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); */
/* printf("item link 1\n"); */
/* LOCK_CLOCK(); */
/* it->it_flags |= ITEM_LINKED; */
/* it->time = current_time; */
/* printf("item link 2\n"); */
/* STATS_LOCK(); */
/* printf("item link 3\n"); */
/* 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); */
/* assoc_insert(it, hv); */
/* item_link_q(it); */
/* refcount_incr(&it->refcount); */
/* UNLOCK_CLOCK(); */
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
it->it_flags |= ITEM_LINKED;
it->time = current_time;
assoc_insert(it, hv);
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 = current_time;
assoc_insert(it);
STATS_LOCK();
stats.curr_bytes += ITEM_ntotal(it);
stats.curr_items += 1;
stats.total_items += 1;
STATS_UNLOCK();
#ifdef USE_REPLICATION
/* Allocate a new CAS ID on link. */
if(!(it->it_flags & ITEM_REPDATA))
it->cas_id = get_cas_id();
#else
/* Allocate a new CAS ID on link. */
it->cas_id = get_cas_id();
#endif /* USE_REPLICATION */
item_link_q(it);
return 1;
}
//将item插入到哈希表和LRU队列中，hv为哈希值
int do_item_link(item *it, const uint32_t hv) {
MEMCACHED_ITEM_LINK(ITEM_key(it), it->nkey, it->nbytes);
//确保这个item已经从slab分配出去并且还没插入到LRU队列中
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
mutex_lock(&cache_lock);
//加入link标记
it->it_flags |= ITEM_LINKED;
it->time = current_time;
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);
//插入到hash表中
assoc_insert(it, hv);
//item插入到链表中
item_link_q(it);
//引用计数加1
refcount_incr(&it->refcount);
mutex_unlock(&cache_lock);
return 1;
}
void slabs_alloc_test(void) {
unsigned int total_chunk = 0;
const char *key = "charliezhao";
size_t nkey = strlen(key) + 1;
item *ptr = (item *)slabs_alloc(1024, slabs_clsid(1024), &total_chunk);
strcpy(ITEM_key(ptr), key);
ptr->nkey = nkey;
strcpy(ITEM_data(ptr), "xuechaozhao");
uint32_t hv = jenkins_hash(key, strlen(key));
assoc_insert(ptr, hv);
for(int i = 0; i <= 10922; ++i) {
void *ptr = slabs_alloc(96, slabs_clsid(96), &total_chunk);
if(ptr == NULL) {
fprintf(stderr, "i: %7d slabs_alloc fail\n",
i);
break;
}
else {
slabs_free(ptr, 96, slabs_clsid(96));
}
}
item *ptr2 = assoc_find(key, nkey, hv);
fprintf(stdout, "key:%20s value:%20s\n", ITEM_key(ptr2), ITEM_data(ptr2));
}
int item_link(item *it) {
int needed = it->ntotal;
unsigned long long maxbytes;
int maxitems;
maxbytes = settings.maxbytes ? settings.maxbytes : UINT_MAX;
maxitems = settings.maxitems ? settings.maxitems : INT_MAX;
while(items_tail && (stats.curr_bytes + needed > maxbytes ||
stats.curr_items + 1 > maxitems)) {
drop_tail();
}
it->it_flags |= ITEM_LINKED;
it->time = time(0);
assoc_insert(it->key, (void *)it);
stats.curr_bytes += needed;
stats.curr_items += 1;
stats.total_items += 1;
item_link_q(it);
return 1;
}
/* 形成了一个完成的 item 后, 就要把它放入两个数据结构中, 一是 memcached 的哈希表,
memcached 运行过程中只有一个哈希表, 二是 item 所在的 slabclass 的 LRU 队列. */
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);
mutex_lock(&cache_lock);
it->it_flags |= ITEM_LINKED;
it->time = current_time;
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);
/* 把 item 放入哈希表 */
assoc_insert(it, hv);
/* 把 item 放入 LRU 队列*/
item_link_q(it);
refcount_incr(&it->refcount);
mutex_unlock(&cache_lock);
return 1;
}
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;
}
static void _item_link(struct item *it) {
assert(it->magic == ITEM_MAGIC);
assert(!item_is_linked(it));
assert(!item_is_slabbed(it));
it->flags |= ITEM_LINKED;
assoc_insert(it);
item_link_q(it, true);
}
int item_link(item *it) {
assert((it->it_flags & (ITEM_LINKED|ITEM_SLABBED)) == 0);
assert(it->nbytes < 1048576);
it->it_flags |= ITEM_LINKED;
it->time = current_time;
assoc_insert(ITEM_key(it), it);
stats.curr_bytes += ITEM_ntotal(it);
stats.curr_items += 1;
stats.total_items += 1;
item_link_q(it);
return 1;
}
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(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;
}
