feat: analytics:maxCache setting in ACP

I removed a TODO from core. Watch your head as flying pigs are abound

public/language/en-GB/admin/settings/advanced.json

@@ -32,5 +32,9 @@
 	"sockets.settings": "WebSocket Settings",
 	"sockets.max-attempts": "Max Reconnection Attempts",
 	"sockets.default-placeholder": "Default: %1",
-	"sockets.delay": "Reconnection Delay"
+	"sockets.delay": "Reconnection Delay",
+
+	"analytics.settings": "Analytics Settings",
+	"analytics.max-cache": "Analytics Cache Max Value",
+	"analytics.max-cache-help": "On high-traffic installs, the cache could be exhausted continuously if there are more concurrent active users than the Max Cache value. (Restart required)"
 }

src/analytics.js

@@ -10,6 +10,7 @@ const LRU = require('lru-cache');
 const db = require('./database');
 const utils = require('./utils');
 const plugins = require('./plugins');
+const meta = require('./meta');
 
 const Analytics = module.exports;
 
@@ -21,21 +22,19 @@ let pageViewsGuest = 0;
 let pageViewsBot = 0;
 let uniqueIPCount = 0;
 let uniquevisitors = 0;
+let ipCache;
 
-/**
- * TODO: allow the cache's max value to be configurable. On high-traffic installs,
- * the cache could be exhausted continuously if there are more than 500 concurrently
- * active users
- */
-var ipCache = new LRU({
-	max: 500,
-	length: function () { return 1; },
-	maxAge: 0,
-});
-
-new cronJob('*/10 * * * * *', function () {
-	Analytics.writeData();
-}, null, true);
+Analytics.init = async function () {
+	ipCache = new LRU({
+		max: parseInt(meta.config['analytics:maxCache'], 10) || 500,
+		length: function () { return 1; },
+		maxAge: 0,
+	});
+
+	new cronJob('*/10 * * * * *', function () {
+		Analytics.writeData();
+	}, null, true);
+};
 
 Analytics.increment = function (keys, callback) {
 	keys = Array.isArray(keys) ? keys : [keys];

src/views/admin/settings/advanced.tpl

@@ -150,4 +150,19 @@
 	</div>
 </div>
 
+<div class="row">
+	<div class="col-sm-2 col-xs-12 settings-header">[[admin/settings/advanced:analytics.settings]]</div>
+	<div class="col-sm-10 col-xs-12">
+		<form>
+			<div class="form-group">
+				<label for="analytics:maxCache">[[admin/settings/advanced:analytics.max-cache]]</label>
+				<input class="form-control" id="analytics:maxCache" type="text" value="500" placeholder="500" data-field="analytics:maxCache" />
+				<p class="help-block">
+					[[admin/settings/advanced:analytics.max-cache-help]]
+				</p>
+			</div>
+		</form>
+	</div>
+</div>
+
 <!-- IMPORT admin/partials/settings/footer.tpl -->

src/webserver.js

@@ -23,6 +23,7 @@ var helmet = require('helmet');
 
 var Benchpress = require('benchpressjs');
 var db = require('./database');
+var analytics = require('./analytics');
 var file = require('./file');
 var emailer = require('./emailer');
 var meta = require('./meta');
@@ -105,6 +106,7 @@ async function initializeNodeBB() {
 	await routes(app, middleware);
 	await meta.blacklist.load();
 	await flags.init();
+	await analytics.init();
 }
 
 function setupExpressApp(app) {