http2.Http2Session

interface Http2Session

• readonly alpnProtocol?: string

  Value will be undefined if the Http2Session is not yet connected to a socket, h2c if the Http2Session is not connected to a TLSSocket, or will return the value of the connected TLSSocket's own alpnProtocol property.

• readonly closed: boolean

  Will be true if this Http2Session instance has been closed, otherwise false.

• readonly connecting: boolean

  Will be true if this Http2Session instance is still connecting, will be set to false before emitting connect event and/or calling the http2.connect callback.

• readonly destroyed: boolean

  Will be true if this Http2Session instance has been destroyed and must no longer be used, otherwise false.

• readonly encrypted?: boolean

  Value is undefined if the Http2Session session socket has not yet been connected, true if the Http2Session is connected with a TLSSocket, and false if the Http2Session is connected to any other kind of socket or stream.

• readonly localSettings: Settings

  A prototype-less object describing the current local settings of this Http2Session. The local settings are local to thisHttp2Session instance.

• readonly originSet?: string[]

  If the Http2Session is connected to a TLSSocket, the originSet property will return an Array of origins for which the Http2Session may be considered authoritative.

  The originSet property is only available when using a secure TLS connection.

• readonly pendingSettingsAck: boolean

  Indicates whether the Http2Session is currently waiting for acknowledgment of a sent SETTINGS frame. Will be true after calling the http2session.settings() method. Will be false once all sent SETTINGS frames have been acknowledged.

• readonly remoteSettings: Settings

  A prototype-less object describing the current remote settings of thisHttp2Session. The remote settings are set by the connected HTTP/2 peer.

• readonly socket: Socket | TLSSocket

  Returns a Proxy object that acts as a net.Socket (or tls.TLSSocket) but limits available methods to ones safe to use with HTTP/2.

  destroy, emit, end, pause, read, resume, and write will throw an error with code ERR_HTTP2_NO_SOCKET_MANIPULATION. See Http2Session and Sockets for more information.

  setTimeout method will be called on this Http2Session.

  All other interactions will be routed directly to the socket.

• readonly state: SessionState

  Provides miscellaneous information about the current state of theHttp2Session.

  An object describing the current status of this Http2Session.

• readonly type: number

  The http2session.type will be equal to http2.constants.NGHTTP2_SESSION_SERVER if this Http2Session instance is a server, and http2.constants.NGHTTP2_SESSION_CLIENT if the instance is a client.

• [events.captureRejectionSymbol](

  error: Error,

  event: string | symbol,

  ...args: any[]

  ): void;

  The Symbol.for('nodejs.rejection') method is called in case a promise rejection happens when emitting an event and captureRejections is enabled on the emitter. It is possible to use events.captureRejectionSymbol in place of Symbol.for('nodejs.rejection').

  import { EventEmitter, captureRejectionSymbol } from 'node:events';
  
  class MyClass extends EventEmitter {
    constructor() {
      super({ captureRejections: true });
    }
  
    [captureRejectionSymbol](err, event, ...args) {
      console.log('rejection happened for', event, 'with', err, ...args);
      this.destroy(err);
    }
  
    destroy(err) {
      // Tear the resource down here.
    }
  }
• addListener<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Alias for emitter.on(eventName, listener).

  addListener(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Alias for emitter.on(eventName, listener).
• close(

  callback?: () => void

  ): void;

  Gracefully closes the Http2Session, allowing any existing streams to complete on their own and preventing new Http2Stream instances from being created. Once closed, http2session.destroy()might be called if there are no open Http2Stream instances.

  If specified, the callback function is registered as a handler for the'close' event.
• destroy(

  error?: Error,

  code?: number

  ): void;

  Immediately terminates the Http2Session and the associated net.Socket or tls.TLSSocket.

  Once destroyed, the Http2Session will emit the 'close' event. If error is not undefined, an 'error' event will be emitted immediately before the 'close' event.

  If there are any remaining open Http2Streams associated with the Http2Session, those will also be destroyed.

  @param error

  An Error object if the Http2Session is being destroyed due to an error.

  @param code

  The HTTP/2 error code to send in the final GOAWAY frame. If unspecified, and error is not undefined, the default is INTERNAL_ERROR, otherwise defaults to NO_ERROR.

• emit<E extends keyof Http2SessionEventMap>(

  eventName: E,

  ...args: Http2SessionEventMap[E]

  ): boolean;

  Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

  Returns true if the event had listeners, false otherwise.

  import { EventEmitter } from 'node:events';
  const myEmitter = new EventEmitter();
  
  // First listener
  myEmitter.on('event', function firstListener() {
    console.log('Helloooo! first listener');
  });
  // Second listener
  myEmitter.on('event', function secondListener(arg1, arg2) {
    console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
  });
  // Third listener
  myEmitter.on('event', function thirdListener(...args) {
    const parameters = args.join(', ');
    console.log(`event with parameters ${parameters} in third listener`);
  });
  
  console.log(myEmitter.listeners('event'));
  
  myEmitter.emit('event', 1, 2, 3, 4, 5);
  
  // Prints:
  // [
  //   [Function: firstListener],
  //   [Function: secondListener],
  //   [Function: thirdListener]
  // ]
  // Helloooo! first listener
  // event with parameters 1, 2 in second listener
  // event with parameters 1, 2, 3, 4, 5 in third listener

  emit(

  eventName: string | symbol,

  ...args: any[]

  ): boolean;

  Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.

  Returns true if the event had listeners, false otherwise.

  import { EventEmitter } from 'node:events';
  const myEmitter = new EventEmitter();
  
  // First listener
  myEmitter.on('event', function firstListener() {
    console.log('Helloooo! first listener');
  });
  // Second listener
  myEmitter.on('event', function secondListener(arg1, arg2) {
    console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
  });
  // Third listener
  myEmitter.on('event', function thirdListener(...args) {
    const parameters = args.join(', ');
    console.log(`event with parameters ${parameters} in third listener`);
  });
  
  console.log(myEmitter.listeners('event'));
  
  myEmitter.emit('event', 1, 2, 3, 4, 5);
  
  // Prints:
  // [
  //   [Function: firstListener],
  //   [Function: secondListener],
  //   [Function: thirdListener]
  // ]
  // Helloooo! first listener
  // event with parameters 1, 2 in second listener
  // event with parameters 1, 2, 3, 4, 5 in third listener
• eventNames(): string | symbol[];

  Returns an array listing the events for which the emitter has registered listeners.

  import { EventEmitter } from 'node:events';
  
  const myEE = new EventEmitter();
  myEE.on('foo', () => {});
  myEE.on('bar', () => {});
  
  const sym = Symbol('symbol');
  myEE.on(sym, () => {});
  
  console.log(myEE.eventNames());
  // Prints: [ 'foo', 'bar', Symbol(symbol) ]

• getMaxListeners(): number;

  Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to events.defaultMaxListeners.

• goaway(

  code?: number,

  lastStreamID?: number,

  opaqueData?: ArrayBufferView<ArrayBufferLike>

  ): void;

  Transmits a GOAWAY frame to the connected peer without shutting down theHttp2Session.

  @param code

  An HTTP/2 error code

  @param lastStreamID

  The numeric ID of the last processed Http2Stream

  @param opaqueData

  A TypedArray or DataView instance containing additional data to be carried within the GOAWAY frame.

• listenerCount<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener?: (...args: Http2SessionEventMap[E]) => void

  ): number;

  Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

  @param eventName

  The name of the event being listened for

  @param listener

  The event handler function

  listenerCount(

  eventName: string | symbol,

  listener?: (...args: any[]) => void

  ): number;

  Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

  @param eventName

  The name of the event being listened for

  @param listener

  The event handler function

• listeners<E extends keyof Http2SessionEventMap>(

  eventName: E

  ): (...args: Http2SessionEventMap[E]) => void[];

  Returns a copy of the array of listeners for the event named eventName.

  server.on('connection', (stream) => {
    console.log('someone connected!');
  });
  console.log(util.inspect(server.listeners('connection')));
  // Prints: [ [Function] ]

  listeners(

  eventName: string | symbol

  ): (...args: any[]) => void[];

  Returns a copy of the array of listeners for the event named eventName.

  server.on('connection', (stream) => {
    console.log('someone connected!');
  });
  console.log(util.inspect(server.listeners('connection')));
  // Prints: [ [Function] ]
• off<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Alias for emitter.removeListener().

  off(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Alias for emitter.removeListener().
• on<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

  server.on('connection', (stream) => {
    console.log('someone connected!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

  import { EventEmitter } from 'node:events';
  const myEE = new EventEmitter();
  myEE.on('foo', () => console.log('a'));
  myEE.prependListener('foo', () => console.log('b'));
  myEE.emit('foo');
  // Prints:
  //   b
  //   a

  @param eventName

  The name of the event.

  @param listener

  The callback function

  on(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

  server.on('connection', (stream) => {
    console.log('someone connected!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  By default, event listeners are invoked in the order they are added. The emitter.prependListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

  import { EventEmitter } from 'node:events';
  const myEE = new EventEmitter();
  myEE.on('foo', () => console.log('a'));
  myEE.prependListener('foo', () => console.log('b'));
  myEE.emit('foo');
  // Prints:
  //   b
  //   a

  @param eventName

  The name of the event.

  @param listener

  The callback function

• once<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

  server.once('connection', (stream) => {
    console.log('Ah, we have our first user!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

  import { EventEmitter } from 'node:events';
  const myEE = new EventEmitter();
  myEE.once('foo', () => console.log('a'));
  myEE.prependOnceListener('foo', () => console.log('b'));
  myEE.emit('foo');
  // Prints:
  //   b
  //   a

  @param eventName

  The name of the event.

  @param listener

  The callback function

  once(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

  server.once('connection', (stream) => {
    console.log('Ah, we have our first user!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

  import { EventEmitter } from 'node:events';
  const myEE = new EventEmitter();
  myEE.once('foo', () => console.log('a'));
  myEE.prependOnceListener('foo', () => console.log('b'));
  myEE.emit('foo');
  // Prints:
  //   b
  //   a

  @param eventName

  The name of the event.

  @param listener

  The callback function

• ping(

  callback: (err: null | Error, duration: number, payload: NonSharedBuffer) => void

  ): boolean;

  Sends a PING frame to the connected HTTP/2 peer. A callback function must be provided. The method will return true if the PING was sent, false otherwise.

  The maximum number of outstanding (unacknowledged) pings is determined by the maxOutstandingPings configuration option. The default maximum is 10.

  If provided, the payload must be a Buffer, TypedArray, or DataView containing 8 bytes of data that will be transmitted with the PING and returned with the ping acknowledgment.

  The callback will be invoked with three arguments: an error argument that will be null if the PING was successfully acknowledged, a duration argument that reports the number of milliseconds elapsed since the ping was sent and the acknowledgment was received, and a Buffer containing the 8-byte PING payload.

  session.ping(Buffer.from('abcdefgh'), (err, duration, payload) => {
    if (!err) {
      console.log(`Ping acknowledged in ${duration} milliseconds`);
      console.log(`With payload '${payload.toString()}'`);
    }
  });

  If the payload argument is not specified, the default payload will be the 64-bit timestamp (little endian) marking the start of the PING duration.

  ping(

  payload: ArrayBufferView,

  callback: (err: null | Error, duration: number, payload: NonSharedBuffer) => void

  ): boolean;
• prependListener<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

  server.prependListener('connection', (stream) => {
    console.log('someone connected!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  @param eventName

  The name of the event.

  @param listener

  The callback function

  prependListener(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

  server.prependListener('connection', (stream) => {
    console.log('someone connected!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  @param eventName

  The name of the event.

  @param listener

  The callback function

• prependOnceListener<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

  server.prependOnceListener('connection', (stream) => {
    console.log('Ah, we have our first user!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  @param eventName

  The name of the event.

  @param listener

  The callback function

  prependOnceListener(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Adds a one-time listener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

  server.prependOnceListener('connection', (stream) => {
    console.log('Ah, we have our first user!');
  });

  Returns a reference to the EventEmitter, so that calls can be chained.

  @param eventName

  The name of the event.

  @param listener

  The callback function

• rawListeners<E extends keyof Http2SessionEventMap>(

  eventName: E

  ): (...args: Http2SessionEventMap[E]) => void[];

  Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

  import { EventEmitter } from 'node:events';
  const emitter = new EventEmitter();
  emitter.once('log', () => console.log('log once'));
  
  // Returns a new Array with a function `onceWrapper` which has a property
  // `listener` which contains the original listener bound above
  const listeners = emitter.rawListeners('log');
  const logFnWrapper = listeners[0];
  
  // Logs "log once" to the console and does not unbind the `once` event
  logFnWrapper.listener();
  
  // Logs "log once" to the console and removes the listener
  logFnWrapper();
  
  emitter.on('log', () => console.log('log persistently'));
  // Will return a new Array with a single function bound by `.on()` above
  const newListeners = emitter.rawListeners('log');
  
  // Logs "log persistently" twice
  newListeners[0]();
  emitter.emit('log');

  rawListeners(

  eventName: string | symbol

  ): (...args: any[]) => void[];

  Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

  import { EventEmitter } from 'node:events';
  const emitter = new EventEmitter();
  emitter.once('log', () => console.log('log once'));
  
  // Returns a new Array with a function `onceWrapper` which has a property
  // `listener` which contains the original listener bound above
  const listeners = emitter.rawListeners('log');
  const logFnWrapper = listeners[0];
  
  // Logs "log once" to the console and does not unbind the `once` event
  logFnWrapper.listener();
  
  // Logs "log once" to the console and removes the listener
  logFnWrapper();
  
  emitter.on('log', () => console.log('log persistently'));
  // Will return a new Array with a single function bound by `.on()` above
  const newListeners = emitter.rawListeners('log');
  
  // Logs "log persistently" twice
  newListeners[0]();
  emitter.emit('log');
• ref(): void;

  Calls ref() on this Http2Session instance's underlying net.Socket.

• removeAllListeners<E extends keyof Http2SessionEventMap>(

  eventName?: E

  ): this;

  Removes all listeners, or those of the specified eventName.

  It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

  Returns a reference to the EventEmitter, so that calls can be chained.

  removeAllListeners(

  eventName?: string | symbol

  ): this;

  Removes all listeners, or those of the specified eventName.

  It is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).

  Returns a reference to the EventEmitter, so that calls can be chained.
• removeListener<E extends keyof Http2SessionEventMap>(

  eventName: E,

  listener: (...args: Http2SessionEventMap[E]) => void

  ): this;

  Removes the specified listener from the listener array for the event named eventName.

  const callback = (stream) => {
    console.log('someone connected!');
  };
  server.on('connection', callback);
  // ...
  server.removeListener('connection', callback);

  removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

  Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

  import { EventEmitter } from 'node:events';
  class MyEmitter extends EventEmitter {}
  const myEmitter = new MyEmitter();
  
  const callbackA = () => {
    console.log('A');
    myEmitter.removeListener('event', callbackB);
  };
  
  const callbackB = () => {
    console.log('B');
  };
  
  myEmitter.on('event', callbackA);
  
  myEmitter.on('event', callbackB);
  
  // callbackA removes listener callbackB but it will still be called.
  // Internal listener array at time of emit [callbackA, callbackB]
  myEmitter.emit('event');
  // Prints:
  //   A
  //   B
  
  // callbackB is now removed.
  // Internal listener array [callbackA]
  myEmitter.emit('event');
  // Prints:
  //   A

  Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

  When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

  import { EventEmitter } from 'node:events';
  const ee = new EventEmitter();
  
  function pong() {
    console.log('pong');
  }
  
  ee.on('ping', pong);
  ee.once('ping', pong);
  ee.removeListener('ping', pong);
  
  ee.emit('ping');
  ee.emit('ping');

  Returns a reference to the EventEmitter, so that calls can be chained.

  removeListener(

  eventName: string | symbol,

  listener: (...args: any[]) => void

  ): this;

  Removes the specified listener from the listener array for the event named eventName.

  const callback = (stream) => {
    console.log('someone connected!');
  };
  server.on('connection', callback);
  // ...
  server.removeListener('connection', callback);

  removeListener() will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener() must be called multiple times to remove each instance.

  Once an event is emitted, all listeners attached to it at the time of emitting are called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events behave as expected.

  import { EventEmitter } from 'node:events';
  class MyEmitter extends EventEmitter {}
  const myEmitter = new MyEmitter();
  
  const callbackA = () => {
    console.log('A');
    myEmitter.removeListener('event', callbackB);
  };
  
  const callbackB = () => {
    console.log('B');
  };
  
  myEmitter.on('event', callbackA);
  
  myEmitter.on('event', callbackB);
  
  // callbackA removes listener callbackB but it will still be called.
  // Internal listener array at time of emit [callbackA, callbackB]
  myEmitter.emit('event');
  // Prints:
  //   A
  //   B
  
  // callbackB is now removed.
  // Internal listener array [callbackA]
  myEmitter.emit('event');
  // Prints:
  //   A

  Because listeners are managed using an internal array, calling this will change the position indexes of any listener registered after the listener being removed. This will not impact the order in which listeners are called, but it means that any copies of the listener array as returned by the emitter.listeners() method will need to be recreated.

  When a single function has been added as a handler multiple times for a single event (as in the example below), removeListener() will remove the most recently added instance. In the example the once('ping') listener is removed:

  import { EventEmitter } from 'node:events';
  const ee = new EventEmitter();
  
  function pong() {
    console.log('pong');
  }
  
  ee.on('ping', pong);
  ee.once('ping', pong);
  ee.removeListener('ping', pong);
  
  ee.emit('ping');
  ee.emit('ping');

  Returns a reference to the EventEmitter, so that calls can be chained.
• setLocalWindowSize(

  windowSize: number

  ): void;

  Sets the local endpoint's window size. The windowSize is the total window size to set, not the delta.

  import http2 from 'node:http2';
  
  const server = http2.createServer();
  const expectedWindowSize = 2 ** 20;
  server.on('connect', (session) => {
  
    // Set local window size to be 2 ** 20
    session.setLocalWindowSize(expectedWindowSize);
  });
• setMaxListeners(

  n: number

  ): this;

  By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

  Returns a reference to the EventEmitter, so that calls can be chained.
• setTimeout(

  msecs: number,

  callback?: () => void

  ): void;

  Used to set a callback function that is called when there is no activity on the Http2Session after msecs milliseconds. The given callback is registered as a listener on the 'timeout' event.
• settings(

  settings: Settings,

  callback?: (err: null | Error, settings: Settings, duration: number) => void

  ): void;

  Updates the current local settings for this Http2Session and sends a new SETTINGS frame to the connected HTTP/2 peer.

  Once called, the http2session.pendingSettingsAck property will be true while the session is waiting for the remote peer to acknowledge the new settings.

  The new settings will not become effective until the SETTINGS acknowledgment is received and the 'localSettings' event is emitted. It is possible to send multiple SETTINGS frames while acknowledgment is still pending.

  @param callback

  Callback that is called once the session is connected or right away if the session is already connected.

• unref(): void;

  Calls unref() on this Http2Sessioninstance's underlying net.Socket.