Used in memory cache adapter in settigs cache manager

refs https://github.com/TryGhost/Toolbox/issues/364

- Settings Manager used to store all of it's settings values in a hash - an in memory cache in disguise. Having a hidden cache made it hard to reason about it's impact of memory usage and did not allow to swap it out for an alternative storage metchanism easily. Having a cache storage abstraction in Settings Manager allows to get rid of long lasting memory problems + decouples storage mechanism from the logic around transforming stored values.

ghost/core/core/server/services/adapter-manager/index.js

@@ -15,11 +15,12 @@ const adapterManager = new AdapterManager({
 adapterManager.registerAdapter('storage', require('ghost-storage-base'));
 adapterManager.registerAdapter('scheduling', require('../../adapters/scheduling/SchedulingBase'));
 adapterManager.registerAdapter('sso', require('../../adapters/sso/Base'));
+adapterManager.registerAdapter('cache', require('../../adapters/cache/Base'));
 
 module.exports = {
     /**
      *
-     * @param {String} name - one of 'storage', 'scheduling', 'sso' etc. Or can contain a "resource" extension like "storage:image"
+     * @param {String} name - one of 'storage', 'scheduling', 'sso', 'cache' etc. Or can contain a "resource" extension like "storage:image"
      * @returns {Object} instance of an adapter
      */
     getAdapter(name) {

ghost/core/core/server/services/settings/settings-service.js

@@ -9,6 +9,7 @@ const events = require('../../lib/common/events');
 const models = require('../../models');
 const labs = require('../../../shared/labs');
 const config = require('../../../shared/config');
+const adapterManager = require('../adapter-manager');
 const SettingsCache = require('../../../shared/settings-cache');
 const SettingsBREADService = require('./settings-bread-service');
 const {obfuscatedSetting, isSecretSetting, hideValueIfSecret} = require('./settings-utils');
@@ -66,8 +67,9 @@ module.exports = {
      * Initialize the cache, used in boot and in testing
      */
     async init() {
+        const cacheStore = adapterManager.getAdapter('cache');
         const settingsCollection = await models.Settings.populateDefaults();
-        SettingsCache.init(events, settingsCollection, this.getCalculatedFields(), {});
+        SettingsCache.init(events, settingsCollection, this.getCalculatedFields(), cacheStore);
     },
 
     /**

ghost/core/core/shared/config/defaults.json

@@ -23,6 +23,9 @@
     "adapters": {
         "sso": {
             "active": "Default"
+        },
+        "cache": {
+            "active": "Memory"
         }
     },
     "storage": {

ghost/core/core/shared/settings-cache/cache.js

@@ -50,30 +50,30 @@ class CacheManager {
         // NOTE: "!this.settingsCache" is for when setting's cache is used
         //       before it had a chance to initialize. Should be fixed when
         //       it is decoupled from the model layer
-        if (!this.settingsCache || !this.settingsCache[key]) {
+        if (!this.settingsCache || !this.settingsCache.get(key)) {
             return;
         }
 
         // Don't try to resolve to the value of the setting
         if (options && options.resolve === false) {
-            return this.settingsCache[key];
+            return this.settingsCache.get(key);
         }
 
         // Default behavior is to try to resolve the value and return that
         try {
             // CASE: handle literal false
-            if (this.settingsCache[key].value === false || this.settingsCache[key].value === 'false') {
+            if (this.settingsCache.get(key).value === false || this.settingsCache.get(key).value === 'false') {
                 return false;
             }
 
             // CASE: if a string contains a number e.g. "1", JSON.parse will auto convert into integer
-            if (!isNaN(Number(this.settingsCache[key].value))) {
-                return this.settingsCache[key].value || null;
+            if (!isNaN(Number(this.settingsCache.get(key).value))) {
+                return this.settingsCache.get(key).value || null;
             }
 
-            return JSON.parse(this.settingsCache[key].value) || null;
+            return JSON.parse(this.settingsCache.get(key).value) || null;
         } catch (err) {
-            return this.settingsCache[key].value || null;
+            return this.settingsCache.get(key).value || null;
         }
     }
 
@@ -111,16 +111,27 @@ class CacheManager {
      * @param {object} value json version of settings model
      */
     set(key, value) {
-        this.settingsCache[key] = _.cloneDeep(value);
+        this.settingsCache.set(key, _.cloneDeep(value));
     }
 
     /**
      * Get the entire cache object
      * Uses clone to prevent modifications from being reflected
+     * This method is dangerous in case the cache is "lazily" initialized
+     * could result in returning only a partially filled cache
      * @return {object} cache
+     * @deprecated this method is not "cache-friendly" and should be avoided from furhter usage
+     *             instead using multiple "get" calls
      */
     getAll() {
-        return _.cloneDeep(this.settingsCache);
+        const keys = this.settingsCache.keys();
+        const all = {};
+
+        keys.forEach((key) => {
+            all[key] = _.cloneDeep(this.settingsCache.get(key));
+        });
+
+        return all;
     }
 
     /**
@@ -139,15 +150,15 @@ class CacheManager {
     }
 
     /**
-     * Initialise the cache
+     * Initialize the cache
      *
      * Optionally takes a collection of settings & can populate the cache with these.
      *
      * @param {EventEmitter} events
      * @param {Bookshelf.Collection<Settings>} settingsCollection
      * @param {Array} calculatedFields
-     * @param {Object} cacheStore - cache storage instance
-     * @return {object}
+     * @param {Object} cacheStore - cache storage instance base on Cache Base Adapter
+     * @return {Object} - filled out instance for Cache Base Adapter
      */
     init(events, settingsCollection, calculatedFields, cacheStore) {
         this.settingsCache = cacheStore;
@@ -182,7 +193,9 @@ class CacheManager {
      * @param {EventEmitter} events
      */
     reset(events) {
-        this.settingsCache = {};
+        if (this.settingsCache) {
+            this.settingsCache.reset();
+        }
 
         events.removeListener('settings.edited', this._updateSettingFromModel);
         events.removeListener('settings.added', this._updateSettingFromModel);

ghost/core/test/unit/shared/settings-cache.test.js

@@ -6,6 +6,7 @@ const events = require('../../../core/server/lib/common/events');
 // Testing  the Private API
 let CacheManager = require('../../../core/shared/settings-cache/cache');
 const publicSettings = require('../../../core/shared/settings-cache/public');
+const InMemoryCache = require('../../../core/server/adapters/cache/Memory');
 
 should.equal(true, true);
 
@@ -13,10 +14,11 @@ describe('UNIT: settings cache', function () {
     let cache;
 
     beforeEach(function () {
+        let cacheStore = new InMemoryCache();
         cache = new CacheManager({
             publicSettings
         });
-        cache.init(events, {}, [], {});
+        cache.init(events, {}, [], cacheStore);
     });
 
     afterEach(function () {
@@ -28,7 +30,7 @@ describe('UNIT: settings cache', function () {
         (typeof cache.get('key1')).should.eql('string');
     });
 
-    it('.get() oes not auto convert string into number: float', function () {
+    it('.get() does not auto convert string into number: float', function () {
         cache.set('key1', {value: '1.4'});
         (typeof cache.get('key1')).should.eql('string');
     });
@@ -128,7 +130,8 @@ describe('UNIT: settings cache', function () {
             }]
         };
 
-        cache.init(events, settingsCollection, []);
+        let cacheStore = new InMemoryCache();
+        cache.init(events, settingsCollection, [], cacheStore);
         cache.get('key1').should.equal('init value');
 
         // check handler only called once on settings.edit
@@ -141,7 +144,8 @@ describe('UNIT: settings cache', function () {
         cache.get('key1').should.equal('first edit');
 
         // init does a reset by default
-        cache.init(events, settingsCollection, []);
+        let cacheStoreForReset = new InMemoryCache();
+        cache.init(events, settingsCollection, [], cacheStoreForReset);
         setSpy.callCount.should.equal(3);
         cache.get('key1').should.equal('init value');