RawDatagramSocket class

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

Constructors

RawDatagramSocket()

Properties

address InternetAddress
The address used by this socket.
read-only
broadcastEnabled bool
Whether IPv4 broadcast is enabled.
read / write
first Future<RawSocketEvent>
The first element of this stream.
read-onlyinherited
hashCode int
The hash code for this object.
read-onlyinherited
isBroadcast bool
Whether this stream is a broadcast stream.
read-onlyinherited
isEmpty Future<bool>
Whether this stream contains any elements.
read-onlyinherited
last Future<RawSocketEvent>
The last element of this stream.
read-onlyinherited
length Future<int>
The number of elements in this stream.
read-onlyinherited
multicastHops int
The maximum network hops for multicast packages originating from this socket.
read / write
multicastInterface NetworkInterface?
The network interface used for outgoing multicast packages.
read / write
multicastLoopback bool
Whether multicast traffic is looped back to the host.
read / write
port int
The port used by this socket.
read-only
readEventsEnabled bool
Whether the RawDatagramSocket should listen for RawSocketEvent.read events.
read / write
runtimeType Type
A representation of the runtime type of the object.
read-onlyinherited
single Future<RawSocketEvent>
The single element of this stream.
read-onlyinherited
writeEventsEnabled bool
Whether the RawDatagramSocket should listen for RawSocketEvent.write events.
read / write

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 indexth 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 event)) 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.