var querystring = require('querystring');
var path = require('path');
var zlib = require('zlib');
+var readline = require('readline');
+var child_process = require('child_process');
var delta = require('./js/json_delta.js');
// Constants.
-var JSON_FILENAME = '/srv/analysis.sesse.net/www/analysis.json';
var HISTORY_TO_KEEP = 5;
var MINIMUM_VERSION = null;
+var COUNT_FROM_VARNISH_LOG = true;
+
+// Filename to serve.
+var json_filename = '/srv/analysis.sesse.net/www/analysis.json';
+if (process.argv.length >= 3) {
+ json_filename = process.argv[2];
+}
+
+// Expected destination filename.
+var serve_url = '/analysis.pl';
+if (process.argv.length >= 4) {
+ serve_url = process.argv[3];
+}
+
+// TCP port to listen on.
+var port = 5000;
+if (process.argv.length >= 5) {
+ port = parseInt(process.argv[4]);
+}
// If set to 1, we are already processing a JSON update and should not
// start a new one. If set to 2, we are _also_ having one in the queue.
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.
+// ourselves, so we need to get it from parsing varnishncsa.
var viewer_count_override = undefined;
var replace_json = function(new_json_contents, mtime) {
}
var reread_file = function(event, filename) {
- if (filename != path.basename(JSON_FILENAME)) {
+ if (filename != path.basename(json_filename)) {
return;
}
if (json_lock >= 2) {
}
json_lock = 1;
- console.log("Rereading " + JSON_FILENAME);
- fs.open(JSON_FILENAME, 'r+', function(err, fd) {
+ console.log("Rereading " + json_filename);
+ fs.open(json_filename, 'r+', function(err, fd) {
if (err) throw err;
fs.fstat(fd, function(err, st) {
if (err) throw err;
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);
+ fs.utimes(json_filename, now, now);
}, 30000);
}
var possibly_wakeup_clients = function() {
response.write('Something went wrong. Sorry.');
response.end();
}
-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, ims, accept_gzip, num_viewers) {
var this_json = diff_json[ims] || json;
'Content-Type': 'text/json',
'X-RGLM': this_json.last_modified,
'X-RGNV': num_viewers,
- 'Access-Control-Expose-Headers': 'X-RGLM, X-RGNV',
+ 'Access-Control-Expose-Headers': 'X-RGLM, X-RGNV, X-RGMV',
'Vary': 'Accept-Encoding',
};
last_seen_clients = new_last_seen_clients;
return num_viewers;
}
+var log = function(str) {
+ console.log("[" + ((new Date).getTime()*1e-3).toFixed(3) + "] " + str);
+}
// 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(null, path.basename(JSON_FILENAME));
+fs.watch(path.dirname(json_filename), reread_file);
+reread_file(null, path.basename(json_filename));
+
+if (COUNT_FROM_VARNISH_LOG) {
+ // Note: We abuse serve_url as a regex.
+ var varnishncsa = child_process.spawn(
+ 'varnishncsa', ['-F', '%{%s}t %U %q tffb=%{Varnish:time_firstbyte}x',
+ '-q', 'ReqURL ~ "^' + serve_url + '"']);
+ var rl = readline.createInterface({
+ input: varnishncsa.stdout,
+ output: varnishncsa.stdin,
+ terminal: false
+ });
+
+ var uniques = [];
+ rl.on('line', function(line) {
+ var v = line.match(/(\d+) .*\?ims=\d+&unique=(.*) tffb=(.*)/);
+ if (v) {
+ uniques[v[2]] = {
+ last_seen: (parseInt(v[1]) + parseFloat(v[3])) * 1e3,
+ grace: null,
+ };
+ log(v[1] + " " + v[2] + " " + v[3]);
+ } else {
+ log("VARNISHNCSA UNPARSEABLE LINE: " + line);
+ }
+ });
+ setInterval(function() {
+ var mtime = json.last_modified - 1000; // Compensate for subsecond issues.
+ var now = (new Date).getTime();
+ var num_viewers = 0;
+
+ for (var unique in uniques) {
+ ++num_viewers;
+ var last_seen = uniques[unique].last_seen;
+ if (now - last_seen <= 5000) {
+ // We've seen this user in the last five seconds;
+ // it's okay.
+ continue;
+ }
+ if (last_seen >= mtime) {
+ // This user has the latest version;
+ // they are probably just hanging.
+ continue;
+ }
+ if (uniques[unique].grace === null) {
+ // They have five seconds after a new JSON has been
+ // provided to get get it, or they're out.
+ // We don't simply use mtime, since we don't want to
+ // reset the grace timer just because a new JSON is
+ // published.
+ uniques[unique].grace = mtime;
+ }
+ if (now - uniques[unique].grace > 5000) {
+ log("Timing out " + unique + " (last_seen=" + last_seen + ", now=" + now +
+ ", mtime=" + mtime, ", grace=" + uniques[unique].grace + ")");
+ delete uniques[unique];
+ --num_viewers;
+ }
+ }
+
+ log(num_viewers + " entries in hash, mtime=" + mtime);
+ viewer_count_override = num_viewers;
+ }, 1000);
+}
var server = http.createServer();
server.on('request', function(request, response) {
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') {
+ log(request.url);
+ if (u.pathname !== serve_url) {
// This is not the request you are looking for.
send_404(response);
return;
}
});
});
-server.listen(5000);
+
+server.listen(port);