server.js

#!/usr/bin/env node

var express = require('express');
var formidable = require('formidable');
var files = require('./files');
var template = require('./template');
var sys = require('sys');

var MAX_FILE_SIZE = 300 * 1024 * 1024;
var HTML_HEADERS = { 'Content-Type': 'text/html; charset=UTF-8' };

var app = express();
// Don't want this public? Uncomment:
// app.use(express.basicAuth('user', 'password'));

app.get('/', function(req, res) {
    res.writeHead(200, HTML_HEADERS);
    res.write(template.htmlHead);
    res.write(template.uploadForm);
    res.write(template.downloadList(files.getFiles()));
    res.write(template.htmlFoot);
    res.end();
});

app.post('/upload', function(req, res) {
    var out, error;

    var form = new formidable.IncomingForm();
    form.encoding = 'utf8';
    form.handlePart = function(part) {
        if (part.name === 'file' && part.filename) {
            console.log({ part: { name: part.name,
                                  filename: part.filename,
                                  mime: part.mime
                                } });
            out = files.addFile({ name: part.filename,
                                  type: part.mime
                                });
            var received = 0;
            part.on('data', function(data) {
                if (out) {
                    received += data.length;
                    if (received > MAX_FILE_SIZE) {
                        out.discard();
                        out = undefined;

                        files.freeBytes(received);
                        error = new Error('Exceeded maximum file size');
                        /* TODO: send response ASAP */
                    } else {
                        files.allocBytes(data.length);
                        req.pause();
                        out.write(data, function() {
                            req.resume();
                        });
                    }
                }
            });
            part.on('end', function() {
                if (out && received > 0) {
                    out.commit(received);
                } else if (out) {
                    out.discard();
                    error = new Error('File is empty');
                }
            });
        }
    };
    form.parse(req, function(err, fields, files) { if (!error) error = err; });

    form.on('end', function() {
        if (!out && !error)
            error = new Error('No file received');

        if (error) {
            /* Error */
            console.error(error.stack);
            res.writeHead(400, HTML_HEADERS);
            res.write(template.htmlHead);
            res.write(template.error(error || new Error('No file received')));
            res.write(template.htmlFoot);
            res.end();
        } else {
            /* Success */
            res.writeHead(200, HTML_HEADERS);
            res.write(template.htmlHead);
            res.write(template.thanks);
            res.write(template.htmlFoot);
            res.end();
        }
    });
});

function fileDownload(req, res, next) {
    var m;
    if ((m = req.url.match(/^\/file\/(\d+)\//))) {
        var id = parseInt(m[1], 10);
        var info = files.getFile(id);
        res.writeHead(200, { 'Content-Type': info.mime,
                             'Content-Length': info.size });
        var read = files.readFile(info.id);
        sys.pump(read, res);
        read.on('close', function() {
            res.end();
        });
    } else
        next();
}

app.use(fileDownload);
app.use(express.static(__dirname + '/public'));
app.use(function(req, res, next) {
    res.writeHead(404, { Location: '/' });
    res.end();
});
var port = parseInt(process.env.PORT || "8000", 10);
app.listen(port, '::');
console.log("Now listening on http://[::1]:" + port);