Function swapdbCommand

src/db.cpp:1757–1805

SWAPDB db1 db2 */

/* SWAPDB db1 db2 */
void swapdbCommand(client *c) {
    int id1, id2, oriIdx;

    /* Not allowed in cluster mode: we have just DB 0 there. */
    if (g_pserver->cluster_enabled) {
        addReplyError(c,"SWAPDB is not allowed in cluster mode");
        return;
    }

    /* Get the two DBs indexes. */
    if (getIntFromObjectOrReply(c, c->argv[1], &id1,
        "invalid first DB index") != C_OK)
        return;

    if (getIntFromObjectOrReply(c, c->argv[2], &id2,
        "invalid second DB index") != C_OK)
        return;

    // get client's original db's index
    for (int idb=0; idb < cserver.dbnum; ++idb) {
        if (g_pserver->db[idb]->id == c->db->id) {
            oriIdx = idb;
            break;
        }
    }

    /* Swap... */
    if (dbSwapDatabases(id1,id2) == C_ERR) {
        addReplyError(c,"DB index is out of range");
        return;
    } else {
        RedisModuleSwapDbInfo si = {REDISMODULE_SWAPDBINFO_VERSION,(int32_t)id1,(int32_t)id2};
        moduleFireServerEvent(REDISMODULE_EVENT_SWAPDB,0,&si);
        g_pserver->dirty++;

        // set client's db to original db
        c->db=g_pserver->db[oriIdx];

        // Persist the databse index to dbid mapping into FLASH for later recovery.
        if (g_pserver->m_pstorageFactory != nullptr && g_pserver->metadataDb != nullptr) {
            std::string dbid_key = "db-" + std::to_string(id1);
            g_pserver->metadataDb->insert(dbid_key.c_str(), dbid_key.length(), &g_pserver->db[id1]->id, sizeof(g_pserver->db[id1]->id), true);

            dbid_key = "db-" + std::to_string(id2);
            g_pserver->metadataDb->insert(dbid_key.c_str(), dbid_key.length(), &g_pserver->db[id2]->id, sizeof(g_pserver->db[id2]->id), true);
        }
        addReply(c,shared.ok);
    }
}

/*-----------------------------------------------------------------------------
 * Expires API