Signal-Desktop/ts/util/batcher.ts

130 lines
3.2 KiB
TypeScript

// Copyright 2019-2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
import PQueue from 'p-queue';
import { sleep } from './sleep';
import * as log from '../logging/log';
import { clearTimeoutIfNecessary } from './clearTimeoutIfNecessary';
declare global {
// We want to extend `window`'s properties, so we need an interface.
// eslint-disable-next-line no-restricted-syntax
interface Window {
// eslint-disable-next-line @typescript-eslint/no-explicit-any
batchers: Array<BatcherType<any>>;
waitForAllBatchers: () => Promise<unknown>;
}
}
window.batchers = [];
window.waitForAllBatchers = async () => {
await Promise.all(window.batchers.map(item => item.flushAndWait()));
};
export type BatcherOptionsType<ItemType> = {
name: string;
wait: number;
maxSize: number;
processBatch: (items: Array<ItemType>) => void | Promise<void>;
};
export type BatcherType<ItemType> = {
add: (item: ItemType) => void;
removeAll: (needle: ItemType) => void;
anyPending: () => boolean;
onIdle: () => Promise<void>;
flushAndWait: () => Promise<void>;
unregister: () => void;
};
export function createBatcher<ItemType>(
options: BatcherOptionsType<ItemType>
): BatcherType<ItemType> {
let batcher: BatcherType<ItemType>;
let timeout: NodeJS.Timeout | null;
let items: Array<ItemType> = [];
const queue = new PQueue({
concurrency: 1,
timeout: 1000 * 60 * 2,
throwOnTimeout: true,
});
function _kickBatchOff() {
clearTimeoutIfNecessary(timeout);
timeout = null;
const itemsRef = items;
items = [];
queue.add(async () => {
await options.processBatch(itemsRef);
});
}
function add(item: ItemType) {
items.push(item);
if (items.length === 1) {
// Set timeout once when we just pushed the first item so that the wait
// time is bounded by `options.wait` and not extended by further pushes.
timeout = setTimeout(_kickBatchOff, options.wait);
} else if (items.length >= options.maxSize) {
_kickBatchOff();
}
}
function removeAll(needle: ItemType) {
items = items.filter(item => item !== needle);
}
function anyPending(): boolean {
return queue.size > 0 || queue.pending > 0 || items.length > 0;
}
async function onIdle() {
while (anyPending()) {
if (queue.size > 0 || queue.pending > 0) {
// eslint-disable-next-line no-await-in-loop
await queue.onIdle();
}
if (items.length > 0) {
// eslint-disable-next-line no-await-in-loop
await sleep(options.wait * 2);
}
}
}
function unregister() {
window.batchers = window.batchers.filter(item => item !== batcher);
}
async function flushAndWait() {
log.info(`Flushing ${options.name} batcher items.length=${items.length}`);
while (anyPending()) {
_kickBatchOff();
if (queue.size > 0 || queue.pending > 0) {
// eslint-disable-next-line no-await-in-loop
await queue.onIdle();
}
}
log.info(`Flushing complete ${options.name} for batcher`);
}
batcher = {
add,
removeAll,
anyPending,
onIdle,
flushAndWait,
unregister,
};
window.batchers.push(batcher);
return batcher;
}