apminsight/lib/instrument/modules/ioredis.js

monitor nodejs applications

var wrapper = require("./../wrapper");
var logger = require("./../../util/logger");

var componentName = "REDIS";

var moduleInfo = {
    functions: [
        {
            functionName: ["prototype.sendCommand"],
            component: componentName,
            wrapper: wrapSendCommand
        },
        {
            functionName: ["Command.prototype.toWritable"],
            component: componentName,
            wrapper: wrapWrite
        }
    ]
};

function wrapSendCommand(actual) {
    return function (command) {
        var curTxn = apmInsightAgentInstance.getCurTxn();
        if (!curTxn || curTxn.isCompleted()) {
            return actual.apply(this, arguments);
        }
        if (!command || !command.name) {
            return actual.apply(this, arguments);
        }
        var parentTracker = apmInsightAgentInstance.getCurTracker();
        var trackerName = componentName + " - " + command.name;
        var trackerInfo = {
            trackerName: trackerName,
            component: componentName,
            stale: true,
            parent: parentTracker
        };
        var curTracker = apmInsightAgentInstance.createTracker(trackerInfo);
        appendMachineInfo(this, curTracker);
        try {
            var result = actual.apply(this, arguments);
            result = wrapper.checkAndWrapPromise(result, curTxn, curTracker);
            return result;
        } catch (e) {
            logger.error("ioredis send command handler", e);
            apmInsightAgentInstance.handleErrorTracker(curTracker, e);
            throw e;
        } finally {
            apmInsightAgentInstance.setCurTracker(parentTracker);
        }
    };
}

function wrapWrite(actual) {
    return function () {
        var parentTracker = apmInsightAgentInstance.getCurTracker();
        if (isRedisTracker(parentTracker)) {
            parentTracker.setActive();
        }
        return actual.apply(this, arguments);
    };
}

function appendMachineInfo(invoker, curTracker) {
    try {
        if (invoker && curTracker) {
            var hostInfo = {};
            hostInfo.host = invoker.options.host;
            hostInfo.port = invoker.options.port;
            curTracker.updateInfo(hostInfo);
        }
    } catch (error) {
        logger.error("Error while getting the machine info of ioredis.");
    }
}

function isRedisTracker(tracker) {
    return tracker && tracker.getComponent() === componentName;
}

module.exports = moduleInfo;