Function ttlGenericCommand

src/expire.cpp:806–850

Implements TTL and PTTL */

/* Implements TTL and PTTL */
void ttlGenericCommand(client *c, int output_ms) {
    long long expire = INVALID_EXPIRE, ttl = -1;

    /* If the key does not exist at all, return -2 */
    if (lookupKeyReadWithFlags(c->db,c->argv[1],LOOKUP_NOTOUCH) == nullptr) {
        addReplyLongLong(c,-2);
        return;
    }

    /* The key exists. Return -1 if it has no expire, or the actual
        * TTL value otherwise. */
    expireEntry *pexpire = c->db->getExpire(c->argv[1]);

    if (c->argc == 2) {
        // primary expire    
        if (pexpire != nullptr)
            pexpire->FGetPrimaryExpire(&expire);
    } else if (c->argc == 3) {
        // We want a subkey expire
        if (pexpire && pexpire->FFat()) {
            for (auto itr : *pexpire) {
                if (itr.subkey() == nullptr)
                    continue;
                if (sdscmp((sds)itr.subkey(), szFromObj(c->argv[2])) == 0) {
                    expire = itr.when();
                    break;
                }
            }
        }
    } else {
        addReplyError(c, "Invalid arguments");
        return;
    }

    
    if (expire != INVALID_EXPIRE) {
        ttl = expire-mstime();
        if (ttl < 0) ttl = 0;
    }
    if (ttl == -1) {
        addReplyLongLong(c,-1);
    } else {
        addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
    }
}

/* TTL key */
void ttlCommand(client *c) {