qrusage.js

/**
 * qrusage -- quick getrusage()
 *
 * Unix getrusage() binding.  Should work on any unix system, but the
 * fields not maintained by Linux are returned as zeros.  These are
 * ixrss, idrss, isrss, nswap, msgsnd, msgrcv, nsignals
 *
 * Copyright (C) 2014-2020 Andras Radics
 * Licensed under the Apache License, Version 2.0
 */


'use strict';

var binding = require('./build/Release/qrusage');

// static Float64Array to receive return values
// Note that node-v0.10 supports Float64Arrays but the plugin does not receive it.
// Testing the return value works, the bindings return nothing if they populated the array.
// Node-v4.x no longer suffers from this.
var _float16;
if (parseInt(process.version.slice(1)) >= 4) {
    _float16 = new Float64Array(16);
}

module.exports = function(which) { return getrusage_array(which); }
module.exports.getrusage = getrusage_array;
module.exports.RUSAGE_SELF = binding.RUSAGE_SELF;
module.exports.RUSAGE_CHILDREN = binding.RUSAGE_CHILDREN;
module.exports.RUSAGE_THREAD = binding.RUSAGE_THREAD;

module.exports.cputime = binding.cputime;               // new 1.1.0 name
module.exports.getrusage_cpu = binding.cputime;         // pre-1.1.0 name

module.exports.gettimeofday = binding.gettimeofday;

module.exports.fptime = binding.gettimeofday;
module.exports.microtime = function() {
    var t = binding.microtime(_float16)
    return _float16 ? _float16[0] : t;
};

module.exports.binding = binding;

module.exports.cpuUsage = function cpuUsage( lastUsage ) {
    var usage = binding.cpuusage(_float16);
    if (_float16) usage = _float16;

    if (!lastUsage) return {
        user: usage[0],
        system: usage[1]
    }
    else return {
        user: usage[0] - lastUsage.user,
        system: usage[1] - lastUsage.system
    };
}

var usageStore = {};
module.exports.storeUsage = function storeUsage( name, rusage ) {
    rusage = rusage || module.exports.getrusage();
    return (usageStore[name] = rusage);
}
module.exports.removeUsage = function removeUsage( name ) {
    var usage = usageStore[name];
    delete usageStore[name];
    return usage;
}
function _lookupUsage( name ) {
    var usage = usageStore[name] || (typeof name === 'object' && name) || null;
    if (usage) return usage; else throw new Error(name + ': usage not stored');
}

module.exports.sumUsage = function sumUsage( /* ,VARARGS */ ) {
    var sum = {};
    for (var i = 0; i < arguments.length; i++) {
        var usage = _lookupUsage(arguments[i]);
        for (var k in usage) {
            sum[k] !== undefined ? sum[k] += usage[k] : sum[k] = usage[k];
        }
    }
    return sum;
}

module.exports.deltaUsage = function deltaUsage( lastUsage, currentUsage ) {
    currentUsage = currentUsage ? _lookupUsage(currentUsage) : module.exports.getrusage();

    // copy the old usage, then revise with the changes
    var delta = module.exports.sumUsage(_lookupUsage(lastUsage));
    for (var k in currentUsage) {
        delta[k] = (delta[k] !== undefined) ? currentUsage[k] - delta[k] : currentUsage[k];
    }
    return delta;
}

function getrusage_array(which) {
    var fields = binding.getrusage_array(which, _float16);
    if (_float16) fields = _float16;
    return {
        utime: fields[0],
        stime: fields[1],
        maxrss: fields[2],
        idrss: fields[3],
        ixrss: fields[4],
        isrss: fields[5],
        minflt: fields[6],
        majflt: fields[7],
        nswap: fields[8],
        inblock: fields[9],
        oublock: fields[10],
        msgsnd: fields[11],
        msgrcv: fields[12],
        nsignals: fields[13],
        nvcsw: fields[14],
        nivcsw: fields[15]
    };
}