--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/nio/channels/AsynchronousByteChannel.java Sun Feb 15 12:25:54 2009 +0000
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2007-2009 Sun Microsystems, Inc. All Rights Reserved.
+ * 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.nio.channels;
+
+import java.nio.ByteBuffer;
+import java.util.concurrent.Future;
+
+/**
+ * An asynchronous channel that can read and write bytes.
+ *
+ * <p> Some channels may not allow more than one read or write to be outstanding
+ * at any given time. If a thread invokes a read method before a previous read
+ * operation has completed then a {@link ReadPendingException} will be thrown.
+ * Similarly, if a write method is invoked before a previous write has completed
+ * then {@link WritePendingException} is thrown. Whether or not other kinds of
+ * I/O operations may proceed concurrently with a read operation depends upon
+ * the type of the channel.
+ *
+ * <p> Note that {@link java.nio.ByteBuffer ByteBuffers} are not safe for use by
+ * multiple concurrent threads. When a read or write operation is initiated then
+ * care must be taken to ensure that the buffer is not accessed until the
+ * operation completes.
+ *
+ * @see Channels#newInputStream(AsynchronousByteChannel)
+ * @see Channels#newOutputStream(AsynchronousByteChannel)
+ *
+ * @since 1.7
+ */
+
+public interface AsynchronousByteChannel
+ extends AsynchronousChannel
+{
+ /**
+ * Reads a sequence of bytes from this channel into the given buffer.
+ *
+ * <p> This method initiates an operation to read a sequence of bytes from
+ * this channel into the given buffer. The method returns a {@link Future}
+ * representing the pending result of the operation. The result of the
+ * operation, obtained by invoking the {@code Future} 's {@link
+ * Future#get() get} method, is the number of bytes read or {@code -1} if
+ * all bytes have been read and the channel has reached end-of-stream.
+ *
+ * <p> This method initiates a read operation to read up to <i>r</i> bytes
+ * from the channel, where <i>r</i> is the number of bytes remaining in the
+ * buffer, that is, {@code dst.remaining()} at the time that the read is
+ * attempted. Where <i>r</i> is 0, the read operation completes immediately
+ * with a result of {@code 0} without initiating an I/O operation.
+ *
+ * <p> Suppose that a byte sequence of length <i>n</i> is read, where
+ * <tt>0</tt> <tt><</tt> <i>n</i> <tt><=</tt> <i>r</i>.
+ * This byte sequence will be transferred into the buffer so that the first
+ * byte in the sequence is at index <i>p</i> and the last byte is at index
+ * <i>p</i> <tt>+</tt> <i>n</i> <tt>-</tt> <tt>1</tt>,
+ * where <i>p</i> is the buffer's position at the moment the read is
+ * performed. Upon completion the buffer's position will be equal to
+ * <i>p</i> <tt>+</tt> <i>n</i>; its limit will not have changed.
+ *
+ * <p> Buffers are not safe for use by multiple concurrent threads so care
+ * should be taken to not to access the buffer until the operaton has completed.
+ *
+ * <p> This method may be invoked at any time. Some channel types may not
+ * allow more than one read to be outstanding at any given time. If a thread
+ * initiates a read operation before a previous read operation has
+ * completed then a {@link ReadPendingException} will be thrown.
+ *
+ * <p> The <tt>handler</tt> parameter is used to specify a {@link
+ * CompletionHandler}. When the read operation completes the handler's
+ * {@link CompletionHandler#completed completed} method is executed.
+ *
+ *
+ * @param dst
+ * The buffer into which bytes are to be transferred
+ * @param attachment
+ * The object to attach to the I/O operation; can be {@code null}
+ * @param handler
+ * The completion handler object; can be {@code null}
+ *
+ * @return A Future representing the result of the operation
+ *
+ * @throws IllegalArgumentException
+ * If the buffer is read-only
+ * @throws ReadPendingException
+ * If the channel does not allow more than one read to be outstanding
+ * and a previous read has not completed
+ */
+ <A> Future<Integer> read(ByteBuffer dst,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler);
+
+ /**
+ * Reads a sequence of bytes from this channel into the given buffer.
+ *
+ * <p> An invocation of this method of the form <tt>c.read(dst)</tt>
+ * behaves in exactly the same manner as the invocation
+ * <blockquote><pre>
+ * c.read(dst, null, null);</pre></blockquote>
+ *
+ * @param dst
+ * The buffer into which bytes are to be transferred
+ *
+ * @return A Future representing the result of the operation
+ *
+ * @throws IllegalArgumentException
+ * If the buffer is read-only
+ * @throws ReadPendingException
+ * If the channel does not allow more than one read to be outstanding
+ * and a previous read has not completed
+ */
+ Future<Integer> read(ByteBuffer dst);
+
+ /**
+ * Writes a sequence of bytes to this channel from the given buffer.
+ *
+ * <p> This method initiates an operation to write a sequence of bytes to
+ * this channel from the given buffer. This method returns a {@link
+ * Future} representing the pending result of the operation. The result
+ * of the operation, obtained by invoking the <tt>Future</tt>'s {@link
+ * Future#get() get} method, is the number of bytes written, possibly zero.
+ *
+ * <p> This method initiates a write operation to write up to <i>r</i> bytes
+ * to the channel, where <i>r</i> is the number of bytes remaining in the
+ * buffer, that is, {@code src.remaining()} at the moment the write is
+ * attempted. Where <i>r</i> is 0, the write operation completes immediately
+ * with a result of {@code 0} without initiating an I/O operation.
+ *
+ * <p> Suppose that a byte sequence of length <i>n</i> is written, where
+ * <tt>0</tt> <tt><</tt> <i>n</i> <tt><=</tt> <i>r</i>.
+ * This byte sequence will be transferred from the buffer starting at index
+ * <i>p</i>, where <i>p</i> is the buffer's position at the moment the
+ * write is performed; the index of the last byte written will be
+ * <i>p</i> <tt>+</tt> <i>n</i> <tt>-</tt> <tt>1</tt>.
+ * Upon completion the buffer's position will be equal to
+ * <i>p</i> <tt>+</tt> <i>n</i>; its limit will not have changed.
+ *
+ * <p> Buffers are not safe for use by multiple concurrent threads so care
+ * should be taken to not to access the buffer until the operaton has completed.
+ *
+ * <p> This method may be invoked at any time. Some channel types may not
+ * allow more than one write to be outstanding at any given time. If a thread
+ * initiates a write operation before a previous write operation has
+ * completed then a {@link WritePendingException} will be thrown.
+ *
+ * <p> The <tt>handler</tt> parameter is used to specify a {@link
+ * CompletionHandler}. When the write operation completes the handler's
+ * {@link CompletionHandler#completed completed} method is executed.
+ *
+ * @param src
+ * The buffer from which bytes are to be retrieved
+ * @param attachment
+ * The object to attach to the I/O operation; can be {@code null}
+ * @param handler
+ * The completion handler object; can be {@code null}
+ *
+ * @return A Future representing the result of the operation
+ *
+ * @throws WritePendingException
+ * If the channel does not allow more than one write to be outstanding
+ * and a previous write has not completed
+ */
+ <A> Future<Integer> write(ByteBuffer src,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler);
+
+ /**
+ * Writes a sequence of bytes to this channel from the given buffer.
+ *
+ * <p> An invocation of this method of the form <tt>c.write(src)</tt>
+ * behaves in exactly the same manner as the invocation
+ * <blockquote><pre>
+ * c.write(src, null, null);</pre></blockquote>
+ *
+ * @param src
+ * The buffer from which bytes are to be retrieved
+ *
+ * @return A Future representing the result of the operation
+ *
+ * @throws WritePendingException
+ * If the channel does not allow more than one write to be outstanding
+ * and a previous write has not completed
+ */
+ Future<Integer> write(ByteBuffer src);
+}