Files
infocom-systems-design/node_modules/chromium-bidi/lib/esm/bidiMapper/modules/session/EventManager.js
2025-10-03 22:27:28 +03:00

226 lines
9.4 KiB
JavaScript

/**
* Copyright 2022 Google LLC.
* Copyright (c) Microsoft Corporation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var _a;
import { ChromiumBidi, } from '../../../protocol/protocol.js';
import { Buffer } from '../../../utils/Buffer.js';
import { DefaultMap } from '../../../utils/DefaultMap.js';
import { distinctValues } from '../../../utils/DistinctValues.js';
import { EventEmitter } from '../../../utils/EventEmitter.js';
import { IdWrapper } from '../../../utils/IdWrapper.js';
import { OutgoingMessage } from '../../OutgoingMessage.js';
import { assertSupportedEvent } from './events.js';
import { SubscriptionManager } from './SubscriptionManager.js';
class EventWrapper {
#idWrapper = new IdWrapper();
#contextId;
#event;
constructor(event, contextId) {
this.#event = event;
this.#contextId = contextId;
}
get id() {
return this.#idWrapper.id;
}
get contextId() {
return this.#contextId;
}
get event() {
return this.#event;
}
}
/**
* Maps event name to a desired buffer length.
*/
const eventBufferLength = new Map([[ChromiumBidi.Log.EventNames.LogEntryAdded, 100]]);
export class EventManager extends EventEmitter {
/**
* Maps event name to a set of contexts where this event already happened.
* Needed for getting buffered events from all the contexts in case of
* subscripting to all contexts.
*/
#eventToContextsMap = new DefaultMap(() => new Set());
/**
* Maps `eventName` + `browsingContext` to buffer. Used to get buffered events
* during subscription. Channel-agnostic.
*/
#eventBuffers = new Map();
/**
* Maps `eventName` + `browsingContext` to Map of channel to last id
* Used to avoid sending duplicated events when user
* subscribes -> unsubscribes -> subscribes.
*/
#lastMessageSent = new Map();
#subscriptionManager;
#browsingContextStorage;
/**
* Map of event name to hooks to be called when client is subscribed to the event.
*/
#subscribeHooks;
constructor(browsingContextStorage) {
super();
this.#browsingContextStorage = browsingContextStorage;
this.#subscriptionManager = new SubscriptionManager(browsingContextStorage);
this.#subscribeHooks = new DefaultMap(() => []);
}
get subscriptionManager() {
return this.#subscriptionManager;
}
/**
* Returns consistent key to be used to access value maps.
*/
static #getMapKey(eventName, browsingContext) {
return JSON.stringify({ eventName, browsingContext });
}
addSubscribeHook(event, hook) {
this.#subscribeHooks.get(event).push(hook);
}
registerEvent(event, contextId) {
this.registerPromiseEvent(Promise.resolve({
kind: 'success',
value: event,
}), contextId, event.method);
}
registerPromiseEvent(event, contextId, eventName) {
const eventWrapper = new EventWrapper(event, contextId);
const sortedChannels = this.#subscriptionManager.getChannelsSubscribedToEvent(eventName, contextId);
this.#bufferEvent(eventWrapper, eventName);
// Send events to channels in the subscription priority.
for (const channel of sortedChannels) {
this.emit("event" /* EventManagerEvents.Event */, {
message: OutgoingMessage.createFromPromise(event, channel),
event: eventName,
});
this.#markEventSent(eventWrapper, channel, eventName);
}
}
async subscribe(eventNames, contextIds, channel) {
for (const name of eventNames) {
assertSupportedEvent(name);
}
// First check if all the contexts are known.
for (const contextId of contextIds) {
if (contextId !== null) {
// Assert the context is known. Throw exception otherwise.
this.#browsingContextStorage.getContext(contextId);
}
}
// List of the subscription items that were actually added. Each contains a specific
// event and context. No module event (like "network") or global context subscription
// (like null) are included.
const addedSubscriptionItems = [];
for (const eventName of eventNames) {
for (const contextId of contextIds) {
addedSubscriptionItems.push(...this.#subscriptionManager.subscribe(eventName, contextId, channel));
for (const eventWrapper of this.#getBufferedEvents(eventName, contextId, channel)) {
// The order of the events is important.
this.emit("event" /* EventManagerEvents.Event */, {
message: OutgoingMessage.createFromPromise(eventWrapper.event, channel),
event: eventName,
});
this.#markEventSent(eventWrapper, channel, eventName);
}
}
}
// Iterate over all new subscription items and call hooks if any. There can be
// duplicates, e.g. when subscribing to the whole module and some specific event in
// the same time ("network", "network.responseCompleted"). `distinctValues` guarantees
// that hooks are called only once per pair event + context.
distinctValues(addedSubscriptionItems).forEach(({ contextId, event }) => {
this.#subscribeHooks.get(event).forEach((hook) => hook(contextId));
});
await this.toggleModulesIfNeeded();
}
async unsubscribe(eventNames, contextIds, channel) {
for (const name of eventNames) {
assertSupportedEvent(name);
}
this.#subscriptionManager.unsubscribeAll(eventNames, contextIds, channel);
await this.toggleModulesIfNeeded();
}
async toggleModulesIfNeeded() {
// TODO(1): Only update changed subscribers
// TODO(2): Enable for Worker Targets
await Promise.all(this.#browsingContextStorage.getAllContexts().map(async (context) => {
return await context.toggleModulesIfNeeded();
}));
}
clearBufferedEvents(contextId) {
for (const eventName of eventBufferLength.keys()) {
const bufferMapKey = _a.#getMapKey(eventName, contextId);
this.#eventBuffers.delete(bufferMapKey);
}
}
/**
* If the event is buffer-able, put it in the buffer.
*/
#bufferEvent(eventWrapper, eventName) {
if (!eventBufferLength.has(eventName)) {
// Do nothing if the event is no buffer-able.
return;
}
const bufferMapKey = _a.#getMapKey(eventName, eventWrapper.contextId);
if (!this.#eventBuffers.has(bufferMapKey)) {
this.#eventBuffers.set(bufferMapKey, new Buffer(eventBufferLength.get(eventName)));
}
this.#eventBuffers.get(bufferMapKey).add(eventWrapper);
// Add the context to the list of contexts having `eventName` events.
this.#eventToContextsMap.get(eventName).add(eventWrapper.contextId);
}
/**
* If the event is buffer-able, mark it as sent to the given contextId and channel.
*/
#markEventSent(eventWrapper, channel, eventName) {
if (!eventBufferLength.has(eventName)) {
// Do nothing if the event is no buffer-able.
return;
}
const lastSentMapKey = _a.#getMapKey(eventName, eventWrapper.contextId);
const lastId = Math.max(this.#lastMessageSent.get(lastSentMapKey)?.get(channel) ?? 0, eventWrapper.id);
const channelMap = this.#lastMessageSent.get(lastSentMapKey);
if (channelMap) {
channelMap.set(channel, lastId);
}
else {
this.#lastMessageSent.set(lastSentMapKey, new Map([[channel, lastId]]));
}
}
/**
* Returns events which are buffered and not yet sent to the given channel events.
*/
#getBufferedEvents(eventName, contextId, channel) {
const bufferMapKey = _a.#getMapKey(eventName, contextId);
const lastSentMessageId = this.#lastMessageSent.get(bufferMapKey)?.get(channel) ?? -Infinity;
const result = this.#eventBuffers
.get(bufferMapKey)
?.get()
.filter((wrapper) => wrapper.id > lastSentMessageId) ?? [];
if (contextId === null) {
// For global subscriptions, events buffered in each context should be sent back.
Array.from(this.#eventToContextsMap.get(eventName).keys())
.filter((_contextId) =>
// Events without context are already in the result.
_contextId !== null &&
// Events from deleted contexts should not be sent.
this.#browsingContextStorage.hasContext(_contextId))
.map((_contextId) => this.#getBufferedEvents(eventName, _contextId, channel))
.forEach((events) => result.push(...events));
}
return result.sort((e1, e2) => e1.id - e2.id);
}
}
_a = EventManager;
//# sourceMappingURL=EventManager.js.map