60 lines
1.2 KiB
TypeScript
60 lines
1.2 KiB
TypeScript
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export type SseStreamEvent = {
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event: string;
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data: unknown;
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};
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type SseStreamListener = (event: SseStreamEvent) => void;
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export class ActiveSseStream {
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private readonly events: SseStreamEvent[] = [];
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private readonly listeners = new Set<SseStreamListener>();
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private completed = false;
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private resolveDone!: () => void;
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readonly done: Promise<void>;
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constructor() {
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this.done = new Promise((resolve) => {
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this.resolveDone = resolve;
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});
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}
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get isCompleted() {
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return this.completed;
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}
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emit(event: string, data: unknown) {
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if (this.completed) return;
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const entry = { event, data };
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this.events.push(entry);
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for (const listener of this.listeners) {
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listener(entry);
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}
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}
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complete(finalEvent?: SseStreamEvent) {
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if (this.completed) return;
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if (finalEvent) {
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this.emit(finalEvent.event, finalEvent.data);
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}
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this.completed = true;
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this.listeners.clear();
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this.resolveDone();
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}
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subscribe(listener: SseStreamListener) {
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for (const event of this.events) {
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listener(event);
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}
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if (this.completed) {
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return () => {};
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}
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this.listeners.add(listener);
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return () => {
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this.listeners.delete(listener);
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};
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}
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}
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