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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// Copyright Joyent and Node contributors. All rights reserved. MIT license.// deno-lint-ignore-file
import EE from "../../events.ts";
function Stream(opts) {  EE.call(this, opts);}Object.setPrototypeOf(Stream.prototype, EE.prototype);Object.setPrototypeOf(Stream, EE);
Stream.prototype.pipe = function (dest, options) {  // deno-lint-ignore no-this-alias  const source = this;
  function ondata(chunk) {    if (dest.writable && dest.write(chunk) === false && source.pause) {      source.pause();    }  }
  source.on("data", ondata);
  function ondrain() {    if (source.readable && source.resume) {      source.resume();    }  }
  dest.on("drain", ondrain);
  // If the 'end' option is not supplied, dest.end() will be called when  // source gets the 'end' or 'close' events.  Only dest.end() once.  if (!dest._isStdio && (!options || options.end !== false)) {    source.on("end", onend);    source.on("close", onclose);  }
  let didOnEnd = false;  function onend() {    if (didOnEnd) return;    didOnEnd = true;
    dest.end();  }
  function onclose() {    if (didOnEnd) return;    didOnEnd = true;
    if (typeof dest.destroy === "function") dest.destroy();  }
  // Don't leave dangling pipes when there are errors.  function onerror(er) {    cleanup();    if (EE.listenerCount(this, "error") === 0) {      this.emit("error", er);    }  }
  prependListener(source, "error", onerror);  prependListener(dest, "error", onerror);
  // Remove all the event listeners that were added.  function cleanup() {    source.removeListener("data", ondata);    dest.removeListener("drain", ondrain);
    source.removeListener("end", onend);    source.removeListener("close", onclose);
    source.removeListener("error", onerror);    dest.removeListener("error", onerror);
    source.removeListener("end", cleanup);    source.removeListener("close", cleanup);
    dest.removeListener("close", cleanup);  }
  source.on("end", cleanup);  source.on("close", cleanup);
  dest.on("close", cleanup);  dest.emit("pipe", source);
  // Allow for unix-like usage: A.pipe(B).pipe(C)  return dest;};
function prependListener(emitter, event, fn) {  // Sadly this is not cacheable as some libraries bundle their own  // event emitter implementation with them.  if (typeof emitter.prependListener === "function") {    return emitter.prependListener(event, fn);  }
  // This is a hack to make sure that our error handler is attached before any  // userland ones.  NEVER DO THIS. This is here only because this code needs  // to continue to work with older versions of Node.js that do not include  // the prependListener() method. The goal is to eventually remove this hack.  if (!emitter._events || !emitter._events[event]) {    emitter.on(event, fn);  } else if (Array.isArray(emitter._events[event])) {    emitter._events[event].unshift(fn);  } else {    emitter._events[event] = [fn, emitter._events[event]];  }}
export { prependListener, Stream };