X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=lib%2Fmemcached_hash.c;h=f365cc0ee6815b817e3304573b316a0d3f098144;hb=013715211f094bb98ab7ed830b6cd24328641eba;hp=7e7814e6818be2802c50d8f25929897bac73e2c8;hpb=c119fcae0b2be6b079fa20a661146b108755399c;p=awesomized%2Flibmemcached diff --git a/lib/memcached_hash.c b/lib/memcached_hash.c index 7e7814e6..f365cc0e 100644 --- a/lib/memcached_hash.c +++ b/lib/memcached_hash.c @@ -8,15 +8,20 @@ static uint32_t FNV_32_INIT= 2166136261UL; static uint32_t FNV_32_PRIME= 16777619; /* Prototypes */ -static uint64_t internal_generate_hash(char *key, size_t key_length); -static uint64_t internal_generate_md5(char *key, size_t key_length); -static uint64_t internal_generate_ketama_md5(char *key, size_t key_length); +static uint32_t internal_generate_hash(char *key, size_t key_length); +static uint32_t internal_generate_md5(char *key, size_t key_length); +static uint32_t internal_generate_ketama_md5(char *key, size_t key_length); unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length) { - uint64_t hash= 1; /* Just here to remove compile warning */ + uint32_t hash= 1; /* Just here to remove compile warning */ unsigned int x; + WATCHPOINT_ASSERT(ptr->number_of_hosts); + + if (ptr->number_of_hosts == 1) + return 0; + switch (ptr->hash) { case MEMCACHED_HASH_DEFAULT: @@ -27,17 +32,22 @@ unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_le break; case MEMCACHED_HASH_CRC: hash= ((hash_crc32(key, key_length) >> 16) & 0x7fff); + if (hash == 0) + hash= 1; break; /* FNV hash'es lifted from Dustin Sallings work */ case MEMCACHED_HASH_FNV1_64: { /* Thanks to pierre@demartines.com for the pointer */ - hash= FNV_64_INIT; + uint64_t temp_hash; + + temp_hash= FNV_64_INIT; for (x= 0; x < key_length; x++) { - hash *= FNV_64_PRIME; - hash ^= key[x]; + temp_hash *= FNV_64_PRIME; + temp_hash ^= key[x]; } + hash= (uint32_t)temp_hash; } break; case MEMCACHED_HASH_FNV1A_64: @@ -75,22 +85,38 @@ unsigned int memcached_generate_hash(memcached_st *ptr, char *key, size_t key_le hash= internal_generate_ketama_md5(key, key_length); break; } + case MEMCACHED_HASH_HSIEH: + { + hash= hsieh_hash(key, key_length); + break; + } + case MEMCACHED_HASH_MURMUR: + { + hash= murmur_hash(key, key_length); + break; + } } WATCHPOINT_ASSERT(hash); - if (ptr->flags & MEM_USE_KETAMA) + + if (ptr->distribution == MEMCACHED_DISTRIBUTION_MODULA) { - WATCHPOINT_ASSERT(0); - return 0; + return hash % ptr->number_of_hosts; } else - return hash % ptr->number_of_hosts; + { + unsigned int server_key; + + server_key= hash % MEMCACHED_WHEEL_SIZE; + + return ptr->wheel[server_key]; + } } -static uint64_t internal_generate_hash(char *key, size_t key_length) +static uint32_t internal_generate_hash(char *key, size_t key_length) { char *ptr= key; - uint64_t value= 0; + uint32_t value= 0; while (--key_length) { @@ -105,19 +131,19 @@ static uint64_t internal_generate_hash(char *key, size_t key_length) return value == 0 ? 1 : value; } -static uint64_t internal_generate_md5(char *key, size_t key_length) +static uint32_t internal_generate_md5(char *key, size_t key_length) { unsigned char results[16]; md5_signature((unsigned char*)key, (unsigned int)key_length, results); - return (uint64_t)(( results[3] << 24 ) + return (uint32_t)(( results[3] << 24 ) | ( results[2] << 16 ) | ( results[1] << 8 ) | results[0] ); } -static uint64_t internal_generate_ketama_md5(char *key, size_t key_length) +static uint32_t internal_generate_ketama_md5(char *key, size_t key_length) { unsigned char results[16];