使用Node.js实现一个简单的FastCGI服务器实例(4)

响应部分相对比较简单，最简单的情况只需要发送两个记录就行了，那就是FCGI_STDOUT和FCGI_END_REQUEST。
具体记录实体的内容就不冗述了，直接看代码吧：

复制代码 代码如下:

var res = (function(){
    var MaxLength = Math.pow(2, 16);

function buffer0(len){
        return new Buffer((new Array(len + 1)).join('\u0000'));
    };

function writeStdout(data){
        var rcdStdoutHd = new Buffer(8),
            contendLength = data.length,
            paddingLength = 8 - contendLength % 8;

rcdStdoutHd[0] = 1;
        rcdStdoutHd[1] = TYPES.FCGI_STDOUT;
        rcdStdoutHd[2] = 0;
        rcdStdoutHd[3] = 1;
        rcdStdoutHd[4] = contendLength >> 8;
        rcdStdoutHd[5] = contendLength;
        rcdStdoutHd[6] = paddingLength;
        rcdStdoutHd[7] = 0;

return Buffer.concat([rcdStdoutHd, data, buffer0(paddingLength)]);
    };

function writeHttpHead(){
        return writeStdout(new Buffer("HTTP/1.1 200 OK\r\nContent-Type:text/html; charset=utf-8\r\nConnection: close\r\n\r\n"));
    }

function writeHttpBody(bodyStr){
        var bodyBuffer = [],
            body = new Buffer(bodyStr);
        for(var i = 0, l = body.length; i < l; i += MaxLength + 1){
            bodyBuffer.push(writeStdout(body.slice(i, i + MaxLength)));
        }
        return Buffer.concat(bodyBuffer);
    }

function writeEnd(){
        var rcdEndHd = new Buffer(8);
        rcdEndHd[0] = 1;
        rcdEndHd[1] = TYPES.FCGI_END_REQUEST;
        rcdEndHd[2] = 0;
        rcdEndHd[3] = 1;
        rcdEndHd[4] = 0;
        rcdEndHd[5] = 8;
        rcdEndHd[6] = 0;
        rcdEndHd[7] = 0;
        return Buffer.concat([rcdEndHd, buffer0(8)]);
    }

return function(data){
        return Buffer.concat([writeHttpHead(), writeHttpBody(data), writeEnd()]);
    };
})();

在最简单的情况下，这样就可以发送一个完整的响应了。把我们最终的代码修改一下：

复制代码 代码如下:

var visitors = 0;
server.on('connection', function(sock){
    visitors++;
    sock.on('data', function(data){
        ...
        var querys = querystring.parse(params.QUERY_STRING);
            var ret = res('欢迎你，' + (querys.name || '亲爱的朋友') + '！你是本站第' + visitors + '位用户哦~');
            sock.write(ret);
            ret = null;
            sock.end();
        ...
    });

打开浏览器访问：?name=yekai，可看到类似“欢迎你，yekai！你是本站第7位用户哦~”。
至此，我们就成功的使用Node.js实现了一个最简单的FastCGI服务。如果需要作为真正的服务使用，接下来只需要对照协议规范完善我们的逻辑就行了。

对比测试

最后，我们需要考虑的问题是这个方案具体是否具有可行性？可能已经有同学看出了问题，我先把简单的压测结果放上来：

复制代码 代码如下:

//FastCGI方式：
500 clients, running 10 sec.
Speed=27678 pages/min, 63277 bytes/sec.
Requests: 3295 susceed, 1318 failed.

500 clients, running 20 sec.
Speed=22131 pages/min, 63359 bytes/sec.
Requests: 6523 susceed, 854 failed.

//proxy方式：
500 clients, running 10 sec.
Speed=28752 pages/min, 73191 bytes/sec.
Requests: 3724 susceed, 1068 failed.

500 clients, running 20 sec.
Speed=26508 pages/min, 66267 bytes/sec.
Requests: 6716 susceed, 2120 failed.

//直接访问Node.js服务方式：
500 clients, running 10 sec.
Speed=101154 pages/min, 264247 bytes/sec.
Requests: 15729 susceed, 1130 failed.