static struct item* _item_alloc(uint8_t id, char *key, uint16_t nkey, int exptime, char *value, uint32_t nbyte) {
struct item *it;
struct item *uit;
assert(id >= SLABCLASS_MIN_ID && id <= SLABCLASS_MAX_ID);
it = item_get_from_lruq(id);
if (it != NULL && item_expired(it)) {
item_reuse(it);
goto done;
}
uit = (settings.evict_opt & EVICT_LRU)? it : NULL;
it = slab_get_item(id);
if (it != NULL) {
goto done;
}
if (uit != NULL) {
it = uit;
item_reuse(it);
goto done;
}
return NULL;
done:
assert(it->id == id);
assert(!item_is_linked(it));
assert(!item_is_slabbed(it));
assert(it->offset != 0);
assert(it->refcount == 0);
it->flags = 0;
it->nbyte = nbyte;
it->exptime = exptime + time_now();
it->nkey = nkey;
memcpy(item_key(it), key, nkey);
memcpy(item_key(it) + nkey, value, nbyte);
return it;
}
struct item *
slab_get_item(uint8_t cid)
{
rstatus_t status;
struct slabclass *c;
struct slabinfo *sinfo;
struct slab *slab;
ASSERT(cid >= SLABCLASS_MIN_ID && cid < nctable);
c = &ctable[cid];
if (itemx_empty()) {
status = slab_evict();
if (status != FC_OK) {
return NULL;
}
}
if (!TAILQ_EMPTY(&c->partial_msinfoq)) {
return _slab_get_item(cid);
}
if (!TAILQ_EMPTY(&free_msinfoq)) {
/* move memory slab from free to partial q */
sinfo = TAILQ_FIRST(&free_msinfoq);
ASSERT(nfree_msinfoq > 0);
nfree_msinfoq--;
TAILQ_REMOVE(&free_msinfoq, sinfo, tqe);
/* init partial sinfo */
TAILQ_INSERT_HEAD(&c->partial_msinfoq, sinfo, tqe);
/* sid is already initialized by slab_init */
/* addr is already initialized by slab_init */
sinfo->nalloc = 0;
sinfo->nfree = 0;
sinfo->cid = cid;
/* mem is already initialized by slab_init */
ASSERT(sinfo->mem == 1);
/* init slab of partial sinfo */
slab = slab_from_maddr(sinfo->addr, false);
slab->magic = SLAB_MAGIC;
slab->cid = cid;
/* unused[] is left uninitialized */
slab->sid = sinfo->sid;
/* data[] is initialized on-demand */
return _slab_get_item(cid);
}
ASSERT(!TAILQ_EMPTY(&full_msinfoq));
ASSERT(nfull_msinfoq > 0);
status = slab_drain();
if (status != FC_OK) {
return NULL;
}
return slab_get_item(cid);
}
/*
* Allocate an item. We allocate an item by consuming the next free item
* from slab of the item's slab class.
*
* On success we return the pointer to the allocated item.
*/
static item_rstatus_e
_item_alloc(struct item **it_p, uint8_t klen, uint32_t vlen, uint8_t olen)
{
uint8_t id = slab_id(item_ntotal(klen, vlen, olen));
struct item *it;
log_verb("allocate item with klen %u vlen %u", klen, vlen);
*it_p = NULL;
if (id == SLABCLASS_INVALID_ID) {
return ITEM_EOVERSIZED;
}
it = slab_get_item(id);
*it_p = it;
if (it != NULL) {
_item_reset(it);
slab_ref(item_to_slab(it)); /* slab to be deref'ed in _item_link */
INCR(slab_metrics, item_curr);
INCR(slab_metrics, item_alloc);
PERSLAB_INCR(id, item_curr);
log_verb("alloc it %p of id %"PRIu8" at offset %"PRIu32, it, it->id,
it->offset);
return ITEM_OK;
} else {
INCR(slab_metrics, item_alloc_ex);
log_warn("server error on allocating item in slab %"PRIu8, id);
return ITEM_ENOMEM;
}
}