static-server/
|
| - bin/
| | - start # 批處理文件
|  
|
| - src/
| | - App.js # main文件
| | - Config.js # 默認(rèn)配置
|
|
·- package.json

let config = {
 host:'localhost' //提升用
 ,port:8080 //服務(wù)器啟動(dòng)時(shí)候的默認(rèn)端口號(hào)
 ,path:path.resolve(__dirname,'..','test-dir') //靜態(tài)服務(wù)器啟動(dòng)時(shí)默認(rèn)的工作目錄
}

class Server(){
 constructor(options){
  /* === 合并配置參數(shù) === */
  this.config = Object.assign({},config,options)
 }
 start(){
  /* === 啟動(dòng)http服務(wù) === */
  let server = http.createServer();
  server.on('request',this.request.bind(this)); 
  server.listen(this.config.port,()=>{
   let url = `${this.config.host}:${this.config.port}`;
   console.log(`server started at ${chalk.green(url)}`)
  })
 }
 async request(req,res){
  /* === 處理客戶(hù)端請(qǐng)求，決定響應(yīng)信息 === */
  // try
  //如果是文件夾 -> 顯示子文件、文件夾列表
  //如果是文件 -> sendFile()
  // catch
  //出錯(cuò) -> sendError()
 }
 sendFile(){
  //對(duì)要返回的文件進(jìn)行預(yù)處理并發(fā)送文件
 }
 handleCache(){
  //獲取和設(shè)置緩存相關(guān)信息
 }
 getEncoding(){
  //獲取和設(shè)置編碼相關(guān)信息
 }
 getStream(){
  //獲取和設(shè)置分塊傳輸相關(guān)信息
 }
 sendError(){
  //錯(cuò)誤提示
 }
}
module.exports = Server;

async request(req,res){
 let pathname = url.parse(req.url);
 if(pathname == '/favicon.ico') return;
 let filepath = path.join(this.config.root,pathname);
 try{
  let statObj = await stat(filepath);
  if(statObj.isDirectory()){
   let files = awaity readdir(filepath);
   files.map(file=>{
    name:file
    ,path:path.join(pathname,file)
   });
   // 讓handlebar 拿著數(shù)去編譯模板
   let html = this.list({
    title:pathname
    ,files
   })
   res.setHeader('Content-Type','text/html');
   res.end(html);
  }else{
   this.sendFile(req,res,filepath,statObj);
  }
 }catch(e){
  this.sendError(e,req,res);
 }
}

sendFile(){
 if(this.handleCache(req,res,filepath,statObj)) return; //如果走緩存，則直接返回。
 res.setHeader('Content-type',mime.getType(filepath)+';charset=utf-8');
 let encoding = this.getEncoding(req,res); //獲取瀏覽器能接收的編碼并選擇一種
 let rs = this.getStream(req,res,filepath,statObj); //支持?jǐn)帱c(diǎn)續(xù)傳
 if(encoding){
  rs.pipe(encoding).pipe(res);
 }else{
  rs.pipe(res);
 }
}

handleCache(req,res,filepath,statObj){
 let ifModifiedSince = req.headers['if-modified-since']; //第一次請(qǐng)求是不會(huì)有的
 let isNoneMatch = req.headers['is-none-match'];
 res.setHeader('Cache-Control','private,max-age=30');
 res.setHeader('Expires',new Date(Date.now()+30*1000).toGMTString()); //此時(shí)間必須為GMT
 
 let etag = statObj.size;
 let lastModified = statObj.ctime.toGMTString(); //此時(shí)間格式可配置
 res.setHeader('Etag',etag);
 res.setHeader('Last-Modified',lastModified);
 
 if(isNoneMatch && isNoneMatch != etag) return false; //若是第一次請(qǐng)求已經(jīng)返回false
 if(ifModifiedSince && ifModifiedSince != lastModified) return false;
 if(isNoneMatch || ifModifiedSince){
 // 說(shuō)明設(shè)置了isNoneMatch或則isModifiedSince且文件沒(méi)有改變
  res.writeHead(304);
  res.end();
  return true;
 }esle{
  return false;
 }
}

getEncoding(req,res){
 let acceptEncoding = req.headers['accept-encoding'];
 if(/\bgzip\b/.test(acceptEncoding)){
  res.setHeader('Content-Encoding','gzip');
  return zlib.createGzip();
 }else if(/\bdeflate\b/.test(acceptEncoding)){
  res.setHeader('Content-Encoding','deflate');
  return zlib.createDeflate();
 }else{
  return null;
 }
}

getStream(req,res,filepath,statObj){
 let start = 0;
 let end = startObj.size - 1;
 let range = req.headers['range'];
 if(range){
  res.setHeader('Accept-Range','bytes');
  res.statusCode = 206; //返回整個(gè)數(shù)據(jù)的一塊
  let result = range.match(/bytes = (\d*)-(\d*)/); //不可能有小數(shù)，網(wǎng)絡(luò)傳輸?shù)淖钚挝粸橐粋€(gè)字節(jié)
  if(result){
   start = isNaN(result[1])?0:parseInt(result[1]);
   end = isNaN(result[2])?end:parseInt(result[2])-1; //因?yàn)閞eadstream的索引是包前又包后故要減去1
  }
 }
 return fs.createReadStream(filepath,{
  start,end
 });
}