node-red-snmp-node - snmp_walker

The code needs to change the following to better comply with net-snmp example.

The code will break out of its branches and is limited to 20 GetNext replies.

May we discuss the merits of the sub-package this is built on and consider one that we can implement bulk request and tables.

var maxRepetitions = 20;

            getSession(host, community, node.version, node.timeout).walk(msg.oid, maxRepetitions, feedCb, function (error) 

    function SnmpWalkerNode(n) {
        RED.nodes.createNode(this, n);
        this.community = n.community;
        this.host = n.host;
        this.version = (n.version === "2c") ? snmp.Version2c : snmp.Version1;
        this.oids = n.oids.replace(/\s/g, "");
        this.timeout = Number(n.timeout || 5) * 1000;
        var node = this;
        var maxRepetitions = 20;
        var response = [];

        function feedCb(varbinds) {
            for (var i = 0; i < varbinds.length; i++) {
                if (snmp.isVarbindError(varbinds[i])) {
                    node.error(snmp.varbindError(varbinds[i]), msg);
                }
                else {
                    //console.log(varbinds[i].oid + "|" + varbinds[i].value);
                    response.push({ oid: varbinds[i].oid, value: varbinds[i].value });
                }
            }
        }

        this.on("input", function (msg) {
            node.msg = msg;
            var oids = node.oids || msg.oid;
            var host = node.host || msg.host;
            var community = node.community || msg.community;
            if (oids) {
                msg.oid = oids;
                getSession(host, community, node.version, node.timeout).walk(msg.oid, maxRepetitions, feedCb, function (error) {
                    if (error) {
                        node.error(error.toString(), msg);
                    }
                    else {
                        // Clone the array
                        msg.payload = response.slice(0);
                        node.send(msg);
                        //Clears response
                        response.length = 0;
                    }
                });
            }
            else {
                node.warn("No oid to search for");
            }
        });
    }

var oids = [
    "1.3.6.1.2.1.1.1.0",
    "1.3.6.1.2.1.1.4.0"
];

session.getNext (oids, function (error, varbinds) {
    if (error) {
        console.error (error.toString ());
    } else {
        for (var i = 0; i < varbinds.length; i++) {
            // for version 1 we can assume all OIDs were successful
            console.log (varbinds[i].oid + "|" + varbinds[i].value);
        
            // for version 2c we must check each OID for an error condition
            if (snmp.isVarbindError (varbinds[i]))
                console.error (snmp.varbindError (varbinds[i]));
            else
                console.log (varbinds[i].oid + "|" + varbinds[i].value);
        }
    }
});

Start at the SnmpWalkerNode input handler, the getSession(...).walk call, and the net-snmp getNext example shown in the issue. Clarify whether done means removing the 20-reply limit and adding bulk-request and table support, then validate the chosen behavior against the node's existing output and error handling.