Пример #1
0
/*
 * Unlinks an item from the LRU and hashtable.
 */
void item_unlink(item *item) {
    uint32_t hv;
    hv = hash(ITEM_key(item), item->nkey, 0);
    item_lock(hv);
    do_item_unlink(item, hv);
    item_unlock(hv);
}
Пример #2
0
/*
 * Decrements the reference count on an item and adds it to the freelist if
 * needed.
 */
void item_remove(item *item) {
    uint32_t hv;
    hv = hash(ITEM_key(item), item->nkey);

    item_lock(hv);
    do_item_remove(item);
    item_unlock(hv);
}
Пример #3
0
item *item_touch(const char *key, size_t nkey, uint32_t exptime) {
    item *it;
    uint32_t hv;
    hv = hash(key, nkey, 0);
    item_lock(hv);
    it = do_item_touch(key, nkey, exptime, hv);
    item_unlock(hv);
    return it;
}
Пример #4
0
/*
 * Returns an item if it hasn't been marked as expired,
 * lazy-expiring as needed.
 */
item *item_get(const char *key, const size_t nkey, conn *c, const bool do_update) {
    item *it;
    uint32_t hv;
    hv = hash(key, nkey);
    item_lock(hv);
    it = do_item_get(key, nkey, hv, c, do_update);
    item_unlock(hv);
    return it;
}
Пример #5
0
/*
 * Returns an item if it hasn't been marked as expired,
 * lazy-expiring as needed.
 */
item *item_get(const char *key, const size_t nkey) {
    item *it;
    uint32_t hv;
    hv = hash(key, nkey);
    item_lock(hv);
    it = do_item_get(key, nkey, hv);
    item_unlock(hv);
    return it;
}
Пример #6
0
/*
 * Links an item into the LRU and hashtable.
 */
int item_link(item *item) {
    int ret;
    uint32_t hv;

    hv = hash(ITEM_key(item), item->nkey, 0);
    item_lock(hv);
    ret = do_item_link(item, hv);
    item_unlock(hv);
    return ret;
}
Пример #7
0
/*
 * Stores an item in the cache (high level, obeys set/add/replace semantics)
 */
enum store_item_type store_item(item *item, int comm, conn* c) {
    enum store_item_type ret;
    uint32_t hv;

    hv = hash(ITEM_key(item), item->nkey);
    item_lock(hv);
    ret = do_store_item(item, comm, c, hv);
    item_unlock(hv);
    return ret;
}
/*
 * Stores an item in the cache (high level, obeys set/add/replace semantics)
 */
enum store_item_type store_item(item *item, int comm, conn* c) { //注意该函数外层在该函数执行完后一般会调用一次item_remove
    enum store_item_type ret;
    uint32_t hv;

    hv = hash(ITEM_key(item), item->nkey);
    item_lock(hv);
    ret = do_store_item(item, comm, c, hv);
    item_unlock(hv);
    return ret;
}
Пример #9
0
/*
 * Does arithmetic on a numeric item value.
 */
enum delta_result_type add_delta(conn *c, const char *key,
                                 const size_t nkey, int incr,
                                 const int64_t delta, char *buf,
                                 uint64_t *cas) {
    enum delta_result_type ret;
    uint32_t hv;

    hv = hash(key, nkey);
    item_lock(hv);
    ret = do_add_delta(c, key, nkey, incr, delta, buf, cas, hv);
    item_unlock(hv);
    return ret;
}
Пример #10
0
/*
 * Stores an item in the cache (high level, obeys set/add/replace semantics)
 * 在缓存中存储一个数据项
 */
enum store_item_type store_item(item *item, int comm, conn* c) {
    enum store_item_type ret;
    uint32_t hv;

    // 先做一次哈希计算
    hv = hash(ITEM_key(item), item->nkey, 0);

    item_lock(hv);
    // 正真存储数据的方法 do_store_item()
    ret = do_store_item(item, comm, c, hv);
    item_unlock(hv);
    return ret;
}
Пример #11
0
static void storage_compact_readback(void *storage, logger *l,
        bool drop_unread, char *readback_buf,
        uint32_t page_id, uint64_t page_version, uint64_t read_size) {
    uint64_t offset = 0;
    unsigned int rescues = 0;
    unsigned int lost = 0;
    unsigned int skipped = 0;

    while (offset < read_size) {
        item *hdr_it = NULL;
        item_hdr *hdr = NULL;
        item *it = (item *)(readback_buf+offset);
        unsigned int ntotal;
        // probably zeroed out junk at the end of the wbuf
        if (it->nkey == 0) {
            break;
        }

        ntotal = ITEM_ntotal(it);
        uint32_t hv = (uint32_t)it->time;
        item_lock(hv);
        // We don't have a conn and don't need to do most of do_item_get
        hdr_it = assoc_find(ITEM_key(it), it->nkey, hv);
        if (hdr_it != NULL) {
            bool do_write = false;
            refcount_incr(hdr_it);

            // Check validity but don't bother removing it.
            if ((hdr_it->it_flags & ITEM_HDR) && !item_is_flushed(hdr_it) &&
                   (hdr_it->exptime == 0 || hdr_it->exptime > current_time)) {
                hdr = (item_hdr *)ITEM_data(hdr_it);
                if (hdr->page_id == page_id && hdr->page_version == page_version) {
                    // Item header is still completely valid.
                    extstore_delete(storage, page_id, page_version, 1, ntotal);
                    // drop inactive items.
                    if (drop_unread && GET_LRU(hdr_it->slabs_clsid) == COLD_LRU) {
                        do_write = false;
                        skipped++;
                    } else {
                        do_write = true;
                    }
                }
            }

            if (do_write) {
                bool do_update = false;
                int tries;
                obj_io io;
                io.len = ntotal;
                io.mode = OBJ_IO_WRITE;
                for (tries = 10; tries > 0; tries--) {
                    if (extstore_write_request(storage, PAGE_BUCKET_COMPACT, PAGE_BUCKET_COMPACT, &io) == 0) {
                        memcpy(io.buf, it, io.len);
                        extstore_write(storage, &io);
                        do_update = true;
                        break;
                    } else {
                        usleep(1000);
                    }
                }

                if (do_update) {
                    if (it->refcount == 2) {
                        hdr->page_version = io.page_version;
                        hdr->page_id = io.page_id;
                        hdr->offset = io.offset;
                        rescues++;
                    } else {
                        lost++;
                        // TODO: re-alloc and replace header.
                    }
                } else {
                    lost++;
                }
            }

            do_item_remove(hdr_it);
        }

        item_unlock(hv);
        offset += ntotal;
        if (read_size - offset < sizeof(struct _stritem))
            break;
    }

    STATS_LOCK();
    stats.extstore_compact_lost += lost;
    stats.extstore_compact_rescues += rescues;
    stats.extstore_compact_skipped += skipped;
    STATS_UNLOCK();
    LOGGER_LOG(l, LOG_SYSEVENTS, LOGGER_COMPACT_READ_END,
            NULL, page_id, offset, rescues, lost, skipped);
}