refactor: posts cache to get rid of require in functions

src/api/posts.js

@@ -7,6 +7,7 @@ const db = require('../database');
 const utils = require('../utils');
 const user = require('../user');
 const posts = require('../posts');
+const postsCache = require('../posts/cache');
 const topics = require('../topics');
 const groups = require('../groups');
 const plugins = require('../plugins');
@@ -225,7 +226,7 @@ postsAPI.purge = async function (caller, data) {
 	if (!canPurge) {
 		throw new Error('[[error:no-privileges]]');
 	}
-	require('../posts/cache').del(data.pid);
+	postsCache.del(data.pid);
 	await posts.purge(data.pid, caller.uid);
 
 	websockets.in(`topic_${postData.tid}`).emit('event:post_purged', postData);

src/controllers/admin/cache.js

@@ -6,7 +6,7 @@ const utils = require('../../utils');
 const plugins = require('../../plugins');
 
 cacheController.get = async function (req, res) {
-	const postCache = require('../../posts/cache');
+	const postCache = require('../../posts/cache').getOrCreate();
 	const groupCache = require('../../groups').cache;
 	const { objectCache } = require('../../database');
 	const localCache = require('../../cache');
@@ -46,7 +46,7 @@ cacheController.get = async function (req, res) {
 
 cacheController.dump = async function (req, res, next) {
 	let caches = {
-		post: require('../../posts/cache'),
+		post: require('../../posts/cache').getOrCreate(),
 		object: require('../../database').objectCache,
 		group: require('../../groups').cache,
 		local: require('../../cache'),

src/posts/cache.js

@@ -3,10 +3,30 @@
 const cacheCreate = require('../cache/lru');
 const meta = require('../meta');
 
-module.exports = cacheCreate({
+let cache = null;
+
+exports.getOrCreate = function () {
+	if (!cache) {
+		cache = cacheCreate({
 			name: 'post',
 			maxSize: meta.config.postCacheSize,
 			sizeCalculation: function (n) { return n.length || 1; },
 			ttl: 0,
 			enabled: global.env === 'production',
 		});
+	}
+
+	return cache;
+};
+
+exports.del = function (pid) {
+	if (cache) {
+		cache.del(pid);
+	}
+}
+
+exports.reset = function () {
+	if (cache) {
+		cache.reset();
+	}
+}

src/posts/parse.js

@@ -10,6 +10,7 @@ const meta = require('../meta');
 const plugins = require('../plugins');
 const translator = require('../translator');
 const utils = require('../utils');
+const postCache = require('./cache');
 
 let sanitizeConfig = {
 	allowedTags: sanitize.defaults.allowedTags.concat([
@@ -52,7 +53,7 @@ module.exports = function (Posts) {
 			return postData;
 		}
 		postData.content = String(postData.content || '');
-		const cache = require('./cache');
+		const cache = postCache.getOrCreate();
 		const pid = String(postData.pid);
 		const cachedContent = cache.get(pid);
 		if (postData.pid && cachedContent !== undefined) {

src/socket.io/admin/cache.js

@@ -7,7 +7,7 @@ const plugins = require('../../plugins');
 
 SocketCache.clear = async function (socket, data) {
 	let caches = {
-		post: require('../../posts/cache'),
+		post: require('../../posts/cache').getOrCreate(),
 		object: db.objectCache,
 		group: require('../../groups').cache,
 		local: require('../../cache'),
@@ -21,7 +21,7 @@ SocketCache.clear = async function (socket, data) {
 
 SocketCache.toggle = async function (socket, data) {
 	let caches = {
-		post: require('../../posts/cache'),
+		post: require('../../posts/cache').getOrCreate(),
 		object: db.objectCache,
 		group: require('../../groups').cache,
 		local: require('../../cache'),

src/socket.io/admin/plugins.js

@@ -5,12 +5,13 @@ const nconf = require('nconf');
 const plugins = require('../../plugins');
 const events = require('../../events');
 const db = require('../../database');
+const postsCache = require('../../posts/cache');
 const { pluginNamePattern } = require('../../constants');
 
 const Plugins = module.exports;
 
 Plugins.toggleActive = async function (socket, plugin_id) {
-	require('../../posts/cache').reset();
+	postsCache.reset();
 	const data = await plugins.toggleActive(plugin_id);
 	await events.log({
 		type: `plugin-${data.active ? 'activate' : 'deactivate'}`,
@@ -21,7 +22,7 @@ Plugins.toggleActive = async function (socket, plugin_id) {
 };
 
 Plugins.toggleInstall = async function (socket, data) {
-	require('../../posts/cache').reset();
+	postsCache.reset();
 	await plugins.checkWhitelist(data.id, data.version);
 	const pluginData = await plugins.toggleInstall(data.id, data.version);
 	await events.log({

test/mocks/databasemock.js

@@ -194,7 +194,7 @@ async function setupMockDefaults() {
 	meta.config.autoDetectLang = 0;
 
 	require('../../src/groups').cache.reset();
-	require('../../src/posts/cache').reset();
+	require('../../src/posts/cache').getOrCreate().reset();
 	require('../../src/cache').reset();
 	require('../../src/middleware/uploads').clearCache();
 	// privileges must be given after cache reset

test/socket.io.js

@@ -740,7 +740,7 @@ describe('socket.io', () => {
 
 	it('should toggle caches', async () => {
 		const caches = {
-			post: require('../src/posts/cache'),
+			post: require('../src/posts/cache').getOrCreate(),
 			object: require('../src/database').objectCache,
 			group: require('../src/groups').cache,
 			local: require('../src/cache'),