kc3-lang/brotli/c/enc/prefix.h

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• Hash : 8a7201c6
  Author :
  Date : 2025-08-05T02:49:08
  

  fix some includes
  
  PiperOrigin-RevId: 791124445
  

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• c/enc/prefix.h

• /* 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 for encoding of integers into prefix codes the amount of extra
     bits, and the actual values of the extra bits. */
  
  #ifndef BROTLI_ENC_PREFIX_H_
  #define BROTLI_ENC_PREFIX_H_
  
  #include "../common/constants.h"
  #include "../common/platform.h"
  #include "fast_log.h"
  
  #if defined(__cplusplus) || defined(c_plusplus)
  extern "C" {
  #endif
  
  /* Here distance_code is an intermediate code, i.e. one of the special codes or
     the actual distance increased by BROTLI_NUM_DISTANCE_SHORT_CODES - 1. */
  static BROTLI_INLINE void PrefixEncodeCopyDistance(size_t distance_code,
                                                     size_t num_direct_codes,
                                                     size_t postfix_bits,
                                                     uint16_t* code,
                                                     uint32_t* extra_bits) {
    if (distance_code < BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes) {
      *code = (uint16_t)distance_code;
      *extra_bits = 0;
      return;
    } else {
      size_t dist = ((size_t)1 << (postfix_bits + 2u)) +
          (distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES - num_direct_codes);
      size_t bucket = Log2FloorNonZero(dist) - 1;
      size_t postfix_mask = (1u << postfix_bits) - 1;
      size_t postfix = dist & postfix_mask;
      size_t prefix = (dist >> bucket) & 1;
      size_t offset = (2 + prefix) << bucket;
      size_t nbits = bucket - postfix_bits;
      *code = (uint16_t)((nbits << 10) |
          (BROTLI_NUM_DISTANCE_SHORT_CODES + num_direct_codes +
           ((2 * (nbits - 1) + prefix) << postfix_bits) + postfix));
      *extra_bits = (uint32_t)((dist - offset) >> postfix_bits);
    }
  }
  
  #if defined(__cplusplus) || defined(c_plusplus)
  }  /* extern "C" */
  #endif
  
  #endif  /* BROTLI_ENC_PREFIX_H_ */
  

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