File indexing completed on 2025-02-02 04:25:58

 /* Copyright 2015 the unarr project authors (see AUTHORS file).
    License: LGPLv3 */
 
 #include "unarr-imp.h"
 
 #ifndef HAVE_ZLIB
 
 /* code adapted from https://gnunet.org/svn/gnunet/src/util/crypto_crc.c (public domain) */
 
 static bool crc_table_ready = false;
 static uint32_t crc_table[256];
 
 uint32_t ar_crc32(uint32_t crc32, const unsigned char *data, size_t data_len)
 {
     if (!crc_table_ready) {
         uint32_t i, j;
         uint32_t h = 1;
         crc_table[0] = 0;
         for (i = 128; i; i >>= 1) {
             h = (h >> 1) ^ ((h & 1) ? 0xEDB88320 : 0);
             for (j = 0; j < 256; j += 2 * i) {
                 crc_table[i + j] = crc_table[j] ^ h;
             }
         }
         crc_table_ready = true;
     }
 
     crc32 = crc32 ^ 0xFFFFFFFF;
     while (data_len-- > 0) {
         crc32 = (crc32 >> 8) ^ crc_table[(crc32 ^ *data++) & 0xFF];
     }
     return crc32 ^ 0xFFFFFFFF;
 }
 
 #else
 
 #include <zlib.h>
 
 uint32_t ar_crc32(uint32_t crc, const unsigned char *data, size_t data_len)
 {
 #if SIZE_MAX > UINT32_MAX
     while (data_len > UINT32_MAX) {
         crc = crc32(crc, data, UINT32_MAX);
         data += UINT32_MAX;
         data_len -= UINT32_MAX;
     }
 #endif
     return crc32(crc, data, (uint32_t)data_len);
 }
 
 #endif