struct item *item_alloc(uint8_t id, char *key, uint16_t nkey, int exptime, char *value, uint32_t nbyte) {
struct item *it, *oit;
pthread_mutex_lock(&cache_lock);
it = _item_alloc(id, key, nkey, exptime, value, nbyte);
if (it == NULL) return NULL;
oit = _item_get(key, nkey);
if (oit != NULL) _item_replace(oit, it);
else {
_item_link(it);
}
if (oit != NULL) _item_remove(oit);
pthread_mutex_unlock(&cache_lock);
return it;
}
item_rstatus_e
item_reserve(struct item **it_p, const struct bstring *key, const struct bstring
*val, uint32_t vlen, uint8_t olen, proc_time_i expire_at)
{
item_rstatus_e status;
struct item *it;
if ((status = _item_alloc(it_p, key->len, vlen, olen)) != ITEM_OK) {
log_debug("item reservation failed");
return status;
}
it = *it_p;
_item_define(it, key, val, olen, expire_at);
log_verb("reserve it %p of id %"PRIu8" for key '%.*s' optional len %"PRIu8,
it, it->id,key->len, key->data, olen);
return ITEM_OK;
}
item_rstatus_e
item_annex(struct item *oit, const struct bstring *key, const struct bstring
*val, bool append)
{
item_rstatus_e status = ITEM_OK;
struct item *nit = NULL;
uint8_t id;
uint32_t ntotal = oit->vlen + val->len;
id = item_slabid(oit->klen, ntotal, oit->olen);
if (id == SLABCLASS_INVALID_ID) {
log_info("client error: annex operation results in oversized item with"
"key size %"PRIu8" old value size %"PRIu32" and new value "
"size %"PRIu32, oit->klen, oit->vlen, ntotal);
return ITEM_EOVERSIZED;
}
if (append) {
/* if it is large enough to hold the extra data and left-aligned,
* which is the default behavior, we copy the delta to the end of
* the existing data. Otherwise, allocate a new item and store the
* payload left-aligned.
*/
if (id == oit->id && !(oit->is_raligned)) {
cc_memcpy(item_data(oit) + oit->vlen, val->data, val->len);
oit->vlen = ntotal;
INCR_N(slab_metrics, item_keyval_byte, val->len);
INCR_N(slab_metrics, item_val_byte, val->len);
item_set_cas(oit);
} else {
status = _item_alloc(&nit, oit->klen, ntotal, oit->olen);
if (status != ITEM_OK) {
log_debug("annex failed due to failure to allocate new item");
return status;
}
_copy_key_item(nit, oit);
nit->expire_at = oit->expire_at;
nit->create_at = time_proc_sec();
item_set_cas(nit);
/* value is left-aligned */
cc_memcpy(item_data(nit), item_data(oit), oit->vlen);
cc_memcpy(item_data(nit) + oit->vlen, val->data, val->len);
nit->vlen = ntotal;
item_insert(nit, key);
}
} else {
/* if oit is large enough to hold the extra data and is already
* right-aligned, we copy the delta to the front of the existing
* data. Otherwise, allocate a new item and store the payload
* right-aligned, assuming more prepends will happen in the future.
*/
if (id == oit->id && oit->is_raligned) {
cc_memcpy(item_data(oit) - val->len, val->data, val->len);
oit->vlen = ntotal;
INCR_N(slab_metrics, item_keyval_byte, val->len);
INCR_N(slab_metrics, item_val_byte, val->len);
item_set_cas(oit);
} else {
status = _item_alloc(&nit, oit->klen, ntotal, oit->olen);
if (status != ITEM_OK) {
log_debug("annex failed due to failure to allocate new item");
return status;
}
_copy_key_item(nit, oit);
nit->expire_at = oit->expire_at;
nit->create_at = time_proc_sec();
item_set_cas(nit);
/* value is right-aligned */
nit->is_raligned = 1;
cc_memcpy(item_data(nit) - ntotal, val->data, val->len);
cc_memcpy(item_data(nit) - oit->vlen, item_data(oit), oit->vlen);
nit->vlen = ntotal;
item_insert(nit, key);
}
}
log_verb("annex to it %p of id %"PRIu8", new it at %p", oit, oit->id,
nit ? oit : nit);
return status;
}
