nodejs下载器，通过chrome代理下载http资源

var config={
//不想访问的东西，节约流量
"404":[
"http://qidian.qpic.cn/qdbimg"
],
//奇数为需要下载的，偶数为不需要下载的
needLoad:[
//匹配需要下载的
[
"/*.js",
"/*.css",
"/*.png"
],
//匹配不需要下载的
[
"/a.js"
]
],
//修改文件保存的地方,默认按照url来的
saveFiles:[
//防止太深文件夹
["(//*/*/*/*/*/)**/","$1"],
//过滤无效文件夹字符
[/(\/\w*)\?+(\w*\/)/gi,"$1$2"]
],
//代理的端口号
port:100
}

function regDir(str){
var reg=str
if(typeof reg=="string"){
reg=reg.replace(/[\[\]\\\^\:\.\?\+]/g,function(m){
return "\\"+m;
})
reg=reg.replace(/\*\*|\*/g,function(m){
if(m=="**"){
return "[\\w\\W]*";
}else{
return "[^\\\/]*";
}

})
reg=new RegExp(reg,"gi")
}
return reg
}
String.prototype.Test=function(regStr){
var reg=regDir(regStr)
return reg.test(this)
}
String.prototype.Replace=function(regStr,fn){
var reg=regDir(regStr)
return this.replace(reg,fn);
}
var fs=require("fs")
function mkdir(filepath){
var path=require("path")
if(!fs.existsSync(path.dirname(filepath))){
mkdir(path.dirname(filepath))
}
if(!fs.existsSync(filepath)){
fs.mkdirSync(filepath)
}
}

function eachHeader (obj, fn) {
if (Array.isArray(obj.rawHeaders)) {
// ideal scenario... >= node v0.11.x
// every even entry is a "key", every odd entry is a "value"
var key = null;
obj.rawHeaders.forEach(function (v) {
if (key === null) {
key = v;
} else {
fn(key, v);
key = null;
}
});
} else {
// otherwise we can *only* proxy the header names as lowercase'd
var headers = obj.headers;
if (!headers) return;
Object.keys(headers).forEach(function (key) {
var value = headers[key];
if (Array.isArray(value)) {
// set-cookie
value.forEach(function (val) {
fn(key, val);
});
} else {
fn(key, value);
}
});
}
}
var hopByHopHeaders = [
'Connection',
'Keep-Alive',
'Proxy-Authenticate',
'Proxy-Authorization',
'TE',
'Trailers',
'Transfer-Encoding',
'Upgrade'
];
// create a case-insensitive RegExp to match "hop by hop" headers
var isHopByHop = new RegExp('^(' + hopByHopHeaders.join('|') + ')$', 'i');
//伪造http
function parse (req, server) {

var parsed = require("url").parse(req.url);
var socket = req.socket;
parsed.uri=parsed.href;
parsed.gzip=true;
// proxy the request HTTP method
parsed.method = req.method;

// setup outbound proxy request HTTP headers
var headers = {};
var hasXForwardedFor = false;
parsed.headers = headers;
eachHeader(req, function (key, value) {
var keyLower = key.toLowerCase();
if (!hasXForwardedFor && 'x-forwarded-for' === keyLower) {
// append to existing "X-Forwarded-For" header
// http://en.wikipedia.org/wiki/X-Forwarded-For hasXForwardedFor = true;
value += ', ' + socket.remoteAddress;
}
if (isHopByHop.test(key)) {
} else {
var v = headers[key];
if (Array.isArray(v)) {
v.push(value);
} else if (null != v) {
headers[key] = [ v, value ];
} else {
headers[key] = value;
}
}
});

if (!hasXForwardedFor) {
headers['X-Forwarded-For'] = socket.remoteAddress;
}
if (null == parsed.port) {
// default the port number if not specified, for >= node v0.11.6...
// https://github.com/joyent/node/issues/6199 parsed.port = 80;
}
return parsed
}

function getPath(url){
var filename=url.Replace("(**)?*","$1").Replace("http://(**/*)","$1")
var dirname=filename.Replace("(**)/*","$1")
mkdir("www/"+dirname)
return "www/"+filename
}
var api={
parse:parse,
mkdir:mkdir,
getPath:getPath
}
/************************************/
var http = require('http');
var fs=require("fs")
var request = require('request');

var server = http.createServer();
server.listen(config.port||100, function () {
var port = server.address().port;
console.log('HTTP(s) proxy server listening on port %d', port);
});

server.on('request', function (req, res) {

var url=req.url
var arr404=config["404"]
var is404=false
arr404.forEach(function(v,k){
if(url.Test(v)){
is404=true
}
})
if(is404){
res.end()
return
}
var parsed=api.parse(req,this)
//是否下载
var isLoaded=false;

//是否下载的列表
var regArr=config.needLoad
var back=false
regArr.forEach(function(v,k){
back=!back
v.forEach(function(v2,k2){
if(url.Test(v2)){
isLoaded=back
}
})
})
//修改保存文件路径
/*
* 匹配规则
* 修改后 */
var saveFiles=config.saveFiles
//    isLoaded=false
if(isLoaded){
saveFiles.forEach(function(v,k){
url=url.Replace(v[0],v[1])
})
console.log(url)
var path=api.getPath(url)
console.log(path)
//下载
var reque=request(parsed,function(err,resp,body){
if(err){
return
}
if(path.Test("/*.css")){
res.writeHead(200,{
"content-type":"text/css"
})
}
fs.createReadStream(path).pipe(res)
})
reque.pipe(fs.createWriteStream(path))
reque.on("error",function(){
console.error(url)
})

}else{
//不下载
var reque=request(parsed)
reque.pipe(res)
reque.on("error",function(){
console.error(url)
})

}

})