refactor to use http-raw for lt server incoming

- http raw exposes a socket to the req/res pair
- cleanup client to be more resilient
- add test for queued requests
This commit is contained in:
Roman Shtylman
2012-12-17 14:23:12 -05:00
parent 741db27084
commit 79ca069c38
6 changed files with 354 additions and 323 deletions

424
server.js
View File

@@ -6,277 +6,106 @@ var url = require('url');
// here be dragons
var HTTPParser = process.binding('http_parser').HTTPParser;
var ServerResponse = http.ServerResponse;
var IncomingMessage = http.IncomingMessage;
// vendor
var log = require('book');
var createRawServer = require('http-raw');
// local
var rand_id = require('./lib/rand_id');
var server = http.createServer();
// id -> client http server
var clients = {};
// available parsers
var parsers = http.parsers;
// data going back to a client (the last client that made a request)
function socketOnData(d, start, end) {
// send this request to the appropriate client
// in -> incoming request stream
function proxy_request(client, req, res, rs, ws) {
var socket = this;
var req = this._httpMessage;
rs = rs || req.createRawStream();
ws = ws || res.createRawStream();
var response_socket = socket.respond_socket;
if (!response_socket) {
log.error('no response socket assigned for http response from backend');
// socket is a tcp connection back to the user hosting the site
var sock = client.sockets.shift();
// queue request
if (!sock) {
log.info('no more clients, queued: %s', req.url);
rs.pause();
client.waiting.push([req, res, rs, ws]);
return;
}
// pass the response from our client back to the requesting socket
response_socket.write(d.slice(start, end));
log.info('handle req: %s', req.url);
if (socket.for_websocket) {
return;
}
// pipe incoming request into tcp socket
// incoming request isn't allowed to end the socket back to lt client
rs.pipe(sock, { end: false });
sock.ws = ws;
sock.req = req;
// since tcp connection to upstream are kept open
// invoke parsing so we know when the response is complete
var parser = response_socket.out_parser;
parser.socket = socket;
var parser = sock.parser;
parser.reinitialize(HTTPParser.RESPONSE);
parser.socket = sock;
var ret = parser.execute(d, start, end - start);
// we have completed a response
// the tcp socket is free again
parser.onIncoming = function (res) {
parser.onMessageComplete = function() {
log.info('ended response: %s', req.url);
// any request we had going on is now done
ws.end();
// no more forwarding
delete sock.ws;
delete parser.onIncoming;
// return socket to available pool
client.sockets.push(sock);
var next = client.waiting.shift();
if (next) {
log.trace('popped');
proxy_request(client, next[0], next[1], next[2], next[3]);
}
};
};
rs.resume();
}
function upstream_response(d, start, end) {
var socket = this;
var ws = socket.ws;
if (!ws) {
log.warn('no stream set for req:', socket.req.url);
return;
}
ws.write(d.slice(start, end));
if (socket.upgraded) {
return;
}
var ret = socket.parser.execute(d, start, end - start);
if (ret instanceof Error) {
log.error(ret);
freeParser(parser, req);
parsers.free(parser);
socket.destroy(ret);
}
}
function freeParser(parser, req) {
if (parser) {
parser._headers = [];
parser.onIncoming = null;
if (parser.socket) {
parser.socket.onend = null;
parser.socket.ondata = null;
parser.socket.parser = null;
}
parser.socket = null;
parser.incoming = null;
parsers.free(parser);
parser = null;
}
if (req) {
req.parser = null;
}
}
var handle_req = function (req, res) {
// single http connection
// gets a single http response back
server.on('connection', function(socket) {
var self = this;
// parser handles incoming requests for the socket
// the request is what lets us know if we proxy or not
var parser = parsers.alloc();
parser.socket = socket;
parser.reinitialize(HTTPParser.REQUEST);
function our_request(req) {
var res = new ServerResponse(req);
res.assignSocket(socket);
self.emit('request', req, res);
return;
}
// a full request is complete
// we wait for the response from the server
parser.onIncoming = function(req, shouldKeepAlive) {
log.trace('request', req.url);
// default is that the data is not for the client
delete parser.sock;
delete parser.buffer;
delete parser.client;
var hostname = req.headers.host;
if (!hostname) {
log.trace('no hostname: %j', req.headers);
return our_request(req);
}
var match = hostname.match(/^([a-z]{4})[.].*/);
if (!match) {
return our_request(req);
}
var client_id = match[1];
var client = clients[client_id];
// requesting a subdomain that doesn't exist
if (!client) {
return socket.end();
}
parser.client = client;
// assigned socket for the client
var sock = client.sockets.shift();
// no free sockets, queue
if (!sock) {
parser.buffer = true;
return;
}
// for tcp proxying
parser.sock = sock;
// set who we will respond back to
sock.respond_socket = socket;
var out_parser = parsers.alloc();
out_parser.reinitialize(HTTPParser.RESPONSE);
socket.out_parser = out_parser;
// we have completed a response
// the tcp socket is free again
out_parser.onIncoming = function (res) {
res.on('end', function() {
log.trace('done with response for: %s', req.url);
// done with the parser
parsers.free(out_parser);
// unset the response
delete sock.respond_socket;
var next = client.waiting.shift();
if (!next) {
// return socket to available
client.sockets.push(sock);
return;
}
// reuse avail socket for next connection
sock.respond_socket = next;
// needed to know when this response will be done
out_parser.reinitialize(HTTPParser.RESPONSE);
next.out_parser = out_parser;
// write original bytes we held cause we were busy
sock.write(next.queue);
// continue with other bytes
next.resume();
return;
});
};
};
// process new data on the client socket
// we may need to forward this it the backend
socket.ondata = function(d, start, end) {
// run through request parser to determine if we should pass to tcp
// onIncoming will be run before this returns
var ret = parser.execute(d, start, end - start);
// invalid request from the user
if (ret instanceof Error) {
log.error(ret);
socket.destroy(ret);
return;
}
// websocket stuff
if (parser.incoming && parser.incoming.upgrade) {
log.trace('upgrade request');
parser.finish();
var hostname = parser.incoming.headers.host;
var match = hostname.match(/^([a-z]{4})[.].*/);
if (!match) {
return our_request(req);
}
var client_id = match[1];
var client = clients[client_id];
var sock = client.sockets.shift();
sock.respond_socket = socket;
sock.for_websocket = true;
socket.ondata = function(d, start, end) {
sock.write(d.slice(start, end));
};
socket.end = function() {
log.trace('websocket end');
delete sock.respond_socket;
client.sockets.push(sock);
}
sock.write(d.slice(start, end));
return;
}
// if no available socket, buffer the request for later
if (parser.buffer) {
// pause any further data on this socket
socket.pause();
// copy the current data since we have already received it
var copy = Buffer(end - start);
d.copy(copy, 0, start, end);
socket.queue = copy;
// add socket to queue
parser.client.waiting.push(socket);
return;
}
if (!parser.sock) {
return;
}
// assert, respond socket should be set
// send through tcp tunnel
// responses will go back to the respond_socket
parser.sock.write(d.slice(start, end));
};
socket.onend = function() {
var ret = parser.finish();
if (ret instanceof Error) {
log.error(ret);
socket.destroy(ret);
return;
}
socket.end();
};
socket.on('close', function() {
parsers.free(parser);
});
});
server.on('request', function(req, res) {
var max_tcp_sockets = req.socket.server.max_tcp_sockets;
// ignore favicon
if (req.url === '/favicon.ico') {
@@ -284,7 +113,26 @@ server.on('request', function(req, res) {
return res.end();
}
var parsed = url.parse(req.url, true);
var hostname = req.headers.host;
if (!hostname) {
log.trace('no hostname: %j', req.headers);
return res.end();
}
var match = hostname.match(/^([a-z]{4})[.].*/);
if (match) {
var client_id = match[1];
var client = clients[client_id];
// no such subdomain
if (!client) {
log.trace('no client found for id: ' + client_id);
res.statusCode = 404;
return res.end();
}
return proxy_request(client, req, res);
}
// redirect main page to github reference
if (req.url === '/' && !parsed.query.new) {
@@ -314,10 +162,6 @@ server.on('request', function(req, res) {
id = rand_id();
}
// maximum number of tcp connections the client can setup
// each tcp channel allows for more parallel requests
var max_tcp_sockets = 4;
// sockets is a list of available sockets for the connection
// waiting is?
var client = clients[id] = {
@@ -345,9 +189,7 @@ server.on('request', function(req, res) {
// user has 5 seconds to connect before their slot is given up
function maybe_tcp_close() {
conn_timeout = setTimeout(function() {
client_server.close();
}, 5000);
conn_timeout = setTimeout(client_server.close.bind(client_server), 5000);
}
maybe_tcp_close();
@@ -371,12 +213,16 @@ server.on('request', function(req, res) {
// no need to close the client server
clearTimeout(conn_timeout);
// multiplexes socket data out to clients
socket.ondata = socketOnData;
// allocate a response parser for the socket
// it only needs one since it will reuse it
socket.parser = parsers.alloc();
socket._orig_ondata = socket.ondata;
socket.ondata = upstream_response;
client.sockets.push(socket);
socket.on('close', function(had_error) {
socket.once('close', function(had_error) {
log.trace('client %s closed socket', id);
// remove this socket
@@ -402,7 +248,75 @@ server.on('request', function(req, res) {
client_server.on('error', function(err) {
log.error(err);
});
});
};
module.exports = server;
var handle_upgrade = function(req, ws) {
if (req.headers.connection !== 'Upgrade') {
return;
}
var hostname = req.headers.host;
if (!hostname) {
return res.end();
}
var match = hostname.match(/^([a-z]{4})[.].*/);
// not a valid client
if (!match) {
return res.end();
}
var client_id = match[1];
var client = clients[client_id];
if (!client) {
// no such subdomain
return res.end();
}
var socket = client.sockets.shift();
if (!socket) {
// no available sockets to upgrade to
return res.end();
}
var stream = req.createRawStream();
socket.ws = ws;
socket.upgraded = true;
stream.once('end', function() {
delete socket.ws;
// when this ends, we just reset the socket to the lt client
// this is easier than trying to figure anything else out
socket.end();
// put socket back into available pool
client.sockets.push(socket);
var next = client.waiting.shift();
if (next) {
log.trace('popped');
proxy_request(client, next[0], next[1], next[2], next[3]);
}
});
stream.pipe(socket, {end: false});
socket.once('end', ws.end.bind(ws));
};
module.exports = function(opt) {
opt = opt || {};
var server = createRawServer();
server.max_tcp_sockets = opt.max_tcp_sockets || 5;
server.on('request', handle_req);
server.on('upgrade', handle_upgrade);
return server;
};