162 lines
3.7 KiB
JavaScript
162 lines
3.7 KiB
JavaScript
/*
|
|
* Storoid worker.
|
|
*
|
|
* Configure in storoid.config.json.
|
|
*/
|
|
|
|
// global includes
|
|
var express = require('express'),
|
|
cluster = require('cluster'),
|
|
http = require('http'),
|
|
fs = require('fs'),
|
|
child_process = require('child_process'),
|
|
querystring = require('querystring');
|
|
|
|
var config;
|
|
|
|
// Get the config
|
|
try {
|
|
config = JSON.parse(fs.readFileSync('./mathoid.config.json', 'utf8'));
|
|
} catch ( e ) {
|
|
// Build a skeleton localSettings to prevent errors later.
|
|
console.error("Please set up your mathoid.config.json from the example " +
|
|
"storoid.config.json.example");
|
|
process.exit(1);
|
|
}
|
|
|
|
/**
|
|
* The name of this instance.
|
|
* @property {string}
|
|
*/
|
|
var instanceName = cluster.isWorker ? 'worker(' + process.pid + ')' : 'master';
|
|
|
|
console.log( ' - ' + instanceName + ' loading...' );
|
|
|
|
|
|
|
|
/*
|
|
* Backend setup
|
|
*/
|
|
var restarts = 10;
|
|
|
|
var backend,
|
|
backendPort,
|
|
requestQueue = [];
|
|
|
|
var startBackend = function () {
|
|
if (backend) {
|
|
backend.kill();
|
|
}
|
|
var backendCB = function (err, stdout, stderr) {
|
|
if (err) {
|
|
restarts--;
|
|
if (restarts > 0) {
|
|
startBackend();
|
|
}
|
|
console.error(err.toString());
|
|
process.exit(1);
|
|
}
|
|
};
|
|
backendPort = Math.floor(9000 + Math.random() * 50000);
|
|
console.error(instanceName + ': Starting backend on port ' + backendPort);
|
|
backend = child_process.exec('phantomjs main.js ' + backendPort, backendCB);
|
|
backend.stdout.pipe(process.stdout);
|
|
backend.stderr.pipe(process.stderr);
|
|
};
|
|
startBackend();
|
|
|
|
/* -------------------- Web service --------------------- */
|
|
|
|
|
|
var app = express.createServer();
|
|
|
|
// Increase the form field size limit from the 2M default.
|
|
app.use(express.bodyParser({maxFieldsSize: 25 * 1024 * 1024}));
|
|
app.use( express.limit( '25mb' ) );
|
|
|
|
app.get('/', function(req, res){
|
|
res.write('<html><body>\n');
|
|
res.write('Welcome to Mathoid. POST to / with var <code>tex</code>');
|
|
res.write('<form action="/" method="POST"><input type="text" name="tex"></form>');
|
|
res.end('</body></html>');
|
|
});
|
|
|
|
// robots.txt: no indexing.
|
|
app.get(/^\/robots.txt$/, function ( req, res ) {
|
|
res.end( "User-agent: *\nDisallow: /\n" );
|
|
});
|
|
|
|
var handleRequests = function() {
|
|
// Call the next request on the queue
|
|
if (requestQueue.length) {
|
|
requestQueue[0]();
|
|
}
|
|
};
|
|
|
|
|
|
function handleRequest(req, res, tex) {
|
|
// do the backend request
|
|
var query = new Buffer(querystring.stringify({tex:tex})),
|
|
options = {
|
|
hostname: 'localhost',
|
|
port: backendPort.toString(),
|
|
path: '/',
|
|
method: 'POST',
|
|
headers: {
|
|
'Content-Length': query.length,
|
|
'Content-Type': 'application/x-www-form-urlencoded',
|
|
'Connection': 'close'
|
|
},
|
|
agent: false
|
|
};
|
|
var chunks = [];
|
|
//console.log(options);
|
|
var httpreq = http.request(options, function(httpres) {
|
|
httpres.on('data', function(chunk) {
|
|
chunks.push(chunk);
|
|
});
|
|
httpres.on('end', function() {
|
|
var buf = Buffer.concat(chunks);
|
|
res.writeHead(200,
|
|
{
|
|
'Content-type': 'application/json',
|
|
'Content-length': buf.length
|
|
});
|
|
res.write(buf);
|
|
res.end();
|
|
requestQueue.shift();
|
|
handleRequests();
|
|
});
|
|
});
|
|
httpreq.on('error', function(err) {
|
|
console.log('error', err.toString());
|
|
res.writeHead(500);
|
|
return res.end(JSON.stringify({error: "Backend error: " + err.toString()}));
|
|
});
|
|
|
|
httpreq.end(query);
|
|
}
|
|
|
|
app.post(/^\/$/, function ( req, res ) {
|
|
// First some rudimentary input validation
|
|
if (!req.body.tex) {
|
|
res.writeHead(400);
|
|
return res.end(JSON.stringify({error: "'tex' post parameter is missing!"}));
|
|
}
|
|
var tex = req.body.tex;
|
|
|
|
requestQueue.push(handleRequest.bind(null, req, res, tex));
|
|
// phantomjs only handles one request at a time. Enforce this.
|
|
if (requestQueue.length === 1) {
|
|
// Start this process
|
|
handleRequests();
|
|
}
|
|
|
|
});
|
|
|
|
|
|
console.log( ' - ' + instanceName + ' ready' );
|
|
|
|
module.exports = app;
|
|
|