如何获取请求的字节大小？

Question

我正在Node.js Express中创建一个API,它可能会收到大量请求.我真的很想知道请求有多大.

//....
router.post('/apiendpoint', function(req, res, next) {
  console.log("The size of incoming request in bytes is");
  console.log(req.????????????); //How to get this?
});
//....

Answer 1

您可以使用req.socket.bytesRead或者您可以使用request-stats模块.

var requestStats = require('request-stats');
var stats = requestStats(server);

stats.on('complete', function (details) {
    var size = details.req.bytes;
});

详细信息对象如下所示:

{
    ok: true,           // `true` if the connection was closed correctly and `false` otherwise 
    time: 0,            // The milliseconds it took to serve the request 
    req: {
        bytes: 0,         // Number of bytes sent by the client 
        headers: { ... }, // The headers sent by the client 
        method: 'POST',   // The HTTP method used by the client 
        path: '...'       // The path part of the request URL 
    },
    res  : {
        bytes: 0,         // Number of bytes sent back to the client 
        headers: { ... }, // The headers sent back to the client 
        status: 200       // The HTTP status code returned to the client 
    }
}

因此,您可以从中获取请求大小details.req.bytes.

另一种选择是req.headers['content-length'](但有些客户端可能不会发送此标头).

Answer 2

您不能使用，req.socket.bytesRead因为socket它是可重用的，因此bytesRead是给定的总流量大小socket，而不是特定请求的大小。
我使用的一个快速解决方案 - 一个小型中间件（我使用 Express）：

const socketBytes = new Map();
app.use((req, res, next) => {
    req.socketProgress = getSocketProgress(req.socket);
    next();
});

/**
 * return kb read delta for given socket
 */
function getSocketProgress(socket) {
    const currBytesRead = socket.bytesRead;
    let prevBytesRead;
    if (!socketBytes.has(socket)) {
        prevBytesRead = 0;
    } else {
        prevBytesRead = socketBytes.get(socket).prevBytesRead;
    }
    socketBytes.set(socket, {prevBytesRead: currBytesRead})
    return (currBytesRead-prevBytesRead)/1024;
} 

然后你就可以req.socketProgress在你的中间件中使用。