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Diffstat (limited to 'web/server/h2o/libh2o/deps/brotli/enc/context.h')
-rw-r--r-- | web/server/h2o/libh2o/deps/brotli/enc/context.h | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/web/server/h2o/libh2o/deps/brotli/enc/context.h b/web/server/h2o/libh2o/deps/brotli/enc/context.h deleted file mode 100644 index 00c065bcc..000000000 --- a/web/server/h2o/libh2o/deps/brotli/enc/context.h +++ /dev/null @@ -1,178 +0,0 @@ -/* Copyright 2013 Google Inc. All Rights Reserved. - - Distributed under MIT license. - See file LICENSE for detail or copy at https://opensource.org/licenses/MIT -*/ - -// Functions to map previous bytes into a context id. - -#ifndef BROTLI_ENC_CONTEXT_H_ -#define BROTLI_ENC_CONTEXT_H_ - -#include "./types.h" - -namespace brotli { - -// Second-order context lookup table for UTF8 byte streams. -// -// If p1 and p2 are the previous two bytes, we calculate the context as -// -// context = kUTF8ContextLookup[p1] | kUTF8ContextLookup[p2 + 256]. -// -// If the previous two bytes are ASCII characters (i.e. < 128), this will be -// equivalent to -// -// context = 4 * context1(p1) + context2(p2), -// -// where context1 is based on the previous byte in the following way: -// -// 0 : non-ASCII control -// 1 : \t, \n, \r -// 2 : space -// 3 : other punctuation -// 4 : " ' -// 5 : % -// 6 : ( < [ { -// 7 : ) > ] } -// 8 : , ; : -// 9 : . -// 10 : = -// 11 : number -// 12 : upper-case vowel -// 13 : upper-case consonant -// 14 : lower-case vowel -// 15 : lower-case consonant -// -// and context2 is based on the second last byte: -// -// 0 : control, space -// 1 : punctuation -// 2 : upper-case letter, number -// 3 : lower-case letter -// -// If the last byte is ASCII, and the second last byte is not (in a valid UTF8 -// stream it will be a continuation byte, value between 128 and 191), the -// context is the same as if the second last byte was an ASCII control or space. -// -// If the last byte is a UTF8 lead byte (value >= 192), then the next byte will -// be a continuation byte and the context id is 2 or 3 depending on the LSB of -// the last byte and to a lesser extent on the second last byte if it is ASCII. -// -// If the last byte is a UTF8 continuation byte, the second last byte can be: -// - continuation byte: the next byte is probably ASCII or lead byte (assuming -// 4-byte UTF8 characters are rare) and the context id is 0 or 1. -// - lead byte (192 - 207): next byte is ASCII or lead byte, context is 0 or 1 -// - lead byte (208 - 255): next byte is continuation byte, context is 2 or 3 -// -// The possible value combinations of the previous two bytes, the range of -// context ids and the type of the next byte is summarized in the table below: -// -// |--------\-----------------------------------------------------------------| -// | \ Last byte | -// | Second \---------------------------------------------------------------| -// | last byte \ ASCII | cont. byte | lead byte | -// | \ (0-127) | (128-191) | (192-) | -// |=============|===================|=====================|==================| -// | ASCII | next: ASCII/lead | not valid | next: cont. | -// | (0-127) | context: 4 - 63 | | context: 2 - 3 | -// |-------------|-------------------|---------------------|------------------| -// | cont. byte | next: ASCII/lead | next: ASCII/lead | next: cont. | -// | (128-191) | context: 4 - 63 | context: 0 - 1 | context: 2 - 3 | -// |-------------|-------------------|---------------------|------------------| -// | lead byte | not valid | next: ASCII/lead | not valid | -// | (192-207) | | context: 0 - 1 | | -// |-------------|-------------------|---------------------|------------------| -// | lead byte | not valid | next: cont. | not valid | -// | (208-) | | context: 2 - 3 | | -// |-------------|-------------------|---------------------|------------------| -static const uint8_t kUTF8ContextLookup[512] = { - // Last byte. - // - // ASCII range. - 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 4, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 8, 12, 16, 12, 12, 20, 12, 16, 24, 28, 12, 12, 32, 12, 36, 12, - 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 32, 32, 24, 40, 28, 12, - 12, 48, 52, 52, 52, 48, 52, 52, 52, 48, 52, 52, 52, 52, 52, 48, - 52, 52, 52, 52, 52, 48, 52, 52, 52, 52, 52, 24, 12, 28, 12, 12, - 12, 56, 60, 60, 60, 56, 60, 60, 60, 56, 60, 60, 60, 60, 60, 56, - 60, 60, 60, 60, 60, 56, 60, 60, 60, 60, 60, 24, 12, 28, 12, 0, - // UTF8 continuation byte range. - 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, - 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, - 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, - 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, - // UTF8 lead byte range. - 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, - 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, - 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, - 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, - // Second last byte. - // - // ASCII range. - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, - 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, - 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, 0, - // UTF8 continuation byte range. - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - // UTF8 lead byte range. - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -}; - -// Context lookup table for small signed integers. -static const uint8_t kSigned3BitContextLookup[] = { - 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, - 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, - 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, - 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, - 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, -}; - -enum ContextType { - CONTEXT_LSB6 = 0, - CONTEXT_MSB6 = 1, - CONTEXT_UTF8 = 2, - CONTEXT_SIGNED = 3 -}; - -static inline uint8_t Context(uint8_t p1, uint8_t p2, ContextType mode) { - switch (mode) { - case CONTEXT_LSB6: - return p1 & 0x3f; - case CONTEXT_MSB6: - return static_cast<uint8_t>(p1 >> 2); - case CONTEXT_UTF8: - return kUTF8ContextLookup[p1] | kUTF8ContextLookup[p2 + 256]; - case CONTEXT_SIGNED: - return static_cast<uint8_t>((kSigned3BitContextLookup[p1] << 3) + - kSigned3BitContextLookup[p2]); - default: - return 0; - } -} - -} // namespace brotli - -#endif // BROTLI_ENC_CONTEXT_H_ |