X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=libmemcached%2Fmemcached_hash.c;h=4956d18e0655e784bbb4e7a4b3c0200d4552bb77;hb=acce29c292b435fef4fd486495dca7d653be2bf2;hp=e2454ac99f068f1aa16b9a29bf8749c8004f2aec;hpb=1d7f999b7d38db3308a0533a83fea23987fb0178;p=awesomized%2Flibmemcached diff --git a/libmemcached/memcached_hash.c b/libmemcached/memcached_hash.c index e2454ac9..4956d18e 100644 --- a/libmemcached/memcached_hash.c +++ b/libmemcached/memcached_hash.c @@ -1,28 +1,23 @@ #include "common.h" + /* Defines */ -static uint64_t FNV_64_INIT= 0xcbf29ce484222325LL; -static uint64_t FNV_64_PRIME= 0x100000001b3LL; +static uint64_t FNV_64_INIT= UINT64_C(0xcbf29ce484222325); +static uint64_t FNV_64_PRIME= UINT64_C(0x100000001b3); static uint32_t FNV_32_INIT= 2166136261UL; static uint32_t FNV_32_PRIME= 16777619; /* Prototypes */ -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_hash(const char *key, size_t key_length); +static uint32_t internal_generate_md5(const char *key, size_t key_length); -uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length) +uint32_t memcached_generate_hash_value(const char *key, size_t key_length, memcached_hash hash_algorithm) { uint32_t hash= 1; /* Just here to remove compile warning */ uint32_t x= 0; - - WATCHPOINT_ASSERT(ptr->number_of_hosts); - - if (ptr->number_of_hosts == 1) - return 0; - - switch (ptr->hash) + switch (hash_algorithm) { case MEMCACHED_HASH_DEFAULT: hash= internal_generate_hash(key, key_length); @@ -52,11 +47,11 @@ uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length) break; case MEMCACHED_HASH_FNV1A_64: { - hash= FNV_64_INIT; + hash= (uint32_t) FNV_64_INIT; for (x= 0; x < key_length; x++) { hash ^= key[x]; - hash *= FNV_64_PRIME; + hash *= (uint32_t) FNV_64_PRIME; } } break; @@ -82,7 +77,9 @@ uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length) break; case MEMCACHED_HASH_HSIEH: { +#ifdef HAVE_HSIEH_HASH hash= hsieh_hash(key, key_length); +#endif break; } case MEMCACHED_HASH_MURMUR: @@ -90,78 +87,79 @@ uint32_t generate_hash(memcached_st *ptr, char *key, size_t key_length) hash= murmur_hash(key, key_length); break; } + case MEMCACHED_HASH_JENKINS: + { + hash=jenkins_hash(key, key_length, 13); + break; + } + default: + { + WATCHPOINT_ASSERT(hash_algorithm); + break; + } } + return hash; +} + +uint32_t generate_hash(memcached_st *ptr, const char *key, size_t key_length) +{ + uint32_t hash= 1; /* Just here to remove compile warning */ + + + WATCHPOINT_ASSERT(ptr->number_of_hosts); + + if (ptr->number_of_hosts == 1) + return 0; + hash= memcached_generate_hash_value(key, key_length, ptr->hash); WATCHPOINT_ASSERT(hash); return hash; } -unsigned int dispatch_host(memcached_st *ptr, uint32_t hash) +static uint32_t dispatch_host(memcached_st *ptr, uint32_t hash) { switch (ptr->distribution) { case MEMCACHED_DISTRIBUTION_CONSISTENT: case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA: { - uint32_t num= ptr->number_of_hosts * MEMCACHED_POINTS_PER_SERVER; + uint32_t num= ptr->continuum_points_counter; WATCHPOINT_ASSERT(ptr->continuum); hash= hash; memcached_continuum_item_st *begin, *end, *left, *right, *middle; begin= left= ptr->continuum; - end= right= ptr->continuum + (num - 1); + end= right= ptr->continuum + num; - while (1) + while (left < right) { - memcached_continuum_item_st *rmiddle; - - middle = left + (right - left) / 2; - - if (middle==end) - return begin->index; - - if (middle==begin) - return end->index; - - rmiddle = middle+1; - - if (hashvalue && hash>=middle->value) - return middle->index; - + middle= left + (right - left) / 2; if (middle->value < hash) - left = middle + 1; - else if (middle->value > hash) - right = middle - 1; - - if (left>right) - return left->index; + left= middle + 1; + else + right= middle; } + if (right == end) + right= begin; + return right->index; } - break; - case MEMCACHED_DISTRIBUTION_CONSISTENT_WHEEL: - { - unsigned int server_key; - - server_key= hash % MEMCACHED_STRIDE * ptr->wheel_count; - - return ptr->wheel[server_key]; - } case MEMCACHED_DISTRIBUTION_MODULA: return hash % ptr->number_of_hosts; + case MEMCACHED_DISTRIBUTION_RANDOM: + return (uint32_t) random() % ptr->number_of_hosts; default: WATCHPOINT_ASSERT(0); /* We have added a distribution without extending the logic */ return hash % ptr->number_of_hosts; } - WATCHPOINT_ASSERT(0); /* We should never reach here */ - return 0; + /* NOTREACHED */ } /* One day make this public, and have it return the actual memcached_server_st to the calling application. */ -uint32_t memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length) +uint32_t memcached_generate_hash(memcached_st *ptr, const char *key, size_t key_length) { uint32_t hash= 1; /* Just here to remove compile warning */ @@ -170,20 +168,44 @@ uint32_t memcached_generate_hash(memcached_st *ptr, char *key, size_t key_length if (ptr->number_of_hosts == 1) return 0; - hash = generate_hash(ptr, key, key_length); + if (ptr->flags & MEM_HASH_WITH_PREFIX_KEY) + { + size_t temp_length= ptr->prefix_key_length + key_length; + char temp[temp_length]; + + if (temp_length > MEMCACHED_MAX_KEY -1) + return 0; + + strncpy(temp, ptr->prefix_key, ptr->prefix_key_length); + strncpy(temp + ptr->prefix_key_length, key, key_length); + hash= generate_hash(ptr, temp, temp_length); + } + else + { + hash= generate_hash(ptr, key, key_length); + } WATCHPOINT_ASSERT(hash); + + if (memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS) && ptr->next_distribution_rebuild) { + struct timeval now; + + if (gettimeofday(&now, NULL) == 0 && + now.tv_sec > ptr->next_distribution_rebuild) + run_distribution(ptr); + } + return dispatch_host(ptr, hash); } -static uint32_t internal_generate_hash(char *key, size_t key_length) +static uint32_t internal_generate_hash(const char *key, size_t key_length) { - char *ptr= key; + const char *ptr= key; uint32_t value= 0; - while (--key_length) + while (key_length--) { - value += *ptr++; + value += (uint32_t) *ptr++; value += (value << 10); value ^= (value >> 6); } @@ -191,10 +213,10 @@ static uint32_t internal_generate_hash(char *key, size_t key_length) value ^= (value >> 11); value += (value << 15); - return value == 0 ? 1 : value; + return value == 0 ? 1 : (uint32_t) value; } -static uint32_t internal_generate_md5(char *key, size_t key_length) +static uint32_t internal_generate_md5(const char *key, size_t key_length) { unsigned char results[16];