int do_item_link(item *it) {
MEMCACHED_ITEM_LINK(ITEM_key(it), it->nkey, it->nbytes);
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
assert(it->nbytes < (1024 * 1024)); /* 1MB max size */
it->it_flags |= ITEM_LINKED;
it->time = current_time;
assoc_insert(it);
#ifdef MOXI_ITEM_MALLOC
it->refcount++;
#endif
STATS_LOCK();
stats.curr_bytes += ITEM_ntotal(it);
stats.curr_items += 1;
stats.total_items += 1;
STATS_UNLOCK();
/* Allocate a new CAS ID on link. */
ITEM_set_cas(it, (settings.use_cas) ? get_cas_id() : 0);
item_link_q(it);
return 1;
}
/*
* adds a delta value to a numeric item.
*
* c connection requesting the operation
* it item to adjust
* incr true to increment value, false to decrement
* delta amount to adjust value by
* buf buffer for response string
*
* returns a response string to send back to the client.
*/
static ENGINE_ERROR_CODE do_add_delta(struct default_engine *engine,
hash_item *it, const bool incr,
const int64_t delta, uint64_t *rcas,
uint64_t *result, const void *cookie) {
const char *ptr;
uint64_t value;
char buf[80];
int res;
if (it->nbytes >= (sizeof(buf) - 1)) {
return ENGINE_EINVAL;
}
ptr = item_get_data(it);
memcpy(buf, ptr, it->nbytes);
buf[it->nbytes] = '\0';
if (!safe_strtoull(buf, &value)) {
return ENGINE_EINVAL;
}
if (incr) {
value += delta;
} else {
if(delta > value) {
value = 0;
} else {
value -= delta;
}
}
*result = value;
if ((res = snprintf(buf, sizeof(buf), "%" PRIu64, value)) == -1) {
return ENGINE_EINVAL;
}
if (it->refcount == 1 && res <= it->nbytes) {
// we can do inline replacement
memcpy(item_get_data(it), buf, res);
memset(item_get_data(it) + res, ' ', it->nbytes - res);
item_set_cas(NULL, NULL, it, get_cas_id());
*rcas = item_get_cas(it);
} else {
hash_item *new_it = do_item_alloc(engine, item_get_key(it),
it->nkey, it->flags,
it->exptime, res,
cookie);
if (new_it == NULL) {
do_item_unlink(engine, it);
return ENGINE_ENOMEM;
}
memcpy(item_get_data(new_it), buf, res);
do_item_replace(engine, it, new_it);
*rcas = item_get_cas(new_it);
do_item_release(engine, new_it); /* release our reference */
}
return ENGINE_SUCCESS;
}
int do_item_link(item *it) {
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
assert(it->nbytes < (1024 * 1024)); /* 1MB max size */
it->it_flags |= ITEM_LINKED;
it->time = current_time;
assoc_insert(it);
STATS_LOCK();
stats.curr_bytes += ITEM_ntotal(it);
stats.curr_items += 1;
stats.total_items += 1;
STATS_UNLOCK();
/* Allocate a new CAS ID on link. */
it->cas_id = get_cas_id();
item_link_q(it);
return 1;
}
int do_item_link(item *it) {
// MEMCACHED_ITEM_LINK(ITEM_key(it), it->nbytes);
// assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
assert(it->nbytes < (1024 * 1024)); /* 1MB max size */
it->it_flags |= ITEM_LINKED;
//<>
it->time = now_ms;
assoc_insert(it);
stats.curr_bytes += ITEM_ntotal(it);
stats.curr_items++;
stats.total_items++;
/* Allocate a new CAS ID on link. */
it->cas_id = get_cas_id();
item_link_q(it);
return 1;
}
int do_item_link(item *it, const uint32_t hv) {
MEMCACHED_ITEM_LINK(ITEM_key(it), it->nkey, it->nbytes);
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
it->it_flags |= ITEM_LINKED;
it->time = current_time;
STATS_LOCK();
stats_state.curr_bytes += ITEM_ntotal(it);
stats_state.curr_items += 1;
stats.total_items += 1;
STATS_UNLOCK();
/* Allocate a new CAS ID on link. */
ITEM_set_cas(it, (settings.use_cas) ? get_cas_id() : 0);
assoc_insert(it, hv);
item_link_q(it);
refcount_incr(&it->refcount);
item_stats_sizes_add(it);
return 1;
}
int do_item_link(struct default_engine *engine, hash_item *it) {
MEMCACHED_ITEM_LINK(item_get_key(it), it->nkey, it->nbytes);
assert((it->iflag & (ITEM_LINKED|ITEM_SLABBED)) == 0);
assert(it->nbytes < (1024 * 1024)); /* 1MB max size */
it->iflag |= ITEM_LINKED;
it->time = engine->server.core->get_current_time();
assoc_insert(engine, engine->server.core->hash(item_get_key(it),
it->nkey, 0),
it);
pthread_mutex_lock(&engine->stats.lock);
engine->stats.curr_bytes += ITEM_ntotal(engine, it);
engine->stats.curr_items += 1;
engine->stats.total_items += 1;
pthread_mutex_unlock(&engine->stats.lock);
/* Allocate a new CAS ID on link. */
item_set_cas(NULL, NULL, it, get_cas_id());
item_link_q(engine, it);
return 1;
}
//将item加入到hashtable和LRU链中
int do_item_link(item *it, const uint32_t hv) {
syslog(LOG_INFO, "[%s:%s:%d]", __FILE__, __func__, __LINE__);
MEMCACHED_ITEM_LINK(ITEM_key(it), it->nkey, it->nbytes);
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0); //判断状态，即没有在hash表LRU链中或被释放
mutex_lock(&cache_lock);
it->it_flags |= ITEM_LINKED; //设置linked状态
it->time = current_time;//设置最近访问的时间
STATS_LOCK();
stats.curr_bytes += ITEM_ntotal(it); //增加每个item所需要的字节大小，包括item结构体和item内容大小
stats.curr_items += 1;
stats.total_items += 1;
STATS_UNLOCK();
/* Allocate a new CAS ID on link. */
ITEM_set_cas(it, (settings.use_cas) ? get_cas_id() : 0); //设置新CAS，CAS是memcache用来处理并发请求的一种机制
assoc_insert(it, hv);//插入hashtable
item_link_q(it); //加入LRU链
refcount_incr(&it->refcount);
mutex_unlock(&cache_lock);
return 1;
}
int do_item_link(struct default_engine *engine, hash_item *it) {
const hash_key* key = item_get_key(it);
MEMCACHED_ITEM_LINK(hash_key_get_client_key(key), hash_key_get_client_key_len(key), it->nbytes);
cb_assert((it->iflag & (ITEM_LINKED|ITEM_SLABBED)) == 0);
it->iflag |= ITEM_LINKED;
it->time = engine->server.core->get_current_time();
assoc_insert(engine, crc32c(hash_key_get_key(key),
hash_key_get_key_len(key), 0),
it);
cb_mutex_enter(&engine->stats.lock);
engine->stats.curr_bytes += ITEM_ntotal(engine, it);
engine->stats.curr_items += 1;
engine->stats.total_items += 1;
cb_mutex_exit(&engine->stats.lock);
/* Allocate a new CAS ID on link. */
item_set_cas(NULL, NULL, it, get_cas_id());
item_link_q(engine, it);
return 1;
}