NioChannel.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.util.net;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ByteChannel;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.GatheringByteChannel;
import java.nio.channels.ScatteringByteChannel;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import org.apache.tomcat.util.net.NioEndpoint.NioSocketWrapper;
import org.apache.tomcat.util.res.StringManager;
/**
* Base class for a SocketChannel wrapper used by the endpoint.
* This way, logic for an SSL socket channel remains the same as for
* a non SSL, making sure we don't need to code for any exception cases.
*/
public class NioChannel implements ByteChannel, ScatteringByteChannel, GatheringByteChannel {
protected static final StringManager sm = StringManager.getManager(NioChannel.class);
protected static final ByteBuffer emptyBuf = ByteBuffer.allocate(0);
protected final SocketBufferHandler bufHandler;
protected SocketChannel sc = null;
protected NioSocketWrapper socketWrapper = null;
public NioChannel(SocketBufferHandler bufHandler) {
this.bufHandler = bufHandler;
}
/**
* Reset the channel
*
* @param channel the socket channel
* @param socketWrapper the socket wrapper
* @throws IOException If a problem was encountered resetting the channel
*/
public void reset(SocketChannel channel, NioSocketWrapper socketWrapper) throws IOException {
this.sc = channel;
this.socketWrapper = socketWrapper;
bufHandler.reset();
}
/**
* @return the socketWrapper
*/
NioSocketWrapper getSocketWrapper() {
return socketWrapper;
}
/**
* Free the channel memory
*/
public void free() {
bufHandler.free();
}
/**
* Returns true if the network buffer has been flushed out and is empty.
*
* @param block Unused. May be used when overridden
* @param s Unused. May be used when overridden
* @param timeout Unused. May be used when overridden
* @return Always returns <code>true</code> since there is no network buffer
* in the regular channel
*
* @throws IOException Never for non-secure channel
*/
public boolean flush(boolean block, Selector s, long timeout)
throws IOException {
return true;
}
/**
* Closes this channel.
*
* @throws IOException If an I/O error occurs
*/
@Override
public void close() throws IOException {
sc.close();
}
/**
* Close the connection.
*
* @param force Should the underlying socket be forcibly closed?
* @throws IOException If closing the secure channel fails.
*/
public void close(boolean force) throws IOException {
if (isOpen() || force) {
close();
}
}
/**
* Tells whether or not this channel is open.
*
* @return <code>true</code> if, and only if, this channel is open
*/
@Override
public boolean isOpen() {
return sc.isOpen();
}
/**
* Writes a sequence of bytes to this channel from the given buffer.
*
* @param src The buffer from which bytes are to be retrieved
* @return The number of bytes written, possibly zero
* @throws IOException If some other I/O error occurs
*/
@Override
public int write(ByteBuffer src) throws IOException {
checkInterruptStatus();
if (!src.hasRemaining()) {
// Nothing left to write
return 0;
}
return sc.write(src);
}
@Override
public long write(ByteBuffer[] srcs) throws IOException {
return write(srcs, 0, srcs.length);
}
@Override
public long write(ByteBuffer[] srcs, int offset, int length)
throws IOException {
checkInterruptStatus();
return sc.write(srcs, offset, length);
}
/**
* Reads a sequence of bytes from this channel into the given buffer.
*
* @param dst The buffer into which bytes are to be transferred
* @return The number of bytes read, possibly zero, or <code>-1</code> if
* the channel has reached end-of-stream
* @throws IOException If some other I/O error occurs
*/
@Override
public int read(ByteBuffer dst) throws IOException {
return sc.read(dst);
}
@Override
public long read(ByteBuffer[] dsts) throws IOException {
return read(dsts, 0, dsts.length);
}
@Override
public long read(ByteBuffer[] dsts, int offset, int length)
throws IOException {
return sc.read(dsts, offset, length);
}
public SocketBufferHandler getBufHandler() {
return bufHandler;
}
public SocketChannel getIOChannel() {
return sc;
}
public boolean isClosing() {
return false;
}
public boolean isHandshakeComplete() {
return true;
}
/**
* Performs SSL handshake hence is a no-op for the non-secure
* implementation.
*
* @param read Unused in non-secure implementation
* @param write Unused in non-secure implementation
* @return Always returns zero
* @throws IOException Never for non-secure channel
*/
public int handshake(boolean read, boolean write) throws IOException {
return 0;
}
@Override
public String toString() {
return super.toString() + ":" + sc;
}
public int getOutboundRemaining() {
return 0;
}
/**
* Return true if the buffer wrote data. NO-OP for non-secure channel.
*
* @return Always returns {@code false} for non-secure channel
* @throws IOException Never for non-secure channel
*/
public boolean flushOutbound() throws IOException {
return false;
}
/**
* This method should be used to check the interrupt status before
* attempting a write.
*
* If a thread has been interrupted and the interrupt has not been cleared
* then an attempt to write to the socket will fail. When this happens the
* socket is removed from the poller without the socket being selected. This
* results in a connection limit leak for NIO as the endpoint expects the
* socket to be selected even in error conditions.
*
* @throws IOException If the current thread was interrupted
*/
protected void checkInterruptStatus() throws IOException {
if (Thread.interrupted()) {
throw new IOException(sm.getString("channel.nio.interrupted"));
}
}
private ApplicationBufferHandler appReadBufHandler;
public void setAppReadBufHandler(ApplicationBufferHandler handler) {
this.appReadBufHandler = handler;
}
protected ApplicationBufferHandler getAppReadBufHandler() {
return appReadBufHandler;
}
static final NioChannel CLOSED_NIO_CHANNEL = new NioChannel(SocketBufferHandler.EMPTY) {
@Override
public void close() throws IOException {
}
@Override
public boolean isOpen() {
return false;
}
@Override
public void reset(SocketChannel channel, NioSocketWrapper socketWrapper) throws IOException {
}
@Override
public void free() {
}
@Override
protected ApplicationBufferHandler getAppReadBufHandler() {
return ApplicationBufferHandler.EMPTY;
}
@Override
public void setAppReadBufHandler(ApplicationBufferHandler handler) {
}
@Override
public int read(ByteBuffer dst) throws IOException {
return -1;
}
@Override
public long read(ByteBuffer[] dsts, int offset, int length)
throws IOException {
return -1L;
}
@Override
public int write(ByteBuffer src) throws IOException {
checkInterruptStatus();
throw new ClosedChannelException();
}
@Override
public long write(ByteBuffer[] srcs, int offset, int length)
throws IOException {
throw new ClosedChannelException();
}
@Override
public String toString() {
return "Closed NioChannel";
}
};
}