int cluster_config_key_is_mine(struct cluster_config *config,
const char *key, size_t nkey, bool *mine,
uint32_t *key_id, uint32_t *self_id)
{
uint32_t server, self;
uint32_t digest;
int ret = 0;
assert(config);
assert(config->continuum);
pthread_mutex_lock(&config->lock);
if (config->is_valid) {
/* cluster is valid */
self = config->self_id;
digest = hash_ketama(key, nkey);
server = find_continuum(config->continuum, config->num_continuum, digest);
*mine = (server == self ? true : false);
if ( key_id) *key_id = server;
if (self_id) *self_id = self;
} else {
/* this case should not be happened. */
ret = -1; /* unknown cluster */
}
pthread_mutex_unlock(&config->lock);
return ret;
}
bool cluster_config_key_is_mine(struct cluster_config *config, const char *key, size_t nkey,
uint32_t *key_id, uint32_t *self_id)
{
uint32_t server, self;
uint32_t digest, mid, prev;
struct continuum_item *beginp, *endp, *midp, *highp, *lowp;
assert(config);
assert(config->continuum);
pthread_mutex_lock(&config->lock);
// this should not be happened
if (config->is_valid == false) {
pthread_mutex_unlock(&config->lock);
return true;
}
self = config->self_id;
digest = hash_ketama(key, nkey);
beginp = lowp = config->continuum;
endp = highp = config->continuum + config->num_continuum;
while (1) {
// pick the middle point
midp = lowp + (highp - lowp) / 2;
if (midp == endp) {
// if at the end, rollback to 0th
server = beginp->index;
break;
}
mid = midp->point;
prev = (midp == beginp) ? 0 : (midp-1)->point;
if (digest <= mid && digest > prev) {
// found the nearest server
server = midp->index;
break;
}
// adjust the limits
if (mid < digest) lowp = midp + 1;
else highp = midp - 1;
if (lowp > highp) {
server = beginp->index;
break;
}
}
if ( key_id) *key_id = server;
if (self_id) *self_id = self;
pthread_mutex_unlock(&config->lock);
return server == self;
}
int vbucket_map(VBUCKET_CONFIG_HANDLE vb, const void *key, size_t nkey,
int *vbucket_id, int *server_idx)
{
uint32_t digest, mid, prev;
struct continuum_item_st *beginp, *endp, *midp, *highp, *lowp;
if (vb->distribution == VBUCKET_DISTRIBUTION_KETAMA) {
assert(vb->continuum);
if (vbucket_id) {
*vbucket_id = 0;
}
digest = hash_ketama(key, nkey);
beginp = lowp = vb->continuum;
endp = highp = vb->continuum + vb->num_continuum;
/* divide and conquer array search to find server with next biggest
* point after what this key hashes to */
while (1)
{
/* pick the middle point */
midp = lowp + (highp - lowp) / 2;
if (midp == endp) {
/* if at the end, roll back to zeroth */
*server_idx = beginp->index;
break;
}
mid = midp->point;
prev = (midp == beginp) ? 0 : (midp-1)->point;
if (digest <= mid && digest > prev) {
/* we found nearest server */
*server_idx = midp->index;
break;
}
/* adjust the limits */
if (mid < digest) {
lowp = midp + 1;
} else {
highp = midp - 1;
}
if (lowp > highp) {
*server_idx = beginp->index;
break;
}
}
} else {
*vbucket_id = vbucket_get_vbucket_by_key(vb, key, nkey);
*server_idx = vbucket_get_master(vb, *vbucket_id);
}
return 0;
}
uint32_t cluster_config_ketama_hash(struct cluster_config *config,
const char *key, size_t nkey)
{
assert(config);
return hash_ketama(key, nkey);
}
