extract.js

const fs = require('fs');
const config = require('config');

const canUseProcessSend = !!process.send;
const isProduction = process.env.NODE_ENV && process.env.NODE_ENV === 'production';

function capitalize(str) {
    return str[0].toUpperCase() + str.substr(1);
}

function safeFeature(feature) {
    if (typeof feature === 'number' && isNaN(feature)) feature = -1;
    if (typeof feature === 'number' && !isFinite(feature)) feature = -2;
    if (feature === false) feature = 0;
    if (feature === true) feature = 1;

    return feature;
}

const features = require('./features');
const statsDecompressor = require('./getstats-deltacompression').decompress;
const statsMangler = require('./getstats-mangle');

// dumps all peerconnections.
function dump(url, client, clientid, data) {
    // ignore connections that never send getUserMedia or peerconnection events.
    if (client.getUserMedia.length === 0 && Object.keys(client.peerConnections).length === 0) return;
    if (!isProduction) {
        let total = 0;
        Object.keys(client.peerConnections).forEach(id => {
            total += client.peerConnections[id].length;
        });
        console.log('DUMP', client.getUserMedia.length, Object.keys(client.peerConnections).length, total);
        return;
    }
}

// Feature generation
function generateFeatures(url, client, clientid) {
    // ignore connections that never send getUserMedia or peerconnection events.
    if (client.getUserMedia.length === 0 && Object.keys(client.peerConnections).length === 0) return;

    // clientFeatures are the same for all peerconnections but are saved together
    // with each peerconnection anyway to make correlation easier.
    const clientFeatures = {};
    Object.keys(features).forEach(fname => {
        if (features[fname].length === 1) {
            let feature = features[fname].apply(null, [client]);
            if (feature !== undefined) {
                if (typeof feature === 'object') {
                    Object.keys(feature).forEach(subname => {
                        feature[subname] = safeFeature(feature[subname]);
                        if (!isProduction) {
                            console.log('PAGE', 'FEATURE', fname + capitalize(subname), '=>', safeFeature(feature[subname]));
                        }
                        clientFeatures[fname + capitalize(subname)] = feature[subname];
                    });
                }  else {
                    feature = safeFeature(feature);
                    if (!isProduction) {
                        console.log('PAGE', 'FEATURE', fname, '=>', feature);
                    }
                    clientFeatures[fname] = feature;
                }
            }
        }
    });
    Object.keys(client.peerConnections).forEach(connid => {
        if (connid === 'null') return; // ignore the null connid
        const conn = client.peerConnections[connid];
        const connectionFeatures = {};
        Object.keys(features).forEach(fname => {
            if (features[fname].length === 2) {
                let feature = features[fname].apply(null, [client, conn]);
                if (feature !== undefined) {
                    if (typeof feature === 'object' && Object.keys(feature || {}).length > 0) {
                        Object.keys(feature).forEach(subname => {
                            feature[subname] = safeFeature(feature[subname]);
                            if (!isProduction) {
                                console.log(connid, 'FEATURE', fname + capitalize(subname), '=>', safeFeature(feature[subname]));
                            }
                            connectionFeatures[fname + capitalize(subname)] = feature[subname];
                        });
                    }  else {
                        feature = safeFeature(feature);
                        if (!isProduction) {
                            console.log(connid, 'FEATURE', fname, '=>', safeFeature(feature));
                        }
                        connectionFeatures[fname] = feature;
                    }
                }
            }
        });
        delete client.peerConnections[connid]; // save memory
        if (!isProduction) return;
        if (canUseProcessSend) {
            process.send({url, clientid, connid, clientFeatures, connectionFeatures});
        } else {
            console.log(url, clientid, connid, clientFeatures, connectionFeatures);
        }
    });
}

var clientid = process.argv[2];
const path = 'temp/' + clientid;
fs.readFile(path, {encoding: 'utf-8'}, (err, data) => {
    if (!err) {
        const baseStats = {};
        const lines = data.split('\n');
        const client = JSON.parse(lines.shift());
        client.peerConnections = {};
        client.getUserMedia = [];
        lines.forEach(line => {
            if (line.length) {
                const data = JSON.parse(line);
                const time = new Date(data.time || data[3]);
                delete data.time;
                switch(data[0]) {
                case 'location':
                    client.location = data[2];
                    break;
                case 'userfeedback': // TODO: might be renamed
                    client.feedback = data[2];
                    break;
                case 'getUserMedia':
                case 'getUserMediaOnSuccess':
                case 'getUserMediaOnFailure':
                case 'navigator.mediaDevices.getUserMedia':
                case 'navigator.mediaDevices.getUserMediaOnSuccess':
                case 'navigator.mediaDevices.getUserMediaOnFailure':
                    client.getUserMedia.push({
                        time: time,
                        type: data[0],
                        value: data[2]
                    });
                    break;
                default:
                    if (!client.peerConnections[data[1]]) {
                        client.peerConnections[data[1]] = [];
                        baseStats[data[1]] = {};
                    }
                    if (data[0] === 'getstats') { // delta-compressed
                        data[2] = statsDecompressor(baseStats[data[1]], data[2]);
                        baseStats[data[1]] = JSON.parse(JSON.stringify(data[2]));
                    }
                    if (data[0] === 'getStats' || data[0] === 'getstats') {
                        data[2] = statsMangler(data[2]);
                        data[0] = 'getStats';
                    }
                    client.peerConnections[data[1]].push({
                        time: time,
                        type: data[0],
                        value: data[2]
                    });
                    break;
                }
            }
        });

        dump(client.url, client, clientid, data);
        generateFeatures(client.url, client, clientid);
    }
});