io.aeron.cluster.service

Interface ClientSession

public interface ClientSession

Session representing a connected external client to the cluster.

Field Summary

Fields

Modifier and Type	Field and Description
static long	MOCKED_OFFER Return value to indicate egress to a session is mocked out by the cluster when in follower mode.

Method Summary

Modifier and Type	Method and Description
void	close() Close of this ContainerClientSession by sending the request to the consensus module.
byte[]	encodedPrincipal() Cluster session encoded principal from when the session was authenticated.
long	id() Cluster session identity uniquely allocated when the session was opened.
boolean	isClosing() Indicates that a request to close this session has been made.
long	offer(DirectBuffer buffer, int offset, int length) Non-blocking publish of a partial buffer containing a message to a cluster.
long	offer(DirectBufferVector[] vectors) Non-blocking publish by gathering buffer vectors into a message.
String	responseChannel() The response channel for responding to the client.
int	responseStreamId() The response channel stream id for responding to the client.
long	tryClaim(int length, BufferClaim bufferClaim) Try to claim a range in the publication log into which a message can be written with zero copy semantics.

Field Detail

MOCKED_OFFER

static final long MOCKED_OFFER

Return value to indicate egress to a session is mocked out by the cluster when in follower mode.

See Also:

Constant Field Values

Method Detail

id

long id()

Cluster session identity uniquely allocated when the session was opened.

Returns:

the cluster session identity uniquely allocated when the session was opened.

responseStreamId

int responseStreamId()

The response channel stream id for responding to the client.

Returns:

response channel stream id for responding to the client.

responseChannel

String responseChannel()

The response channel for responding to the client.

Returns:

response channel for responding to the client.

encodedPrincipal

byte[] encodedPrincipal()

Cluster session encoded principal from when the session was authenticated.

Returns:

The encoded Principal passed. May be 0 length to indicate none present.

close

void close()

Close of this ContainerClientSession by sending the request to the consensus module.

This method is idempotent.

isClosing

boolean isClosing()

Indicates that a request to close this session has been made.

Returns:

whether a request to close this session has been made.

offer

long offer(DirectBuffer buffer,
           int offset,
           int length)

Non-blocking publish of a partial buffer containing a message to a cluster.

Parameters:

buffer - containing message.

offset - offset in the buffer at which the encoded message begins.

length - in bytes of the encoded message.

Returns:

the same as Publication.offer(DirectBuffer, int, int) when in Cluster.Role.LEADER, otherwise MOCKED_OFFER when a follower.

offer

long offer(DirectBufferVector[] vectors)

Non-blocking publish by gathering buffer vectors into a message. The first vector will be replaced by the cluster egress header so must be left unused.

Parameters:

vectors - which make up the message.

Returns:

the same as Publication.offer(DirectBufferVector[]).

See Also:

when in {@link Cluster.Role#LEADER}, otherwise {@link #MOCKED_OFFER} when a follower.

tryClaim

long tryClaim(int length,
              BufferClaim bufferClaim)

Try to claim a range in the publication log into which a message can be written with zero copy semantics. Once the message has been written then BufferClaim.commit() should be called thus making it available.

On successful claim, the Cluster egress header will be written to the start of the claimed buffer section. Clients MUST write into the claimed buffer region at offset + AeronCluster.SESSION_HEADER_LENGTH.

     final DirectBuffer srcBuffer = acquireMessage();

     if (session.tryClaim(length, bufferClaim) > 0L)
     {
         try
         {
              final MutableDirectBuffer buffer = bufferClaim.buffer();
              final int offset = bufferClaim.offset();
              // ensure that data is written at the correct offset
              buffer.putBytes(offset + AeronCluster.SESSION_HEADER_LENGTH, srcBuffer, 0, length);
         }
         finally
         {
             bufferClaim.commit();
         }
     }
 

Parameters:

length - of the range to claim in bytes. The additional bytes for the session header will be added.

bufferClaim - to be populated if the claim succeeds.

Returns:

The new stream position, otherwise a negative error value as specified in Publication.tryClaim(int, BufferClaim) when in Cluster.Role.LEADER, otherwise MOCKED_OFFER when a follower.

Throws:

IllegalArgumentException - if the length is greater than Publication.maxPayloadLength().

See Also:

Publication.tryClaim(int, BufferClaim), BufferClaim.commit(), BufferClaim.abort()