hostr/lib/routes/statics.js

A simple web server for the current working directory. Used for hello world style web sites hosting only files in current directory structure. Watches files and integrates with LiveReload.

'use strict';

var fs = require('fs');
var url = require('url');
var crypto = require('crypto');
var mime = require('mime-types');

var debug = require('../debug')(process.env.QUIET === 'true');

/**
 * Static files route
 *
 * @param {http.incomingMessage} req      A request Object
 * @param {http.ServerResponse}  res      A response Object
 * @param {Function}             callback A callback, function(err)
 */
module.exports = function(options) {
  options = options || {};

  var _seed = Math.random();

  // Expiration time (sec)
  var _expirationTime = options.cacheExpiration || 60;

  var _handler = function(req, res, next) {
    var resource = url.parse(req.url);
    var resourcePathname = resource.pathname || '/';
    resourcePathname = resourcePathname.replace(/\/\.\./, "").replace(/\.\.\//, "");
    var filePath = process.cwd()+resourcePathname;

    if(filePath[filePath.length-1] === '/') filePath += 'index.html';

    var startTime = process.hrtime();
    fs.stat(filePath, function(err, stat) {
      if(err) {
        return next(err);
      }

      // ETag hash
      var uniqueHash = crypto.createHash('md5').update(new Buffer([
        _seed,
        filePath,
        (stat.mtime && stat.mtime.getTime())
      ].join(''))).digest('hex');
      var eTag = 'W/"'+uniqueHash+'"';

      // Use cache
      var headers = req.headers || {};
      var matchETag = headers['if-none-match'] === eTag;
      var matchExpiration = ((new Date(headers['if-modified-since'])).getTime() - Date.now()) >= 0;

      res.setHeader('ETag', eTag);

      if(matchExpiration && matchETag) {
        res.writeHead(304);
        res.end();
        return;
      }

      res.setHeader('Last-Modified', new Date(Date.now() + _expirationTime * 1000));
      res.setHeader('Cache-Control', "max-age="+ _expirationTime);

      // Interpret mime types
      res.setHeader('Content-Type', mime.lookup(filePath));

      var readStream = fs.createReadStream(filePath);
      readStream.on('open', function() {
        readStream.pipe(res);
      });

      readStream.on('error', function(err) {
        if(err && err.code === 'ENOENT') {
          return next();

        } else {
          res.writeHead(500);
          res.end();
        }
      });

    });

    // Log request
    res.on('finish', function() {
      var deltaTime = process.hrtime(startTime);

      debug.log([
        res.statusCode,
        req.method,
        req.url,
        Math.ceil((deltaTime[0] * 1e9 + deltaTime[1]) / 1e6) + 'ms'
      ].join(' '));
    });

  };

  /**
   * Reset seed
   */
  _handler.reset = function() {
    _seed = Math.random();
  };

  return _handler;
};