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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
package java.nio.channels;
import java.io.IOException;
import java.nio.channels.spi.*;
/**
* A pair of channels that implements a unidirectional pipe.
*
* <p> A pipe consists of a pair of channels: A writable {@link
* Pipe.SinkChannel </code>sink<code>} channel and a readable {@link
* Pipe.SourceChannel </code>source<code>} channel. Once some bytes are
* written to the sink channel they can be read from source channel in exactly
* the order in which they were written.
*
* <p> Whether or not a thread writing bytes to a pipe will block until another
* thread reads those bytes, or some previously-written bytes, from the pipe is
* system-dependent and therefore unspecified. Many pipe implementations will
* buffer up to a certain number of bytes between the sink and source channels,
* but such buffering should not be assumed. </p>
*
*
* @author Mark Reinhold
* @author JSR-51 Expert Group
* @since 1.4
*/
public abstract class Pipe {
/**
* A channel representing the readable end of a {@link Pipe}. </p>
*
* @since 1.4
*/
public static abstract class SourceChannel
extends AbstractSelectableChannel
implements ReadableByteChannel, ScatteringByteChannel
{
/**
* Constructs a new instance of this class.
*/
protected SourceChannel(SelectorProvider provider) {
super(provider);
}
/**
* Returns an operation set identifying this channel's supported
* operations.
*
* <p> Pipe-source channels only support reading, so this method
* returns {@link SelectionKey#OP_READ}. </p>
*
* @return The valid-operation set
*/
public final int validOps() {
return SelectionKey.OP_READ;
}
}
/**
* A channel representing the writable end of a {@link Pipe}. </p>
*
* @since 1.4
*/
public static abstract class SinkChannel
extends AbstractSelectableChannel
implements WritableByteChannel, GatheringByteChannel
{
/**
* Initializes a new instance of this class.
*/
protected SinkChannel(SelectorProvider provider) {
super(provider);
}
/**
* Returns an operation set identifying this channel's supported
* operations.
*
* <p> Pipe-sink channels only support writing, so this method returns
* {@link SelectionKey#OP_WRITE}. </p>
*
* @return The valid-operation set
*/
public final int validOps() {
return SelectionKey.OP_WRITE;
}
}
/**
* Initializes a new instance of this class.
*/
protected Pipe() { }
/**
* Returns this pipe's source channel. </p>
*
* @return This pipe's source channel
*/
public abstract SourceChannel source();
/**
* Returns this pipe's sink channel. </p>
*
* @return This pipe's sink channel
*/
public abstract SinkChannel sink();
/**
* Opens a pipe.
*
* <p> The new pipe is created by invoking the {@link
* java.nio.channels.spi.SelectorProvider#openPipe openPipe} method of the
* system-wide default {@link java.nio.channels.spi.SelectorProvider}
* object. </p>
*
* @return A new pipe
*
* @throws IOException
* If an I/O error occurs
*/
public static Pipe open() throws IOException {
return SelectorProvider.provider().openPipe();
}
}