X-Git-Url: https://git.sesse.net/?p=remoteglot;a=blobdiff_plain;f=www%2Fserve-analysis.js;h=100cd4a6f53e4c2340a02bd5d3ce84d65241b2cd;hp=5b08484d1693fb85f0c969a45a389a314308c256;hb=af901f11d1572468431e92d55a5f9980d39f3609;hpb=5426efdc76c6a78aceb84ab8b3de262ccb3cfdf3 diff --git a/www/serve-analysis.js b/www/serve-analysis.js index 5b08484..100cd4a 100644 --- a/www/serve-analysis.js +++ b/www/serve-analysis.js @@ -7,17 +7,19 @@ var fs = require('fs'); var url = require('url'); var querystring = require('querystring'); var path = require('path'); +var zlib = require('zlib'); // Constants. var json_filename = '/srv/analysis.sesse.net/www/analysis.json'; // The current contents of the file to hand out, and its last modified time. -var json_contents = null; -var json_last_modified = null; +var json_contents = undefined; +var json_contents_gz = undefined; +var json_last_modified = undefined; -// The list of clients that are waiting for new data to show up, -// and their associated timers. Uniquely keyed by request_id -// so that we can take them out of the queue if they time out. +// The list of clients that are waiting for new data to show up. +// Uniquely keyed by request_id so that we can take them out of +// the queue if they close the socket. var sleeping_clients = {}; var request_id = 0; @@ -25,6 +27,15 @@ var request_id = 0; // Used to show a viewer count to the user. var last_seen_clients = {}; +// The timer used to touch the file every 30 seconds if nobody +// else does it for us. This makes sure we don't have clients +// hanging indefinitely (which might have them return errors). +var touch_timer = undefined; + +// If we are behind Varnish, we can't count the number of clients +// ourselves, so some external log-tailing daemon needs to tell us. +var viewer_count_override = undefined; + var reread_file = function(event, filename) { if (filename != path.basename(json_filename)) { return; @@ -38,18 +49,35 @@ var reread_file = function(event, filename) { fs.read(fd, buffer, 0, 1048576, 0, function(err, bytesRead, buffer) { if (err) throw err; fs.close(fd, function() { - json_contents = buffer.toString('utf8', 0, bytesRead); - json_last_modified = st.mtime.getTime(); - possibly_wakeup_clients(); + var new_json_contents = buffer.toString('utf8', 0, bytesRead); + zlib.gzip(new_json_contents, function(err, buffer) { + if (err) throw err; + json_contents = new_json_contents; + json_contents_gz = buffer; + json_last_modified = st.mtime.getTime(); + possibly_wakeup_clients(); + }); }); }); }); }); + + if (touch_timer !== undefined) { + clearTimeout(touch_timer); + } + touch_timer = setTimeout(function() { + console.log("Touching analysis.json due to no other activity"); + var now = Date.now() / 1000; + fs.utimes(json_filename, now, now); + }, 30000); } var possibly_wakeup_clients = function() { + var num_viewers = count_viewers(); for (var i in sleeping_clients) { - clearTimeout(sleeping_clients[i].timer); - send_json(sleeping_clients[i].response); + mark_recently_seen(sleeping_clients[i].unique); + send_json(sleeping_clients[i].response, + sleeping_clients[i].accept_gzip, + num_viewers); } sleeping_clients = {}; } @@ -60,34 +88,71 @@ var send_404 = function(response) { response.write('Something went wrong. Sorry.'); response.end(); } -var send_json = function(response) { - response.writeHead(200, { +var handle_viewer_override = function(request, u, response) { + // Only accept requests from localhost. + var peer = request.socket.localAddress; + if ((peer != '127.0.0.1' && peer != '::1') || request.headers['x-forwarded-for']) { + console.log("Refusing viewer override from " + peer); + send_404(response); + } else { + viewer_count_override = (u.query)['num']; + response.writeHead(200, { + 'Content-Type': 'text/plain', + }); + response.write('OK.'); + response.end(); + } +} +var send_json = function(response, accept_gzip, num_viewers) { + var headers = { 'Content-Type': 'text/json', 'X-Remoteglot-Last-Modified': json_last_modified, - 'X-Remoteglot-Num-Viewers': count_viewers(), - 'Access-Control-Allow-Origin': 'http://analysis.sesse.net', + 'X-Remoteglot-Num-Viewers': num_viewers, 'Access-Control-Expose-Headers': 'X-Remoteglot-Last-Modified, X-Remoteglot-Num-Viewers', 'Expires': 'Mon, 01 Jan 1970 00:00:00 UTC', - }); - response.write(json_contents); + 'Vary': 'Accept-Encoding', + }; + + if (accept_gzip) { + headers['Content-Encoding'] = 'gzip'; + response.writeHead(200, headers); + response.write(json_contents_gz); + } else { + response.writeHead(200, headers); + response.write(json_contents); + } response.end(); } -var timeout_client = function(client) { - send_json(client.response); - delete sleeping_clients[client.request_id]; +var mark_recently_seen = function(unique) { + if (unique) { + last_seen_clients[unique] = (new Date).getTime(); + } } var count_viewers = function() { + if (viewer_count_override !== undefined) { + return viewer_count_override; + } + var now = (new Date).getTime(); // Go through and remove old viewers, and count them at the same time. var new_last_seen_clients = {}; var num_viewers = 0; for (var unique in last_seen_clients) { - if (now - last_seen_clients[unique] < 60000) { + if (now - last_seen_clients[unique] < 5000) { ++num_viewers; new_last_seen_clients[unique] = last_seen_clients[unique]; } } + + // Also add sleeping clients that we would otherwise assume timed out. + for (var request_id in sleeping_clients) { + var unique = sleeping_clients[request_id].unique; + if (unique && !(unique in new_last_seen_clients)) { + ++num_viewers; + } + } + last_seen_clients = new_last_seen_clients; return num_viewers; } @@ -95,38 +160,60 @@ var count_viewers = function() { // Set up a watcher to catch changes to the file, then do an initial read // to make sure we have a copy. fs.watch(path.dirname(json_filename), reread_file); -reread_file(); +reread_file(null, path.basename(json_filename)); -http.createServer(function(request, response) { +var server = http.createServer(); +server.on('request', function(request, response) { var u = url.parse(request.url, true); var ims = (u.query)['ims']; var unique = (u.query)['unique']; console.log((new Date).getTime()*1e-3 + " " + request.url); - + if (u.pathname === '/override-num-viewers') { + handle_viewer_override(request, u, response); + return; + } if (u.pathname !== '/analysis.pl') { // This is not the request you are looking for. send_404(response); return; } - if (unique) { - last_seen_clients[unique] = (new Date).getTime(); + mark_recently_seen(unique); + + var accept_encoding = request.headers['accept-encoding']; + var accept_gzip; + if (accept_encoding !== undefined && accept_encoding.match(/\bgzip\b/)) { + accept_gzip = true; + } else { + accept_gzip = false; } // If we already have something newer than what the user has, // just send it out and be done with it. - if (!ims || json_last_modified > ims) { - send_json(response); + if (json_last_modified !== undefined && (!ims || json_last_modified > ims)) { + send_json(response, accept_gzip, count_viewers()); return; } // OK, so we need to hang until we have something newer. - // Put the user on the wait list; if we don't get anything - // in 30 seconds, though, we'll send something anyway. + // Put the user on the wait list. var client = {}; client.response = response; - client.timer = setTimeout(function() { timeout_client(client); }, 30000); client.request_id = request_id; + client.accept_gzip = accept_gzip; + client.unique = unique; sleeping_clients[request_id++] = client; -}).listen(5000); + + request.socket.client = client; +}); +server.on('connection', function(socket) { + socket.on('close', function() { + var client = socket.client; + if (client) { + mark_recently_seen(client.unique); + delete sleeping_clients[client.request_id]; + } + }); +}); +server.listen(5000);