Generating hash values directly

Hash a key value

SYNOPSIS

#include <libmemcached/memcached.h>
Compile and link with -lmemcachedutil -lmemcached
uint32_t memcached_generate_hash_value(const char *key, size_t key_length, memcached_hash_t hash_algorithm)
Parameters:
  • key -- the key to generate a hash of
  • key_length -- the length of the key without any terminating zero
  • hash_algorithm -- memcached_hash_t, the algorithm to use
Returns:

a 32 bit hash value
uint32_t memcached_generate_hash(memcached_st *ptr, const char *key, size_t key_length)
Parameters:
  • ptr -- pointer to an initialized memcached_st struct
  • key -- the key to generate a hash of
  • key_length -- the length of the key without any terminating zero
Returns:

a 32 bit hash value
enum memcached_hash_t memcached_hash_t
enum memcached_hash_t
enumerator MEMCACHED_HASH_DEFAULT
enumerator MEMCACHED_HASH_MD5
enumerator MEMCACHED_HASH_CRC
enumerator MEMCACHED_HASH_FNV1_64
enumerator MEMCACHED_HASH_FNV1A_64
enumerator MEMCACHED_HASH_FNV1_32
enumerator MEMCACHED_HASH_FNV1A_32
enumerator MEMCACHED_HASH_HSIEH
enumerator MEMCACHED_HASH_MURMUR
enumerator MEMCACHED_HASH_JENKINS
enumerator MEMCACHED_HASH_MURMUR3
enumerator MEMCACHED_HASH_CUSTOM

DESCRIPTION

memcached_generate_hash_value() allows you to hash a key using one of the hash functions defined in the library. This method is provided for the convenience of higher-level language bindings and is not necessary for normal memcache operations.

Support for MEMCACHED_HASH_HSIEH is a compile time option that is disabled by default. To enable tests for this hashing algorithm, configure and build libmemcached with the Hsieh hash enabled.

memcached_generate_hash() takes a memcached_st structure and produces the hash value that would have been generated based on the defaults of memcached_st.

As of version 0.36 all hash methods have been placed into the library libhashkit(3) which is linked with libmemcached(3). For more information please see its documentation.

RETURN VALUE

A 32-bit integer which is the result of hashing the given key. For 64-bit hash algorithms, only the least-significant 32 bits are returned.

SEE ALSO