uthash.h File Reference

Go to the source code of this file.

Macros
#define	HASH_FUNCTION(keyptr, keylen, hashv)
#define	HASH_JEN_MIX(a, b, c)

Macro Definition Documentation

HASH_FUNCTION

#define HASH_FUNCTION	(		keyptr,
			keylen,
			hashv
	)

Value:

  do {                                                                                                                 \
    if (!(keyptr) || (keylen) == 0) {                                                                                  \
      (hashv) = 1; /* Non-zero constant for safety */                                                                  \
    } else {                                                                                                           \
      (hashv) = fnv1a_hash_bytes((keyptr), (keylen));                                                                  \
    }                                                                                                                  \
  } while (0)

Definition at line 41 of file uthash.h.

     {                                                                                                                 \
    if (!(keyptr) || (keylen) == 0) {                                                                                  \
      (hashv) = 1; /* Non-zero constant for safety */                                                                  \
    } else {                                                                                                           \
      (hashv) = fnv1a_hash_bytes((keyptr), (keylen));                                                                  \
    }                                                                                                                  \
  } while (0)

HASH_JEN_MIX

#define HASH_JEN_MIX	(		a,
			b,
			c
	)

Definition at line 59 of file uthash.h.

     {                                                                                                                 \
    /* Use 64-bit arithmetic for shifts to avoid undefined behavior, then mask back to 32-bit */                       \
    uint64_t _a = (uint64_t)(a), _b = (uint64_t)(b), _c = (uint64_t)(c);                                               \
    _a -= _b;                                                                                                          \
    _a -= _c;                                                                                                          \
    _a ^= (_c >> 13);                                                                                                  \
    a = (unsigned)(_a & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _b -= _c;                                                                                                          \
    _b -= (uint64_t)a;                                                                                                 \
    _b ^= (((uint64_t)a << 8) & 0xFFFFFFFFU);                                                                          \
    b = (unsigned)(_b & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _c -= (uint64_t)a;                                                                                                 \
    _c -= (uint64_t)b;                                                                                                 \
    _c ^= ((uint64_t)b >> 13);                                                                                         \
    c = (unsigned)(_c & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _a = (uint64_t)a;                                                                                                  \
    _a -= (uint64_t)b;                                                                                                 \
    _a -= (uint64_t)c;                                                                                                 \
    _a ^= ((uint64_t)c >> 12);                                                                                         \
    a = (unsigned)(_a & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _b = (uint64_t)b;                                                                                                  \
    _b -= (uint64_t)c;                                                                                                 \
    _b -= (uint64_t)a;                                                                                                 \
    _b ^= (((uint64_t)a << 16) & 0xFFFFFFFFU);                                                                         \
    b = (unsigned)(_b & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _c = (uint64_t)c;                                                                                                  \
    _c -= (uint64_t)a;                                                                                                 \
    _c -= (uint64_t)b;                                                                                                 \
    _c ^= ((uint64_t)b >> 5);                                                                                          \
    c = (unsigned)(_c & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _a = (uint64_t)a;                                                                                                  \
    _a -= (uint64_t)b;                                                                                                 \
    _a -= (uint64_t)c;                                                                                                 \
    _a ^= ((uint64_t)c >> 3);                                                                                          \
    a = (unsigned)(_a & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _b = (uint64_t)b;                                                                                                  \
    _b -= (uint64_t)c;                                                                                                 \
    _b -= (uint64_t)a;                                                                                                 \
    _b ^= (((uint64_t)a << 10) & 0xFFFFFFFFU);                                                                         \
    b = (unsigned)(_b & 0xFFFFFFFFU);                                                                                  \
                                                                                                                       \
    _c = (uint64_t)c;                                                                                                  \
    _c -= (uint64_t)a;                                                                                                 \
    _c -= (uint64_t)b;                                                                                                 \
    _c ^= ((uint64_t)b >> 15);                                                                                         \
    c = (unsigned)(_c & 0xFFFFFFFFU);                                                                                  \
  } while (0)