RawSynchronousSocket abstract interface

abstract interface class RawSynchronousSocket

A low-level class for communicating synchronously over a TCP socket.

Warning: RawSynchronousSocket should probably only be used to connect to 'localhost'. The operations below will block the calling thread to wait for a response from the network. The thread can process no other events while waiting for these operations to complete. RawSynchronousSocket is not suitable for applications that require high performance or asynchronous I/O such as a server. Instead such applications should use the non-blocking sockets and asynchronous operations in the Socket or RawSocket classes.

Properties

address no setter

InternetAddress get address

The InternetAddress used to connect this socket.

Implementation

InternetAddress get address;

hashCode no setter inherited

int get hashCode

The hash code for this object.

A hash code is a single integer which represents the state of the object that affects operator == comparisons.

All objects have hash codes. The default hash code implemented by Object represents only the identity of the object, the same way as the default operator == implementation only considers objects equal if they are identical (see identityHashCode).

If operator == is overridden to use the object state instead, the hash code must also be changed to represent that state, otherwise the object cannot be used in hash based data structures like the default Set and Map implementations.

Hash codes must be the same for objects that are equal to each other according to operator ==. The hash code of an object should only change if the object changes in a way that affects equality. There are no further requirements for the hash codes. They need not be consistent between executions of the same program and there are no distribution guarantees.

Objects that are not equal are allowed to have the same hash code. It is even technically allowed that all instances have the same hash code, but if clashes happen too often, it may reduce the efficiency of hash-based data structures like HashSet or HashMap.

If a subclass overrides hashCode, it should override the operator == operator as well to maintain consistency.

Inherited from Object.

Implementation

external int get hashCode;

port no setter

int get port

The port used by this socket.

Implementation

int get port;

remoteAddress no setter

InternetAddress get remoteAddress

The remote InternetAddress connected to by this socket.

Implementation

InternetAddress get remoteAddress;

remotePort no setter

int get remotePort

The remote port connected to by this socket.

Implementation

int get remotePort;

runtimeType no setter inherited

Type get runtimeType

A representation of the runtime type of the object.

Inherited from Object.

Implementation

external Type get runtimeType;

Methods

available()

int available()

The number of received and unread bytes in the socket that can be read.

Implementation

int available();

closeSync()

void closeSync()

Closes the RawSynchronousSocket.

Once closeSync has been called, attempting to call readSync, readIntoSync, writeFromSync, remoteAddress, and remotePort will cause a SocketException to be thrown.

Implementation

void closeSync();

noSuchMethod() inherited

dynamic noSuchMethod(Invocation invocation)

Invoked when a nonexistent method or property is accessed.

A dynamic member invocation can attempt to call a member which doesn't exist on the receiving object. Example:

dynamic object = 1;
object.add(42); // Statically allowed, run-time error

This invalid code will invoke the noSuchMethod method of the integer 1 with an Invocation representing the .add(42) call and arguments (which then throws).

Classes can override noSuchMethod to provide custom behavior for such invalid dynamic invocations.

A class with a non-default noSuchMethod invocation can also omit implementations for members of its interface. Example:

class MockList<T> implements List<T> {
  noSuchMethod(Invocation invocation) {
    log(invocation);
    super.noSuchMethod(invocation); // Will throw.
  }
}
void main() {
  MockList().add(42);
}

This code has no compile-time warnings or errors even though the MockList class has no concrete implementation of any of the List interface methods. Calls to List methods are forwarded to noSuchMethod, so this code will log an invocation similar to Invocation.method(#add, [42]) and then throw.

If a value is returned from noSuchMethod, it becomes the result of the original invocation. If the value is not of a type that can be returned by the original invocation, a type error occurs at the invocation.

The default behavior is to throw a NoSuchMethodError.

Inherited from Object.

Implementation

@pragma("vm:entry-point")
@pragma("wasm:entry-point")
external dynamic noSuchMethod(Invocation invocation);

readIntoSync()

int readIntoSync(List<int> buffer, [int start = 0, int? end])

Reads bytes into an existing buffer.

Reads bytes and writes then into the range of buffer from start to end. The start must be non-negative and no greater than buffer.length. If end is omitted, it defaults to buffer.length. Otherwise end must be no less than start and no greater than buffer.length.

Returns the number of bytes read. This maybe be less than end - start if the file doesn't have that many bytes to read.

Implementation

int readIntoSync(List<int> buffer, [int start = 0, int? end]);

readSync()

List<int>? readSync(int bytes)

Reads up to bytes bytes from the socket.

Blocks and waits for a response of up to a specified number of bytes sent by the socket. bytes specifies the maximum number of bytes to be read. Returns the list of bytes read, which could be less than the value specified by bytes.

Implementation

List<int>? readSync(int bytes);

shutdown()

void shutdown(SocketDirection direction)

Shuts down a socket in the provided direction.

Calling shutdown will never throw an exception and calling it several times is supported. If both SocketDirection.receive and SocketDirection.send directions are closed, the socket is closed completely, the same as if closeSync has been called.

Implementation

void shutdown(SocketDirection direction);

toString() inherited

String toString()

A string representation of this object.

Some classes have a default textual representation, often paired with a static parse function (like int.parse). These classes will provide the textual representation as their string representation.

Other classes have no meaningful textual representation that a program will care about. Such classes will typically override toString to provide useful information when inspecting the object, mainly for debugging or logging.

Inherited from Object.

Implementation

external String toString();

writeFromSync()

void writeFromSync(List<int> buffer, [int start = 0, int? end])

Writes from a buffer to the socket.

Will read the buffer from index start to index end. The start must be non-negative and no greater than buffer.length. If end is omitted, it defaults to buffer.length. Otherwise end must be no less than start and no greater than buffer.length.

Implementation

void writeFromSync(List<int> buffer, [int start = 0, int? end]);

Operators

operator ==() inherited

bool operator ==(Object other)

The equality operator.

The default behavior for all Objects is to return true if and only if this object and other are the same object.

Override this method to specify a different equality relation on a class. The overriding method must still be an equivalence relation. That is, it must be:

• Total: It must return a boolean for all arguments. It should never throw.

• Reflexive: For all objects o, o == o must be true.

• Symmetric: For all objects o1 and o2, o1 == o2 and o2 == o1 must either both be true, or both be false.

• Transitive: For all objects o1, o2, and o3, if o1 == o2 and o2 == o3 are true, then o1 == o3 must be true.

The method should also be consistent over time, so whether two objects are equal should only change if at least one of the objects was modified.

If a subclass overrides the equality operator, it should override the hashCode method as well to maintain consistency.

Inherited from Object.

Implementation

external bool operator ==(Object other);

Static Methods

connectSync()

RawSynchronousSocket connectSync(dynamic host, int port)

Creates a new socket connection and returns a RawSynchronousSocket.

The host can either be a String or an InternetAddress. If host is a String, connectSync will perform a InternetAddress.lookup and try all returned InternetAddresses, until connected. Unless a connection was established, the error from the first failing connection is returned.

Implementation

external static RawSynchronousSocket connectSync(host, int port);