我正在尝试实现我从这里得到的 SuperFastHash 算法; http://www.azillionmonkeys.com/qed/hash.html
这是我的 .h 和 .cpp SuperFastHash.h
#ifndef SUPER_FAST_HASH
#define SUPER_FAST_HASH
// #include "pstdint.h" /* Replace with <stdint.h> if appropriate */
#include <stdint.h>
#include <cstddef>
#undef get16bits
#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
|| defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
#define get16bits(d) (*((const uint16_t *) (d)))
#endif
#if !defined (get16bits)
#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
+(uint32_t)(((const uint8_t *)(d))[0]) )
#endif
uint32_t SuperFastHash (const char * data, int len);
#endif
这是我的.cpp
#include "SuperFastHash.h"
uint32_t SuperFastHash (const char * data, int len) {
uint32_t hash = len, tmp;
int rem = 0;
if (len <= 0 || data == NULL) return 0;
rem = len & 3;
len >>= 2;
/* Main loop */
for (;len > 0; len--) {
hash += get16bits (data);
tmp = (get16bits (data+2) << 11) ^ hash;
hash = (hash << 16) ^ tmp;
data += 2*sizeof (uint16_t);
hash += hash >> 11;
}
/* Handle end cases */
switch (rem) {
case 3: hash += get16bits (data);
hash ^= hash << 16;
hash ^= ((signed char)data[sizeof (uint16_t)]) << 18;
hash += hash >> 11;
break;
case 2: hash += get16bits (data);
hash ^= hash << 11;
hash += hash >> 17;
break;
case 1: hash += (signed char)*data;
hash ^= hash << 10;
hash += hash >> 1;
}
/* Force "avalanching" of final 127 bits */
hash ^= hash << 3;
hash += hash >> 5;
hash ^= hash << 4;
hash += hash >> 17;
hash ^= hash << 25;
hash += hash >> 6;
return hash;
}
问题是,当我运行这条线时,它似乎崩溃了: uint32_t entityHashId = SuperFastHash(entityname.c_str(), strlen(entityname.c_str()));
(实体名是一个 const std::string& 实体名)
它thorws此错误消息:调试错误{Path to .exe file} Invalid allocation size: 4294967295 bytes。(按重试调试应用程序)[中止] [重试] [忽略]