345 lines
10 KiB
JavaScript
Executable file
345 lines
10 KiB
JavaScript
Executable file
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.Polling = void 0;
|
|
const transport_1 = require("../transport");
|
|
const zlib_1 = require("zlib");
|
|
const accepts = require("accepts");
|
|
const debug_1 = require("debug");
|
|
const debug = (0, debug_1.default)("engine:polling");
|
|
const compressionMethods = {
|
|
gzip: zlib_1.createGzip,
|
|
deflate: zlib_1.createDeflate,
|
|
};
|
|
class Polling extends transport_1.Transport {
|
|
/**
|
|
* HTTP polling constructor.
|
|
*
|
|
* @api public.
|
|
*/
|
|
constructor(req) {
|
|
super(req);
|
|
this.closeTimeout = 30 * 1000;
|
|
}
|
|
/**
|
|
* Transport name
|
|
*
|
|
* @api public
|
|
*/
|
|
get name() {
|
|
return "polling";
|
|
}
|
|
get supportsFraming() {
|
|
return false;
|
|
}
|
|
/**
|
|
* Overrides onRequest.
|
|
*
|
|
* @param {http.IncomingMessage}
|
|
* @api private
|
|
*/
|
|
onRequest(req) {
|
|
const res = req.res;
|
|
// remove the reference to the ServerResponse object (as the first request of the session is kept in memory by default)
|
|
req.res = null;
|
|
if ("GET" === req.method) {
|
|
this.onPollRequest(req, res);
|
|
}
|
|
else if ("POST" === req.method) {
|
|
this.onDataRequest(req, res);
|
|
}
|
|
else {
|
|
res.writeHead(500);
|
|
res.end();
|
|
}
|
|
}
|
|
/**
|
|
* The client sends a request awaiting for us to send data.
|
|
*
|
|
* @api private
|
|
*/
|
|
onPollRequest(req, res) {
|
|
if (this.req) {
|
|
debug("request overlap");
|
|
// assert: this.res, '.req and .res should be (un)set together'
|
|
this.onError("overlap from client");
|
|
res.writeHead(400);
|
|
res.end();
|
|
return;
|
|
}
|
|
debug("setting request");
|
|
this.req = req;
|
|
this.res = res;
|
|
const onClose = () => {
|
|
this.onError("poll connection closed prematurely");
|
|
};
|
|
const cleanup = () => {
|
|
req.removeListener("close", onClose);
|
|
this.req = this.res = null;
|
|
};
|
|
req.cleanup = cleanup;
|
|
req.on("close", onClose);
|
|
this.writable = true;
|
|
this.emit("drain");
|
|
// if we're still writable but had a pending close, trigger an empty send
|
|
if (this.writable && this.shouldClose) {
|
|
debug("triggering empty send to append close packet");
|
|
this.send([{ type: "noop" }]);
|
|
}
|
|
}
|
|
/**
|
|
* The client sends a request with data.
|
|
*
|
|
* @api private
|
|
*/
|
|
onDataRequest(req, res) {
|
|
if (this.dataReq) {
|
|
// assert: this.dataRes, '.dataReq and .dataRes should be (un)set together'
|
|
this.onError("data request overlap from client");
|
|
res.writeHead(400);
|
|
res.end();
|
|
return;
|
|
}
|
|
const isBinary = "application/octet-stream" === req.headers["content-type"];
|
|
if (isBinary && this.protocol === 4) {
|
|
return this.onError("invalid content");
|
|
}
|
|
this.dataReq = req;
|
|
this.dataRes = res;
|
|
let chunks = isBinary ? Buffer.concat([]) : "";
|
|
const cleanup = () => {
|
|
req.removeListener("data", onData);
|
|
req.removeListener("end", onEnd);
|
|
req.removeListener("close", onClose);
|
|
this.dataReq = this.dataRes = chunks = null;
|
|
};
|
|
const onClose = () => {
|
|
cleanup();
|
|
this.onError("data request connection closed prematurely");
|
|
};
|
|
const onData = (data) => {
|
|
let contentLength;
|
|
if (isBinary) {
|
|
chunks = Buffer.concat([chunks, data]);
|
|
contentLength = chunks.length;
|
|
}
|
|
else {
|
|
chunks += data;
|
|
contentLength = Buffer.byteLength(chunks);
|
|
}
|
|
if (contentLength > this.maxHttpBufferSize) {
|
|
res.writeHead(413).end();
|
|
cleanup();
|
|
}
|
|
};
|
|
const onEnd = () => {
|
|
this.onData(chunks);
|
|
const headers = {
|
|
// text/html is required instead of text/plain to avoid an
|
|
// unwanted download dialog on certain user-agents (GH-43)
|
|
"Content-Type": "text/html",
|
|
"Content-Length": 2,
|
|
};
|
|
res.writeHead(200, this.headers(req, headers));
|
|
res.end("ok");
|
|
cleanup();
|
|
};
|
|
req.on("close", onClose);
|
|
if (!isBinary)
|
|
req.setEncoding("utf8");
|
|
req.on("data", onData);
|
|
req.on("end", onEnd);
|
|
}
|
|
/**
|
|
* Processes the incoming data payload.
|
|
*
|
|
* @param {String} encoded payload
|
|
* @api private
|
|
*/
|
|
onData(data) {
|
|
debug('received "%s"', data);
|
|
const callback = (packet) => {
|
|
if ("close" === packet.type) {
|
|
debug("got xhr close packet");
|
|
this.onClose();
|
|
return false;
|
|
}
|
|
this.onPacket(packet);
|
|
};
|
|
if (this.protocol === 3) {
|
|
this.parser.decodePayload(data, callback);
|
|
}
|
|
else {
|
|
this.parser.decodePayload(data).forEach(callback);
|
|
}
|
|
}
|
|
/**
|
|
* Overrides onClose.
|
|
*
|
|
* @api private
|
|
*/
|
|
onClose() {
|
|
if (this.writable) {
|
|
// close pending poll request
|
|
this.send([{ type: "noop" }]);
|
|
}
|
|
super.onClose();
|
|
}
|
|
/**
|
|
* Writes a packet payload.
|
|
*
|
|
* @param {Object} packet
|
|
* @api private
|
|
*/
|
|
send(packets) {
|
|
this.writable = false;
|
|
if (this.shouldClose) {
|
|
debug("appending close packet to payload");
|
|
packets.push({ type: "close" });
|
|
this.shouldClose();
|
|
this.shouldClose = null;
|
|
}
|
|
const doWrite = (data) => {
|
|
const compress = packets.some((packet) => {
|
|
return packet.options && packet.options.compress;
|
|
});
|
|
this.write(data, { compress });
|
|
};
|
|
if (this.protocol === 3) {
|
|
this.parser.encodePayload(packets, this.supportsBinary, doWrite);
|
|
}
|
|
else {
|
|
this.parser.encodePayload(packets, doWrite);
|
|
}
|
|
}
|
|
/**
|
|
* Writes data as response to poll request.
|
|
*
|
|
* @param {String} data
|
|
* @param {Object} options
|
|
* @api private
|
|
*/
|
|
write(data, options) {
|
|
debug('writing "%s"', data);
|
|
this.doWrite(data, options, () => {
|
|
this.req.cleanup();
|
|
});
|
|
}
|
|
/**
|
|
* Performs the write.
|
|
*
|
|
* @api private
|
|
*/
|
|
doWrite(data, options, callback) {
|
|
// explicit UTF-8 is required for pages not served under utf
|
|
const isString = typeof data === "string";
|
|
const contentType = isString
|
|
? "text/plain; charset=UTF-8"
|
|
: "application/octet-stream";
|
|
const headers = {
|
|
"Content-Type": contentType,
|
|
};
|
|
const respond = (data) => {
|
|
headers["Content-Length"] =
|
|
"string" === typeof data ? Buffer.byteLength(data) : data.length;
|
|
this.res.writeHead(200, this.headers(this.req, headers));
|
|
this.res.end(data);
|
|
callback();
|
|
};
|
|
if (!this.httpCompression || !options.compress) {
|
|
respond(data);
|
|
return;
|
|
}
|
|
const len = isString ? Buffer.byteLength(data) : data.length;
|
|
if (len < this.httpCompression.threshold) {
|
|
respond(data);
|
|
return;
|
|
}
|
|
const encoding = accepts(this.req).encodings(["gzip", "deflate"]);
|
|
if (!encoding) {
|
|
respond(data);
|
|
return;
|
|
}
|
|
this.compress(data, encoding, (err, data) => {
|
|
if (err) {
|
|
this.res.writeHead(500);
|
|
this.res.end();
|
|
callback(err);
|
|
return;
|
|
}
|
|
headers["Content-Encoding"] = encoding;
|
|
respond(data);
|
|
});
|
|
}
|
|
/**
|
|
* Compresses data.
|
|
*
|
|
* @api private
|
|
*/
|
|
compress(data, encoding, callback) {
|
|
debug("compressing");
|
|
const buffers = [];
|
|
let nread = 0;
|
|
compressionMethods[encoding](this.httpCompression)
|
|
.on("error", callback)
|
|
.on("data", function (chunk) {
|
|
buffers.push(chunk);
|
|
nread += chunk.length;
|
|
})
|
|
.on("end", function () {
|
|
callback(null, Buffer.concat(buffers, nread));
|
|
})
|
|
.end(data);
|
|
}
|
|
/**
|
|
* Closes the transport.
|
|
*
|
|
* @api private
|
|
*/
|
|
doClose(fn) {
|
|
debug("closing");
|
|
let closeTimeoutTimer;
|
|
if (this.dataReq) {
|
|
debug("aborting ongoing data request");
|
|
this.dataReq.destroy();
|
|
}
|
|
const onClose = () => {
|
|
clearTimeout(closeTimeoutTimer);
|
|
fn();
|
|
this.onClose();
|
|
};
|
|
if (this.writable) {
|
|
debug("transport writable - closing right away");
|
|
this.send([{ type: "close" }]);
|
|
onClose();
|
|
}
|
|
else if (this.discarded) {
|
|
debug("transport discarded - closing right away");
|
|
onClose();
|
|
}
|
|
else {
|
|
debug("transport not writable - buffering orderly close");
|
|
this.shouldClose = onClose;
|
|
closeTimeoutTimer = setTimeout(onClose, this.closeTimeout);
|
|
}
|
|
}
|
|
/**
|
|
* Returns headers for a response.
|
|
*
|
|
* @param {http.IncomingMessage} request
|
|
* @param {Object} extra headers
|
|
* @api private
|
|
*/
|
|
headers(req, headers) {
|
|
headers = headers || {};
|
|
// prevent XSS warnings on IE
|
|
// https://github.com/LearnBoost/socket.io/pull/1333
|
|
const ua = req.headers["user-agent"];
|
|
if (ua && (~ua.indexOf(";MSIE") || ~ua.indexOf("Trident/"))) {
|
|
headers["X-XSS-Protection"] = "0";
|
|
}
|
|
headers["cache-control"] = "no-store";
|
|
this.emit("headers", headers, req);
|
|
return headers;
|
|
}
|
|
}
|
|
exports.Polling = Polling;
|