Function scanFilterAndReply

src/db.cpp:1349–1410

}

void scanFilterAndReply(client *c, list *keys, sds pat, sds type, int use_pattern, robj_roptr o, unsigned long cursor)
{
    listNode *node, *nextnode;
    int patlen = (pat != nullptr) ? sdslen(pat) : 0;
    
    /* Step 3: Filter elements. */
    node = listFirst(keys);
    while (node) {
        robj *kobj = (robj*)listNodeValue(node);
        nextnode = listNextNode(node);
        int filter = 0;

        /* Filter element if it does not match the pattern. */
        if (use_pattern) {
            if (filterKey(kobj, pat, patlen))
                filter = 1;
        }

        /* Filter an element if it isn't the type we want. */
        if (!filter && o == nullptr && type){
            robj_roptr typecheck = lookupKeyReadWithFlags(c->db, kobj, LOOKUP_NOTOUCH);
            const char* typeT = getObjectTypeName(typecheck);
            if (strcasecmp((char*) type, typeT)) filter = 1;
        }

        /* Filter element if it is an expired key. */
        if (!filter && o == nullptr && expireIfNeeded(c->db, kobj)) filter = 1;

        /* Remove the element and its associated value if needed. */
        if (filter) {
            decrRefCount(kobj);
            listDelNode(keys, node);
        }

        /* If this is a hash or a sorted set, we have a flat list of
         * key-value elements, so if this element was filtered, remove the
         * value, or skip it if it was not filtered: we only match keys. */
        if (o && (o->type == OBJ_ZSET || o->type == OBJ_HASH)) {
            node = nextnode;
            serverAssert(node); /* assertion for valgrind (avoid NPD) */
            nextnode = listNextNode(node);
            if (filter) {
                kobj = (robj*)listNodeValue(node);
                decrRefCount(kobj);
                listDelNode(keys, node);
            }
        }
        node = nextnode;
    }

    /* Step 4: Reply to the client. */
    addReplyArrayLen(c, 2);
    addReplyBulkLongLong(c,cursor);

    addReplyArrayLen(c, listLength(keys));
    while ((node = listFirst(keys)) != NULL) {
        robj *kobj = (robj*)listNodeValue(node);
        addReplyBulk(c, kobj);