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import { delay } from "awaiting";
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import { getLogger } from "@cocalc/conat/client";
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import { type Role } from "./util";
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const logger = getLogger("socket:keepalive");
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export function keepAlive(opts: {
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  role: Role;
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  ping: () => Promise<any>;
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  disconnect: () => void;
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  keepAlive: number;
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}) {
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  return new KeepAlive(opts.ping, opts.disconnect, opts.keepAlive, opts.role);
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}
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export class KeepAlive {
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  private last: number = Date.now();
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  private state: "ready" | "closed" = "ready";
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  constructor(
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    private ping: () => Promise<any>,
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    private disconnect: () => void,
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    private keepAlive: number,
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    private role: Role,
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  ) {
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    this.run();
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  }
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  private run = async () => {
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    while (this.state == "ready") {
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      try {
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        logger.silly(this.role, "keepalive -- sending ping");
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        await this.ping?.();
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      } catch (err) {
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        logger.silly(this.role, "keepalive -- ping failed -- disconnecting");
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        this.disconnect?.();
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        this.close();
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        return;
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      }
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      this.last = Date.now();
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      if (this.state == ("closed" as any)) {
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        return;
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      }
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      await delay(this.keepAlive - (Date.now() - this.last));
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    }
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  };
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  // call this when any data is received, which defers having to waste resources on
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  // sending a ping
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  recv = () => {
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    this.last = Date.now();
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  };
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  close = () => {
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    this.state = "closed";
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    // @ts-ignore
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    delete this.last;
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    // @ts-ignore
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    delete this.ping;
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    // @ts-ignore
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    delete this.disconnect;
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  };
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}
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