mirror of
https://github.com/swc-project/swc.git
synced 2024-12-23 05:32:09 +03:00
260 lines
7.6 KiB
TypeScript
260 lines
7.6 KiB
TypeScript
// Loaded from https://deno.land/x/oak/server_sent_event.ts
|
|
|
|
|
|
// Copyright 2018-2021 the oak authors. All rights reserved. MIT license.
|
|
|
|
import type { Application } from "./application.ts";
|
|
import { assert, BufWriter } from "./deps.ts";
|
|
import type { ServerRequest } from "./types.d.ts";
|
|
|
|
const encoder = new TextEncoder();
|
|
|
|
export interface ServerSentEventInit extends EventInit {
|
|
/** An optional `id` which will be sent with the event and exposed in the
|
|
* client `EventSource`. */
|
|
id?: number;
|
|
|
|
/** The replacer is passed to `JSON.stringify` when converting the `data`
|
|
* property to a JSON string. */
|
|
replacer?:
|
|
| (string | number)[]
|
|
// deno-lint-ignore no-explicit-any
|
|
| ((this: any, key: string, value: any) => any);
|
|
|
|
/** Space is passed to `JSON.stringify` when converting the `data` property
|
|
* to a JSON string. */
|
|
space?: string | number;
|
|
}
|
|
|
|
export interface ServerSentEventTargetOptions {
|
|
/** Additional headers to send to the client during startup. These headers
|
|
* will overwrite any of the default headers if the key is duplicated. */
|
|
headers?: Headers;
|
|
}
|
|
|
|
class CloseEvent extends Event {
|
|
constructor(eventInit: EventInit) {
|
|
super("close", eventInit);
|
|
}
|
|
}
|
|
|
|
/** An event which contains information which will be sent to the remote
|
|
* connection and be made available in an `EventSource` as an event. */
|
|
export class ServerSentEvent extends Event {
|
|
#data: string;
|
|
#id?: number;
|
|
#type: string;
|
|
|
|
constructor(
|
|
type: string,
|
|
// deno-lint-ignore no-explicit-any
|
|
data: any,
|
|
{ replacer, space, ...eventInit }: ServerSentEventInit = {},
|
|
) {
|
|
super(type, eventInit);
|
|
this.#type = type;
|
|
try {
|
|
this.#data = typeof data === "string"
|
|
? data
|
|
: JSON.stringify(data, replacer as (string | number)[], space);
|
|
} catch (e) {
|
|
assert(e instanceof Error);
|
|
throw new TypeError(
|
|
`data could not be coerced into a serialized string.\n ${e.message}`,
|
|
);
|
|
}
|
|
const { id } = eventInit;
|
|
this.#id = id;
|
|
}
|
|
|
|
/** The data associated with the event, which will be sent to the client and
|
|
* be made available in the `EventSource`. */
|
|
get data(): string {
|
|
return this.#data;
|
|
}
|
|
|
|
/** The optional ID associated with the event that will be sent to the client
|
|
* and be made available in the `EventSource`. */
|
|
get id(): number | undefined {
|
|
return this.#id;
|
|
}
|
|
|
|
toString(): string {
|
|
const data = `data: ${this.#data.split("\n").join("\ndata: ")}\n`;
|
|
return `${this.#type === "__message" ? "" : `event: ${this.#type}\n`}${
|
|
this.#id ? `id: ${String(this.#id)}\n` : ""
|
|
}${data}\n`;
|
|
}
|
|
}
|
|
|
|
const response = `HTTP/1.1 200 OK\n`;
|
|
|
|
const responseHeaders = new Headers(
|
|
[
|
|
["Connection", "Keep-Alive"],
|
|
["Content-Type", "text/event-stream"],
|
|
["Cache-Control", "no-cache"],
|
|
["Keep-Alive", `timeout=${Number.MAX_SAFE_INTEGER}`],
|
|
],
|
|
);
|
|
|
|
export class ServerSentEventTarget extends EventTarget {
|
|
#app: Application;
|
|
#closed = false;
|
|
#prev = Promise.resolve();
|
|
#ready: Promise<void> | true;
|
|
#serverRequest: ServerRequest;
|
|
#writer: BufWriter;
|
|
|
|
#send = async (payload: string, prev: Promise<void>): Promise<void> => {
|
|
if (this.#closed) {
|
|
return;
|
|
}
|
|
if (this.#ready !== true) {
|
|
await this.#ready;
|
|
this.#ready = true;
|
|
}
|
|
try {
|
|
await prev;
|
|
await this.#writer.write(encoder.encode(payload));
|
|
await this.#writer.flush();
|
|
} catch (error) {
|
|
this.dispatchEvent(new CloseEvent({ cancelable: false }));
|
|
const errorEvent = new ErrorEvent("error", { error });
|
|
this.dispatchEvent(errorEvent);
|
|
this.#app.dispatchEvent(errorEvent);
|
|
}
|
|
};
|
|
|
|
#setup = async (overrideHeaders?: Headers): Promise<void> => {
|
|
const headers = new Headers(responseHeaders);
|
|
if (overrideHeaders) {
|
|
for (const [key, value] of overrideHeaders) {
|
|
headers.set(key, value);
|
|
}
|
|
}
|
|
let payload = response;
|
|
for (const [key, value] of headers) {
|
|
payload += `${key}: ${value}\n`;
|
|
}
|
|
payload += `\n`;
|
|
try {
|
|
await this.#writer.write(encoder.encode(payload));
|
|
await this.#writer.flush();
|
|
} catch (error) {
|
|
this.dispatchEvent(new CloseEvent({ cancelable: false }));
|
|
const errorEvent = new ErrorEvent("error", { error });
|
|
this.dispatchEvent(errorEvent);
|
|
this.#app.dispatchEvent(errorEvent);
|
|
throw error;
|
|
}
|
|
};
|
|
|
|
/** Is set to `true` if events cannot be sent to the remote connection.
|
|
* Otherwise it is set to `false`.
|
|
*
|
|
* *Note*: This flag is lazily set, and might not reflect a closed state until
|
|
* another event, comment or message is attempted to be processed. */
|
|
get closed(): boolean {
|
|
return this.#closed;
|
|
}
|
|
|
|
constructor(
|
|
app: Application,
|
|
serverRequest: ServerRequest,
|
|
{ headers }: ServerSentEventTargetOptions = {},
|
|
) {
|
|
super();
|
|
this.#app = app;
|
|
this.#serverRequest = serverRequest;
|
|
this.#writer = this.#serverRequest.w;
|
|
this.addEventListener("close", () => {
|
|
this.#closed = true;
|
|
try {
|
|
this.#serverRequest.conn.close();
|
|
} catch (error) {
|
|
if (!(error instanceof Deno.errors.BadResource)) {
|
|
const errorEvent = new ErrorEvent("error", { error });
|
|
this.dispatchEvent(errorEvent);
|
|
this.#app.dispatchEvent(errorEvent);
|
|
}
|
|
}
|
|
});
|
|
this.#ready = this.#setup(headers);
|
|
}
|
|
|
|
/** Stop sending events to the remote connection and close the connection. */
|
|
async close(): Promise<void> {
|
|
if (this.#ready !== true) {
|
|
await this.#ready;
|
|
}
|
|
await this.#prev;
|
|
this.dispatchEvent(new CloseEvent({ cancelable: false }));
|
|
}
|
|
|
|
/** Send a comment to the remote connection. Comments are not exposed to the
|
|
* client `EventSource` but are used for diagnostics and helping ensure a
|
|
* connection is kept alive.
|
|
*
|
|
* ```ts
|
|
* import { Application } from "https://deno.land/x/oak/mod.ts";
|
|
*
|
|
* const app = new Application();
|
|
*
|
|
* app.use((ctx) => {
|
|
* const sse = ctx.getSSETarget();
|
|
* sse.dispatchComment("this is a comment");
|
|
* });
|
|
*
|
|
* await app.listen();
|
|
* ```
|
|
*/
|
|
dispatchComment(comment: string): boolean {
|
|
this.#prev = this.#send(
|
|
`: ${comment.split("\n").join("\n: ")}\n\n`,
|
|
this.#prev,
|
|
);
|
|
return true;
|
|
}
|
|
|
|
/** Dispatch a message to the client. This message will contain `data: ` only
|
|
* and be available on the client `EventSource` on the `onmessage` or an event
|
|
* listener of type `"message"`. */
|
|
// deno-lint-ignore no-explicit-any
|
|
dispatchMessage(data: any): boolean {
|
|
const event = new ServerSentEvent("__message", data);
|
|
return this.dispatchEvent(event);
|
|
}
|
|
|
|
/** Dispatch a server sent event to the client. The event `type` will be
|
|
* sent as `event: ` to the client which will be raised as a `MessageEvent`
|
|
* on the `EventSource` in the client.
|
|
*
|
|
* Any local event handlers will be dispatched to first, and if the event
|
|
* is cancelled, it will not be sent to the client.
|
|
*
|
|
* ```ts
|
|
* import { Application, ServerSentEvent } from "https://deno.land/x/oak/mod.ts";
|
|
*
|
|
* const app = new Application();
|
|
*
|
|
* app.use((ctx) => {
|
|
* const sse = ctx.getSSETarget();
|
|
* const evt = new ServerSentEvent("ping", "hello");
|
|
* sse.dispatchEvent(evt);
|
|
* });
|
|
*
|
|
* await app.listen();
|
|
* ```
|
|
*/
|
|
dispatchEvent(event: ServerSentEvent): boolean;
|
|
dispatchEvent(event: CloseEvent | ErrorEvent): boolean;
|
|
dispatchEvent(event: ServerSentEvent | CloseEvent | ErrorEvent): boolean {
|
|
const dispatched = super.dispatchEvent(event);
|
|
if (dispatched && event instanceof ServerSentEvent) {
|
|
this.#prev = this.#send(String(event), this.#prev);
|
|
}
|
|
return dispatched;
|
|
}
|
|
}
|