[core.uiSettings] Add cache for raw settings.

Author: lukeelmers

src/core/public/ui_settings/ui_settings_client.ts

@@ -34,7 +34,7 @@ export class UiSettingsClient implements IUiSettingsClient {
   constructor(params: UiSettingsClientParams) {
     this.api = params.api;
     this.defaults = cloneDeep(params.defaults);
-    this.cache = defaultsDeep({}, this.defaults, cloneDeep(params.initialSettings));
+    this.cache = defaultsDeep({ ...this.defaults }, cloneDeep(params.initialSettings));
 
     params.done$.subscribe({
       complete: () => {
@@ -177,7 +177,7 @@ You can use \`IUiSettingsClient.get("${key}", defaultValue)\`, which will just r
 
     try {
       const { settings } = await this.api.batchSet(key, newVal);
-      this.cache = defaultsDeep({}, defaults, settings);
+      this.cache = defaultsDeep({ ...defaults }, settings);
       this.saved$.next({ key, newValue: newVal, oldValue: initialVal });
       return true;
     } catch (error) {

src/core/server/ui_settings/ui_settings_client.test.ts

@@ -6,6 +6,7 @@
  * Side Public License, v 1.
  */
 
+import _ from 'lodash';
 import Chance from 'chance';
 import { schema } from '@kbn/config-schema';
 
@@ -724,18 +725,25 @@ describe('ui settings', () => {
       });
 
       it('getAll', async () => {
+        const lodashDefaultsDeep = jest.spyOn(_, 'defaultsDeep');
+
         const esDocSource = {};
         const { uiSettings, savedObjectsClient } = setup({ esDocSource });
 
         await uiSettings.getAll();
         expect(savedObjectsClient.get).toHaveBeenCalledTimes(1);
+        expect(lodashDefaultsDeep).toHaveBeenCalledTimes(1);
 
         await uiSettings.getAll();
         expect(savedObjectsClient.get).toHaveBeenCalledTimes(1);
+        expect(lodashDefaultsDeep).toHaveBeenCalledTimes(1);
 
         jest.advanceTimersByTime(10000);
         await uiSettings.getAll();
         expect(savedObjectsClient.get).toHaveBeenCalledTimes(2);
+        expect(lodashDefaultsDeep).toHaveBeenCalledTimes(2);
+
+        lodashDefaultsDeep.mockRestore();
       });
 
       it('getUserProvided', async () => {

src/core/server/ui_settings/ui_settings_client.ts

@@ -49,6 +49,7 @@ export class UiSettingsClient implements IUiSettingsClient {
   private readonly defaults: NonNullable<UiSettingsServiceOptions['defaults']>;
   private readonly log: Logger;
   private readonly cache: Cache;
+  private readonly rawCache: Cache;
 
   constructor(options: UiSettingsServiceOptions) {
     const { type, id, buildNum, savedObjectsClient, log, defaults = {}, overrides = {} } = options;
@@ -60,6 +61,7 @@ export class UiSettingsClient implements IUiSettingsClient {
     this.overrides = overrides;
     this.log = log;
     this.cache = new Cache();
+    this.rawCache = new Cache();
   }
 
   getRegistered() {
@@ -107,6 +109,7 @@ export class UiSettingsClient implements IUiSettingsClient {
 
   async setMany(changes: Record<string, any>) {
     this.cache.del();
+    this.rawCache.del();
     this.onWriteHook(changes);
     await this.write({ changes });
   }
@@ -143,8 +146,17 @@ export class UiSettingsClient implements IUiSettingsClient {
   }
 
   private async getRaw(): Promise<UiSettingsRaw> {
+    const cachedValue = this.rawCache.get();
+    if (cachedValue) {
+      return cachedValue;
+    }
+
     const userProvided = await this.getUserProvided();
-    return defaultsDeep({}, userProvided, this.defaults);
+    const result = defaultsDeep({ ...userProvided }, this.defaults);
+
+    this.rawCache.set(result);
+
+    return result;
   }
 
   private validateKey(key: string, value: unknown) {