static void do_item_unlink(struct demo_engine *engine, hash_item *it,
enum item_unlink_cause cause)
{
/* cause: item unlink cause will be used, later
*/
const char *key = dm_item_get_key(it);
size_t stotal = ITEM_stotal(engine, it);
MEMCACHED_ITEM_UNLINK(key, it->nkey, it->nbytes);
if ((it->iflag & ITEM_LINKED) != 0) {
/* unlink the item from hash table */
dm_assoc_delete(engine, it->hval, key, it->nkey);
it->iflag &= ~ITEM_LINKED;
/* update item statistics */
pthread_mutex_lock(&engine->stats.lock);
engine->stats.curr_bytes -= stotal;
engine->stats.curr_items -= 1;
pthread_mutex_unlock(&engine->stats.lock);
/* free the item if no one reference it */
if (it->refcount == 0) {
do_item_free(engine, it);
}
}
}
void do_item_unlink(item *it) {
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;
STATS_LOCK();
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
assoc_delete(ITEM_key(it), it->nkey);
item_unlink_q(it);
if (it->refcount == 0) item_free(it);
}
}
/* FIXME: Is it necessary to keep this copy/pasted code? */
void do_item_unlink_nolock(item *it, const uint32_t hv) {
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;
STATS_LOCK();
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
assoc_delete(ITEM_key(it), it->nkey, hv);
item_unlink_q(it);
do_item_remove(it);
}
}
/* slawek */
void do_item_unlink_nolock_nostat(item *it, const uint32_t hv, uint64_t *items_removed, uint64_t *bytes_removed) {
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;
*items_removed += 1;
*bytes_removed += ITEM_ntotal(it);
assoc_delete(ITEM_key(it), it->nkey, hv);
item_unlink_q(it);
do_item_remove(it);
}
}
/* FIXME: Is it necessary to keep this copy/pasted code? */
void do_item_unlink_nolock(item *it, const uint32_t hv) {
syslog(LOG_INFO, "[%s:%s:%d]", __FILE__, __func__, __LINE__);
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;
STATS_LOCK();
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
assoc_delete(ITEM_key(it), it->nkey, hv);
item_unlink_q(it);
do_item_remove(it);
}
}
//将item从hashtable和LRU链中移除,而且还释放掉 item 所占的内存 (其实只是把 item 放到空闲链表中),是do_item_link的逆操作
void do_item_unlink(item *it, const uint32_t hv)
{
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
mutex_lock(&cache_lock);//执行同步
if ((it->it_flags & ITEM_LINKED) != 0) {//判断状态值，保证item还在LRU队列中
it->it_flags &= ~ITEM_LINKED;//修改状态值
STATS_LOCK();//更新统计信息
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
assoc_delete(ITEM_key(it), it->nkey, hv);//从Hash表中删除
item_unlink_q(it);//将item从slabclass对应的LRU队列摘除
do_item_remove(it);//释放 item 所占的内存
}
mutex_unlock(&cache_lock);
}
void do_item_unlink(item *it, const uint32_t hv) {
syslog(LOG_INFO, "[%s:%s:%d]", __FILE__, __func__, __LINE__);
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
mutex_lock(&cache_lock);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;//设置为非linked
STATS_LOCK();
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
assoc_delete(ITEM_key(it), it->nkey, hv); //从hash表中删除
item_unlink_q(it); //从LRU链中删除
do_item_remove(it);
}
mutex_unlock(&cache_lock);
}
void do_item_unlink(struct default_engine *engine, hash_item *it) {
MEMCACHED_ITEM_UNLINK(item_get_key(it), it->nkey, it->nbytes);
if ((it->iflag & ITEM_LINKED) != 0) {
it->iflag &= ~ITEM_LINKED;
pthread_mutex_lock(&engine->stats.lock);
engine->stats.curr_bytes -= ITEM_ntotal(engine, it);
engine->stats.curr_items -= 1;
pthread_mutex_unlock(&engine->stats.lock);
assoc_delete(engine, engine->server.core->hash(item_get_key(it),
it->nkey, 0),
item_get_key(it), it->nkey);
item_unlink_q(engine, it);
if (it->refcount == 0) {
item_free(engine, it);
}
}
}
//从哈希表和LRU中删除
void do_item_unlink(item *it, const uint32_t hv) {
MEMCACHED_ITEM_UNLINK(ITEM_key(it), it->nkey, it->nbytes);
mutex_lock(&cache_lock);
if ((it->it_flags & ITEM_LINKED) != 0) {
it->it_flags &= ~ITEM_LINKED;
STATS_LOCK();
stats.curr_bytes -= ITEM_ntotal(it);
stats.curr_items -= 1;
STATS_UNLOCK();
//从哈希表中删除
assoc_delete(ITEM_key(it), it->nkey, hv);
//从链表中删除
item_unlink_q(it);
//向slab归还这个item
do_item_remove(it);
}
mutex_unlock(&cache_lock);
}
void do_item_unlink(struct default_engine *engine, hash_item *it) {
const hash_key* key = item_get_key(it);
MEMCACHED_ITEM_UNLINK(hash_key_get_client_key(key),
hash_key_get_client_key_len(key),
it->nbytes);
if ((it->iflag & ITEM_LINKED) != 0) {
it->iflag &= ~ITEM_LINKED;
cb_mutex_enter(&engine->stats.lock);
engine->stats.curr_bytes -= ITEM_ntotal(engine, it);
engine->stats.curr_items -= 1;
cb_mutex_exit(&engine->stats.lock);
assoc_delete(engine, crc32c(hash_key_get_key(key),
hash_key_get_key_len(key), 0),
key);
item_unlink_q(engine, it);
if (it->refcount == 0 || engine->scrubber.force_delete) {
item_free(engine, it);
}
}
}
