nostrdb

an unfairly fast embedded nostr database backed by lmdb
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PMurHash.h (1982B)


      1 /*-----------------------------------------------------------------------------
      2  * MurmurHash3 was written by Austin Appleby, and is placed in the public
      3  * domain.
      4  *
      5  * This implementation was written by Shane Day, and is also public domain.
      6  *
      7  * This is a portable ANSI C implementation of MurmurHash3_x86_32 (Murmur3A)
      8  * with support for progressive processing.
      9  */
     10 
     11 /* ------------------------------------------------------------------------- */
     12 /* Determine what native type to use for uint32_t */
     13 
     14 /* We can't use the name 'uint32_t' here because it will conflict with
     15  * any version provided by the system headers or application. */
     16 
     17 /* First look for special cases */
     18 #if defined(_MSC_VER)
     19   #define MH_UINT32 unsigned long
     20 #endif
     21 
     22 /* If the compiler says it's C99 then take its word for it */
     23 #if !defined(MH_UINT32) && ( \
     24      defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L )
     25   #include <stdint.h>
     26   #define MH_UINT32 uint32_t
     27 #endif
     28 
     29 /* Otherwise try testing against max value macros from limit.h */
     30 #if !defined(MH_UINT32)
     31   #include  <limits.h>
     32   #if   (USHRT_MAX == 0xffffffffUL)
     33     #define MH_UINT32 unsigned short
     34   #elif (UINT_MAX == 0xffffffffUL)
     35     #define MH_UINT32 unsigned int
     36   #elif (ULONG_MAX == 0xffffffffUL)
     37     #define MH_UINT32 unsigned long
     38   #endif
     39 #endif
     40 
     41 #if !defined(MH_UINT32)
     42   #error Unable to determine type name for unsigned 32-bit int
     43 #endif
     44 
     45 /* I'm yet to work on a platform where 'unsigned char' is not 8 bits */
     46 #define MH_UINT8  unsigned char
     47 
     48 
     49 /* ------------------------------------------------------------------------- */
     50 /* Prototypes */
     51 
     52 #ifdef __cplusplus
     53 extern "C" {
     54 #endif
     55 
     56 void PMurHash32_Process(MH_UINT32 *ph1, MH_UINT32 *pcarry, const void *key, int len);
     57 MH_UINT32 PMurHash32_Result(MH_UINT32 h1, MH_UINT32 carry, MH_UINT32 total_length);
     58 MH_UINT32 PMurHash32(MH_UINT32 seed, const void *key, int len);
     59 
     60 void PMurHash32_test(const void *key, int len, MH_UINT32 seed, void *out);
     61 
     62 #ifdef __cplusplus
     63 }
     64 #endif