org.eclipse.jetty.io.EndPoint Maven / Gradle / Ivy
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// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
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// and Apache License v2.0 which accompanies this distribution.
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package org.eclipse.jetty.io;
import java.io.Closeable;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ReadPendingException;
import java.nio.channels.WritePendingException;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.FutureCallback;
import org.eclipse.jetty.util.IteratingCallback;
import org.eclipse.jetty.util.thread.Invocable;
/**
* EndPoint is the abstraction for an I/O channel that transports bytes.
*
* Asynchronous Methods
* The asynchronous scheduling methods of {@link EndPoint}
* has been influenced by NIO.2 Futures and Completion
* handlers, but does not use those actual interfaces because they have
* some inefficiencies.
* This class will frequently be used in conjunction with some of the utility
* implementations of {@link Callback}, such as {@link FutureCallback} and
* {@link IteratingCallback}.
*
* Reads
* A {@link FutureCallback} can be used to block until an endpoint is ready
* to fill bytes - the notification will be emitted by the NIO subsystem:
*
* FutureCallback callback = new FutureCallback();
* endPoint.fillInterested(callback);
*
* // Blocks until read to fill bytes.
* callback.get();
*
* // Now bytes can be filled in a ByteBuffer.
* int filled = endPoint.fill(byteBuffer);
*
*
* Asynchronous Reads
* A {@link Callback} can be used to read asynchronously in its own dispatched
* thread:
*
* endPoint.fillInterested(new Callback()
* {
* public void onSucceeded()
* {
* executor.execute(() ->
* {
* // Fill bytes in a different thread.
* int filled = endPoint.fill(byteBuffer);
* });
* }
* public void onFailed(Throwable failure)
* {
* endPoint.close();
* }
* });
*
*
* Blocking Writes
* The write contract is that the callback is completed when all the bytes
* have been written or there is a failure.
* Blocking writes look like this:
*
* FutureCallback callback = new FutureCallback();
* endpoint.write(callback, headerBuffer, contentBuffer);
*
* // Blocks until the write succeeds or fails.
* future.get();
*
* Note also that multiple buffers may be passed in {@link #write(Callback, ByteBuffer...)}
* so that gather writes can be performed for efficiency.
*/
public interface EndPoint extends Closeable
{
/**
* @return The local Inet address to which this {@code EndPoint} is bound, or {@code null}
* if this {@code EndPoint} does not represent a network connection.
*/
InetSocketAddress getLocalAddress();
/**
* @return The remote Inet address to which this {@code EndPoint} is bound, or {@code null}
* if this {@code EndPoint} does not represent a network connection.
*/
InetSocketAddress getRemoteAddress();
/**
* @return whether this EndPoint is open
*/
boolean isOpen();
/**
* @return the epoch time in milliseconds when this EndPoint was created
*/
long getCreatedTimeStamp();
/**
* Shutdown the output.
* This call indicates that no more data will be sent on this endpoint that
* that the remote end should read an EOF once all previously sent data has been
* consumed. Shutdown may be done either at the TCP/IP level, as a protocol exchange (Eg
* TLS close handshake) or both.
*
* If the endpoint has {@link #isInputShutdown()} true, then this call has the same effect
* as {@link #close()}.
*/
void shutdownOutput();
/**
* Test if output is shutdown.
* The output is shutdown by a call to {@link #shutdownOutput()}
* or {@link #close()}.
*
* @return true if the output is shutdown or the endpoint is closed.
*/
boolean isOutputShutdown();
/**
* Test if the input is shutdown.
* The input is shutdown if an EOF has been read while doing
* a {@link #fill(ByteBuffer)}. Once the input is shutdown, all calls to
* {@link #fill(ByteBuffer)} will return -1, until such time as the
* end point is close, when they will return {@link EofException}.
*
* @return True if the input is shutdown or the endpoint is closed.
*/
boolean isInputShutdown();
/**
* Close any backing stream associated with the endpoint
*/
@Override
void close();
/**
* Fill the passed buffer with data from this endpoint. The bytes are appended to any
* data already in the buffer by writing from the buffers limit up to it's capacity.
* The limit is updated to include the filled bytes.
*
* @param buffer The buffer to fill. The position and limit are modified during the fill. After the
* operation, the position is unchanged and the limit is increased to reflect the new data filled.
* @return an {@code int} value indicating the number of bytes
* filled or -1 if EOF is read or the input is shutdown.
* @throws IOException if the endpoint is closed.
*/
int fill(ByteBuffer buffer) throws IOException;
/**
* Flush data from the passed header/buffer to this endpoint. As many bytes as can be consumed
* are taken from the header/buffer position up until the buffer limit. The header/buffers position
* is updated to indicate how many bytes have been consumed.
*
* @param buffer the buffers to flush
* @return True IFF all the buffers have been consumed and the endpoint has flushed the data to its
* destination (ie is not buffering any data).
* @throws IOException If the endpoint is closed or output is shutdown.
*/
boolean flush(ByteBuffer... buffer) throws IOException;
/**
* @return The underlying transport object (socket, channel, etc.)
*/
Object getTransport();
/**
* Get the max idle time in ms.
*
The max idle time is the time the endpoint can be idle before
* extraordinary handling takes place.
*
* @return the max idle time in ms or if ms <= 0 implies an infinite timeout
*/
long getIdleTimeout();
/**
* Set the idle timeout.
*
* @param idleTimeout the idle timeout in MS. Timeout <= 0 implies an infinite timeout
*/
void setIdleTimeout(long idleTimeout);
/**
*
Requests callback methods to be invoked when a call to {@link #fill(ByteBuffer)} would return data or EOF.
*
* @param callback the callback to call when an error occurs or we are readable. The callback may implement the {@link Invocable} interface to
* self declare its blocking status. Non-blocking callbacks may be called more efficiently without dispatch delays.
* @throws ReadPendingException if another read operation is concurrent.
*/
void fillInterested(Callback callback) throws ReadPendingException;
/**
* Requests callback methods to be invoked when a call to {@link #fill(ByteBuffer)} would return data or EOF.
*
* @param callback the callback to call when an error occurs or we are readable. The callback may implement the {@link Invocable} interface to
* self declare its blocking status. Non-blocking callbacks may be called more efficiently without dispatch delays.
* @return true if set
*/
boolean tryFillInterested(Callback callback);
/**
* @return whether {@link #fillInterested(Callback)} has been called, but {@link #fill(ByteBuffer)} has not yet
* been called
*/
boolean isFillInterested();
/**
* Writes the given buffers via {@link #flush(ByteBuffer...)} and invokes callback methods when either
* all the data has been flushed or an error occurs.
*
* @param callback the callback to call when an error occurs or the write completed. The callback may implement the {@link Invocable} interface to
* self declare its blocking status. Non-blocking callbacks may be called more efficiently without dispatch delays.
* @param buffers one or more {@link ByteBuffer}s that will be flushed.
* @throws WritePendingException if another write operation is concurrent.
*/
void write(Callback callback, ByteBuffer... buffers) throws WritePendingException;
/**
* @return the {@link Connection} associated with this EndPoint
* @see #setConnection(Connection)
*/
Connection getConnection();
/**
* @param connection the {@link Connection} associated with this EndPoint
* @see #getConnection()
* @see #upgrade(Connection)
*/
void setConnection(Connection connection);
/**
* Callback method invoked when this EndPoint is opened.
*
* @see #onClose()
*/
void onOpen();
/**
* Callback method invoked when this EndPoint is close.
*
* @see #onOpen()
*/
void onClose();
/**
* Is the endpoint optimized for DirectBuffer usage
*
* @return True if direct buffers can be used optimally.
*/
boolean isOptimizedForDirectBuffers();
/**
* Upgrades this EndPoint from the current connection to the given new connection.
* Closes the current connection, links this EndPoint to the new connection and
* then opens the new connection.
* If the current connection is an instance of {@link Connection.UpgradeFrom} then
* a buffer of unconsumed bytes is requested.
* If the buffer of unconsumed bytes is non-null and non-empty, then the new
* connection is tested: if it is an instance of {@link Connection.UpgradeTo}, then
* the unconsumed buffer is passed to the new connection; otherwise, an exception
* is thrown since there are unconsumed bytes that cannot be consumed by the new
* connection.
*
* @param newConnection the connection to upgrade to
*/
void upgrade(Connection newConnection);
}