description

# RawDatagramSocket class abstract interface

An unbuffered interface to a UDP socket.

The raw datagram socket delivers a Stream of RawSocketEvents in the same chunks as the underlying operating system receives them.

Note that the event RawSocketEvent.readClosed will never be received as an UDP socket cannot be closed by a remote peer.

It is not the same as a POSIX raw socket.

    import 'dart:io';
    import 'dart:typed_data';

    void main() async {
      // Read the current time from an NTP server.
      final serverAddress = (await InternetAddress.lookup('pool.ntp.org')).first;
      final clientSocket = await RawDatagramSocket.bind(
          serverAddress.type == InternetAddressType.IPv6
              ? InternetAddress.anyIPv6
              : InternetAddress.anyIPv4,
          0);
      final ntpQuery = Uint8List(48);
      ntpQuery[0] = 0x23; // See RFC 5905 7.3

      clientSocket.listen((event) {
        switch (event) {
          case RawSocketEvent.read:
            final datagram = clientSocket.receive();
            // Parse `datagram.data`
            clientSocket.close();
            break;
          case RawSocketEvent.write:
            if (clientSocket.send(ntpQuery, serverAddress, 123) > 0) {
              clientSocket.writeEventsEnabled = false;
            }
            break;
          case RawSocketEvent.closed:
            break;
          default:
            throw "Unexpected event $event";
        }
      });
    }

Inheritance
  - Object
  - Stream<RawSocketEvent>
  - RawDatagramSocket

## Properties

address → InternetAddress
  The address used by this socket.
  no setter
broadcastEnabled ↔ bool
  Whether IPv4 broadcast is enabled.
  getter/setter pair
first → Future<RawSocketEvent>
  The first element of this stream.
  no setter inherited
hashCode → int
  The hash code for this object.
  no setter inherited
isBroadcast → bool
  Whether this stream is a broadcast stream.
  no setter inherited
isEmpty → Future<bool>
  Whether this stream contains any elements.
  no setter inherited
last → Future<RawSocketEvent>
  The last element of this stream.
  no setter inherited
length → Future<int>
  The number of elements in this stream.
  no setter inherited
multicastHops ↔ int
  The maximum network hops for multicast packages originating from this socket.
  getter/setter pair
multicastInterface ↔ NetworkInterface?
  The network interface used for outgoing multicast packages.
  getter/setter pair
multicastLoopback ↔ bool
  Whether multicast traffic is looped back to the host.
  getter/setter pair
port → int
  The port used by this socket.
  no setter
readEventsEnabled ↔ bool
  Whether the RawDatagramSocket should listen for RawSocketEvent.read events.
  getter/setter pair
runtimeType → Type
  A representation of the runtime type of the object.
  no setter inherited
single → Future<RawSocketEvent>
  The single element of this stream.
  no setter inherited
writeEventsEnabled ↔ bool
  Whether the RawDatagramSocket should listen for RawSocketEvent.write events.
  getter/setter pair

## Methods

any(bool test(RawSocketEvent element)) → Future<bool>
  Checks whether `test` accepts any element provided by this stream.
  inherited
asBroadcastStream({void onListen(StreamSubscription<RawSocketEvent> subscription)?, void onCancel(StreamSubscription<RawSocketEvent> subscription)?}) → Stream<RawSocketEvent>
  Returns a multi-subscription stream that produces the same events as this.
  inherited
asyncExpand<E>(Stream<E>? convert(RawSocketEvent event)) → Stream<E>
  Transforms each element into a sequence of asynchronous events.
  inherited
asyncMap<E>(FutureOr<E> convert(RawSocketEvent event)) → Stream<E>
  Creates a new stream with each data event of this stream asynchronously mapped to a new event.
  inherited
cast<R>() → Stream<R>
  Adapt this stream to be a `Stream<R>`.
  inherited
close() → void
  Closes the datagram socket.
contains(Object? needle) → Future<bool>
  Returns whether `needle` occurs in the elements provided by this stream.
  inherited
distinct([bool equals(RawSocketEvent previous, RawSocketEvent next)?]) → Stream<RawSocketEvent>
  Skips data events if they are equal to the previous data event.
  inherited
drain<E>([E? futureValue]) → Future<E>
  Discards all data on this stream, but signals when it is done or an error occurred.
  inherited
elementAt(int index) → Future<RawSocketEvent>
  Returns the value of the `index`th data event of this stream.
  inherited
every(bool test(RawSocketEvent element)) → Future<bool>
  Checks whether `test` accepts all elements provided by this stream.
  inherited
expand<S>(Iterable<S> convert(RawSocketEvent element)) → Stream<S>
  Transforms each element of this stream into a sequence of elements.
  inherited
firstWhere(bool test(RawSocketEvent element), {RawSocketEvent orElse()?}) → Future<RawSocketEvent>
  Finds the first element of this stream matching `test`.
  inherited
fold<S>(S initialValue, S combine(S previous, RawSocketEvent element)) → Future<S>
  Combines a sequence of values by repeatedly applying `combine`.
  inherited
forEach(void action(RawSocketEvent element)) → Future<void>
  Executes `action` on each element of this stream.
  inherited
getRawOption(RawSocketOption option) → Uint8List
  Reads low level information about the RawSocket.
handleError(Function onError, {bool test(dynamic error)?}) → Stream<RawSocketEvent>
  Creates a wrapper Stream that intercepts some errors from this stream.
  inherited
join([String separator = ""]) → Future<String>
  Combines the string representation of elements into a single string.
  inherited
joinMulticast(InternetAddress group, [NetworkInterface? interface]) → void
  Joins a multicast group.
lastWhere(bool test(RawSocketEvent element), {RawSocketEvent orElse()?}) → Future<RawSocketEvent>
  Finds the last element in this stream matching `test`.
  inherited
leaveMulticast(InternetAddress group, [NetworkInterface? interface]) → void
  Leaves a multicast group.
listen(void onData(RawSocketEvent event)?, {Function? onError, void onDone()?, bool? cancelOnError}) → StreamSubscription<RawSocketEvent>
  Adds a subscription to this stream.
  inherited
map<S>(S convert(RawSocketEvent event)) → Stream<S>
  Transforms each element of this stream into a new stream event.
  inherited
noSuchMethod(Invocation invocation) → dynamic
  Invoked when a nonexistent method or property is accessed.
  inherited
pipe(StreamConsumer<RawSocketEvent> streamConsumer) → Future
  Pipes the events of this stream into `streamConsumer`.
  inherited
receive() → Datagram?
  Receives a datagram.
reduce(RawSocketEvent combine(RawSocketEvent previous, RawSocketEvent element)) → Future<RawSocketEvent>
  Combines a sequence of values by repeatedly applying `combine`.
  inherited
send(List<int> buffer, InternetAddress address, int port) → int
  Asynchronously sends a datagram.
setRawOption(RawSocketOption option) → void
  Customizes the RawSocket.
singleWhere(bool test(RawSocketEvent element), {RawSocketEvent orElse()?}) → Future<RawSocketEvent>
  Finds the single element in this stream matching `test`.
  inherited
skip(int count) → Stream<RawSocketEvent>
  Skips the first `count` data events from this stream.
  inherited
skipWhile(bool test(RawSocketEvent element)) → Stream<RawSocketEvent>
  Skip data events from this stream while they are matched by `test`.
  inherited
take(int count) → Stream<RawSocketEvent>
  Provides at most the first `count` data events of this stream.
  inherited
takeWhile(bool test(RawSocketEvent element)) → Stream<RawSocketEvent>
  Forwards data events while `test` is successful.
  inherited
timeout(Duration timeLimit, {void onTimeout(EventSink<RawSocketEvent> sink)?}) → Stream<RawSocketEvent>
  Creates a new stream with the same events as this stream.
  inherited
toList() → Future<List<RawSocketEvent>>
  Collects all elements of this stream in a List.
  inherited
toSet() → Future<Set<RawSocketEvent>>
  Collects the data of this stream in a Set.
  inherited
toString() → String
  A string representation of this object.
  inherited
transform<S>(StreamTransformer<RawSocketEvent, S> streamTransformer) → Stream<S>
  Applies `streamTransformer` to this stream.
  inherited
where(bool test(RawSocketEvent element)) → Stream<RawSocketEvent>
  Creates a new stream from this stream that discards some elements.
  inherited

## Operators

operator ==(Object other) → bool
  The equality operator.
  inherited

## Static Methods

bind(dynamic host, int port, {bool reuseAddress = true, bool reusePort = false, int ttl = 1}) → Future<RawDatagramSocket>
  Binds a socket to the given `host` and `port`.