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

• Show log

  Commit

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

  fix some includes
  
  PiperOrigin-RevId: 791124445
  

Download

• c/enc/find_match_length.h

• /* Copyright 2010 Google Inc. All Rights Reserved.
  
     Distributed under MIT license.
     See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
  */
  
  /* Function to find maximal matching prefixes of strings. */
  
  #ifndef BROTLI_ENC_FIND_MATCH_LENGTH_H_
  #define BROTLI_ENC_FIND_MATCH_LENGTH_H_
  
  #include "../common/platform.h"
  
  #if defined(__cplusplus) || defined(c_plusplus)
  extern "C" {
  #endif
  
  /* Separate implementation for little-endian 64-bit targets, for speed. */
  #if defined(BROTLI_TZCNT64) && BROTLI_64_BITS && BROTLI_LITTLE_ENDIAN
  static BROTLI_INLINE size_t FindMatchLengthWithLimit(const uint8_t* s1,
                                                       const uint8_t* s2,
                                                       size_t limit) {
    const uint8_t *s1_orig = s1;
    for (; limit >= 8; limit -= 8) {
      uint64_t x = BROTLI_UNALIGNED_LOAD64LE(s2) ^
                   BROTLI_UNALIGNED_LOAD64LE(s1);
      s2 += 8;
      if (x != 0) {
        size_t matching_bits = (size_t)BROTLI_TZCNT64(x);
        return (size_t)(s1 - s1_orig) + (matching_bits >> 3);
      }
      s1 += 8;
    }
    while (limit && *s1 == *s2) {
      limit--;
      ++s2;
      ++s1;
    }
    return (size_t)(s1 - s1_orig);
  }
  #else
  static BROTLI_INLINE size_t FindMatchLengthWithLimit(const uint8_t* s1,
                                                       const uint8_t* s2,
                                                       size_t limit) {
    size_t matched = 0;
    const uint8_t* s2_limit = s2 + limit;
    const uint8_t* s2_ptr = s2;
    /* Find out how long the match is. We loop over the data 32 bits at a
       time until we find a 32-bit block that doesn't match; then we find
       the first non-matching bit and use that to calculate the total
       length of the match. */
    while (s2_ptr <= s2_limit - 4 &&
           BrotliUnalignedRead32(s2_ptr) ==
           BrotliUnalignedRead32(s1 + matched)) {
      s2_ptr += 4;
      matched += 4;
    }
    while ((s2_ptr < s2_limit) && (s1[matched] == *s2_ptr)) {
      ++s2_ptr;
      ++matched;
    }
    return matched;
  }
  #endif
  
  #if defined(__cplusplus) || defined(c_plusplus)
  }  /* extern "C" */
  #endif
  
  #endif  /* BROTLI_ENC_FIND_MATCH_LENGTH_H_ */
  

Download