORM_IDENTITY + <suffix> */
if (s[0] == ' ') {
AddMatch(id + n, l + 1, l, matches);
if (s[1] == 'a') {
if (s[2] == ' ') {
AddMatch(id + 28 * n, l + 3, l, matches);
} else if (s[2] == 's') {
if (s[3] == ' ') AddMatch(id + 46 * n, l + 4, l, matches);
} else if (s[2] == 't') {
if (s[3] == ' ') AddMatch(id + 60 * n, l + 4, l, matches);
} else if (s[2] == 'n') {
if (s[3] == 'd' && s[4] == ' ') {
AddMatch(id + 10 * n, l + 5, l, matches);
}
}
} else if (s[1] == 'b') {
if (s[2] == 'y' && s[3] == ' ') {
AddMatch(id + 38 * n, l + 4, l, matches);
}
} else if (s[1] == 'i') {
if (s[2] == 'n') {
if (s[3] == ' ') AddMatch(id + 16 * n, l + 4, l, matches);
} else if (s[2] == 's') {
if (s[3] == ' ') AddMatch(id + 47 * n, l + 4, l, matches);
}
} else if (s[1] == 'f') {
if (s[2] == 'o') {
if (s[3] == 'r' && s[4] == ' ') {
AddMatch(id + 25 * n, l + 5, l, matches);
}
} else if (s[2] == 'r') {
if (s[3] == 'o' && s[4] == 'm' && s[5] == ' ') {
AddMatch(id + 37 * n, l + 6, l, matches);
}
}
} else if (s[1] == 'o') {
if (s[2] == 'f') {
if (s[3] == ' ') AddMatch(id + 8 * n, l + 4, l, matches);
} else if (s[2] == 'n') {
if (s[3] == ' ') AddMatch(id + 45 * n, l + 4, l, matches);
}
} else if (s[1] == 'n') {
if (s[2] == 'o' && s[3] == 't' && s[4] == ' ') {
AddMatch(id + 80 * n, l + 5, l, matches);
}
} else if (s[1] == 't') {
if (s[2] == 'h') {
if (s[3] == 'e') {
if (s[4] == ' ') AddMatch(id + 5 * n, l + 5, l, matches);
} else if (s[3] == 'a') {
if (s[4] == 't' && s[5] == ' ') {
AddMatch(id + 29 * n, l + 6, l, matches);
}
}
} else if (s[2] == 'o') {
if (s[3] == ' ') AddMatch(id + 17 * n, l + 4, l, matches);
}
} else if (s[1] == 'w') {
if (s[2] == 'i' && s[3] == 't' && s[4] == 'h' && s[5] == ' ') {
AddMatch(id + 35 * n, l + 6, l, matches);
}
}
} else if (s[0] == '"') {
AddMatch(id + 19 * n, l + 1, l, matches);
if (s[1] == '>') {
AddMatch(id + 21 * n, l + 2, l, matches);
}
} else if (s[0] == '.') {
AddMatch(id + 20 * n, l + 1, l, matches);
if (s[1] == ' ') {
AddMatch(id + 31 * n, l + 2, l, matches);
if (s[2] == 'T' && s[3] == 'h') {
if (s[4] == 'e') {
if (s[5] == ' ') AddMatch(id + 43 * n, l + 6, l, matches);
} else if (s[4] == 'i') {
if (s[5] == 's' && s[6] == ' ') {
AddMatch(id + 75 * n, l + 7, l, matches);
}
}
}
}
} else if (s[0] == ',') {
AddMatch(id + 76 * n, l + 1, l, matches);
if (s[1] == ' ') {
AddMatch(id + 14 * n, l + 2, l, matches);
}
} else if (s[0] == '\n') {
AddMatch(id + 22 * n, l + 1, l, matches);
if (s[1] == '\t') {
AddMatch(id + 50 * n, l + 2, l, matches);
}
} else if (s[0] == ']') {
AddMatch(id + 24 * n, l + 1, l, matches);
} else if (s[0] == '\'') {
AddMatch(id + 36 * n, l + 1, l, matches);
} else if (s[0] == ':') {
AddMatch(id + 51 * n, l + 1, l, matches);
} else if (s[0] == '(') {
AddMatch(id + 57 * n, l + 1, l, matches);
} else if (s[0] == '=') {
if (s[1] == '"') {
AddMatch(id + 70 * n, l + 2, l, matches);
} else if (s[1] == '\'') {
AddMatch(id + 86 * n, l + 2, l, matches);
}
} else if (s[0] == 'a') {
if (s[1] == 'l' && s[2] == ' ') {
AddMatch(id + 84 * n, l + 3, l, matches);
}
} else if (s[0] == 'e') {
if (s[1] == 'd') {
if (s[2] == ' ') AddMatch(id + 53 * n, l + 3, l, matches);
} else if (s[1] == 'r') {
if (s[2] == ' ') AddMatch(id + 82 * n, l + 3, l, matches);
} else if (s[1] == 's') {
if (s[2] == 't' && s[3] == ' ') {
AddMatch(id + 95 * n, l + 4, l, matches);
}
}
} else if (s[0] == 'f') {
if (s[1] == 'u' && s[2] == 'l' && s[3] == ' ') {
AddMatch(id + 90 * n, l + 4, l, matches);
}
} else if (s[0] == 'i') {
if (s[1] == 'v') {
if (s[2] == 'e' && s[3] == ' ') {
AddMatch(id + 92 * n, l + 4, l, matches);
}
} else if (s[1] == 'z') {
if (s[2] == 'e' && s[3] == ' ') {
AddMatch(id + 100 * n, l + 4, l, matches);
}
}
} else if (s[0] == 'l') {
if (s[1] == 'e') {
if (s[2] == 's' && s[3] == 's' && s[4] == ' ') {
AddMatch(id + 93 * n, l + 5, l, matches);
}
} else if (s[1] == 'y') {
if (s[2] == ' ') AddMatch(id + 61 * n, l + 3, l, matches);
}
} else if (s[0] == 'o') {
if (s[1] == 'u' && s[2] == 's' && s[3] == ' ') {
AddMatch(id + 106 * n, l + 4, l, matches);
}
}
} else {
/* Set is_all_caps=0 for BROTLI_TRANSFORM_UPPERCASE_FIRST and
is_all_caps=1 otherwise (BROTLI_TRANSFORM_UPPERCASE_ALL)
transform. */
const BROTLI_BOOL is_all_caps =
TO_BROTLI_BOOL(w.transform != BROTLI_TRANSFORM_UPPERCASE_FIRST);
const uint8_t* s;
if (!IsMatch(dictionary->words, w, data, max_length)) {
continue;
}
/* Transform "" + kUppercase{First,All} + "" */
AddMatch(id + (is_all_caps ? 44 : 9) * n, l, l, matches);
has_found_match = BROTLI_TRUE;
if (l + 1 >= max_length) {
continue;
}
/* Transforms "" + kUppercase{First,All} + <suffix> */
s = &data[l];
if (s[0] == ' ') {
AddMatch(id + (is_all_caps ? 68 : 4) * n, l + 1, l, matches);
} else if (s[0] == '"') {
AddMatch(id + (is_all_caps ? 87 : 66) * n, l + 1, l, matches);
if (s[1] == '>') {
AddMatch(id + (is_all_caps ? 97 : 69) * n, l + 2, l, matches);
}
} else if (s[0] == '.') {
AddMatch(id + (is_all_caps ? 101 : 79) * n, l + 1, l, matches);
if (s[1] == ' ') {
AddMatch(id + (is_all_caps ? 114 : 88) * n, l + 2, l, matches);
}
} else if (s[0] == ',') {
AddMatch(id + (is_all_caps ? 112 : 99) * n, l + 1, l, matches);
if (s[1] == ' ') {
AddMatch(id + (is_all_caps ? 107 : 58) * n, l + 2, l, matches);
}
} else if (s[0] == '\'') {
AddMatch(id + (is_all_caps ? 94 : 74) * n, l + 1, l, matches);
} else if (s[0] == '(') {
AddMatch(id + (is_all_caps ? 113 : 78) * n, l + 1, l, matches);
} else if (s[0] == '=') {
if (s[1] == '"') {
AddMatch(id + (is_all_caps ? 105 : 104) * n, l + 2, l, matches);
} else if (s[1] == '\'') {
AddMatch(id + (is_all_caps ? 116 : 108) * n, l + 2, l, matches);
}
}
}
}
}
/* Transforms with prefixes " " and "." */
if (max_length >= 5 && (data[0] == ' ' || data[0] == '.')) {
BROTLI_BOOL is_space = TO_BROTLI_BOOL(data[0] == ' ');
size_t offset = dictionary->buckets[Hash(&data[1])];
BROTLI_BOOL end = !offset;
while (!end) {
DictWord w = dictionary->dict_words[offset++];
const size_t l = w.len & 0x1F;
const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
const size_t id = w.idx;
end = !!(w.len & 0x80);
w.len = (uint8_t)l;
if (w.transform == 0) {
const uint8_t* s;
if (!IsMatch(dictionary->words, w, &data[1], max_length - 1)) {
continue;
}
/* Transforms " " + BROTLI_TRANSFORM_IDENTITY + "" and
"." + BROTLI_TRANSFORM_IDENTITY + "" */
AddMatch(id + (is_space ? 6 : 32) * n, l + 1, l, matches);
has_found_match = BROTLI_TRUE;
if (l + 2 >= max_length) {
continue;
}
/* Transforms " " + BROTLI_TRANSFORM_IDENTITY + <suffix> and
"." + BROTLI_TRANSFORM_IDENTITY + <suffix>
*/
s = &data[l + 1];
if (s[0] == ' ') {
AddMatch(id + (is_space ? 2 : 77) * n, l + 2, l, matches);
} else if (s[0] == '(') {
AddMatch(id + (is_space ? 89 : 67) * n, l + 2, l, matches);
} else if (is_space) {
if (s[0] == ',') {
AddMatch(id + 103 * n, l + 2, l, matches);
if (s[1] == ' ') {
AddMatch(id + 33 * n, l + 3, l, matches);
}
} else if (s[0] == '.') {
AddMatch(id + 71 * n, l + 2, l, matches);
if (s[1] == ' ') {
AddMatch(id + 52 * n, l + 3, l, matches);
}
} else if (s[0] == '=') {
if (s[1] == '"') {
AddMatch(id + 81 * n, l + 3, l, matches);
} else if (s[1] == '\'') {
AddMatch(id + 98 * n, l + 3, l, matches);
}
}
}
} else if (is_space) {
/* Set is_all_caps=0 for BROTLI_TRANSFORM_UPPERCASE_FIRST and
is_all_caps=1 otherwise (BROTLI_TRANSFORM_UPPERCASE_ALL)
transform. */
const BROTLI_BOOL is_all_caps =
TO_BROTLI_BOOL(w.transform != BROTLI_TRANSFORM_UPPERCASE_FIRST);
const uint8_t* s;
if (!IsMatch(dictionary->words, w, &data[1], max_length - 1)) {
continue;
}
/* Transforms " " + kUppercase{First,All} + "" */
AddMatch(id + (is_all_caps ? 85 : 30) * n, l + 1, l, matches);
has_found_match = BROTLI_TRUE;
if (l + 2 >= max_length) {
continue;
}
/* Transforms " " + kUppercase{First,All} + <suffix> */
s = &data[l + 1];
if (s[0] == ' ') {
AddMatch(id + (is_all_caps ? 83 : 15) * n, l + 2, l, matches);
} else if (s[0] == ',') {
if (!is_all_caps) {
AddMatch(id + 109 * n, l + 2, l, matches);
}
if (s[1] == ' ') {
AddMatch(id + (is_all_caps ? 111 : 65) * n, l + 3, l, matches);
}
} else if (s[0] == '.') {
AddMatch(id + (is_all_caps ? 115 : 96) * n, l + 2, l, matches);
if (s[1] == ' ') {
AddMatch(id + (is_all_caps ? 117 : 91) * n, l + 3, l, matches);
}
} else if (s[0] == '=') {
if (s[1] == '"') {
AddMatch(id + (is_all_caps ? 110 : 118) * n, l + 3, l, matches);
} else if (s[1] == '\'') {
AddMatch(id + (is_all_caps ? 119 : 120) * n, l + 3, l, matches);
}
}
}
}
}
if (max_length >= 6) {
/* Transforms with prefixes "e ", "s ", ", " and "\xC2\xA0" */
if ((data[1] == ' ' &&
(data[0] == 'e' || data[0] == 's' || data[0] == ',')) ||
(data[0] == 0xC2 && data[1] == 0xA0)) {
size_t offset = dictionary->buckets[Hash(&data[2])];
BROTLI_BOOL end = !offset;
while (!end) {
DictWord w = dictionary->dict_words[offset++];
const size_t l = w.len & 0x1F;
const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
const size_t id = w.idx;
end = !!(w.len & 0x80);
w.len = (uint8_t)l;
if (w.transform == 0 &&
IsMatch(dictionary->words, w, &data[2], max_length - 2)) {
if (data[0] == 0xC2) {
AddMatch(id + 102 * n, l + 2, l, matches);
has_found_match = BROTLI_TRUE;
} else if (l + 2 < max_length && data[l + 2] == ' ') {
size_t t = data[0] == 'e' ? 18 : (data[0] == 's' ? 7 : 13);
AddMatch(id + t * n, l + 3, l, matches);
has_found_match = BROTLI_TRUE;
}
}
}
}
}
if (max_length >= 9) {
/* Transforms with prefixes " the " and ".com/" */
if ((data[0] == ' ' && data[1] == 't' && data[2] == 'h' &&
data[3] == 'e' && data[4] == ' ') ||
(data[0] == '.' && data[1] == 'c' && data[2] == 'o' &&
data[3] == 'm' && data[4] == '/')) {
size_t offset = dictionary->buckets[Hash(&data[5])];
BROTLI_BOOL end = !offset;
while (!end) {
DictWord w = dictionary->dict_words[offset++];
const size_t l = w.len & 0x1F;
const size_t n = (size_t)1 << dictionary->words->size_bits_by_length[l];
const size_t id = w.idx;
end = !!(w.len & 0x80);
w.len = (uint8_t)l;
if (w.transform == 0 &&
IsMatch(dictionary->words, w, &data[5], max_length - 5)) {
AddMatch(id + (data[0] == ' ' ? 41 : 72) * n, l + 5, l, matches);
has_found_match = BROTLI_TRUE;
if (l + 5 < max_length) {
const uint8_t* s = &data[l + 5];
if (data[0] == ' ') {
if (l + 8 < max_length &&
s[0] == ' ' && s[1] == 'o' && s[2] == 'f' && s[3] == ' ') {
AddMatch(id + 62 * n, l + 9, l, matches);
if (l + 12 < max_length &&
s[4] == 't' && s[5] == 'h' && s[6] == 'e' && s[7] == ' ') {
AddMatch(id + 73 * n, l + 13, l, matches);
}
}
}
}
}
}
}
}
return has_found_match;
}
/* Finds matches for one or more dictionaries, if multiple are present
in the contextual dictionary */
BROTLI_BOOL BrotliFindAllStaticDictionaryMatches(
const BrotliEncoderDictionary* dictionary, const uint8_t* data,
size_t min_length, size_t max_length, uint32_t* matches) {
BROTLI_BOOL has_found_match =
BrotliFindAllStaticDictionaryMatchesFor(
dictionary, data, min_length, max_length, matches);
if (!!dictionary->parent && dictionary->parent->num_dictionaries > 1) {
uint32_t matches2[BROTLI_MAX_STATIC_DICTIONARY_MATCH_LEN + 1];
int l;
const BrotliEncoderDictionary* dictionary2 = dictionary->parent->dict[0];
if (dictionary2 == dictionary) {
dictionary2 = dictionary->parent->dict[1];
}
for (l = 0; l < BROTLI_MAX_STATIC_DICTIONARY_MATCH_LEN + 1; l++) {
matches2[l] = kInvalidMatch;
}
has_found_match |= BrotliFindAllStaticDictionaryMatchesFor(
dictionary2, data, min_length, max_length, matches2);
for (l = 0; l < BROTLI_MAX_STATIC_DICTIONARY_MATCH_LEN + 1; l++) {
if (matches2[l] != kInvalidMatch) {
uint32_t dist = (uint32_t)(matches2[l] >> 5);
uint32_t len_code = matches2[l] & 31;
uint32_t skipdist = (uint32_t)((uint32_t)(1 << dictionary->words->
size_bits_by_length[len_code]) & ~1u) *
(uint32_t)dictionary->num_transforms;
/* TODO(lode): check for dist overflow */
dist += skipdist;
AddMatch(dist, (size_t)l, len_code, matches);
}
}
}
return has_found_match;
}
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
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