diff options
Diffstat (limited to 'modules/brotli/common/transform.c')
| -rw-r--r-- | modules/brotli/common/transform.c | 62 |
1 files changed, 59 insertions, 3 deletions
diff --git a/modules/brotli/common/transform.c b/modules/brotli/common/transform.c index 426e635fd..f8fa4335e 100644 --- a/modules/brotli/common/transform.c +++ b/modules/brotli/common/transform.c @@ -24,8 +24,8 @@ static const char kPrefixSuffix[217] = /* 8x _0 _ _3 _8 _C _E _ _1 _7 _F */ " not \3er \3al \4ful \4ive \5less \4es" /* Ax _5 _9 _D _2 _7 _D */ - "t \4ize \2\xc2\xa0\4ous \5 the \2e \0"; -/* Cx _2 _7___ ___ _A _F _5 _8 */ + "t \4ize \2\xc2\xa0\4ous \5 the \2e "; /* \0 - implicit trailing zero. */ +/* Cx _2 _7___ ___ _A _F _5 _8 */ static const uint16_t kPrefixSuffixMap[50] = { 0x00, 0x02, 0x05, 0x0E, 0x13, 0x16, 0x18, 0x1E, 0x23, 0x25, @@ -160,12 +160,13 @@ static const uint8_t kTransformsData[] = { 0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 34, }; -static BrotliTransforms kBrotliTransforms = { +static const BrotliTransforms kBrotliTransforms = { sizeof(kPrefixSuffix), (const uint8_t*)kPrefixSuffix, kPrefixSuffixMap, sizeof(kTransformsData) / (3 * sizeof(kTransformsData[0])), kTransformsData, + NULL, /* no extra parameters */ {0, 12, 27, 23, 42, 63, 56, 48, 59, 64} }; @@ -190,6 +191,48 @@ static int ToUpperCase(uint8_t* p) { return 3; } +static int Shift(uint8_t* word, int word_len, uint16_t parameter) { + /* Limited sign extension: scalar < (1 << 24). */ + uint32_t scalar = + (parameter & 0x7FFFu) + (0x1000000u - (parameter & 0x8000u)); + if (word[0] < 0x80) { + /* 1-byte rune / 0sssssss / 7 bit scalar (ASCII). */ + scalar += (uint32_t)word[0]; + word[0] = (uint8_t)(scalar & 0x7Fu); + return 1; + } else if (word[0] < 0xC0) { + /* Continuation / 10AAAAAA. */ + return 1; + } else if (word[0] < 0xE0) { + /* 2-byte rune / 110sssss AAssssss / 11 bit scalar. */ + if (word_len < 2) return 1; + scalar += (uint32_t)((word[1] & 0x3Fu) | ((word[0] & 0x1Fu) << 6u)); + word[0] = (uint8_t)(0xC0 | ((scalar >> 6u) & 0x1F)); + word[1] = (uint8_t)((word[1] & 0xC0) | (scalar & 0x3F)); + return 2; + } else if (word[0] < 0xF0) { + /* 3-byte rune / 1110ssss AAssssss BBssssss / 16 bit scalar. */ + if (word_len < 3) return word_len; + scalar += (uint32_t)((word[2] & 0x3Fu) | ((word[1] & 0x3Fu) << 6u) | + ((word[0] & 0x0Fu) << 12u)); + word[0] = (uint8_t)(0xE0 | ((scalar >> 12u) & 0x0F)); + word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 6u) & 0x3F)); + word[2] = (uint8_t)((word[2] & 0xC0) | (scalar & 0x3F)); + return 3; + } else if (word[0] < 0xF8) { + /* 4-byte rune / 11110sss AAssssss BBssssss CCssssss / 21 bit scalar. */ + if (word_len < 4) return word_len; + scalar += (uint32_t)((word[3] & 0x3Fu) | ((word[2] & 0x3Fu) << 6u) | + ((word[1] & 0x3Fu) << 12u) | ((word[0] & 0x07u) << 18u)); + word[0] = (uint8_t)(0xF0 | ((scalar >> 18u) & 0x07)); + word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 12u) & 0x3F)); + word[2] = (uint8_t)((word[2] & 0xC0) | ((scalar >> 6u) & 0x3F)); + word[3] = (uint8_t)((word[3] & 0xC0) | (scalar & 0x3F)); + return 4; + } + return 1; +} + int BrotliTransformDictionaryWord(uint8_t* dst, const uint8_t* word, int len, const BrotliTransforms* transforms, int transform_idx) { int idx = 0; @@ -221,6 +264,19 @@ int BrotliTransformDictionaryWord(uint8_t* dst, const uint8_t* word, int len, uppercase += step; len -= step; } + } else if (t == BROTLI_TRANSFORM_SHIFT_FIRST) { + uint16_t param = (uint16_t)(transforms->params[transform_idx * 2] + + (transforms->params[transform_idx * 2 + 1] << 8u)); + Shift(&dst[idx - len], len, param); + } else if (t == BROTLI_TRANSFORM_SHIFT_ALL) { + uint16_t param = (uint16_t)(transforms->params[transform_idx * 2] + + (transforms->params[transform_idx * 2 + 1] << 8u)); + uint8_t* shift = &dst[idx - len]; + while (len > 0) { + int step = Shift(shift, len, param); + shift += step; + len -= step; + } } } { |