#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_ketama_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);
-unsigned int memcached_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_t hash_algorithm)
{
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;
+ uint32_t x= 0;
- switch (ptr->hash)
+ switch (hash_algorithm)
{
case MEMCACHED_HASH_DEFAULT:
hash= internal_generate_hash(key, key_length);
hash= 1;
break;
/* FNV hash'es lifted from Dustin Sallings work */
- case MEMCACHED_HASH_FNV1_64:
+ case MEMCACHED_HASH_FNV1_64:
{
/* Thanks to pierre@demartines.com for the pointer */
uint64_t temp_hash;
temp_hash= FNV_64_INIT;
- for (x= 0; x < key_length; x++)
+ for (x= 0; x < key_length; x++)
{
temp_hash *= FNV_64_PRIME;
- temp_hash ^= key[x];
+ temp_hash ^= (uint64_t)key[x];
}
hash= (uint32_t)temp_hash;
}
break;
- case MEMCACHED_HASH_FNV1A_64:
+ case MEMCACHED_HASH_FNV1A_64:
{
- hash= FNV_64_INIT;
- for (x= 0; x < key_length; x++)
+ hash= (uint32_t) FNV_64_INIT;
+ for (x= 0; x < key_length; x++)
{
- hash ^= key[x];
- hash *= FNV_64_PRIME;
+ uint32_t val= (uint32_t)key[x];
+ hash ^= val;
+ hash *= (uint32_t) FNV_64_PRIME;
}
}
break;
- case MEMCACHED_HASH_FNV1_32:
+ case MEMCACHED_HASH_FNV1_32:
{
hash= FNV_32_INIT;
- for (x= 0; x < key_length; x++)
+ for (x= 0; x < key_length; x++)
{
+ uint32_t val= (uint32_t)key[x];
hash *= FNV_32_PRIME;
- hash ^= key[x];
+ hash ^= val;
}
}
break;
- case MEMCACHED_HASH_FNV1A_32:
+ case MEMCACHED_HASH_FNV1A_32:
{
hash= FNV_32_INIT;
- for (x= 0; x < key_length; x++)
+ for (x= 0; x < key_length; x++)
{
- hash ^= key[x];
+ uint32_t val= (uint32_t)key[x];
+ hash ^= val;
hash *= FNV_32_PRIME;
}
}
break;
- case MEMCACHED_HASH_KETAMA:
- {
- hash= internal_generate_ketama_md5(key, key_length);
- break;
- }
case MEMCACHED_HASH_HSIEH:
{
+#ifdef HAVE_HSIEH_HASH
hash= hsieh_hash(key, key_length);
+#endif
break;
}
case MEMCACHED_HASH_MURMUR:
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;
+}
- if (ptr->distribution == MEMCACHED_DISTRIBUTION_MODULA)
+static uint32_t dispatch_host(memcached_st *ptr, uint32_t hash)
+{
+ switch (ptr->distribution)
{
+ case MEMCACHED_DISTRIBUTION_CONSISTENT:
+ case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA:
+ case MEMCACHED_DISTRIBUTION_CONSISTENT_KETAMA_SPY:
+ {
+ 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;
+
+ while (left < right)
+ {
+ middle= left + (right - left) / 2;
+ if (middle->value < hash)
+ left= middle + 1;
+ else
+ right= middle;
+ }
+ if (right == end)
+ right= begin;
+ return right->index;
+ }
+ 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;
}
+
+ /* 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, 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;
+
+ if (ptr->flags.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
{
- unsigned int server_key;
+ hash= generate_hash(ptr, key, key_length);
+ }
+
+ WATCHPOINT_ASSERT(hash);
- server_key= hash % MEMCACHED_WHEEL_SIZE;
+ if (memcached_behavior_get(ptr, MEMCACHED_BEHAVIOR_AUTO_EJECT_HOSTS) && ptr->next_distribution_rebuild) {
+ struct timeval now;
- return ptr->wheel[server_key];
+ 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++;
+ uint32_t val= (uint32_t) *ptr++;
+ value += val;
value += (value << 10);
value ^= (value >> 6);
}
value += (value << 3);
value ^= (value >> 11);
- value += (value << 15);
-
- return value == 0 ? 1 : value;
-}
-
-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);
+ value += (value << 15);
- return (uint32_t)(( results[3] << 24 )
- | ( results[2] << 16 )
- | ( results[1] << 8 )
- | results[0] );
+ return value == 0 ? 1 : (uint32_t) value;
}
-static uint32_t internal_generate_ketama_md5(char *key, size_t key_length)
+static uint32_t internal_generate_md5(const char *key, size_t key_length)
{
unsigned char results[16];
projects / m6w6 / libmemcached / blobdiff