Files
typedserver/ts_web_serviceworker/classes.eventbus.ts

410 lines
10 KiB
TypeScript

import { logger } from './logging.js';
/**
* Event types for service worker internal communication
*/
export enum ServiceWorkerEvent {
// Cache events
CACHE_HIT = 'cache:hit',
CACHE_MISS = 'cache:miss',
CACHE_ERROR = 'cache:error',
CACHE_INVALIDATE = 'cache:invalidate',
CACHE_INVALIDATE_ALL = 'cache:invalidate_all',
CACHE_REVALIDATE = 'cache:revalidate',
// Update events
UPDATE_CHECK_START = 'update:check_start',
UPDATE_CHECK_COMPLETE = 'update:check_complete',
UPDATE_AVAILABLE = 'update:available',
UPDATE_APPLIED = 'update:applied',
UPDATE_ERROR = 'update:error',
// Network events
NETWORK_REQUEST_START = 'network:request_start',
NETWORK_REQUEST_COMPLETE = 'network:request_complete',
NETWORK_REQUEST_ERROR = 'network:request_error',
NETWORK_ONLINE = 'network:online',
NETWORK_OFFLINE = 'network:offline',
// Connection events
CLIENT_CONNECTED = 'connection:client_connected',
CLIENT_DISCONNECTED = 'connection:client_disconnected',
// Lifecycle events
INSTALL = 'lifecycle:install',
ACTIVATE = 'lifecycle:activate',
READY = 'lifecycle:ready',
}
/**
* Event payload interfaces
*/
export interface ICacheEventPayload {
url: string;
method?: string;
bytes?: number;
error?: string;
}
export interface IUpdateEventPayload {
oldVersion?: string;
newVersion?: string;
oldHash?: string;
newHash?: string;
error?: string;
}
export interface INetworkEventPayload {
url: string;
method?: string;
status?: number;
duration?: number;
bytes?: number;
error?: string;
}
export interface IConnectionEventPayload {
clientId?: string;
tabId?: string;
}
export interface ILifecycleEventPayload {
timestamp: number;
}
/**
* Union type for all event payloads
*/
export type TEventPayload =
| ICacheEventPayload
| IUpdateEventPayload
| INetworkEventPayload
| IConnectionEventPayload
| ILifecycleEventPayload
| Record<string, unknown>;
/**
* Event listener callback type
*/
export type TEventListener<T extends TEventPayload = TEventPayload> = (
event: ServiceWorkerEvent,
payload: T
) => void | Promise<void>;
/**
* Subscription interface
*/
export interface ISubscription {
unsubscribe: () => void;
}
/**
* Event bus for decoupled communication between service worker components.
* Implements a simple pub/sub pattern.
*/
export class EventBus {
private static instance: EventBus;
private listeners: Map<ServiceWorkerEvent, Set<TEventListener>>;
private globalListeners: Set<TEventListener>;
private eventHistory: Array<{ event: ServiceWorkerEvent; payload: TEventPayload; timestamp: number }>;
private readonly maxHistorySize = 100;
private debugMode = false;
private constructor() {
this.listeners = new Map();
this.globalListeners = new Set();
this.eventHistory = [];
}
/**
* Gets the singleton instance
*/
public static getInstance(): EventBus {
if (!EventBus.instance) {
EventBus.instance = new EventBus();
}
return EventBus.instance;
}
/**
* Enables or disables debug mode (logs all events)
*/
public setDebugMode(enabled: boolean): void {
this.debugMode = enabled;
}
/**
* Emits an event to all subscribed listeners
*/
public emit<T extends TEventPayload>(event: ServiceWorkerEvent, payload: T): void {
if (this.debugMode) {
logger.log('note', `[EventBus] Emit: ${event} ${JSON.stringify(payload)}`);
}
// Record in history
this.recordEvent(event, payload);
// Notify specific listeners
const specificListeners = this.listeners.get(event);
if (specificListeners) {
for (const listener of specificListeners) {
try {
const result = listener(event, payload);
if (result instanceof Promise) {
result.catch((err) => {
logger.log('error', `[EventBus] Async listener error for ${event}: ${err}`);
});
}
} catch (err) {
logger.log('error', `[EventBus] Listener error for ${event}: ${err}`);
}
}
}
// Notify global listeners
for (const listener of this.globalListeners) {
try {
const result = listener(event, payload);
if (result instanceof Promise) {
result.catch((err) => {
logger.log('error', `[EventBus] Global async listener error for ${event}: ${err}`);
});
}
} catch (err) {
logger.log('error', `[EventBus] Global listener error for ${event}: ${err}`);
}
}
}
/**
* Subscribes to a specific event
*/
public on<T extends TEventPayload>(
event: ServiceWorkerEvent,
listener: TEventListener<T>
): ISubscription {
if (!this.listeners.has(event)) {
this.listeners.set(event, new Set());
}
this.listeners.get(event)!.add(listener as TEventListener);
return {
unsubscribe: () => {
this.off(event, listener as TEventListener);
},
};
}
/**
* Subscribes to multiple events at once
*/
public onMany<T extends TEventPayload>(
events: ServiceWorkerEvent[],
listener: TEventListener<T>
): ISubscription {
const subscriptions = events.map((event) =>
this.on(event, listener as TEventListener)
);
return {
unsubscribe: () => {
subscriptions.forEach((sub) => sub.unsubscribe());
},
};
}
/**
* Subscribes to all events
*/
public onAll<T extends TEventPayload>(listener: TEventListener<T>): ISubscription {
this.globalListeners.add(listener as TEventListener);
return {
unsubscribe: () => {
this.globalListeners.delete(listener as TEventListener);
},
};
}
/**
* Subscribes to an event for only one emission
*/
public once<T extends TEventPayload>(
event: ServiceWorkerEvent,
listener: TEventListener<T>
): ISubscription {
const onceListener: TEventListener = (evt, payload) => {
this.off(event, onceListener);
return listener(evt, payload as T);
};
return this.on(event, onceListener);
}
/**
* Unsubscribes a listener from an event
*/
public off(event: ServiceWorkerEvent, listener: TEventListener): void {
const listeners = this.listeners.get(event);
if (listeners) {
listeners.delete(listener);
if (listeners.size === 0) {
this.listeners.delete(event);
}
}
}
/**
* Removes all listeners for an event
*/
public removeAllListeners(event?: ServiceWorkerEvent): void {
if (event) {
this.listeners.delete(event);
} else {
this.listeners.clear();
this.globalListeners.clear();
}
}
/**
* Gets the count of listeners for an event
*/
public listenerCount(event: ServiceWorkerEvent): number {
const listeners = this.listeners.get(event);
return (listeners?.size ?? 0) + this.globalListeners.size;
}
/**
* Gets the event history
*/
public getHistory(): Array<{ event: ServiceWorkerEvent; payload: TEventPayload; timestamp: number }> {
return [...this.eventHistory];
}
/**
* Gets events of a specific type from history
*/
public getHistoryByType(event: ServiceWorkerEvent): Array<{ payload: TEventPayload; timestamp: number }> {
return this.eventHistory
.filter((entry) => entry.event === event)
.map(({ payload, timestamp }) => ({ payload, timestamp }));
}
/**
* Clears the event history
*/
public clearHistory(): void {
this.eventHistory = [];
}
/**
* Waits for an event to be emitted (returns a promise)
*/
public waitFor<T extends TEventPayload>(
event: ServiceWorkerEvent,
timeout?: number
): Promise<T> {
return new Promise((resolve, reject) => {
let timeoutId: ReturnType<typeof setTimeout> | undefined;
const subscription = this.once<T>(event, (_, payload) => {
if (timeoutId) {
clearTimeout(timeoutId);
}
resolve(payload);
});
if (timeout) {
timeoutId = setTimeout(() => {
subscription.unsubscribe();
reject(new Error(`Timeout waiting for event: ${event}`));
}, timeout);
}
});
}
/**
* Records an event in history
*/
private recordEvent(event: ServiceWorkerEvent, payload: TEventPayload): void {
this.eventHistory.push({
event,
payload,
timestamp: Date.now(),
});
// Trim history if needed
if (this.eventHistory.length > this.maxHistorySize) {
this.eventHistory = this.eventHistory.slice(-this.maxHistorySize);
}
}
// ===================
// Convenience Methods
// ===================
/**
* Emits a cache hit event
*/
public emitCacheHit(url: string, bytes?: number): void {
this.emit(ServiceWorkerEvent.CACHE_HIT, { url, bytes });
}
/**
* Emits a cache miss event
*/
public emitCacheMiss(url: string): void {
this.emit(ServiceWorkerEvent.CACHE_MISS, { url });
}
/**
* Emits a cache error event
*/
public emitCacheError(url: string, error?: string): void {
this.emit(ServiceWorkerEvent.CACHE_ERROR, { url, error });
}
/**
* Emits a cache invalidation event
*/
public emitCacheInvalidate(url?: string): void {
if (url) {
this.emit(ServiceWorkerEvent.CACHE_INVALIDATE, { url });
} else {
this.emit(ServiceWorkerEvent.CACHE_INVALIDATE_ALL, {});
}
}
/**
* Emits an update available event
*/
public emitUpdateAvailable(oldVersion: string, newVersion: string, oldHash: string, newHash: string): void {
this.emit(ServiceWorkerEvent.UPDATE_AVAILABLE, { oldVersion, newVersion, oldHash, newHash });
}
/**
* Emits an update applied event
*/
public emitUpdateApplied(newVersion: string, newHash: string): void {
this.emit(ServiceWorkerEvent.UPDATE_APPLIED, { newVersion, newHash });
}
/**
* Emits a network online event
*/
public emitNetworkOnline(): void {
this.emit(ServiceWorkerEvent.NETWORK_ONLINE, {});
}
/**
* Emits a network offline event
*/
public emitNetworkOffline(): void {
this.emit(ServiceWorkerEvent.NETWORK_OFFLINE, {});
}
}
// Export singleton getter for convenience
export const getEventBus = (): EventBus => EventBus.getInstance();