From 64290d5ae628d227c9a2c01debbe0cb1d426d6d9 Mon Sep 17 00:00:00 2001 From: Bruno Windels Date: Fri, 25 Sep 2020 16:53:19 +0200 Subject: [PATCH] flush promises manually in idb event handler --- src/legacy-polyfill.js | 10 + src/matrix/storage/idb/utils.js | 27 ++- src/utils/Promifill.js | 380 ++++++++++++++++++++++++++++++++ 3 files changed, 411 insertions(+), 6 deletions(-) create mode 100644 src/utils/Promifill.js diff --git a/src/legacy-polyfill.js b/src/legacy-polyfill.js index 80be7a61..30bb8f6d 100644 --- a/src/legacy-polyfill.js +++ b/src/legacy-polyfill.js @@ -15,6 +15,10 @@ limitations under the License. */ // polyfills needed for IE11 + +const hasNativePromise = typeof window.Promise === "function"; + +// TODO: don't include a polyfill for promises as we already provide one import "core-js/stable"; import "regenerator-runtime/runtime"; import "mdn-polyfills/Element.prototype.closest"; @@ -24,6 +28,12 @@ import "mdn-polyfills/Element.prototype.closest"; // it will also include the file supporting *all* the encodings, // weighing a good extra 500kb :-( import "text-encoding"; +import {Promifill} from "./utils/Promifill.js"; + +// console.log("hasNativePromise", hasNativePromise); +// if (!hasNativePromise) { + window.Promise = Promifill; +// } // TODO: contribute this to mdn-polyfills if (!Element.prototype.remove) { diff --git a/src/matrix/storage/idb/utils.js b/src/matrix/storage/idb/utils.js index 7cdc30fd..41d472d9 100644 --- a/src/matrix/storage/idb/utils.js +++ b/src/matrix/storage/idb/utils.js @@ -16,7 +16,7 @@ limitations under the License. import { StorageError } from "../common.js"; -class WrappedDOMException extends StorageError { +class IDBRequestError extends StorageError { constructor(request) { const source = request?.source; const storeName = source?.name || ""; @@ -50,15 +50,27 @@ export function openDatabase(name, createObjectStore, version) { export function reqAsPromise(req) { return new Promise((resolve, reject) => { - req.addEventListener("success", event => resolve(event.target.result)); - req.addEventListener("error", event => reject(new WrappedDOMException(event.target))); + req.addEventListener("success", event => { + resolve(event.target.result); + Promise.flushQueue && Promise.flushQueue(); + }); + req.addEventListener("error", () => { + reject(new IDBRequestError(req)); + Promise.flushQueue && Promise.flushQueue(); + }); }); } export function txnAsPromise(txn) { return new Promise((resolve, reject) => { - txn.addEventListener("complete", resolve); - txn.addEventListener("abort", event => reject(new WrappedDOMException(event.target))); + txn.addEventListener("complete", () => { + resolve(); + Promise.flushQueue && Promise.flushQueue(); + }); + txn.addEventListener("abort", () => { + reject(new IDBRequestError(txn)); + Promise.flushQueue && Promise.flushQueue(); + }); }); } @@ -66,13 +78,15 @@ export function iterateCursor(cursorRequest, processValue) { // TODO: does cursor already have a value here?? return new Promise((resolve, reject) => { cursorRequest.onerror = () => { - reject(new StorageError("Query failed", cursorRequest.error)); + reject(new IDBRequestError(cursorRequest)); + Promise.flushQueue && Promise.flushQueue(); }; // collect results cursorRequest.onsuccess = (event) => { const cursor = event.target.result; if (!cursor) { resolve(false); + Promise.flushQueue && Promise.flushQueue(); return; // end of results } const result = processValue(cursor.value, cursor.key); @@ -81,6 +95,7 @@ export function iterateCursor(cursorRequest, processValue) { if (done) { resolve(true); + Promise.flushQueue && Promise.flushQueue(); } else if(jumpTo) { cursor.continue(jumpTo); } else { diff --git a/src/utils/Promifill.js b/src/utils/Promifill.js new file mode 100644 index 00000000..d4111c45 --- /dev/null +++ b/src/utils/Promifill.js @@ -0,0 +1,380 @@ +"use strict"; + +const [PENDING, FULFILLED, REJECTED] = + [void 0, true, false]; + +export class Promifill { + get state () { + return PENDING; + } + + get value () { + return void 0; + } + + get settled () { + return false; + } + + constructor (executor) { + if (typeof executor != "function") { + throw new TypeError(`Promise resolver ${Object.prototype.toString.call(executor)} is not a function`); + } + + defineProperty(this, "chain", []); + defineProperty(this, "observers", []); + + const secret = []; + + const resolve = + (value, bypassKey) => { + if (this.settled && bypassKey !== secret) { + return; + } + + defineProperty(this, "settled", true); + + const then_ = value && value.then; + const thenable = typeof then_ == "function"; + + if (thenable) { + defineProperty(value, "preventThrow", true); + } + + if (thenable && value.state === PENDING) { + then_.call( + value, + (v) => + resolve(v, secret), + (r) => + reject(r, secret) + ); + } else { + defineProperty(this, "value", + thenable + ? value.value + : value); + defineProperty(this, "state", + thenable + ? value.state + : FULFILLED); + + schedule( + this.observers.map((observer) => ( + { + handler: this.state === FULFILLED + ? observer.onfulfill + : observer.onreject, + value: this.value + })) + ); + + if (this.state === REJECTED) { + raiseUnhandledPromiseRejectionException(this.value, this); + } + } + }; + + const reject = + (reason, bypassKey) => { + if (this.settled && bypassKey !== secret) { + return; + } + + defineProperty(this, "settled", true); + + defineProperty(this, "value", reason); + defineProperty(this, "state", REJECTED); + + schedule( + this.observers.map((observer) => ( + { + handler: observer.onreject, + value: this.value + })) + ); + + raiseUnhandledPromiseRejectionException(this.value, this); + }; + + try { + executor(resolve, reject); + } catch (error) { + reject(error); + } + } + + then (onfulfill, onreject) { + const chainedPromise = new this.constructor((resolve, reject) => { + const internalOnfulfill = + (value) => { + try { + resolve( + typeof onfulfill == "function" + ? onfulfill(value) + : value + ); + } catch (error) { + reject(error); + } + }; + + const internalOnreject = + (reason) => { + try { + if (typeof onreject == "function") { + resolve(onreject(reason)); + } else { + reject(reason); + } + } catch (error) { + reject(error); + } + }; + + if (this.state === PENDING) { + this.observers.push({ onfulfill: internalOnfulfill, onreject: internalOnreject }); + } else { + schedule( + [{ + handler: this.state === FULFILLED + ? internalOnfulfill + : internalOnreject, + value: this.value + }] + ); + } + }); + + this.chain.push(chainedPromise); + return chainedPromise; + } + + catch (onreject) { + return this.then(null, onreject); + } + + finally (oncomplete) { + const chainedPromise = new this.constructor((resolve, reject) => { + const internalOncomplete = + () => { + try { + oncomplete(); + if (this.state === FULFILLED) { + resolve(this.value); + } else { + reject(this.value); + } + } catch (error) { + reject(error); + } + }; + + if (this.state === PENDING) { + this.observers.push({ onfulfill: internalOncomplete, onreject: internalOncomplete }); + } else { + schedule([{ + handler: internalOncomplete + }]); + } + }); + + this.chain.push(chainedPromise); + return chainedPromise; + } + + static resolve (value) { + return value && value.constructor === Promifill + ? value + : new Promifill((resolve) => { + resolve(value); + }); + } + + static reject (reason) { + return new Promifill((_, reject) => { + reject(reason); + }); + } + + static all (iterable) { + return new Promifill((resolve, reject) => { + validateIterable(iterable); + + let iterableSize = 0; + const values = []; + + if (isEmptyIterable(iterable)) { + return resolve(values); + } + + const add = + (value, index) => { + values[index] = value; + if (values.filter(() => true).length === iterableSize) { + resolve(values); + } + }; + + for (let item of iterable) { + ((entry, index) => { + Promifill.resolve(entry) + .then( + (value) => + add(value, index), + reject + ); + })(item, iterableSize++); + } + }); + } + + static race (iterable) { + return new Promifill((resolve, reject) => { + validateIterable(iterable); + + if (isEmptyIterable(iterable)) { + return; + } + + for (let entry of iterable) { + Promifill.resolve(entry) + .then(resolve, reject); + } + }); + } + + static flushQueue() { + console.log("flushing promise queue sync"); + schedule.flushQueue(); + } +} + +const defineProperty = + (obj, propName, propValue) => { + Object.defineProperty(obj, propName, { value: propValue }); + }; + +const defer = + (handler) => + (...args) => { + setTimeout(handler, 0, ...args); + }; + +const thrower = + (error) => { + throw error instanceof Error + ? error + : new Error(error); + }; + +const raiseUnhandledPromiseRejectionException = + defer((error, promise) => { + if (promise.preventThrow || promise.chain.length > 0) { + return; + } + thrower(error); + }); + +class MutationObserverStrategy { + constructor (handler) { + const observer = new MutationObserver(handler); + const node = this.node = + document.createTextNode(""); + observer.observe(node, { characterData: true }); + } + + trigger () { + this.node.data = this.node.data === 1 + ? 0 + : 1; + } +} + +class NextTickStrategy { + constructor (handler) { + this.scheduleNextTick = + () => process.nextTick(handler); + } + + trigger () { + this.scheduleNextTick(); + } +} + +class BetterThanNothingStrategy { + constructor (handler) { + this.scheduleAsap = + () => setTimeout(handler, 0); + } + + trigger () { + this.scheduleAsap(); + } +} + +const getStrategy = + () => { + if (typeof window != "undefined" && typeof window.MutationObserver == "function") { + return MutationObserverStrategy; + } + if (typeof global != "undefined" && typeof process != "undefined" && typeof process.nextTick == "function") { + return NextTickStrategy; + } + + return BetterThanNothingStrategy; + }; + +const schedule = + (() => { + let microtasks = []; + + const run = + () => { + let handler, value; + while (microtasks.length > 0 && ({ handler, value } = microtasks.shift())) { + handler(value); + } + }; + + const Strategy = getStrategy(); + const ctrl = new Strategy(run); + + const scheduleFn = (observers) => { + if (observers.length == 0) { + return; + } + + microtasks = microtasks.concat(observers); + observers.length = 0; + + ctrl.trigger(); + }; + + scheduleFn.flushQueue = function() { + run(); + }; + + return scheduleFn; + })(); + +const isIterable = + (subject) => subject != null && typeof subject[Symbol.iterator] == "function"; + +const validateIterable = + (subject) => { + if (isIterable(subject)) { + return; + } + + throw new TypeError(`Cannot read property 'Symbol(Symbol.iterator)' of ${Object.prototype.toString.call(subject)}.`); + }; + +const isEmptyIterable = + (subject) => { + for (let _ of subject) { // eslint-disable-line no-unused-vars + return false; + } + + return true; + };