From 389856795d7a1c5506d13c31ec91976a2c7454f3 Mon Sep 17 00:00:00 2001 From: mike12345567 Date: Fri, 24 Jun 2022 13:34:00 +0100 Subject: [PATCH] Updating writethrough cache a bit to make sure it implements the PouchDB API properly. --- packages/backend-core/cache.js | 1 + .../src/cache/tests/writethrough.spec.js | 16 ++--- .../backend-core/src/cache/writethrough.ts | 62 ++++++++++++++----- 3 files changed, 54 insertions(+), 25 deletions(-) diff --git a/packages/backend-core/cache.js b/packages/backend-core/cache.js index 932fd7b901..6b319357c4 100644 --- a/packages/backend-core/cache.js +++ b/packages/backend-core/cache.js @@ -3,5 +3,6 @@ const generic = require("./src/cache/generic") module.exports = { user: require("./src/cache/user"), app: require("./src/cache/appMetadata"), + writethrough: require("./src/cache/writethrough"), ...generic, } diff --git a/packages/backend-core/src/cache/tests/writethrough.spec.js b/packages/backend-core/src/cache/tests/writethrough.spec.js index a0ada8b51b..eafa002b3e 100644 --- a/packages/backend-core/src/cache/tests/writethrough.spec.js +++ b/packages/backend-core/src/cache/tests/writethrough.spec.js @@ -9,30 +9,30 @@ tk.freeze(START_DATE) const DELAY = 5000 const db = dangerousGetDB("test") -const writethrough = new Writethrough(db) +const writethrough = new Writethrough(db, DELAY) describe("writethrough", () => { describe("put", () => { let first it("should be able to store, will go to DB", async () => { - const response = await writethrough.put({ _id: "test", value: 1 }, DELAY) - const output = await db.get(response._id) + const response = await writethrough.put({ _id: "test", value: 1 }) + const output = await db.get(response.id) first = output expect(output.value).toBe(1) }) it("second put shouldn't update DB", async () => { - const response = await writethrough.put({ ...first, value: 2 }, DELAY) - const output = await db.get(response._id) + const response = await writethrough.put({ ...first, value: 2 }) + const output = await db.get(response.id) expect(first._rev).toBe(output._rev) expect(output.value).toBe(1) }) it("should put it again after delay period", async () => { tk.freeze(START_DATE + DELAY + 1) - const response = await writethrough.put({ ...first, value: 3 }, DELAY) - const output = await db.get(response._id) - expect(response._rev).not.toBe(first._rev) + const response = await writethrough.put({ ...first, value: 3 }) + const output = await db.get(response.id) + expect(response.rev).not.toBe(first._rev) expect(output.value).toBe(3) }) }) diff --git a/packages/backend-core/src/cache/writethrough.ts b/packages/backend-core/src/cache/writethrough.ts index 02932d0c2c..472c78a72d 100644 --- a/packages/backend-core/src/cache/writethrough.ts +++ b/packages/backend-core/src/cache/writethrough.ts @@ -5,7 +5,7 @@ const DEFAULT_WRITE_RATE_MS = 10000 let CACHE: BaseCache | null = null interface CacheItem { - value: any + doc: any lastWrite: number } @@ -17,57 +17,85 @@ async function getCache() { return CACHE } -function makeCacheItem(value: any, lastWrite: number | null = null): CacheItem { - return { value, lastWrite: lastWrite || Date.now() } +function makeCacheItem(doc: any, lastWrite: number | null = null): CacheItem { + return { doc, lastWrite: lastWrite || Date.now() } } export async function put( db: PouchDB.Database, - value: any, + doc: any, writeRateMs: number = DEFAULT_WRITE_RATE_MS ) { const cache = await getCache() - const key = value._id + const key = doc._id let cacheItem: CacheItem | undefined = await cache.get(key) const updateDb = !cacheItem || cacheItem.lastWrite < Date.now() - writeRateMs - let output = value + let output = doc if (updateDb) { - // value should contain the _id and _rev - const response = await db.put(value) + // doc should contain the _id and _rev + const response = await db.put(doc) output = { - ...value, + ...doc, _id: response.id, _rev: response.rev, } } // if we are updating the DB then need to set the lastWrite to now - cacheItem = makeCacheItem(value, updateDb ? null : cacheItem?.lastWrite) + cacheItem = makeCacheItem(output, updateDb ? null : cacheItem?.lastWrite) await cache.store(key, cacheItem) - return output + return { ok: true, id: output._id, rev: output._rev } } export async function get(db: PouchDB.Database, id: string): Promise { const cache = await getCache() let cacheItem: CacheItem = await cache.get(id) if (!cacheItem) { - const value = await db.get(id) - cacheItem = makeCacheItem(value) + const doc = await db.get(id) + cacheItem = makeCacheItem(doc) await cache.store(id, cacheItem) } - return cacheItem.value + return cacheItem.doc +} + +export async function remove( + db: PouchDB.Database, + docOrId: any, + rev?: any +): Promise { + const cache = await getCache() + if (!docOrId) { + throw new Error("No ID/Rev provided.") + } + const id = typeof docOrId === "string" ? docOrId : docOrId._id + rev = typeof docOrId === "string" ? rev : docOrId._rev + try { + await cache.delete(id) + } finally { + await db.remove(id, rev) + } } export class Writethrough { db: PouchDB.Database - constructor(db: PouchDB.Database) { + writeRateMs: number + + constructor( + db: PouchDB.Database, + writeRateMs: number = DEFAULT_WRITE_RATE_MS + ) { this.db = db + this.writeRateMs = writeRateMs } - async put(value: any, writeRateMs: number = DEFAULT_WRITE_RATE_MS) { - return put(this.db, value, writeRateMs) + async put(doc: any) { + return put(this.db, doc, this.writeRateMs) } async get(id: string) { return get(this.db, id) } + + async remove(docOrId: any, rev?: any) { + return remove(this.db, docOrId, rev) + } }