Moved Tags Content API to api-level caching

refs https://github.com/TryGhost/Toolbox/issues/522

- Caching on a repository level was pretty hard to achieve with more complex models like "posts", so that approach was abandoned in favor of API-response level caching.
- Also removed use of "public-resource-repository" as it was not serving any specific purpose anymore.

ghost/core/core/server/api/endpoints/tags-public.js

@@ -14,6 +14,7 @@ module.exports = {
     docName: 'tags',
 
     browse: {
+        cache: tagsPublicService.api?.cache,
         options: [
             'include',
             'filter',
@@ -32,7 +33,7 @@ module.exports = {
         },
         permissions: true,
         query(frame) {
-            return tagsPublicService.api.browse(frame.options);
+            return models.TagPublic.findPage(frame.options);
         }
     },
 

ghost/core/core/server/services/tags-public/service.js

@@ -6,24 +6,35 @@ class TagsPublicServiceWrapper {
         }
 
         // Wire up all the dependencies
-        const {TagPublic} = require('../../models');
         const adapterManager = require('../adapter-manager');
         const config = require('../../../shared/config');
+        const EventAwareCacheWrapper = require('@tryghost/event-aware-cache-wrapper');
+        const EventRegistry = require('../../lib/common/events');
 
         let tagsCache;
         if (config.get('hostSettings:tagsPublicCache:enabled')) {
-            tagsCache = adapterManager.getAdapter('cache:tagsPublic');
+            let tagsPublicCache = adapterManager.getAdapter('cache:tagsPublic');
+            tagsCache = new EventAwareCacheWrapper({
+                cache: tagsPublicCache,
+                resetEvents: ['site.changed'],
+                eventRegistry: EventRegistry
+            });
         }
 
-        const {PublicResourcesRepository} = require('@tryghost/public-resource-repository');
-
-        this.tagsPublicRepository = new PublicResourcesRepository({
-            Model: TagPublic,
-            cache: tagsCache
-        });
-
+        let cache;
+        if (tagsCache) {
+            // @NOTE: exposing cache through getter and setter to not loose the context of "this"
+            cache = {
+                get() {
+                    return tagsCache.get(...arguments);
+                },
+                set() {
+                    return tagsCache.set(...arguments);
+                }
+            };
+        }
         this.api = {
-            browse: this.tagsPublicRepository.getAll.bind(this.tagsPublicRepository)
+            cache: cache
         };
     }
 }