feat: new read model for client feature toggle cache (#8975)

This is based on the exising client feature toggle store, but some
alterations.

1. We support all of the querying it did before.
2. Added support to filter by **featureNames**
3. Simplified logic, so we do not have admin API logic
- no return of tags
- no return of last seen
- no return of favorites
- no playground logic


Next PR will try to include the revision ID.

src/lib/features/client-feature-toggles/cache/client-feature-toggle-cache-read-model-type.ts

@@ -0,0 +1,14 @@
+import type { IFeatureToggleQuery } from '../../../types';
+import type { FeatureConfigurationClient } from '../../feature-toggle/types/feature-toggle-strategies-store-type';
+
+export interface FeatureConfigurationCacheClient
+    extends FeatureConfigurationClient {
+    description: string;
+    impressionData: false;
+}
+
+export interface IClientFeatureToggleCacheReadModel {
+    getAll(
+        featureQuery: IFeatureToggleQuery,
+    ): Promise<FeatureConfigurationCacheClient[]>;
+}

src/lib/features/client-feature-toggles/cache/client-feature-toggle-cache-read-model.ts

@@ -0,0 +1,242 @@
+import { Knex } from 'knex';
+
+import Raw = Knex.Raw;
+
+import type EventEmitter from 'events';
+import { ALL_PROJECTS, ensureStringValue, mapValues } from '../../../util';
+import type {
+    FeatureConfigurationCacheClient,
+    IClientFeatureToggleCacheReadModel,
+} from './client-feature-toggle-cache-read-model-type';
+import type { Db } from '../../../db/db';
+import {
+    DB_TIME,
+    type IFeatureToggleCacheQuery,
+    type IStrategyConfig,
+    type PartialDeep,
+} from '../../../internals';
+import metricsHelper from '../../../util/metrics-helper';
+import FeatureToggleStore from '../../feature-toggle/feature-toggle-store';
+
+export default class ClientFeatureToggleCacheReadModel
+    implements IClientFeatureToggleCacheReadModel
+{
+    private db: Db;
+
+    private timer: Function;
+
+    constructor(db: Db, eventBus: EventEmitter) {
+        this.db = db;
+        this.timer = (action: string) =>
+            metricsHelper.wrapTimer(eventBus, DB_TIME, {
+                store: 'client-feature-toggle-cache-read-model',
+                action,
+            });
+    }
+
+    public async getAll(
+        featureQuery: IFeatureToggleCacheQuery,
+    ): Promise<FeatureConfigurationCacheClient[]> {
+        const environment = featureQuery.environment;
+        const stopTimer = this.timer(`getAll`);
+
+        const selectColumns = [
+            'features.name as name',
+            'features.description as description',
+            'features.type as type',
+            'features.project as project',
+            'features.stale as stale',
+            'features.impression_data as impression_data',
+            'features.created_at as created_at',
+            'fe.variants as variants',
+            'fe.enabled as enabled',
+            'fe.environment as environment',
+            'fs.id as strategy_id',
+            'fs.strategy_name as strategy_name',
+            'fs.title as strategy_title',
+            'fs.disabled as strategy_disabled',
+            'fs.parameters as parameters',
+            'fs.constraints as constraints',
+            'fs.sort_order as sort_order',
+            'fs.variants as strategy_variants',
+            'segments.id as segment_id',
+            'segments.constraints as segment_constraints',
+            'df.parent as parent',
+            'df.variants as parent_variants',
+            'df.enabled as parent_enabled',
+        ] as (string | Raw<any>)[];
+
+        let query = this.db('features')
+            .modify(FeatureToggleStore.filterByArchived, false)
+            .leftJoin(
+                this.db('feature_strategies')
+                    .select('*')
+                    .where({ environment })
+                    .as('fs'),
+                'fs.feature_name',
+                'features.name',
+            )
+            .leftJoin(
+                this.db('feature_environments')
+                    .select(
+                        'feature_name',
+                        'enabled',
+                        'environment',
+                        'variants',
+                    )
+                    .where({ environment })
+                    .as('fe'),
+                'fe.feature_name',
+                'features.name',
+            )
+            .leftJoin(
+                'feature_strategy_segment as fss',
+                `fss.feature_strategy_id`,
+                `fs.id`,
+            )
+            .leftJoin('segments', `segments.id`, `fss.segment_id`)
+            .leftJoin('dependent_features as df', 'df.child', 'features.name');
+
+        if (featureQuery?.toggleNames && featureQuery?.toggleNames.length > 0) {
+            query = query.whereIn('features.name', featureQuery.toggleNames);
+        }
+        query = query.select(selectColumns);
+
+        if (featureQuery) {
+            if (featureQuery.tag) {
+                const tagQuery = this.db
+                    .from('feature_tag')
+                    .select('feature_name')
+                    .whereIn(['tag_type', 'tag_value'], featureQuery.tag);
+                query = query.whereIn('features.name', tagQuery);
+            }
+            if (
+                featureQuery.project &&
+                !featureQuery.project.includes(ALL_PROJECTS)
+            ) {
+                query = query.whereIn('project', featureQuery.project);
+            }
+            if (featureQuery.namePrefix) {
+                query = query.where(
+                    'features.name',
+                    'like',
+                    `${featureQuery.namePrefix}%`,
+                );
+            }
+        }
+        const rows = await query;
+        stopTimer();
+
+        const featureToggles = rows.reduce((acc, r) => {
+            const feature: PartialDeep<FeatureConfigurationCacheClient> = acc[
+                r.name
+            ] ?? {
+                strategies: [],
+            };
+            if (this.isUnseenStrategyRow(feature, r) && !r.strategy_disabled) {
+                feature.strategies?.push(this.rowToStrategy(r));
+            }
+            if (featureQuery?.inlineSegmentConstraints && r.segment_id) {
+                this.addSegmentToStrategy(feature, r);
+            } else if (
+                !featureQuery?.inlineSegmentConstraints &&
+                r.segment_id
+            ) {
+                this.addSegmentIdsToStrategy(feature, r);
+            }
+            if (r.parent) {
+                feature.dependencies = feature.dependencies || [];
+                feature.dependencies.push({
+                    feature: r.parent,
+                    enabled: r.parent_enabled,
+                    ...(r.parent_enabled
+                        ? { variants: r.parent_variants }
+                        : {}),
+                });
+            }
+            feature.impressionData = r.impression_data;
+            feature.enabled = !!r.enabled;
+            feature.name = r.name;
+            feature.description = r.description;
+            feature.project = r.project;
+            feature.stale = r.stale;
+            feature.type = r.type;
+            feature.variants = r.variants || [];
+            feature.project = r.project;
+
+            acc[r.name] = feature;
+            return acc;
+        }, {});
+
+        const features: FeatureConfigurationCacheClient[] =
+            Object.values(featureToggles);
+
+        // strip away unwanted properties
+        const cleanedFeatures = features.map(({ strategies, ...rest }) => ({
+            ...rest,
+            strategies: strategies
+                ?.sort((strategy1, strategy2) => {
+                    if (
+                        typeof strategy1.sortOrder === 'number' &&
+                        typeof strategy2.sortOrder === 'number'
+                    ) {
+                        return strategy1.sortOrder - strategy2.sortOrder;
+                    }
+                    return 0;
+                })
+                .map(({ id, title, sortOrder, ...strategy }) => ({
+                    ...strategy,
+                })),
+        }));
+
+        return cleanedFeatures;
+    }
+
+    private addSegmentIdsToStrategy(
+        feature: PartialDeep<FeatureConfigurationCacheClient>,
+        row: Record<string, any>,
+    ) {
+        const strategy = feature.strategies?.find(
+            (s) => s?.id === row.strategy_id,
+        );
+        if (!strategy) {
+            return;
+        }
+        if (!strategy.segments) {
+            strategy.segments = [];
+        }
+        strategy.segments.push(row.segment_id);
+    }
+
+    private rowToStrategy(row: Record<string, any>): IStrategyConfig {
+        const strategy: IStrategyConfig = {
+            id: row.strategy_id,
+            name: row.strategy_name,
+            title: row.strategy_title,
+            constraints: row.constraints || [],
+            parameters: mapValues(row.parameters || {}, ensureStringValue),
+            sortOrder: row.sort_order,
+        };
+        strategy.variants = row.strategy_variants || [];
+        return strategy;
+    }
+
+    private isUnseenStrategyRow(
+        feature: PartialDeep<FeatureConfigurationCacheClient>,
+        row: Record<string, any>,
+    ): boolean {
+        return (
+            row.strategy_id &&
+            !feature.strategies?.find((s) => s?.id === row.strategy_id)
+        );
+    }
+
+    private addSegmentToStrategy(
+        feature: PartialDeep<FeatureConfigurationCacheClient>,
+        row: Record<string, any>,
+    ) {
+        feature.strategies
+            ?.find((s) => s?.id === row.strategy_id)
+            ?.constraints?.push(...row.segment_constraints);
+    }
+}

src/lib/features/client-feature-toggles/cache/client-feature-toggle-cache.ts

@@ -1,7 +1,6 @@
 import type {
     IEventStore,
     IFeatureToggleClient,
-    IFeatureToggleClientStore,
     IFeatureToggleQuery,
     IFlagResolver,
 } from '../../../types';
@@ -9,6 +8,7 @@ import type { FeatureConfigurationClient } from '../../feature-toggle/types/feat
 import type ConfigurationRevisionService from '../../feature-toggle/configuration-revision-service';
 import { UPDATE_REVISION } from '../../feature-toggle/configuration-revision-service';
 import { RevisionCache } from './revision-cache';
+import type { IClientFeatureToggleCacheReadModel } from './client-feature-toggle-cache-read-model-type';
 
 type DeletedFeature = {
     name: string;
@@ -90,7 +90,7 @@ export const calculateRequiredClientRevision = (
 };
 
 export class ClientFeatureToggleCache {
-    private clientFeatureToggleStore: IFeatureToggleClientStore;
+    private clientFeatureToggleCacheReadModel: IClientFeatureToggleCacheReadModel;
 
     private cache: Revisions = {};
 
@@ -105,14 +105,15 @@ export class ClientFeatureToggleCache {
     private configurationRevisionService: ConfigurationRevisionService;
 
     constructor(
-        clientFeatureToggleStore: IFeatureToggleClientStore,
+        clientFeatureToggleCacheReadModel: IClientFeatureToggleCacheReadModel,
         eventStore: IEventStore,
         configurationRevisionService: ConfigurationRevisionService,
         flagResolver: IFlagResolver,
     ) {
         this.eventStore = eventStore;
         this.configurationRevisionService = configurationRevisionService;
-        this.clientFeatureToggleStore = clientFeatureToggleStore;
+        this.clientFeatureToggleCacheReadModel =
+            clientFeatureToggleCacheReadModel;
         this.flagResolver = flagResolver;
         this.onUpdateRevisionEvent = this.onUpdateRevisionEvent.bind(this);
         this.cache = {};
@@ -272,36 +273,10 @@ export class ClientFeatureToggleCache {
     }
 
     async getClientFeatures(
-        query?: IFeatureToggleQuery,
+        query: IFeatureToggleQuery,
     ): Promise<FeatureConfigurationClient[]> {
-        const result = await this.clientFeatureToggleStore.getClient(
-            query || {},
-        );
-
-        return result.map(
-            ({
-                name,
-                type,
-                enabled,
-                project,
-                stale,
-                strategies,
-                variants,
-                description,
-                impressionData,
-                dependencies,
-            }) => ({
-                name,
-                type,
-                enabled,
-                project,
-                stale,
-                strategies,
-                variants,
-                description,
-                impressionData,
-                dependencies,
-            }),
-        );
+        const result =
+            await this.clientFeatureToggleCacheReadModel.getAll(query);
+        return result;
     }
 }

src/lib/features/client-feature-toggles/cache/createClientFeatureToggleCache.ts

@@ -3,8 +3,7 @@ import EventStore from '../../events/event-store';
 import ConfigurationRevisionService from '../../feature-toggle/configuration-revision-service';
 import type { IUnleashConfig } from '../../../types';
 import type { Db } from '../../../db/db';
-
-import FeatureToggleClientStore from '../client-feature-toggle-store';
+import ClientFeatureToggleCacheReadModel from './client-feature-toggle-cache-read-model';
 
 export const createClientFeatureToggleCache = (
     db: Db,
@@ -13,18 +12,15 @@ export const createClientFeatureToggleCache = (
     const { getLogger, eventBus, flagResolver } = config;
 
     const eventStore = new EventStore(db, getLogger);
-    const featureToggleClientStore = new FeatureToggleClientStore(
-        db,
-        eventBus,
-        getLogger,
-        flagResolver,
-    );
+
+    const clientFeatureToggleCacheReadModel =
+        new ClientFeatureToggleCacheReadModel(db, eventBus);
 
     const configurationRevisionService =
         ConfigurationRevisionService.getInstance({ eventStore }, config);
 
     const clientFeatureToggleCache = new ClientFeatureToggleCache(
-        featureToggleClientStore,
+        clientFeatureToggleCacheReadModel,
         eventStore,
         configurationRevisionService,
         flagResolver,

src/lib/features/client-feature-toggles/tests/client-feature-toggles.e2e.test.ts

@@ -130,6 +130,7 @@ beforeAll(async () => {
             experimental: {
                 flags: {
                     strictSchemaValidation: true,
+                    deltaApi: true,
                 },
             },
         },
@@ -322,3 +323,19 @@ test('should match snapshot from /api/client/features', async () => {
 
     expect(result.body).toMatchSnapshot();
 });
+
+test('should match with /api/client/features/delta', async () => {
+    await setupFeatures(db, app);
+
+    const { body } = await app.request
+        .get('/api/client/features')
+        .expect('Content-Type', /json/)
+        .expect(200);
+
+    const { body: deltaBody } = await app.request
+        .get('/api/client/features/delta')
+        .expect('Content-Type', /json/)
+        .expect(200);
+
+    expect(body.features).toMatchObject(deltaBody.updated);
+});

src/lib/types/model.ts

@@ -345,6 +345,11 @@ export interface IFeatureToggleQuery {
     inlineSegmentConstraints?: boolean;
 }
 
+export interface IFeatureToggleCacheQuery extends IFeatureToggleQuery {
+    toggleNames?: string[];
+    environment: string;
+}
+
 export interface ITag {
     value: string;
     type: string;