在 Node.js 中使用流来缓冲 HTTP 通信

Question

我正在尝试在 Node 中使用流.js基本上构建一个 HTTP 数据的运行缓冲区，直到完成一些处理，但我正在努力解决流的细节。一些伪代码可能会有所帮助：

var server = http.createServer(function(request, response) {
    // Create a buffer stream to hold data generated by the asynchronous process
    // to be piped to the response after headers and other obvious response data
    var buffer = new http.ServerResponse();
    // Start the computation of the full response as soon as possible, passing
    // in the buffer stream to hold returned data until headers are written
    beginAsyncProcess(request, buffer);
    // Send headers and other static data while waiting for the full response
    // to be generated by 'beginAsyncProcess'
    sendObviousData(response, function() {
        // Once obvious data is written (unfortunately HTTP and Node.js have
        // certain requirements for the order data must be written in) then pipe
        // the stream with the data from 'beginAsyncProcess' into the response
        buffer.pipe(response);
    });
});

其中大部分几乎是合法的代码，但它不起作用。基本问题是找到一种方法来利用 Node 的异步特性.js当存在与 HTTP 请求相关的某些顺序要求时，即标头必须始终首先写入。

虽然我肯定会感谢任何带有小技巧的答案，以便在不直接解决流的情况下解决订单问题，但我想利用这个机会更好地了解它们。有很多类似的情况，但这种情况更多的是打开蠕虫的罐头，而不是其他任何事情。

Answer 1

让我们在

Node 中使用回调和流.js并.pause()/.resume()流函数：

var server = http.createServer(function(request, response) {
    // Handle the request first, then..
    var body = new Stream(); // <-- you can implement stream.Duplex for read / write operations
        body.on('open', function(){
            body.pause();
            // API generate data
            // body.write( generated data ) <-- write to the stream
            body.resume();
        });
    var firstPartOfThePage = getHTMLSomeHow();
    response.writeHead(200, { 'Content-Type': 'text/html'});
    response.write(firstPartOfThePage, function(){ // <-- callback after sending first part, our body already being processed
        body.pipe( response ); // <-- This should fire after being resumed
        body.on('end', function(){
            response.end(); // <-- end the response
        });
    });
});

检查此内容：http://codewinds.com/blog/2013-08-31-nodejs-duplex-streams.html 用于创建 costum 双工流。

注意：它仍然是伪代码