benchmark

#!/usr/bin/env node

const fs = require( 'fs' );
const path = require( 'path' );
const program = require( 'commander' );
const transformer = require( '../enketo-core/node_modules/enketo-transformer' );
const puppeteer = require( 'puppeteer' );
const graphite = require( 'graphite' );
const config = require( './config.json' );
const client = graphite.createClient( `plaintext://${config[ 'graphite url' ]}` );
const pkg = require( './package.json' );

program
    .version( pkg.version )
    .option( '-a, --all', 'benchmark all forms' )
    .option( '-f, --filename [filename]', 'specific XForm file to benchmark' )
    .parse( process.argv );

const options = program.opts();

if ( options.all ) {
    console.log( '================================================================\nbenchmarking all forms\n================================================================' );

    _getFileNames()
        .then( fileNames => {
            const funcs = fileNames.map( filename => () => _transform( filename )
                .then( _writeHtmlFile )
                .then( _render )
                .then( _send )
                .catch( e => console.error( e ) )
            );
            // run sequentially so they don't influence each other
            return funcs.reduce( ( p, fn ) => p.then( fn ), Promise.resolve() )
                .then( process.exit );
        } )
        .catch( _logError )
        .then( process.exit );

} else if ( options.filename ) {
    console.log( '================================================================\nbenchmarking %s\n================================================================', program.filename );

    _transform( options.filename )
        .then( _writeHtmlFile )
        .then( _render )
        .then( _send )
        .catch( _logError )
        .then( process.exit );
} else {
    console.log( 'nothing to do' );
}

function _getFileNames() {
    return new Promise( ( resolve, reject ) => {
        fs.readdir( path.join( __dirname, 'forms' ), ( err, filenames ) => {
            if ( err ) {
                reject( err );
            } else {
                resolve( filenames.filter( filename => filename.lastIndexOf( '.xml' ) === filename.length - 4 ) );
            }
        } );
    } );
}

function _transform( filename ) {
    console.log( `transforming ${filename}...` );
    const start = Date.now();
    return _getFileContents( filename )
        .then( transformer.transform )
        .then( result => {
            // add filename without extension
            result.formId = filename.substring( 0, filename.length - 4 );
            result.metrics = {};
            result.metrics.transform = Date.now() - start;
            return result;
        } );
}

function _getFileContents( filename ) {
    const filePath = path.join( __dirname, './forms', filename );

    return new Promise( ( resolve, reject ) => {
        fs.readFile( filePath, ( err, xform ) => {
            if ( err ) {
                reject( err );
            } else {
                resolve( {
                    xform
                } );
            }
        } );
    } );
}

async function _render( survey ) {

    console.log( 'rendering...' );

    const browser = await puppeteer.launch();
    const closeBrowser = error => {
        browser.close();
        console.log( 'error occurred, closed browser' );
        throw error;
    }
    const page = await browser.newPage();

    // intercept any resources requested by the page and assume they are for external data so just return XML
    await page.setRequestInterception( true );
    page.on( 'request', interceptedRequest => {
        if ( interceptedRequest.url().startsWith( 'jr:' ) ) {
            interceptedRequest.abort();
        } else {
            interceptedRequest.continue();
        }
    } );

    // render performance
    const renderStart = Date.now();
    const url = `file:${path.join( __dirname, config[ 'enketo core path' ], '/build/', survey.formId+'.html')}`;
    await page.goto( url ).catch( closeBrowser );
    survey.metrics.render = Date.now() - renderStart;

    // save a screenshot, useful to check if the form actually loaded
    const screenshotPath = path.join( __dirname, `screenshots/${survey.formId}.png` );
    await page.screenshot( { path: screenshotPath } ).catch( closeBrowser );

    // validation performance
    const validationStart = Date.now()
    await page.evaluate( () => window.form.validateAll() );
    survey.metrics.validate = Date.now() - validationStart;

    await browser.close();

    return survey;
}


function _writeHtmlFile( survey ) {
    const filePath = path.join( __dirname, config[ 'enketo core path' ], '/build', `${survey.formId}.html` );

    console.log( 'write to static html file', filePath );

    return new Promise( ( resolve, reject ) => {
        _getBaseHtml()
            .then( html => {
                // clean up model to allow it be a javascript variable
                survey.model = survey.model.replace( /\n/g, "" ).replace( /\"/g, "'" );

                html = html.replace( /\/\/\s*{{globalModelStr}}/m, `var globalModelStr = "${survey.model}"` );
                html = html.replace( "<!-- {{<form>}} -->" /*/<!--\s*<form>\s*-->/m*/ , survey.form );

                // write to a temporary html file in the enketo-core folder that has the correct relative resource references
                fs.writeFile( filePath, html, err => {
                    if ( err ) {
                        reject( err );
                    } else {
                        resolve( survey );
                    }
                } );
            } );
    } );
}

function _getBaseHtml() {

    return new Promise( ( resolve, reject ) => {
        fs.readFile( path.join( path.join( __dirname, config[ 'enketo core path' ], '/build/index.html' ) ), ( err, html ) => {
            if ( err ) {
                reject( err );
            } else {
                resolve( html.toString() );
            }
        } );
    } );
}

function _send( survey ) {
    const metrics = {};

    metrics[ [ `${config[ 'data prefix' ]}.${survey.formId}` ] ] = survey.metrics;

    console.log( 'sending data to graphite...', metrics );

    return new Promise( function( resolve, reject ) {
        client.write( metrics, function( err ) {
            if ( err ) {
                reject( err );
            } else {
                console.log( 'sent data successfully!\n----------------------------------------------------------------' );
                resolve();
            }
        } );
    } );
    //return Promise.resolve();
}

function _logError( error ) {
    if ( error.code === 'ENOENT' ) {
        console.error( `${options.filename} could not be found` );
    } else {
        console.error( 'error occurred', error );
    }
}