Moved all objects to a single data store: the cache.

config/environment.default.js

@@ -10,5 +10,9 @@ module.exports = {
   "ui": {
     "nameSpace": "/",
     "baseURL": "http://localhost:3000"
+  },
+  "cache": {
+    // how long should objects be cached for by default
+    "msToLive": 15 * 60 * 1000  //15 minutes
   }
-}
+};

src/app/core/core.module.ts

@@ -4,6 +4,7 @@ import { SharedModule } from "../shared/shared.module";
 import { isNotEmpty } from "../shared/empty.util";
 import { DSpaceRESTv2Service } from "./dspace-rest-v2/dspace-rest-v2.service";
 import { CollectionDataService } from "./data-services/collection/collection-data.service";
+import { CacheService } from "./data-services/cache/cache.service";
 
 const IMPORTS = [
   CommonModule,
@@ -18,7 +19,8 @@ const EXPORTS = [
 
 const PROVIDERS = [
   CollectionDataService,
-  DSpaceRESTv2Service
+  DSpaceRESTv2Service,
+  CacheService
 ];
 
 @NgModule({

src/app/core/core.reducers.ts

@@ -3,13 +3,16 @@ import {
   CollectionDataState,
   collectionDataReducer
 } from "./data-services/collection/collection-data.reducer";
+import { CacheState, cacheReducer } from "./data-services/cache/cache.reducer";
 
 export interface CoreState {
-  collectionData: CollectionDataState
+  collectionData: CollectionDataState,
+  cache: CacheState
 }
 
 export const reducers = {
   collectionData: collectionDataReducer,
+  cache: cacheReducer
 };
 
 export function coreReducer(state: any, action: any) {

src/app/core/data-services/cache/cache.actions.ts

@@ -0,0 +1,33 @@
+import { Action } from "@ngrx/store";
+import { type } from "../../../shared/ngrx/type";
+import { CacheableObject } from "./cache.reducer";
+
+export const CacheActionTypes = {
+  ADD: type('dspace/core/data/cache/ADD'),
+  REMOVE: type('dspace/core/data/cache/REMOVE')
+};
+
+export class AddToCacheAction implements Action {
+  type = CacheActionTypes.ADD;
+  payload: {
+    objectToCache: CacheableObject;
+    msToLive: number;
+  };
+
+  constructor(objectToCache: CacheableObject, msToLive: number) {
+    this.payload = { objectToCache, msToLive };
+  }
+}
+
+export class RemoveFromCacheAction implements Action {
+  type = CacheActionTypes.REMOVE;
+  payload: string;
+
+  constructor(uuid: string) {
+    this.payload = uuid;
+  }
+}
+
+export type CacheAction
+  = AddToCacheAction
+  | RemoveFromCacheAction

src/app/core/data-services/cache/cache.reducer.ts

@@ -0,0 +1,58 @@
+import { CacheAction, CacheActionTypes, AddToCacheAction, RemoveFromCacheAction } from "./cache.actions";
+import { hasValue } from "../../../shared/empty.util";
+
+export interface CacheableObject {
+  uuid: string;
+}
+
+export interface CacheEntry {
+  data: CacheableObject;
+  timeAdded: number;
+  msToLive: number;
+}
+
+export interface CacheState {
+  [uuid: string]: CacheEntry
+}
+
+// Object.create(null) ensures the object has no default js properties (e.g. `__proto__`)
+const initialState: CacheState = Object.create(null);
+
+export const cacheReducer = (state = initialState, action: CacheAction): CacheState => {
+  switch (action.type) {
+
+    case CacheActionTypes.ADD: {
+      return addToCache(state, <AddToCacheAction>action);
+    }
+
+    case CacheActionTypes.REMOVE: {
+      return removeFromCache(state, <RemoveFromCacheAction>action)
+    }
+
+    default: {
+      return state;
+    }
+  }
+};
+
+function addToCache(state: CacheState, action: AddToCacheAction): CacheState {
+  return Object.assign({}, state, {
+    [action.payload.objectToCache.uuid]: {
+      data: action.payload.objectToCache,
+      timeAdded: new Date().getTime(),
+      msToLive: action.payload.msToLive
+    }
+  });
+}
+
+function removeFromCache(state: CacheState, action: RemoveFromCacheAction): CacheState {
+  if (hasValue(state[action.payload])) {
+    let newCache = Object.assign({}, state);
+    delete newCache[action.payload];
+
+    return newCache;
+  }
+  else {
+    return state;
+  }
+}

src/app/core/data-services/cache/cache.service.ts

@@ -0,0 +1,58 @@
+import { Injectable } from "@angular/core";
+import { Store } from "@ngrx/store";
+import { CacheState, CacheEntry, CacheableObject } from "./cache.reducer";
+import { AddToCacheAction, RemoveFromCacheAction } from "./cache.actions";
+import { Observable } from "rxjs";
+import { hasNoValue } from "../../../shared/empty.util";
+
+@Injectable()
+export class CacheService {
+  constructor(
+    private store: Store<CacheState>
+  ) {}
+
+  add(objectToCache: CacheableObject, msToLive: number): void {
+    this.store.dispatch(new AddToCacheAction(objectToCache, msToLive));
+  }
+
+  remove(uuid: string): void {
+    this.store.dispatch(new RemoveFromCacheAction(uuid));
+  }
+
+  get<T extends CacheableObject>(uuid: string): Observable<T> {
+    return this.store.select<CacheEntry>('core', 'cache', uuid)
+      .filter(entry => this.isValid(entry))
+      .map((entry: CacheEntry) => <T> entry.data);
+  }
+
+  getList<T extends CacheableObject>(uuids: Array<string>): Observable<Array<T>> {
+    return Observable.combineLatest(
+      uuids.map((id: string) => this.get<T>(id))
+    );
+  }
+
+  has(uuid: string): boolean {
+    let result: boolean;
+
+    this.store.select<CacheEntry>('core', 'cache', uuid)
+      .take(1)
+      .subscribe(entry => result = this.isValid(entry));
+
+    return result;
+  }
+
+  private isValid(entry: CacheEntry): boolean {
+    if (hasNoValue(entry)) {
+      return false;
+    }
+    else {
+      const timeOutdated = entry.timeAdded + entry.msToLive;
+      const isOutDated = new Date().getTime() > timeOutdated;
+      if (isOutDated) {
+        this.store.dispatch(new RemoveFromCacheAction(entry.data.uuid));
+      }
+      return !isOutDated;
+    }
+  }
+
+}

src/app/core/data-services/collection/collection-data.effects.ts

@@ -1,5 +1,5 @@
 import { Injectable } from "@angular/core";
-import { Actions, Effect } from "@ngrx/effects";
+import { Actions, Effect, toPayload } from "@ngrx/effects";
 import { Collection } from "../../shared/collection.model";
 import { Observable } from "rxjs";
 import {
@@ -15,33 +15,52 @@ import {
 import { DSpaceRESTV2Response } from "../../dspace-rest-v2/dspace-rest-v2-response.model";
 import { DSpaceRESTv2Serializer } from "../../dspace-rest-v2/dspace-rest-v2.serializer";
 import { DSpaceRESTv2Service } from "../../dspace-rest-v2/dspace-rest-v2.service";
+import { CacheService } from "../cache/cache.service";
+import { GlobalConfig } from "../../../../config";
 
 
 @Injectable()
 export class CollectionDataEffects {
   constructor(
     private actions$: Actions,
-    private restApiService: DSpaceRESTv2Service
+    private restApi: DSpaceRESTv2Service,
+    private cache: CacheService
   ) {}
 
+  // TODO, results of a findall aren't retrieved from cache for now,
+  // because currently the cache is more of an object store. We need to move
+  // more towards memoization for things like this.
   @Effect() findAll$ = this.actions$
     .ofType(CollectionFindMultipleActionTypes.FIND_MULTI_REQUEST)
     .switchMap(() => {
-      return this.restApiService.get('/collections')
+      return this.restApi.get('/collections')
         .map((data: DSpaceRESTV2Response) => new DSpaceRESTv2Serializer(Collection).deserializeArray(data))
-        .map((collections: Collection[]) => new CollectionFindMultipleSuccessAction(collections))
+        .do((collections: Collection[]) => {
+          collections.forEach((collection) => {
+            this.cache.add(collection, GlobalConfig.cache.msToLive);
+          });
+        })
+        .map((collections: Array<Collection>) => collections.map(collection => collection.id))
+        .map((ids: Array<string>) => new CollectionFindMultipleSuccessAction(ids))
         .catch((errorMsg: string) => Observable.of(new CollectionFindMultipleErrorAction(errorMsg)));
     });
 
   @Effect() findById$ = this.actions$
     .ofType(CollectionFindSingleActionTypes.FIND_BY_ID_REQUEST)
     .switchMap(action => {
-      return this.restApiService.get(`/collections/${action.payload}`)
-        .map((data: DSpaceRESTV2Response) => {
-          const t = new DSpaceRESTv2Serializer(Collection).deserialize(data);
-          return t;
-        })
-        .map((collection: Collection) => new CollectionFindByIdSuccessAction(collection))
-        .catch((errorMsg: string) => Observable.of(new CollectionFindByIdErrorAction(errorMsg)));
+      if (this.cache.has(action.payload)) {
+        return this.cache.get<Collection>(action.payload)
+          .map(collection => new CollectionFindByIdSuccessAction(collection.id));
+      }
+      else {
+        return this.restApi.get(`/collections/${action.payload}`)
+          .map((data: DSpaceRESTV2Response) => new DSpaceRESTv2Serializer(Collection).deserialize(data))
+          .do((collection: Collection) => {
+            this.cache.add(collection, GlobalConfig.cache.msToLive);
+          })
+          .map((collection: Collection) => new CollectionFindByIdSuccessAction(collection.id))
+          .catch((errorMsg: string) => Observable.of(new CollectionFindByIdErrorAction(errorMsg)));
+      }
     });
+
 }

src/app/core/data-services/collection/collection-data.service.ts

@@ -5,26 +5,29 @@ import { Store } from "@ngrx/store";
 import { Collection } from "../../shared/collection.model";
 import { CollectionFindMultipleRequestAction } from "./collection-find-multiple.actions";
 import { CollectionFindByIdRequestAction } from "./collection-find-single.actions";
-import { isNotEmpty } from "../../../shared/empty.util";
-import 'rxjs/add/operator/filter';
+import { CacheService } from "../cache/cache.service";
+import 'rxjs/add/observable/forkJoin';
 
 @Injectable()
 export class CollectionDataService {
   constructor(
-    private store: Store<CollectionDataState>
+    private store: Store<CollectionDataState>,
+    private cache: CacheService
   ) { }
 
   findAll(scope?: Collection): Observable<Collection[]> {
     this.store.dispatch(new CollectionFindMultipleRequestAction(scope));
-    return this.store.select<Collection[]>('core', 'collectionData', 'findMultiple', 'collections');
+    //get an observable of the IDs from the collectionData store
+    return this.store.select<Array<string>>('core', 'collectionData', 'findMultiple', 'collectionsIDs')
+      .flatMap((collectionIds: Array<string>) => {
+        // use those IDs to fetch the actual collection objects from the cache
+        return this.cache.getList<Collection>(collectionIds);
+      });
   }
 
   findById(id: string): Observable<Collection> {
     this.store.dispatch(new CollectionFindByIdRequestAction(id));
-    return this.store.select<Collection>('core', 'collectionData', 'findSingle', 'collection')
-      //this filter is necessary because the same collection
-      //object in the state is used for every findById call
-      .filter(collection => isNotEmpty(collection) && collection.id === id);
+    return this.cache.get<Collection>(id);
   }
 
 }

src/app/core/data-services/collection/collection-find-multiple.actions.ts

@@ -33,10 +33,10 @@ export class CollectionFindMultipleRequestAction implements Action {
 
 export class CollectionFindMultipleSuccessAction implements Action {
   type = CollectionFindMultipleActionTypes.FIND_MULTI_SUCCESS;
-  payload: Collection[];
+  payload: Array<string>;
 
-  constructor(collections: Collection[]) {
-    this.payload = collections;
+  constructor(collectionIDs: Array<string>) {
+    this.payload = collectionIDs;
   }
 }
 

src/app/core/data-services/collection/collection-find-multiple.reducer.ts

@@ -8,7 +8,7 @@ import {
 
 export interface CollectionFindMultipleState {
   scope: Collection;
-  collections: Collection[];
+  collectionsIDs: Array<String>;
   isLoading: boolean;
   errorMessage: string;
   paginationOptions: PaginationOptions;
@@ -17,7 +17,7 @@ export interface CollectionFindMultipleState {
 
 const initialState: CollectionFindMultipleState = {
   scope: undefined,
-  collections: [],
+  collectionsIDs: [],
   isLoading: false,
   errorMessage: undefined,
   paginationOptions: undefined,
@@ -30,7 +30,7 @@ export const findMultipleReducer = (state = initialState, action: CollectionFind
     case CollectionFindMultipleActionTypes.FIND_MULTI_REQUEST: {
       return Object.assign({}, state, {
         scope: action.payload.scope,
-        collections: [],
+        collectionsIDs: [],
         isLoading: true,
         errorMessage: undefined,
         paginationOptions: action.payload.paginationOptions,
@@ -41,7 +41,7 @@ export const findMultipleReducer = (state = initialState, action: CollectionFind
     case CollectionFindMultipleActionTypes.FIND_MULTI_SUCCESS: {
       return Object.assign({}, state, {
         isLoading: false,
-        collections: action.payload,
+        collectionsIDs: action.payload,
         errorMessage: undefined
       });
     }

src/app/core/data-services/collection/collection-find-single.actions.ts

@@ -19,10 +19,10 @@ export class CollectionFindByIdRequestAction implements Action {
 
 export class CollectionFindByIdSuccessAction implements Action {
   type = CollectionFindSingleActionTypes.FIND_BY_ID_SUCCESS;
-  payload: Collection;
+  payload: string;
 
-  constructor(collection: Collection) {
-    this.payload = collection;
+  constructor(collectionID: string) {
+    this.payload = collectionID;
   }
 }
 

src/app/core/data-services/collection/collection-find-single.reducer.ts

@@ -5,17 +5,15 @@ import {
 } from "./collection-find-single.actions";
 
 export interface CollectionFindSingleState {
-  collection: Collection;
   isLoading: boolean;
   errorMessage: string;
-  id: string;
+  collectionID: string;
 }
 
 const initialState: CollectionFindSingleState = {
-  collection: undefined,
   isLoading: false,
   errorMessage: undefined,
-  id: undefined,
+  collectionID: undefined
 };
 
 export const findSingleReducer = (state = initialState, action: CollectionFindSingleAction): CollectionFindSingleState => {
@@ -24,17 +22,15 @@ export const findSingleReducer = (state = initialState, action: CollectionFindSi
     case CollectionFindSingleActionTypes.FIND_BY_ID_REQUEST: {
       return Object.assign({}, state, {
         isLoading: true,
-        id: action.payload,
-        collections: undefined,
         errorMessage: undefined,
+        collectionID: action.payload
       });
     }
 
     case CollectionFindSingleActionTypes.FIND_BY_ID_SUCCESS: {
       return Object.assign({}, state, {
         isLoading: false,
-        collection: action.payload,
-        errorMessage: undefined
+        errorMessage: undefined,
       });
     }
 

src/app/core/shared/dspace-object.model.ts

@@ -1,11 +1,12 @@
 import { autoserialize, autoserializeAs } from "cerialize";
 import { Metadatum } from "./metadatum.model"
 import { isEmpty, isNotEmpty } from "../../shared/empty.util";
+import { CacheableObject } from "../data-services/cache/cache.reducer";
 
 /**
  * An abstract model class for a DSpaceObject.
  */
-export abstract class DSpaceObject {
+export abstract class DSpaceObject implements CacheableObject {
 
     /**
      * The identifier of this DSpaceObject
@@ -64,4 +65,12 @@ export abstract class DSpaceObject {
         return undefined;
       }
     }
+
+    get uuid(): string {
+      return this.id;
+    }
+
+    set uuid(val: string) {
+      this.id = val;
+    }
 }

src/app/shared/demo-cache.service.ts

@@ -1,8 +1,8 @@
 import { Inject, Injectable, isDevMode } from '@angular/core';
 
 @Injectable()
-export class CacheService {
-  static KEY = 'CacheService';
+export class DemoCacheService {
+  static KEY = 'DemoCacheService';
 
   constructor( @Inject('LRU') public _cache: Map<string, any>) {
 
@@ -71,7 +71,7 @@ export class CacheService {
    */
   normalizeKey(key: string | number): string {
     if (isDevMode() && this._isInvalidValue(key)) {
-      throw new Error('Please provide a valid key to save in the CacheService');
+      throw new Error('Please provide a valid key to save in the DemoCacheService');
     }
 
     return key + '';

src/app/shared/model/model.service.ts

@@ -4,7 +4,7 @@ import 'rxjs/add/observable/of';
 import 'rxjs/add/operator/do';
 import 'rxjs/add/operator/share';
 
-import { CacheService  } from '../cache.service';
+import { DemoCacheService  } from '../demo-cache.service';
 import { ApiService  } from '../api.service';
 
 export function hashCodeString(str: string): string {
@@ -24,7 +24,7 @@ export function hashCodeString(str: string): string {
 @Injectable()
 export class ModelService {
   // This is only one example of one Model depending on your domain
-  constructor(public _api: ApiService, public _cache: CacheService) {
+  constructor(public _api: ApiService, public _cache: DemoCacheService) {
 
   }
 

src/backend/api.ts

@@ -92,7 +92,7 @@ export function createMockApi() {
 
   router.route('/collections/:collection_id')
     .get(function(req, res) {
-      console.log('GET', util.inspect(req.collection, { colors: true }));
+      console.log('GET', util.inspect(req.collection.id, { colors: true }));
       res.json(toHALResponse(req, req.collection));
     // })
     // .put(function(req, res) {

src/browser.module.ts

@@ -10,7 +10,7 @@ import { TranslateLoader, TranslateModule, TranslateStaticLoader } from 'ng2-tra
 
 import { AppModule, AppComponent } from './app/app.module';
 import { SharedModule } from './app/shared/shared.module';
-import { CacheService } from './app/shared/cache.service';
+import { DemoCacheService } from './app/shared/demo-cache.service';
 import { CoreModule } from "./app/core/core.module";
 
 // Will be merged into @angular/platform-browser in a later release
@@ -70,7 +70,7 @@ export const UNIVERSAL_KEY = 'UNIVERSAL_CACHE';
 
     { provide: 'LRU', useFactory: getLRU, deps: [] },
 
-    CacheService,
+    DemoCacheService,
 
     Meta,
 
@@ -78,14 +78,14 @@ export const UNIVERSAL_KEY = 'UNIVERSAL_CACHE';
   ]
 })
 export class MainModule {
-  constructor(public cache: CacheService) {
+  constructor(public cache: DemoCacheService) {
     // TODO(gdi2290): refactor into a lifecycle hook
     this.doRehydrate();
   }
 
   doRehydrate() {
     let defaultValue = {};
-    let serverCache = this._getCacheValue(CacheService.KEY, defaultValue);
+    let serverCache = this._getCacheValue(DemoCacheService.KEY, defaultValue);
     this.cache.rehydrate(serverCache);
   }
 

src/node.module.ts

@@ -9,7 +9,7 @@ import { TranslateLoader, TranslateModule, TranslateStaticLoader } from 'ng2-tra
 
 import { AppModule, AppComponent } from './app/app.module';
 import { SharedModule } from './app/shared/shared.module';
-import { CacheService } from './app/shared/cache.service';
+import { DemoCacheService } from './app/shared/demo-cache.service';
 import { CoreModule } from "./app/core/core.module";
 
 // Will be merged into @angular/platform-browser in a later release
@@ -61,13 +61,13 @@ export const UNIVERSAL_KEY = 'UNIVERSAL_CACHE';
 
     { provide: 'LRU', useFactory: getLRU, deps: [] },
 
-    CacheService,
+    DemoCacheService,
 
     Meta,
   ]
 })
 export class MainModule {
-  constructor(public cache: CacheService) {
+  constructor(public cache: DemoCacheService) {
 
   }
 
@@ -76,7 +76,7 @@ export class MainModule {
    * in Universal for now until it's fixed
    */
   universalDoDehydrate = (universalCache) => {
-    universalCache[CacheService.KEY] = JSON.stringify(this.cache.dehydrate());
+    universalCache[DemoCacheService.KEY] = JSON.stringify(this.cache.dehydrate());
   }
 
   /**