implement QuantumKVCache

1 files changed, 431 insertions, 0 deletions

diff --git a/packages/backend/test/unit/misc/cache.ts b/packages/backend/test/unit/misc/cache.ts
new file mode 100644
index 0000000000..5b242c47d4
--- /dev/null
+++ b/packages/backend/test/unit/misc/cache.ts
@@ -0,0 +1,431 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { jest } from '@jest/globals';
+import { FakeInternalEventService } from '../../misc/FakeInternalEventService.js';
+import { QuantumKVCache, QuantumKVOpts } from '@/misc/cache.js';
+
+describe(QuantumKVCache, () => {
+	let fakeInternalEventService: FakeInternalEventService;
+	let madeCaches: { dispose: () => void }[];
+
+	function makeCache<T>(opts?: Partial<QuantumKVOpts<T>> & { name?: string }): QuantumKVCache<T> {
+		const _opts = {
+			name: 'test',
+			lifetime: Infinity,
+			fetcher: () => { throw new Error('not implemented'); },
+		} satisfies QuantumKVOpts<T> & { name: string };
+
+		if (opts) {
+			Object.assign(_opts, opts);
+		}
+
+		const cache = new QuantumKVCache<T>(fakeInternalEventService, _opts.name, _opts);
+		madeCaches.push(cache);
+		return cache;
+	}
+
+	beforeEach(() => {
+		madeCaches = [];
+		fakeInternalEventService = new FakeInternalEventService();
+	});
+
+	afterEach(() => {
+		madeCaches.forEach(cache => {
+			cache.dispose();
+		});
+	});
+
+	it('should connect on construct', () => {
+		makeCache();
+
+		expect(fakeInternalEventService._calls).toContainEqual(['on', ['quantumCacheUpdated', expect.anything(), { ignoreLocal: true }]]);
+	});
+
+	it('should disconnect on dispose', () => {
+		const cache = makeCache();
+
+		cache.dispose();
+
+		const callback = fakeInternalEventService._calls
+			.find(c => c[0] === 'on' && c[1][0] === 'quantumCacheUpdated')
+			?.[1][1];
+		expect(fakeInternalEventService._calls).toContainEqual(['off', ['quantumCacheUpdated', callback]]);
+	});
+
+	it('should store in memory cache', async () => {
+		const cache = makeCache<string>();
+
+		await cache.set('foo', 'bar');
+		await cache.set('alpha', 'omega');
+
+		const result1 = await cache.get('foo');
+		const result2 = await cache.get('alpha');
+
+		expect(result1).toBe('bar');
+		expect(result2).toBe('omega');
+	});
+
+	it('should emit event when storing', async () => {
+		const cache = makeCache<string>({ name: 'fake' });
+
+		await cache.set('foo', 'bar');
+
+		expect(fakeInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' }]]);
+	});
+
+	it('should call onSet when storing', async () => {
+		const fakeOnSet = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			onSet: fakeOnSet,
+		});
+
+		await cache.set('foo', 'bar');
+
+		expect(fakeOnSet).toHaveBeenCalledWith('foo', cache);
+	});
+
+	it('should not emit event when storing unchanged value', async () => {
+		const cache = makeCache<string>({ name: 'fake' });
+
+		await cache.set('foo', 'bar');
+		await cache.set('foo', 'bar');
+
+		expect(fakeInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
+	});
+
+	it('should not call onSet when storing unchanged value', async () => {
+		const fakeOnSet = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			onSet: fakeOnSet,
+		});
+
+		await cache.set('foo', 'bar');
+		await cache.set('foo', 'bar');
+
+		expect(fakeOnSet).toHaveBeenCalledTimes(1);
+	});
+
+	it('should fetch when getting an unknown value', async () => {
+		const cache = makeCache<string>({
+			name: 'fake',
+			fetcher: key => `value#${key}`,
+		});
+
+		const result = await cache.get('foo');
+
+		expect(result).toBe('value#foo');
+	});
+
+	it('should store fetched value in memory cache', async () => {
+		const cache = makeCache<string>({
+			name: 'fake',
+			fetcher: key => `value#${key}`,
+		});
+
+		await cache.get('foo');
+
+		const result = cache.has('foo');
+		expect(result).toBe(true);
+	});
+
+	it('should call onSet when fetching', async () => {
+		const fakeOnSet = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			fetcher: key => `value#${key}`,
+			onSet: fakeOnSet,
+		});
+
+		await cache.get('foo');
+
+		expect(fakeOnSet).toHaveBeenCalledWith('foo', cache);
+	});
+
+	it('should not emit event when fetching', async () => {
+		const cache = makeCache<string>({
+			name: 'fake',
+			fetcher: key => `value#${key}`,
+		});
+
+		await cache.get('foo');
+
+		expect(fakeInternalEventService._calls).not.toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' }]]);
+	});
+
+	it('should delete from memory cache', async () => {
+		const cache = makeCache<string>();
+
+		await cache.set('foo', 'bar');
+		await cache.delete('foo');
+
+		const result = cache.has('foo');
+		expect(result).toBe(false);
+	});
+
+	it('should call onDelete when deleting', async () => {
+		const fakeOnDelete = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			onDelete: fakeOnDelete,
+		});
+
+		await cache.set('foo', 'bar');
+		await cache.delete('foo');
+
+		expect(fakeOnDelete).toHaveBeenCalledWith('foo', cache);
+	});
+
+	it('should emit event when deleting', async () => {
+		const cache = makeCache<string>({ name: 'fake' });
+
+		await cache.set('foo', 'bar');
+		await cache.delete('foo');
+
+		expect(fakeInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', op: 'd', key: 'foo' }]]);
+	});
+
+	it('should delete when receiving set event', async () => {
+		const cache = makeCache<string>({ name: 'fake' });
+		await cache.set('foo', 'bar');
+
+		await fakeInternalEventService._emitRedis('quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' });
+
+		const result = cache.has('foo');
+		expect(result).toBe(false);
+	});
+
+	it('should call onSet when receiving set event', async () => {
+		const fakeOnSet = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			onSet: fakeOnSet,
+		});
+
+		await fakeInternalEventService._emitRedis('quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' });
+
+		expect(fakeOnSet).toHaveBeenCalledWith('foo', cache);
+	});
+
+	it('should delete when receiving delete event', async () => {
+		const cache = makeCache<string>({ name: 'fake' });
+		await cache.set('foo', 'bar');
+
+		await fakeInternalEventService._emitRedis('quantumCacheUpdated', { name: 'fake', op: 'd', key: 'foo' });
+
+		const result = cache.has('foo');
+		expect(result).toBe(false);
+	});
+
+	it('should call onDelete when receiving delete event', async () => {
+		const fakeOnDelete = jest.fn(() => Promise.resolve());
+		const cache = makeCache<string>({
+			name: 'fake',
+			onDelete: fakeOnDelete,
+		});
+		await cache.set('foo', 'bar');
+
+		await fakeInternalEventService._emitRedis('quantumCacheUpdated', { name: 'fake', op: 'd', key: 'foo' });
+
+		expect(fakeOnDelete).toHaveBeenCalledWith('foo', cache);
+	});
+
+	describe('fetch', () => {
+		it('should perform same logic as get', async () => {
+			const fakeOnSet = jest.fn(() => Promise.resolve());
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+				onSet: fakeOnSet,
+			});
+
+			// noinspection JSDeprecatedSymbols
+			const result = await cache.fetch('foo');
+
+			expect(result).toBe('value#foo');
+			expect(fakeOnSet).toHaveBeenCalledWith('foo', cache);
+			expect(fakeInternalEventService._calls).not.toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' }]]);
+		});
+	});
+
+	describe('refresh', () => {
+		it('should populate the value', async () => {
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+			});
+
+			await cache.refresh('foo');
+
+			const result = cache.has('foo');
+			expect(result).toBe(true);
+		});
+
+		it('should return the value', async () => {
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+			});
+
+			const result = await cache.refresh('foo');
+
+			expect(result).toBe('value#foo');
+		});
+
+		it('should replace the value if it exists', async () => {
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+			});
+
+			await cache.set('foo', 'bar');
+			const result = await cache.refresh('foo');
+
+			expect(result).toBe('value#foo');
+		});
+
+		it('should call onSet', async () => {
+			const fakeOnSet = jest.fn(() => Promise.resolve());
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+				onSet: fakeOnSet,
+			});
+
+			await cache.refresh('foo')
+
+			expect(fakeOnSet).toHaveBeenCalledWith('foo', cache);
+		});
+
+		it('should emit event', async () => {
+			const cache = makeCache<string>({
+				name: 'fake',
+				fetcher: key => `value#${key}`,
+			});
+
+			await cache.refresh('foo');
+
+			expect(fakeInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', op: 's', key: 'foo' }]]);
+		});
+	});
+
+	describe('has', () => {
+		it('should return false when empty', () => {
+			const cache = makeCache();
+			const result = cache.has('foo');
+			expect(result).toBe(false);
+		});
+
+		it('should return false when value is not in memory', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = cache.has('alpha');
+
+			expect(result).toBe(false);
+		});
+
+		it('should return true when value is in memory', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = cache.has('foo');
+
+			expect(result).toBe(true);
+		});
+	});
+
+	describe('size', () => {
+		it('should return 0 when empty', () => {
+			const cache = makeCache();
+			expect(cache.size).toBe(0);
+		});
+
+		it('should return correct size when populated', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			expect(cache.size).toBe(1);
+		});
+	});
+
+	describe('entries', () => {
+		it('should return empty when empty', () => {
+			const cache = makeCache();
+
+			const result = Array.from(cache.entries());
+
+			expect(result).toHaveLength(0);
+		});
+
+		it('should return all entries when populated', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = Array.from(cache.entries());
+
+			expect(result).toEqual([['foo', 'bar']]);
+		});
+	});
+
+	describe('keys', () => {
+		it('should return empty when empty', () => {
+			const cache = makeCache();
+
+			const result = Array.from(cache.keys());
+
+			expect(result).toHaveLength(0);
+		});
+
+		it('should return all keys when populated', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = Array.from(cache.keys());
+
+			expect(result).toEqual(['foo']);
+		});
+	});
+
+	describe('values', () => {
+		it('should return empty when empty', () => {
+			const cache = makeCache();
+
+			const result = Array.from(cache.values());
+
+			expect(result).toHaveLength(0);
+		});
+
+		it('should return all values when populated', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = Array.from(cache.values());
+
+			expect(result).toEqual(['bar']);
+		});
+	});
+
+	describe('[Symbol.iterator]', () => {
+		it('should return empty when empty', () => {
+			const cache = makeCache();
+
+			const result = Array.from(cache);
+
+			expect(result).toHaveLength(0);
+		});
+
+		it('should return all entries when populated', async () => {
+			const cache = makeCache<string>();
+			await cache.set('foo', 'bar');
+
+			const result = Array.from(cache);
+
+			expect(result).toEqual([['foo', 'bar']]);
+		});
+	});
+});