//basic server的配置文件
var port = 3000;
var server = require('./basicserver').createServer();
server.useFavIcon("localhost", "./docroot/favicon.png");
server.addContainer(".*", "/l/(.*)$", require('./redirector'), {})
server.docroot("localhost", "/", "./docroot");
//server.useFavIcon("127.0.0.1", "./docroot/favicon.png");
//server.docroot("127.0.0.1", "/", "./docroot");
server.listen(port);

var mime = require('mime');
var mimeType = mime.lookup('image.gif'); //==> image/gif
res.setHeader('Content-Type', mimeType);

res.setHeader('Set-Cookie2', ..cookie value..);

/*
 Basic Server的核心模塊會(huì)創(chuàng)建一個(gè)HTTP服務(wù)器對(duì)象，附加Basic Server上用于檢查請(qǐng)求，然后給予適當(dāng)響應(yīng)的功能
 Basic Server可以通過(guò)判斷Host頭部匹配的容器對(duì)象響應(yīng)來(lái)自多個(gè)域名的請(qǐng)求
 */
var http = require('http');
var url = require('url');
exports.createServer = function(){
  var htserver = http.createServer(function(req, res){
    req.basicServer = {urlparsed: url.parse(req.url, true)};
    processHeaders(req, res);
    dispatchToContainer(htserver, req, res);
  });
  htserver.basicServer = {containers: []};
  htserver.addContainer = function(host, path, module, options){
    if (lookupContainer(htserver, host, path) != undefined){
      throw new Error("Already mapped " + host + "/" + path);
    }
    htserver.basicServer.containers.push({host: host, path: path, module: module, options: options});
    return this;
  }
  htserver.useFavIcon = function(host, path){
    return this.addContainer(host, "/favicon.ico", require('./faviconHandler'), {iconPath: path});
  }
  htserver.docroot = function(host, path, rootPath){
    return this.addContainer(host, path, require('./staticHandler'), {docroot: rootPath});
  }
  return htserver;
}
var lookupContainer = function(htserver, host, path){
  for (var i = 0; i < htserver.basicServer.containers.length; i++){
    var container = htserver.basicServer.containers[i];
    var hostMatches = host.toLowerCase().match(container.host);
    var pathMatches = path.match(container.path);
    if (hostMatches !== null && pathMatches !== null){
      return {container: container, host: hostMatches, path: pathMatches};
    }
  }
  return undefined;
}
//用于搜索req.headers數(shù)組以查找cookie和host頭部，因?yàn)檫@兩個(gè)字段對(duì)請(qǐng)求的分派都很重要
//這個(gè)函數(shù)在每一個(gè)HTTP請(qǐng)求到達(dá)時(shí)都會(huì)被調(diào)用
//還有很多其他的HTTP頭部字段(Accept Accept-Encoding Accept-Language User-Agent)
var processHeaders = function(req, res){
  req.basicServer.cookies = [];
  var keys = Object.keys(req.headers);
  for (var i = 0; i < keys.length; i++){
    var hname = keys[i];
    var hval = req.headers[hname];
    if (hname.toLowerCase() === "host"){
      req.basicServer.host = hval;
    }
    //提取瀏覽器發(fā)送的cookie
    if (hname.toLowerCase() === "cookie"){
      req.basicServer.cookies.push(hval);
    }
  }
}
//查找匹配的容器，分派請(qǐng)求到對(duì)應(yīng)的容器中
//這個(gè)函數(shù)在每一個(gè)HTTP請(qǐng)求到達(dá)時(shí)都會(huì)被調(diào)用
var dispatchToContainer = function(htserver, req, res){
  var container = lookupContainer(htserver, req.basicServer.host, req.basicServer.urlparsed.pathname);
  if (container !== undefined){
    req.basicServer.hostMatches = container.host;
    req.basicServer.pathMatches = container.path;
    req.basicServer.container = container.container;
    container.container.module.handle(req, res);
  }else {
    res.writeHead(404, {'Content-Type': 'text/plain'});
    res.end("no handler found for " + req.basicServer.host + "/" + req.basicServer.urlparsed);
  }
}

//用于處理文件系統(tǒng)內(nèi)的文件，docroot選項(xiàng)指被存放文件所在文件夾的路徑，讀取該目錄下的指定文件
var fs = require('fs');
var mime = require('mime');
var sys = require('sys');
exports.handle = function(req, res){
  if (req.method !== "GET"){
    res.writeHead(404, {'Content-Type': 'text/plain'});
    res.end("invalid method " + req.method);
  } else {
    var fname = req.basicServer.container.options.docroot + req.basicServer.urlparsed.pathname;
    if (fname.match(/\/$/)) fname += "index.html"; //如果URL以/結(jié)尾
    fs.stat(fname, function(err, stats){
      if (err){
        res.writeHead(500, {'Content-Type': 'text/plain'});
        res.end("file " + fname + " not found " + err);
      } else {
        fs.readFile(fname, function(err, buf){
          if (err){
            res.writeHead(500, {'Content-Type': 'text/plain'});
            res.end("file " + fname + " not readable " + err);
          } else {
            res.writeHead(200, {'Content-Type': mime.lookup(fname),
              'Content-Length': buf.length});
            res.end(buf);
          }
        });
      }
    });
  }
}

//這個(gè)處理函數(shù)處理對(duì)favicon.ico的請(qǐng)求
//MIME模塊根據(jù)給出的圖標(biāo)文件確定正確的MIME類型，網(wǎng)站圖標(biāo)favicon可以是任何類型的圖片，但是我們必須要告訴瀏覽器是哪個(gè)類型
//MIME模塊，用于生成正確的Content-Type頭
var fs = require('fs');
var mime = require('mime');
exports.handle = function(req, res){
  if (req.method !== "GET"){
    res.writeHead(404, {'Content-Type': 'text/plain'});
    res.end("invalid method " + req.method);
  } else if (req.basicServer.container.options.iconPath !== undefined){
    fs.readFile(req.basicServer.container.options.iconPath, function(err, buf){
      if (err){
        res.writeHead(500, {'Content-Type': 'text/plain'});
        res.end(req.basicServer.container.options.iconPath + "not found");
      } else {
        res.writeHead(200, {'Content-Type': mime.lookup(req.basicServer.container.options.iconPath),
        'Content-Length': buf.length});
        res.end(buf);
      }
    });
  } else {
    res.writeHead(404, {'Content-Type': 'text/plain'});
    res.end("no favicon");
  }
}

/*
 把一個(gè)域的請(qǐng)求重定向到另一個(gè)上，例如將www.example.com重定向到example.com上，或者使用簡(jiǎn)短的URL跳轉(zhuǎn)到較長(zhǎng)的URL
 實(shí)現(xiàn)這兩種情況，我們需要在HTTP響應(yīng)中發(fā)送301(永久移除)或者302(臨時(shí)移除)狀態(tài)碼，并且指定location頭信息。有了這個(gè)組合
 信號(hào)，web瀏覽器就知道要跳轉(zhuǎn)到另一個(gè)web位置了
 */
//地址http://localhost:3000/l/ex1 會(huì)跳轉(zhuǎn)到http://example1.com
var util = require('util');
var code2url = {'ex1': 'http://example1.com', 'ex2': "http://example2.com"};
var notFound = function(req, res){
  res.writeHead(404, {'Content-Type': 'text/plain'});
  res.end("no matching redirect code found for " + req.basicServer.host + "/" + req.basicServer.urlparsed.pathname);
}
exports.handle = function(req, res){
  if (req.basicServer.pathMatches[1]){
    var code = req.basicServer.pathMatches[1];
    if (code2url[code]){
      var url = code2url[code];
      res.writeHead(302, {'Location': url});
      res.end();
    } else {
      notFound(req, res);
    }
  } else {
    notFound(req, res);
  }
}

<html>
<head>
</head>
<body>
  <h1>Index</h1>
  <p>this is a index html.</p>
</body>
</html>