Esempio n. 1
0
 private static unsafe bool IsMatch(
     DictWord w, byte *data, size_t max_length)
 {
     if (w.len > max_length)
     {
         return(false);
     }
     else
     {
         size_t offset = kBrotliDictionaryOffsetsByLength[w.len] +
                         (size_t)w.len * (size_t)w.idx;
         fixed(byte *dict = &kBrotliDictionary[offset])
         {
             if (w.transform == 0)
             {
                 /* Match against base dictionary word. */
                 return
                     (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(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(false);
                         }
                     }
                     else
                     {
                         if (dict[i] != data[i])
                         {
                             return(false);
                         }
                     }
                 }
                 return(true);
             }
         }
     }
 }
Esempio n. 2
0
        private static unsafe bool BrotliFindAllStaticDictionaryMatches(
            byte *data, size_t min_length,
            size_t max_length, uint *matches)
        {
            bool has_found_match = false;

            {
                size_t offset = kStaticDictionaryBuckets[Hash(data)];
                bool   end    = offset == 0;
                while (!end)
                {
                    DictWord w  = kStaticDictionaryWords[offset++];
                    size_t   l  = w.len & 0x1F;
                    size_t   n  = (size_t)1 << kBrotliDictionarySizeBitsByLength[l];
                    size_t   id = w.idx;
                    end   = (w.len & 0x80) != 0;
                    w.len = (byte)l;
                    if (w.transform == 0)
                    {
                        size_t matchlen =
                            DictMatchLength(data, id, l, max_length);
                        byte * s;
                        size_t minlen;
                        size_t maxlen;
                        size_t len;
                        /* Transform "" + kIdentity + "" */
                        if (matchlen == l)
                        {
                            AddMatch(id, l, l, matches);
                            has_found_match = true;
                        }
                        /* Transforms "" + kOmitLast1 + "" and "" + kOmitLast1 + "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 = true;
                        }
                        /* Transform "" + kOmitLastN + "" (N = 2 .. 9) */
                        minlen = min_length;
                        if (l > 9)
                        {
                            minlen = Math.Max(minlen, l - 9);
                        }
                        maxlen = Math.Min(matchlen, l - 2);
                        for (len = minlen; len <= maxlen; ++len)
                        {
                            AddMatch(id + kOmitLastNTransforms[l - len] * n, len, l, matches);
                            has_found_match = true;
                        }
                        if (matchlen < l || l + 6 >= max_length)
                        {
                            continue;
                        }
                        s = &data[l];
                        /* Transforms "" + kIdentity + <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 kUppercaseFirst and
                         *     is_all_caps=1 otherwise (kUppercaseAll) transform. */
                        bool is_all_caps =
                            (w.transform != kUppercaseFirst);
                        byte *s;
                        if (!IsMatch(w, data, max_length))
                        {
                            continue;
                        }
                        /* Transform "" + kUppercase{First,All} + "" */
                        AddMatch(id + (is_all_caps ? 44 : 9) * n, l, l, matches);
                        has_found_match = 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] == '.'))
            {
                bool   is_space = (data[0] == ' ');
                size_t offset   = kStaticDictionaryBuckets[Hash(&data[1])];
                bool   end      = offset == 0;
                while (!end)
                {
                    DictWord w  = kStaticDictionaryWords[offset++];
                    size_t   l  = w.len & 0x1F;
                    size_t   n  = (size_t)1 << kBrotliDictionarySizeBitsByLength[l];
                    size_t   id = w.idx;
                    end   = (w.len & 0x80) != 0;
                    w.len = (byte)l;
                    if (w.transform == 0)
                    {
                        byte *s;
                        if (!IsMatch(w, &data[1], max_length - 1))
                        {
                            continue;
                        }
                        /* Transforms " " + kIdentity + "" and "." + kIdentity + "" */
                        AddMatch(id + (is_space ? 6 : 32) * n, l + 1, l, matches);
                        has_found_match = true;
                        if (l + 2 >= max_length)
                        {
                            continue;
                        }

                        /* Transforms " " + kIdentity + <suffix> and "." + kIdentity + <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 kUppercaseFirst and
                         *     is_all_caps=1 otherwise (kUppercaseAll) transform. */
                        bool is_all_caps =
                            (w.transform != kUppercaseFirst);
                        byte *s;
                        if (!IsMatch(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 = 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 = kStaticDictionaryBuckets[Hash(&data[2])];
                    bool   end    = offset == 0;
                    while (!end)
                    {
                        DictWord w  = kStaticDictionaryWords[offset++];
                        size_t   l  = w.len & 0x1F;
                        size_t   n  = (size_t)1 << kBrotliDictionarySizeBitsByLength[l];
                        size_t   id = w.idx;
                        end   = (w.len & 0x80) != 0;
                        w.len = (byte)l;
                        if (w.transform == 0 &&
                            IsMatch(w, &data[2], max_length - 2))
                        {
                            if (data[0] == 0xc2)
                            {
                                AddMatch(id + 102 * n, l + 2, l, matches);
                                has_found_match = 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 = 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 = kStaticDictionaryBuckets[Hash(&data[5])];
                    bool   end    = offset == 0;
                    while (!end)
                    {
                        DictWord w  = kStaticDictionaryWords[offset++];
                        size_t   l  = w.len & 0x1F;
                        size_t   n  = (size_t)1 << kBrotliDictionarySizeBitsByLength[l];
                        size_t   id = w.idx;
                        end   = (w.len & 0x80) != 0;
                        w.len = (byte)l;
                        if (w.transform == 0 &&
                            IsMatch(w, &data[5], max_length - 5))
                        {
                            AddMatch(id + (data[0] == ' ' ? 41 : 72) * n, l + 5, l, matches);
                            has_found_match = true;
                            if (l + 5 < max_length)
                            {
                                byte *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);
        }