magnetar/fe_calckey/frontend/calckey-js/src/streaming.ts

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import { EventEmitter } from "eventemitter3";
import ReconnectingWebsocket from "reconnecting-websocket";
import { BroadcastEvents, Channels } from "./streaming.types";
function autobind(instance: any): void {
const prototype = Object.getPrototypeOf(instance);
const propertyNames = Object.getOwnPropertyNames(prototype);
for (const key of propertyNames) {
const descriptor = Object.getOwnPropertyDescriptor(prototype, key);
if (typeof descriptor?.value === "function" && key !== "constructor") {
Object.defineProperty(instance, key, {
value: instance[key].bind(instance),
enumerable: descriptor.enumerable,
configurable: descriptor.configurable,
writable: descriptor.writable,
});
}
}
}
export function urlQuery(
obj: Record<string, string | number | boolean | undefined>,
): string {
const params = Object.entries(obj)
.filter(([, v]) => (Array.isArray(v) ? v.length : v !== undefined))
// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
.reduce(
(a, [k, v]) => ((a[k] = v!), a),
{} as Record<string, string | number | boolean>,
);
return Object.entries(params)
.map((e) => `${e[0]}=${encodeURIComponent(e[1])}`)
.join("&");
}
type AnyOf<T extends Record<any, any>> = T[keyof T];
type StreamEvents = {
_connected_: void;
_disconnected_: void;
} & BroadcastEvents;
/**
* Misskey stream connection
*/
export default class Stream extends EventEmitter<StreamEvents> {
private stream: ReconnectingWebsocket;
public state: "initializing" | "reconnecting" | "connected" = "initializing";
private sharedConnectionPools: Pool[] = [];
private sharedConnections: SharedConnection[] = [];
private nonSharedConnections: NonSharedConnection[] = [];
private idCounter = 0;
constructor(
origin: string,
user: { token: string } | null,
options?: {
WebSocket?: any;
},
) {
super();
autobind(this);
options = options || {};
const query = urlQuery({
i: user?.token,
// To prevent cache of an HTML such as error screen
_t: Date.now(),
});
const wsOrigin = origin
.replace("http://", "ws://")
.replace("https://", "wss://");
this.stream = new ReconnectingWebsocket(
`${wsOrigin}/streaming?${query}`,
"",
{
minReconnectionDelay: 1, // https://github.com/pladaria/reconnecting-websocket/issues/91
WebSocket: options.WebSocket,
},
);
this.stream.addEventListener("open", this.onOpen);
this.stream.addEventListener("close", this.onClose);
this.stream.addEventListener("message", this.onMessage);
}
private genId(): string {
return (++this.idCounter).toString();
}
public useChannel<C extends keyof Channels>(
channel: C,
params?: Channels[C]["params"],
name?: string,
): Connection<Channels[C]> {
if (params) {
return this.connectToChannel(channel, params);
} else {
return this.useSharedConnection(channel, name);
}
}
private useSharedConnection<C extends keyof Channels>(
channel: C,
name?: string,
): SharedConnection<Channels[C]> {
let pool = this.sharedConnectionPools.find((p) => p.channel === channel);
if (pool == null) {
pool = new Pool(this, channel, this.genId());
this.sharedConnectionPools.push(pool);
}
const connection = new SharedConnection(this, channel, pool, name);
this.sharedConnections.push(connection);
return connection;
}
public removeSharedConnection(connection: SharedConnection): void {
this.sharedConnections = this.sharedConnections.filter(
(c) => c !== connection,
);
}
public removeSharedConnectionPool(pool: Pool): void {
this.sharedConnectionPools = this.sharedConnectionPools.filter(
(p) => p !== pool,
);
}
private connectToChannel<C extends keyof Channels>(
channel: C,
params: Channels[C]["params"],
): NonSharedConnection<Channels[C]> {
const connection = new NonSharedConnection(
this,
channel,
this.genId(),
params,
);
this.nonSharedConnections.push(connection);
return connection;
}
public disconnectToChannel(connection: NonSharedConnection): void {
this.nonSharedConnections = this.nonSharedConnections.filter(
(c) => c !== connection,
);
}
/**
* Callback of when open connection
*/
private onOpen(): void {
const isReconnect = this.state === "reconnecting";
this.state = "connected";
this.emit("_connected_");
// チャンネル再接続
if (isReconnect) {
for (const p of this.sharedConnectionPools) p.connect();
for (const c of this.nonSharedConnections) c.connect();
}
}
/**
* Callback of when close connection
*/
private onClose(): void {
if (this.state === "connected") {
this.state = "reconnecting";
this.emit("_disconnected_");
}
}
/**
* Callback of when received a message from connection
*/
private onMessage(message: { data: string }): void {
const { type, body } = JSON.parse(message.data);
if (type === "channel") {
const id = body.id;
let connections: Connection[];
connections = this.sharedConnections.filter((c) => c.id === id);
if (connections.length === 0) {
const found = this.nonSharedConnections.find((c) => c.id === id);
if (found) {
connections = [found];
}
}
for (const c of connections) {
c.emit(body.type, body.body);
c.inCount++;
}
} else {
this.emit(type, body);
}
}
/**
* Send a message to connection
*/
public send(typeOrPayload: any, payload?: any): void {
const data =
payload === undefined
? typeOrPayload
: {
type: typeOrPayload,
body: payload,
};
this.stream.send(JSON.stringify(data));
}
/**
* Close this connection
*/
public close(): void {
this.stream.close();
}
}
// TODO: これらのクラスを Stream クラスの内部クラスにすれば余計なメンバをpublicにしないで済むかも
// もしくは @internal を使う? https://www.typescriptlang.org/tsconfig#stripInternal
class Pool {
public channel: string;
public id: string;
protected stream: Stream;
public users = 0;
private disposeTimerId: any;
private isConnected = false;
constructor(stream: Stream, channel: string, id: string) {
this.channel = channel;
this.stream = stream;
this.id = id;
this.stream.on("_disconnected_", this.onStreamDisconnected);
}
private onStreamDisconnected(): void {
this.isConnected = false;
}
public inc(): void {
if (this.users === 0 && !this.isConnected) {
this.connect();
}
this.users++;
// タイマー解除
if (this.disposeTimerId) {
clearTimeout(this.disposeTimerId);
this.disposeTimerId = null;
}
}
public dec(): void {
this.users--;
// そのコネクションの利用者が誰もいなくなったら
if (this.users === 0) {
// また直ぐに再利用される可能性があるので、一定時間待ち、
// 新たな利用者が現れなければコネクションを切断する
this.disposeTimerId = setTimeout(() => {
this.disconnect();
}, 3000);
}
}
public connect(): void {
if (this.isConnected) return;
this.isConnected = true;
this.stream.send("connect", {
channel: this.channel,
id: this.id,
});
}
private disconnect(): void {
this.stream.off("_disconnected_", this.onStreamDisconnected);
this.stream.send("disconnect", { id: this.id });
this.stream.removeSharedConnectionPool(this);
}
}
export abstract class Connection<
Channel extends AnyOf<Channels> = any,
> extends EventEmitter<Channel["events"]> {
public channel: string;
protected stream: Stream;
public abstract id: string;
public name?: string; // for debug
public inCount = 0; // for debug
public outCount = 0; // for debug
constructor(stream: Stream, channel: string, name?: string) {
super();
this.stream = stream;
this.channel = channel;
this.name = name;
}
public send<T extends keyof Channel["receives"]>(
type: T,
body: Channel["receives"][T],
): void {
this.stream.send("ch", {
id: this.id,
type: type,
body: body,
});
this.outCount++;
}
public abstract dispose(): void;
}
class SharedConnection<
Channel extends AnyOf<Channels> = any,
> extends Connection<Channel> {
private pool: Pool;
public get id(): string {
return this.pool.id;
}
constructor(stream: Stream, channel: string, pool: Pool, name?: string) {
super(stream, channel, name);
this.pool = pool;
this.pool.inc();
}
public dispose(): void {
this.pool.dec();
this.removeAllListeners();
this.stream.removeSharedConnection(this);
}
}
class NonSharedConnection<
Channel extends AnyOf<Channels> = any,
> extends Connection<Channel> {
public id: string;
protected params: Channel["params"];
constructor(
stream: Stream,
channel: string,
id: string,
params: Channel["params"],
) {
super(stream, channel);
this.params = params;
this.id = id;
this.connect();
}
public connect(): void {
this.stream.send("connect", {
channel: this.channel,
id: this.id,
params: this.params,
});
}
public dispose(): void {
this.removeAllListeners();
this.stream.send("disconnect", { id: this.id });
this.stream.disconnectToChannel(this);
}
}