mirror of
https://github.com/google/brotli.git
synced 2024-11-09 21:50:07 +00:00
292 lines
10 KiB
C
292 lines
10 KiB
C
/* Copyright 2013 Google Inc. All Rights Reserved.
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Distributed under MIT license.
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See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
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*/
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#include "transform.h"
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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/* RFC 7932 transforms string data */
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static const char kPrefixSuffix[217] =
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"\1 \2, \10 of the \4 of \2s \1.\5 and \4 "
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/* 0x _0 _2 __5 _E _3 _6 _8 _E */
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"in \1\"\4 to \2\">\1\n\2. \1]\5 for \3 a \6 "
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/* 2x _3_ _5 _A_ _D_ _F _2 _4 _A _E */
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"that \1\'\6 with \6 from \4 by \1(\6. T"
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/* 4x _5_ _7 _E _5 _A _C */
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"he \4 on \4 as \4 is \4ing \2\n\t\1:\3ed "
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/* 6x _3 _8 _D _2 _7_ _ _A _C */
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"\2=\"\4 at \3ly \1,\2=\'\5.com/\7. This \5"
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/* 8x _0 _ _3 _8 _C _E _ _1 _7 _F */
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" not \3er \3al \4ful \4ive \5less \4es"
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/* Ax _5 _9 _D _2 _7 _D */
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"t \4ize \2\xc2\xa0\4ous \5 the \2e "; /* \0 - implicit trailing zero. */
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/* Cx _2 _7___ ___ _A _F _5 _8 */
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static const uint16_t kPrefixSuffixMap[50] = {
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0x00, 0x02, 0x05, 0x0E, 0x13, 0x16, 0x18, 0x1E, 0x23, 0x25,
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0x2A, 0x2D, 0x2F, 0x32, 0x34, 0x3A, 0x3E, 0x45, 0x47, 0x4E,
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0x55, 0x5A, 0x5C, 0x63, 0x68, 0x6D, 0x72, 0x77, 0x7A, 0x7C,
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0x80, 0x83, 0x88, 0x8C, 0x8E, 0x91, 0x97, 0x9F, 0xA5, 0xA9,
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0xAD, 0xB2, 0xB7, 0xBD, 0xC2, 0xC7, 0xCA, 0xCF, 0xD5, 0xD8
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};
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/* RFC 7932 transforms */
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static const uint8_t kTransformsData[] = {
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49, BROTLI_TRANSFORM_IDENTITY, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 0,
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0, BROTLI_TRANSFORM_IDENTITY, 0,
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49, BROTLI_TRANSFORM_OMIT_FIRST_1, 49,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 47,
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0, BROTLI_TRANSFORM_IDENTITY, 49,
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4, BROTLI_TRANSFORM_IDENTITY, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 3,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 6,
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49, BROTLI_TRANSFORM_OMIT_FIRST_2, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_1, 49,
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1, BROTLI_TRANSFORM_IDENTITY, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 1,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 7,
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49, BROTLI_TRANSFORM_IDENTITY, 9,
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48, BROTLI_TRANSFORM_IDENTITY, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 8,
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49, BROTLI_TRANSFORM_IDENTITY, 5,
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49, BROTLI_TRANSFORM_IDENTITY, 10,
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49, BROTLI_TRANSFORM_IDENTITY, 11,
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49, BROTLI_TRANSFORM_OMIT_LAST_3, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 13,
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49, BROTLI_TRANSFORM_IDENTITY, 14,
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49, BROTLI_TRANSFORM_OMIT_FIRST_3, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_2, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 15,
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49, BROTLI_TRANSFORM_IDENTITY, 16,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 12,
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5, BROTLI_TRANSFORM_IDENTITY, 49,
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0, BROTLI_TRANSFORM_IDENTITY, 1,
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49, BROTLI_TRANSFORM_OMIT_FIRST_4, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 18,
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49, BROTLI_TRANSFORM_IDENTITY, 17,
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49, BROTLI_TRANSFORM_IDENTITY, 19,
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49, BROTLI_TRANSFORM_IDENTITY, 20,
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49, BROTLI_TRANSFORM_OMIT_FIRST_5, 49,
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49, BROTLI_TRANSFORM_OMIT_FIRST_6, 49,
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47, BROTLI_TRANSFORM_IDENTITY, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_4, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 22,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 23,
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49, BROTLI_TRANSFORM_IDENTITY, 24,
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49, BROTLI_TRANSFORM_IDENTITY, 25,
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49, BROTLI_TRANSFORM_OMIT_LAST_7, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_1, 26,
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49, BROTLI_TRANSFORM_IDENTITY, 27,
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49, BROTLI_TRANSFORM_IDENTITY, 28,
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0, BROTLI_TRANSFORM_IDENTITY, 12,
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49, BROTLI_TRANSFORM_IDENTITY, 29,
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49, BROTLI_TRANSFORM_OMIT_FIRST_9, 49,
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49, BROTLI_TRANSFORM_OMIT_FIRST_7, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_6, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 21,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 1,
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49, BROTLI_TRANSFORM_OMIT_LAST_8, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 31,
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49, BROTLI_TRANSFORM_IDENTITY, 32,
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47, BROTLI_TRANSFORM_IDENTITY, 3,
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49, BROTLI_TRANSFORM_OMIT_LAST_5, 49,
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49, BROTLI_TRANSFORM_OMIT_LAST_9, 49,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 1,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 8,
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5, BROTLI_TRANSFORM_IDENTITY, 21,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 0,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 10,
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49, BROTLI_TRANSFORM_IDENTITY, 30,
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0, BROTLI_TRANSFORM_IDENTITY, 5,
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35, BROTLI_TRANSFORM_IDENTITY, 49,
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47, BROTLI_TRANSFORM_IDENTITY, 2,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 17,
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49, BROTLI_TRANSFORM_IDENTITY, 36,
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49, BROTLI_TRANSFORM_IDENTITY, 33,
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5, BROTLI_TRANSFORM_IDENTITY, 0,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 21,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 5,
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49, BROTLI_TRANSFORM_IDENTITY, 37,
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0, BROTLI_TRANSFORM_IDENTITY, 30,
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49, BROTLI_TRANSFORM_IDENTITY, 38,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 0,
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49, BROTLI_TRANSFORM_IDENTITY, 39,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 49,
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49, BROTLI_TRANSFORM_IDENTITY, 34,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 8,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 12,
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0, BROTLI_TRANSFORM_IDENTITY, 21,
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49, BROTLI_TRANSFORM_IDENTITY, 40,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 12,
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49, BROTLI_TRANSFORM_IDENTITY, 41,
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49, BROTLI_TRANSFORM_IDENTITY, 42,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 17,
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49, BROTLI_TRANSFORM_IDENTITY, 43,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 5,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 10,
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0, BROTLI_TRANSFORM_IDENTITY, 34,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 33,
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49, BROTLI_TRANSFORM_IDENTITY, 44,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 5,
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45, BROTLI_TRANSFORM_IDENTITY, 49,
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0, BROTLI_TRANSFORM_IDENTITY, 33,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 30,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 30,
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49, BROTLI_TRANSFORM_IDENTITY, 46,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 1,
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49, BROTLI_TRANSFORM_UPPERCASE_FIRST, 34,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 33,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 30,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 1,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 33,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 21,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 12,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 5,
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49, BROTLI_TRANSFORM_UPPERCASE_ALL, 34,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 12,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 30,
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0, BROTLI_TRANSFORM_UPPERCASE_ALL, 34,
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0, BROTLI_TRANSFORM_UPPERCASE_FIRST, 34,
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};
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static const BrotliTransforms kBrotliTransforms = {
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sizeof(kPrefixSuffix),
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(const uint8_t*)kPrefixSuffix,
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kPrefixSuffixMap,
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sizeof(kTransformsData) / (3 * sizeof(kTransformsData[0])),
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kTransformsData,
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NULL, /* no extra parameters */
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{0, 12, 27, 23, 42, 63, 56, 48, 59, 64}
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};
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const BrotliTransforms* BrotliGetTransforms(void) {
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return &kBrotliTransforms;
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}
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static int ToUpperCase(uint8_t* p) {
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if (p[0] < 0xC0) {
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if (p[0] >= 'a' && p[0] <= 'z') {
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p[0] ^= 32;
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}
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return 1;
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}
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/* An overly simplified uppercasing model for UTF-8. */
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if (p[0] < 0xE0) {
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p[1] ^= 32;
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return 2;
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}
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/* An arbitrary transform for three byte characters. */
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p[2] ^= 5;
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return 3;
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}
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static int Shift(uint8_t* word, int word_len, uint16_t parameter) {
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/* Limited sign extension: scalar < (1 << 24). */
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uint32_t scalar =
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(parameter & 0x7FFFu) + (0x1000000u - (parameter & 0x8000u));
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if (word[0] < 0x80) {
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/* 1-byte rune / 0sssssss / 7 bit scalar (ASCII). */
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scalar += (uint32_t)word[0];
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word[0] = (uint8_t)(scalar & 0x7Fu);
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return 1;
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} else if (word[0] < 0xC0) {
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/* Continuation / 10AAAAAA. */
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return 1;
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} else if (word[0] < 0xE0) {
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/* 2-byte rune / 110sssss AAssssss / 11 bit scalar. */
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if (word_len < 2) return 1;
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scalar += (uint32_t)((word[1] & 0x3Fu) | ((word[0] & 0x1Fu) << 6u));
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word[0] = (uint8_t)(0xC0 | ((scalar >> 6u) & 0x1F));
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word[1] = (uint8_t)((word[1] & 0xC0) | (scalar & 0x3F));
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return 2;
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} else if (word[0] < 0xF0) {
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/* 3-byte rune / 1110ssss AAssssss BBssssss / 16 bit scalar. */
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if (word_len < 3) return word_len;
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scalar += (uint32_t)((word[2] & 0x3Fu) | ((word[1] & 0x3Fu) << 6u) |
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((word[0] & 0x0Fu) << 12u));
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word[0] = (uint8_t)(0xE0 | ((scalar >> 12u) & 0x0F));
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word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 6u) & 0x3F));
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word[2] = (uint8_t)((word[2] & 0xC0) | (scalar & 0x3F));
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return 3;
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} else if (word[0] < 0xF8) {
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/* 4-byte rune / 11110sss AAssssss BBssssss CCssssss / 21 bit scalar. */
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if (word_len < 4) return word_len;
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scalar += (uint32_t)((word[3] & 0x3Fu) | ((word[2] & 0x3Fu) << 6u) |
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((word[1] & 0x3Fu) << 12u) | ((word[0] & 0x07u) << 18u));
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word[0] = (uint8_t)(0xF0 | ((scalar >> 18u) & 0x07));
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word[1] = (uint8_t)((word[1] & 0xC0) | ((scalar >> 12u) & 0x3F));
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word[2] = (uint8_t)((word[2] & 0xC0) | ((scalar >> 6u) & 0x3F));
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word[3] = (uint8_t)((word[3] & 0xC0) | (scalar & 0x3F));
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return 4;
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}
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return 1;
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}
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int BrotliTransformDictionaryWord(uint8_t* dst, const uint8_t* word, int len,
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const BrotliTransforms* transforms, int transform_idx) {
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int idx = 0;
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const uint8_t* prefix = BROTLI_TRANSFORM_PREFIX(transforms, transform_idx);
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uint8_t type = BROTLI_TRANSFORM_TYPE(transforms, transform_idx);
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const uint8_t* suffix = BROTLI_TRANSFORM_SUFFIX(transforms, transform_idx);
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{
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int prefix_len = *prefix++;
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while (prefix_len--) { dst[idx++] = *prefix++; }
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}
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{
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const int t = type;
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int i = 0;
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if (t <= BROTLI_TRANSFORM_OMIT_LAST_9) {
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len -= t;
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} else if (t >= BROTLI_TRANSFORM_OMIT_FIRST_1
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&& t <= BROTLI_TRANSFORM_OMIT_FIRST_9) {
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int skip = t - (BROTLI_TRANSFORM_OMIT_FIRST_1 - 1);
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word += skip;
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len -= skip;
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}
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while (i < len) { dst[idx++] = word[i++]; }
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if (t == BROTLI_TRANSFORM_UPPERCASE_FIRST) {
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ToUpperCase(&dst[idx - len]);
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} else if (t == BROTLI_TRANSFORM_UPPERCASE_ALL) {
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uint8_t* uppercase = &dst[idx - len];
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while (len > 0) {
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int step = ToUpperCase(uppercase);
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uppercase += step;
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len -= step;
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}
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} else if (t == BROTLI_TRANSFORM_SHIFT_FIRST) {
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uint16_t param = (uint16_t)(transforms->params[transform_idx * 2]
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+ (transforms->params[transform_idx * 2 + 1] << 8u));
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Shift(&dst[idx - len], len, param);
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} else if (t == BROTLI_TRANSFORM_SHIFT_ALL) {
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uint16_t param = (uint16_t)(transforms->params[transform_idx * 2]
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+ (transforms->params[transform_idx * 2 + 1] << 8u));
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uint8_t* shift = &dst[idx - len];
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while (len > 0) {
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int step = Shift(shift, len, param);
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shift += step;
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len -= step;
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}
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}
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}
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{
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int suffix_len = *suffix++;
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while (suffix_len--) { dst[idx++] = *suffix++; }
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return idx;
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}
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}
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#if defined(__cplusplus) || defined(c_plusplus)
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} /* extern "C" */
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#endif
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