/*
* 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.CompletionHandler;
import java.util.Iterator;
import java.util.concurrent.Executor;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock.WriteLock;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.buf.ByteBufferHolder;
import org.apache.tomcat.util.res.StringManager;
public abstract class SocketWrapperBase<E> {
private static final Log log = LogFactory.getLog(SocketWrapperBase.class);
protected static final StringManager sm = StringManager.getManager(SocketWrapperBase.class);
private final E socket;
private final AbstractEndpoint<E,?> endpoint;
// Volatile because I/O and setting the timeout values occurs on a different
// thread to the thread checking the timeout.
private volatile long readTimeout = -1;
private volatile long writeTimeout = -1;
private volatile int keepAliveLeft = 100;
private volatile boolean upgraded = false;
private boolean secure = false;
private String negotiatedProtocol = null;
/*
* Following cached for speed / reduced GC
*/
protected String localAddr = null;
protected String localName = null;
protected int localPort = -1;
protected String remoteAddr = null;
protected String remoteHost = null;
protected int remotePort = -1;
/*
* Used if block/non-blocking is set at the socket level. The client is
* responsible for the thread-safe use of this field via the locks provided.
*/
private volatile boolean blockingStatus = true;
private final Lock blockingStatusReadLock;
private final WriteLock blockingStatusWriteLock;
/*
* Used to record the first IOException that occurs during non-blocking
* read/writes that can't be usefully propagated up the stack since there is
* no user code or appropriate container code in the stack to handle it.
*/
private volatile IOException error = null;
/**
* The buffers used for communicating with the socket.
*/
protected volatile SocketBufferHandler socketBufferHandler = null;
/**
* For "non-blocking" writes use an external set of buffers. Although the
* API only allows one non-blocking write at a time, due to buffering and
* the possible need to write HTTP headers, there may be more than one write
* to the OutputBuffer.
*/
protected final LinkedBlockingDeque<ByteBufferHolder> bufferedWrites = new LinkedBlockingDeque<>();
/**
* The max size of the buffered write buffer
*/
protected int bufferedWriteSize = 64 * 1024; // 64k default write buffer
public SocketWrapperBase(E socket, AbstractEndpoint<E,?> endpoint) {
this.socket = socket;
this.endpoint = endpoint;
ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
this.blockingStatusReadLock = lock.readLock();
this.blockingStatusWriteLock = lock.writeLock();
}
public E getSocket() {
return socket;
}
protected AbstractEndpoint<E,?> getEndpoint() {
return endpoint;
}
/**
* Transfers processing to a container thread.
*
* @param runnable The actions to process on a container thread
*
* @throws RejectedExecutionException If the runnable cannot be executed
*/
public void execute(Runnable runnable) {
Executor executor = endpoint.getExecutor();
if (!endpoint.isRunning() || executor == null) {
throw new RejectedExecutionException();
}
executor.execute(runnable);
}
public IOException getError() { return error; }
public void setError(IOException error) {
// Not perfectly thread-safe but good enough. Just needs to ensure that
// once this.error is non-null, it can never be null.
if (this.error != null) {
return;
}
this.error = error;
}
public void checkError() throws IOException {
if (error != null) {
throw error;
}
}
public boolean isUpgraded() { return upgraded; }
public void setUpgraded(boolean upgraded) { this.upgraded = upgraded; }
public boolean isSecure() { return secure; }
public void setSecure(boolean secure) { this.secure = secure; }
public String getNegotiatedProtocol() { return negotiatedProtocol; }
public void setNegotiatedProtocol(String negotiatedProtocol) {
this.negotiatedProtocol = negotiatedProtocol;
}
/**
* Set the timeout for reading. Values of zero or less will be changed to
* -1.
*
* @param readTimeout The timeout in milliseconds. A value of -1 indicates
* an infinite timeout.
*/
public void setReadTimeout(long readTimeout) {
if (readTimeout > 0) {
this.readTimeout = readTimeout;
} else {
this.readTimeout = -1;
}
}
public long getReadTimeout() {
return this.readTimeout;
}
/**
* Set the timeout for writing. Values of zero or less will be changed to
* -1.
*
* @param writeTimeout The timeout in milliseconds. A value of zero or less
* indicates an infinite timeout.
*/
public void setWriteTimeout(long writeTimeout) {
if (writeTimeout > 0) {
this.writeTimeout = writeTimeout;
} else {
this.writeTimeout = -1;
}
}
public long getWriteTimeout() {
return this.writeTimeout;
}
public void setKeepAliveLeft(int keepAliveLeft) {
this.keepAliveLeft = keepAliveLeft;
}
public int decrementKeepAlive() {
return --keepAliveLeft;
}
public String getRemoteHost() {
if (remoteHost == null) {
populateRemoteHost();
}
return remoteHost;
}
protected abstract void populateRemoteHost();
public String getRemoteAddr() {
if (remoteAddr == null) {
populateRemoteAddr();
}
return remoteAddr;
}
protected abstract void populateRemoteAddr();
public int getRemotePort() {
if (remotePort == -1) {
populateRemotePort();
}
return remotePort;
}
protected abstract void populateRemotePort();
public String getLocalName() {
if (localName == null) {
populateLocalName();
}
return localName;
}
protected abstract void populateLocalName();
public String getLocalAddr() {
if (localAddr == null) {
populateLocalAddr();
}
return localAddr;
}
protected abstract void populateLocalAddr();
public int getLocalPort() {
if (localPort == -1) {
populateLocalPort();
}
return localPort;
}
protected abstract void populateLocalPort();
public boolean getBlockingStatus() { return blockingStatus; }
public void setBlockingStatus(boolean blockingStatus) {
this.blockingStatus = blockingStatus;
}
public Lock getBlockingStatusReadLock() { return blockingStatusReadLock; }
public WriteLock getBlockingStatusWriteLock() {
return blockingStatusWriteLock;
}
public SocketBufferHandler getSocketBufferHandler() { return socketBufferHandler; }
public boolean hasDataToWrite() {
return !socketBufferHandler.isWriteBufferEmpty() || bufferedWrites.size() > 0;
}
/**
* Checks to see if there are any writes pending and if there are calls
* {@link #registerWriteInterest()} to trigger a callback once the pending
* writes have completed.
* <p>
* Note: Once this method has returned <code>false</code> it <b>MUST NOT</b>
* be called again until the pending write has completed and the
* callback has been fired.
* TODO: Modify {@link #registerWriteInterest()} so the above
* restriction is enforced there rather than relying on the caller.
*
* @return <code>true</code> if no writes are pending and data can be
* written otherwise <code>false</code>
*/
public boolean isReadyForWrite() {
boolean result = canWrite();
if (!result) {
registerWriteInterest();
}
return result;
}
public boolean canWrite() {
if (socketBufferHandler == null) {
throw new IllegalStateException(sm.getString("socket.closed"));
}
return socketBufferHandler.isWriteBufferWritable() && bufferedWrites.size() == 0;
}
/**
* Overridden for debug purposes. No guarantees are made about the format of
* this message which may vary significantly between point releases.
* <p>
* {@inheritDoc}
*/
@Override
public String toString() {
return super.toString() + ":" + String.valueOf(socket);
}
public abstract int read(boolean block, byte[] b, int off, int len) throws IOException;
public abstract int read(boolean block, ByteBuffer to) throws IOException;
public abstract boolean isReadyForRead() throws IOException;
public abstract void setAppReadBufHandler(ApplicationBufferHandler handler);
protected int populateReadBuffer(byte[] b, int off, int len) {
socketBufferHandler.configureReadBufferForRead();
ByteBuffer readBuffer = socketBufferHandler.getReadBuffer();
int remaining = readBuffer.remaining();
// Is there enough data in the read buffer to satisfy this request?
// Copy what data there is in the read buffer to the byte array
if (remaining > 0) {
remaining = Math.min(remaining, len);
readBuffer.get(b, off, remaining);
if (log.isDebugEnabled()) {
log.debug("Socket: [" + this + "], Read from buffer: [" + remaining + "]");
}
}
return remaining;
}
protected int populateReadBuffer(ByteBuffer to) {
// Is there enough data in the read buffer to satisfy this request?
// Copy what data there is in the read buffer to the byte array
socketBufferHandler.configureReadBufferForRead();
int nRead = transfer(socketBufferHandler.getReadBuffer(), to);
if (log.isDebugEnabled()) {
log.debug("Socket: [" + this + "], Read from buffer: [" + nRead + "]");
}
return nRead;
}
/**
* Return input that has been read to the input buffer for re-reading by the
* correct component. There are times when a component may read more data
* than it needs before it passes control to another component. One example
* of this is during HTTP upgrade. If an (arguably misbehaving client) sends
* data associated with the upgraded protocol before the HTTP upgrade
* completes, the HTTP handler may read it. This method provides a way for
* that data to be returned so it can be processed by the correct component.
*
* @param returnedInput The input to return to the input buffer.
*/
public void unRead(ByteBuffer returnedInput) {
if (returnedInput != null) {
socketBufferHandler.configureReadBufferForWrite();
socketBufferHandler.getReadBuffer().put(returnedInput);
}
}
public abstract void close() throws IOException;
public abstract boolean isClosed();
/**
* Writes the provided data to the socket, buffering any remaining data if
* used in non-blocking mode.
*
* @param block <code>true</code> if a blocking write should be used,
* otherwise a non-blocking write will be used
* @param buf The byte array containing the data to be written
* @param off The offset within the byte array of the data to be written
* @param len The length of the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
public final void write(boolean block, byte[] buf, int off, int len) throws IOException {
if (len == 0 || buf == null) {
return;
}
// While the implementations for blocking and non-blocking writes are
// very similar they have been split into separate methods to allow
// sub-classes to override them individually. NIO2, for example,
// overrides the non-blocking write but not the blocking write.
if (block) {
writeBlocking(buf, off, len);
} else {
writeNonBlocking(buf, off, len);
}
}
/**
* Writes the provided data to the socket, buffering any remaining data if
* used in non-blocking mode.
*
* @param block <code>true</code> if a blocking write should be used,
* otherwise a non-blocking write will be used
* @param from The ByteBuffer containing the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
public final void write(boolean block, ByteBuffer from) throws IOException {
if (from == null || from.remaining() == 0) {
return;
}
// While the implementations for blocking and non-blocking writes are
// very similar they have been split into separate methods to allow
// sub-classes to override them individually. NIO2, for example,
// overrides the non-blocking write but not the blocking write.
if (block) {
writeBlocking(from);
} else {
writeNonBlocking(from);
}
}
/**
* Transfers the data to the socket write buffer (writing that data to the
* socket if the buffer fills up using a blocking write) until all the data
* has been transferred and space remains in the socket write buffer.
*
* @param buf The byte array containing the data to be written
* @param off The offset within the byte array of the data to be written
* @param len The length of the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
protected void writeBlocking(byte[] buf, int off, int len) throws IOException {
// Note: There is an implementation assumption that if the switch from
// non-blocking to blocking has been made then any pending
// non-blocking writes were flushed at the time the switch
// occurred.
// Keep writing until all the data has been transferred to the socket
// write buffer and space remains in that buffer
socketBufferHandler.configureWriteBufferForWrite();
int thisTime = transfer(buf, off, len, socketBufferHandler.getWriteBuffer());
while (socketBufferHandler.getWriteBuffer().remaining() == 0) {
len = len - thisTime;
off = off + thisTime;
doWrite(true);
socketBufferHandler.configureWriteBufferForWrite();
thisTime = transfer(buf, off, len, socketBufferHandler.getWriteBuffer());
}
}
/**
* Write the data to the socket (writing that data to the socket using a
* blocking write) until all the data has been transferred and space remains
* in the socket write buffer. If it is possible use the provided buffer
* directly and do not transfer to the socket write buffer.
*
* @param from The ByteBuffer containing the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
protected void writeBlocking(ByteBuffer from) throws IOException {
// Note: There is an implementation assumption that if the switch from
// non-blocking to blocking has been made then any pending
// non-blocking writes were flushed at the time the switch
// occurred.
// If it is possible write the data to the socket directly from the
// provided buffer otherwise transfer it to the socket write buffer
if (socketBufferHandler.isWriteBufferEmpty()) {
writeByteBufferBlocking(from);
} else {
socketBufferHandler.configureWriteBufferForWrite();
transfer(from, socketBufferHandler.getWriteBuffer());
if (!socketBufferHandler.isWriteBufferWritable()) {
doWrite(true);
writeByteBufferBlocking(from);
}
}
}
protected void writeByteBufferBlocking(ByteBuffer from) throws IOException {
// The socket write buffer capacity is socket.appWriteBufSize
int limit = socketBufferHandler.getWriteBuffer().capacity();
int fromLimit = from.limit();
while (from.remaining() >= limit) {
from.limit(from.position() + limit);
doWrite(true, from);
from.limit(fromLimit);
}
if (from.remaining() > 0) {
socketBufferHandler.configureWriteBufferForWrite();
transfer(from, socketBufferHandler.getWriteBuffer());
}
}
/**
* Transfers the data to the socket write buffer (writing that data to the
* socket if the buffer fills up using a non-blocking write) until either
* all the data has been transferred and space remains in the socket write
* buffer or a non-blocking write leaves data in the socket write buffer.
*
* @param buf The byte array containing the data to be written
* @param off The offset within the byte array of the data to be written
* @param len The length of the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
protected void writeNonBlocking(byte[] buf, int off, int len) throws IOException {
if (bufferedWrites.size() == 0 && socketBufferHandler.isWriteBufferWritable()) {
socketBufferHandler.configureWriteBufferForWrite();
int thisTime = transfer(buf, off, len, socketBufferHandler.getWriteBuffer());
len = len - thisTime;
while (!socketBufferHandler.isWriteBufferWritable()) {
off = off + thisTime;
doWrite(false);
if (len > 0 && socketBufferHandler.isWriteBufferWritable()) {
socketBufferHandler.configureWriteBufferForWrite();
thisTime = transfer(buf, off, len, socketBufferHandler.getWriteBuffer());
} else {
// Didn't write any data in the last non-blocking write.
// Therefore the write buffer will still be full. Nothing
// else to do here. Exit the loop.
break;
}
len = len - thisTime;
}
}
if (len > 0) {
// Remaining data must be buffered
addToBuffers(buf, off, len);
}
}
/**
* Writes the data to the socket (writing that data to the socket using a
* non-blocking write) until either all the data has been transferred and
* space remains in the socket write buffer or a non-blocking write leaves
* data in the socket write buffer. If it is possible use the provided
* buffer directly and do not transfer to the socket write buffer.
*
* @param from The ByteBuffer containing the data to be written
*
* @throws IOException If an IO error occurs during the write
*/
protected void writeNonBlocking(ByteBuffer from) throws IOException {
if (bufferedWrites.size() == 0 && socketBufferHandler.isWriteBufferWritable()) {
writeNonBlockingInternal(from);
}
if (from.remaining() > 0) {
// Remaining data must be buffered
addToBuffers(from);
}
}
private boolean writeNonBlockingInternal(ByteBuffer from) throws IOException {
if (socketBufferHandler.isWriteBufferEmpty()) {
return writeByteBufferNonBlocking(from);
} else {
socketBufferHandler.configureWriteBufferForWrite();
transfer(from, socketBufferHandler.getWriteBuffer());
if (!socketBufferHandler.isWriteBufferWritable()) {
doWrite(false);
if (socketBufferHandler.isWriteBufferWritable()) {
return writeByteBufferNonBlocking(from);
}
}
}
return !socketBufferHandler.isWriteBufferWritable();
}
protected boolean writeByteBufferNonBlocking(ByteBuffer from) throws IOException {
// The socket write buffer capacity is socket.appWriteBufSize
int limit = socketBufferHandler.getWriteBuffer().capacity();
int fromLimit = from.limit();
while (from.remaining() >= limit) {
int newLimit = from.position() + limit;
from.limit(newLimit);
doWrite(false, from);
from.limit(fromLimit);
if (from.position() != newLimit) {
// Didn't write the whole amount of data in the last
// non-blocking write.
// Exit the loop.
return true;
}
}
if (from.remaining() > 0) {
socketBufferHandler.configureWriteBufferForWrite();
transfer(from, socketBufferHandler.getWriteBuffer());
}
return false;
}
/**
* Writes as much data as possible from any that remains in the buffers.
*
* @param block <code>true</code> if a blocking write should be used,
* otherwise a non-blocking write will be used
*
* @return <code>true</code> if data remains to be flushed after this method
* completes, otherwise <code>false</code>. In blocking mode
* therefore, the return value should always be <code>false</code>
*
* @throws IOException If an IO error occurs during the write
*/
public boolean flush(boolean block) throws IOException {
boolean result = false;
if (block) {
// A blocking flush will always empty the buffer.
flushBlocking();
} else {
result = flushNonBlocking();
}
return result;
}
protected void flushBlocking() throws IOException {
doWrite(true);
if (bufferedWrites.size() > 0) {
Iterator<ByteBufferHolder> bufIter = bufferedWrites.iterator();
while (bufIter.hasNext()) {
ByteBufferHolder buffer = bufIter.next();
buffer.flip();
writeBlocking(buffer.getBuf());
if (buffer.getBuf().remaining() == 0) {
bufIter.remove();
}
}
if (!socketBufferHandler.isWriteBufferEmpty()) {
doWrite(true);
}
}
}
protected boolean flushNonBlocking() throws IOException {
boolean dataLeft = !socketBufferHandler.isWriteBufferEmpty();
// Write to the socket, if there is anything to write
if (dataLeft) {
doWrite(false);
dataLeft = !socketBufferHandler.isWriteBufferEmpty();
}
if (!dataLeft && bufferedWrites.size() > 0) {
Iterator<ByteBufferHolder> bufIter = bufferedWrites.iterator();
while (!dataLeft && bufIter.hasNext()) {
ByteBufferHolder buffer = bufIter.next();
buffer.flip();
dataLeft = writeNonBlockingInternal(buffer.getBuf());
if (buffer.getBuf().remaining() == 0) {
bufIter.remove();
}
}
if (!dataLeft && !socketBufferHandler.isWriteBufferEmpty()) {
doWrite(false);
dataLeft = !socketBufferHandler.isWriteBufferEmpty();
}
}
return dataLeft;
}
/**
* Write the contents of the socketWriteBuffer to the socket. For blocking
* writes either then entire contents of the buffer will be written or an
* IOException will be thrown. Partial blocking writes will not occur.
*
* @param block Should the write be blocking or not?
*
* @throws IOException If an I/O error such as a timeout occurs during the
* write
*/
protected void doWrite(boolean block) throws IOException {
socketBufferHandler.configureWriteBufferForRead();
doWrite(block, socketBufferHandler.getWriteBuffer());
}
/**
* Write the contents of the ByteBuffer to the socket. For blocking writes
* either then entire contents of the buffer will be written or an
* IOException will be thrown. Partial blocking writes will not occur.
*
* @param block Should the write be blocking or not?
* @param from the ByteBuffer containing the data to be written
*
* @throws IOException If an I/O error such as a timeout occurs during the
* write
*/
protected abstract void doWrite(boolean block, ByteBuffer from) throws IOException;
protected void addToBuffers(byte[] buf, int offset, int length) {
ByteBufferHolder holder = getByteBufferHolder(length);
holder.getBuf().put(buf, offset, length);
}
protected void addToBuffers(ByteBuffer from) {
ByteBufferHolder holder = getByteBufferHolder(from.remaining());
holder.getBuf().put(from);
}
private ByteBufferHolder getByteBufferHolder(int capacity) {
ByteBufferHolder holder = bufferedWrites.peekLast();
if (holder == null || holder.isFlipped() || holder.getBuf().remaining() < capacity) {
ByteBuffer buffer = ByteBuffer.allocate(Math.max(bufferedWriteSize, capacity));
holder = new ByteBufferHolder(buffer, false);
bufferedWrites.add(holder);
}
return holder;
}
public void processSocket(SocketEvent socketStatus, boolean dispatch) {
endpoint.processSocket(this, socketStatus, dispatch);
}
public abstract void registerReadInterest();
public abstract void registerWriteInterest();
public abstract SendfileDataBase createSendfileData(String filename, long pos, long length);
/**
* Starts the sendfile process. It is expected that if the sendfile process
* does not complete during this call and does not report an error, that the
* caller <b>will not</b> add the socket to the poller (or equivalent). That
* is the responsibility of this method.
*
* @param sendfileData Data representing the file to send
*
* @return The state of the sendfile process after the first write.
*/
public abstract SendfileState processSendfile(SendfileDataBase sendfileData);
/**
* Require the client to perform CLIENT-CERT authentication if it hasn't
* already done so.
*
* @param sslSupport The SSL/TLS support instance currently being used by
* the connection that may need updating after the client
* authentication
*/
public abstract void doClientAuth(SSLSupport sslSupport);
public abstract SSLSupport getSslSupport(String clientCertProvider);
// ------------------------------------------------------- NIO 2 style APIs
public enum BlockingMode {
/**
* The operation will now block. If there are pending operations,
* the operation will return CompletionState.NOT_DONE.
*/
NON_BLOCK,
/**
* The operation will block until pending operations are completed, but
* will not block after performing it.
*/
SEMI_BLOCK,
/**
* The operation will block until completed.
*/
BLOCK
}
public enum CompletionState {
/**
* Operation is still pending.
*/
PENDING,
/**
* Operation was pending and non blocking.
*/
NOT_DONE,
/**
* The operation completed inline.
*/
INLINE,
/**
* The operation completed inline but failed.
*/
ERROR,
/**
* The operation completed, but not inline.
*/
DONE
}
public enum CompletionHandlerCall {
/**
* Operation should continue, the completion handler shouldn't be
* called.
*/
CONTINUE,
/**
* The operation completed but the completion handler shouldn't be
* called.
*/
NONE,
/**
* The operation is complete, the completion handler should be
* called.
*/
DONE
}
public interface CompletionCheck {
/**
* Determine what call, if any, should be made to the completion
* handler.
*
* @param state of the operation (done or done in-line since the
* IO call is done)
* @param buffers ByteBuffer[] that has been passed to the
* original IO call
* @param offset that has been passed to the original IO call
* @param length that has been passed to the original IO call
*
* @return The call, if any, to make to the completion handler
*/
public CompletionHandlerCall callHandler(CompletionState state, ByteBuffer[] buffers,
int offset, int length);
}
/**
* This utility CompletionCheck will cause the write to fully write
* all remaining data. If the operation completes inline, the
* completion handler will not be called.
*/
public static final CompletionCheck COMPLETE_WRITE = new CompletionCheck() {
@Override
public CompletionHandlerCall callHandler(CompletionState state, ByteBuffer[] buffers,
int offset, int length) {
for (int i = 0; i < length; i++) {
if (buffers[offset + i].remaining() > 0) {
return CompletionHandlerCall.CONTINUE;
}
}
return (state == CompletionState.DONE) ? CompletionHandlerCall.DONE
: CompletionHandlerCall.NONE;
}
};
/**
* This utility CompletionCheck will cause the completion handler
* to be called once some data has been read. If the operation
* completes inline, the completion handler will not be called.
*/
public static final CompletionCheck READ_DATA = new CompletionCheck() {
@Override
public CompletionHandlerCall callHandler(CompletionState state, ByteBuffer[] buffers,
int offset, int length) {
return (state == CompletionState.DONE) ? CompletionHandlerCall.DONE
: CompletionHandlerCall.NONE;
}
};
/**
* Allows using NIO2 style read/write only for connectors that can
* efficiently support it.
*
* @return This default implementation always returns {@code false}
*/
public boolean hasAsyncIO() {
return false;
}
/**
* Allows checking if an asynchronous read operation is currently pending.
* @return <code>true</code> if the endpoint supports asynchronous IO and
* a read operation is being processed asynchronously
*/
public boolean isReadPending() {
return false;
}
/**
* Allows checking if an asynchronous write operation is currently pending.
* @return <code>true</code> if the endpoint supports asynchronous IO and
* a write operation is being processed asynchronously
*/
public boolean isWritePending() {
return false;
}
/**
* If an asynchronous read operation is pending, this method will block
* until the operation completes, or the specified amount of time
* has passed.
* @param timeout The maximum amount of time to wait
* @param unit The unit for the timeout
* @return <code>true</code> if the read operation is complete,
* <code>false</code> if the operation is still pending and
* the specified timeout has passed
*/
public boolean awaitReadComplete(long timeout, TimeUnit unit) {
return true;
}
/**
* If an asynchronous write operation is pending, this method will block
* until the operation completes, or the specified amount of time
* has passed.
* @param timeout The maximum amount of time to wait
* @param unit The unit for the timeout
* @return <code>true</code> if the read operation is complete,
* <code>false</code> if the operation is still pending and
* the specified timeout has passed
*/
public boolean awaitWriteComplete(long timeout, TimeUnit unit) {
return true;
}
/**
* Scatter read. The completion handler will be called once some
* data has been read or an error occurred. If a CompletionCheck
* object has been provided, the completion handler will only be
* called if the callHandler method returned true. If no
* CompletionCheck object has been provided, the default NIO2
* behavior is used: the completion handler will be called as soon
* as some data has been read, even if the read has completed inline.
*
* @param block is the blocking mode that will be used for this operation
* @param timeout timeout duration for the read
* @param unit units for the timeout duration
* @param attachment an object to attach to the I/O operation that will be
* used when calling the completion handler
* @param check for the IO operation completion
* @param handler to call when the IO is complete
* @param dsts buffers
* @param <A> The attachment type
* @return the completion state (done, done inline, or still pending)
*/
public final <A> CompletionState read(BlockingMode block, long timeout,
TimeUnit unit, A attachment, CompletionCheck check,
CompletionHandler<Long, ? super A> handler, ByteBuffer... dsts) {
if (dsts == null) {
throw new IllegalArgumentException();
}
return read(dsts, 0, dsts.length, block, timeout, unit, attachment, check, handler);
}
/**
* Scatter read. The completion handler will be called once some
* data has been read or an error occurred. If a CompletionCheck
* object has been provided, the completion handler will only be
* called if the callHandler method returned true. If no
* CompletionCheck object has been provided, the default NIO2
* behavior is used: the completion handler will be called as soon
* as some data has been read, even if the read has completed inline.
*
* @param dsts buffers
* @param offset in the buffer array
* @param length in the buffer array
* @param block is the blocking mode that will be used for this operation
* @param timeout timeout duration for the read
* @param unit units for the timeout duration
* @param attachment an object to attach to the I/O operation that will be
* used when calling the completion handler
* @param check for the IO operation completion
* @param handler to call when the IO is complete
* @param <A> The attachment type
* @return the completion state (done, done inline, or still pending)
*/
public <A> CompletionState read(ByteBuffer[] dsts, int offset, int length,
BlockingMode block, long timeout, TimeUnit unit, A attachment,
CompletionCheck check, CompletionHandler<Long, ? super A> handler) {
throw new UnsupportedOperationException();
}
/**
* Gather write. The completion handler will be called once some
* data has been written or an error occurred. If a CompletionCheck
* object has been provided, the completion handler will only be
* called if the callHandler method returned true. If no
* CompletionCheck object has been provided, the default NIO2
* behavior is used: the completion handler will be called, even
* if the write is incomplete and data remains in the buffers, or
* if the write completed inline.
*
* @param block is the blocking mode that will be used for this operation
* @param timeout timeout duration for the write
* @param unit units for the timeout duration
* @param attachment an object to attach to the I/O operation that will be
* used when calling the completion handler
* @param check for the IO operation completion
* @param handler to call when the IO is complete
* @param srcs buffers
* @param <A> The attachment type
* @return the completion state (done, done inline, or still pending)
*/
public final <A> CompletionState write(BlockingMode block, long timeout,
TimeUnit unit, A attachment, CompletionCheck check,
CompletionHandler<Long, ? super A> handler, ByteBuffer... srcs) {
if (srcs == null) {
throw new IllegalArgumentException();
}
return write(srcs, 0, srcs.length, block, timeout, unit, attachment, check, handler);
}
/**
* Gather write. The completion handler will be called once some
* data has been written or an error occurred. If a CompletionCheck
* object has been provided, the completion handler will only be
* called if the callHandler method returned true. If no
* CompletionCheck object has been provided, the default NIO2
* behavior is used: the completion handler will be called, even
* if the write is incomplete and data remains in the buffers, or
* if the write completed inline.
*
* @param srcs buffers
* @param offset in the buffer array
* @param length in the buffer array
* @param block is the blocking mode that will be used for this operation
* @param timeout timeout duration for the write
* @param unit units for the timeout duration
* @param attachment an object to attach to the I/O operation that will be
* used when calling the completion handler
* @param check for the IO operation completion
* @param handler to call when the IO is complete
* @param <A> The attachment type
* @return the completion state (done, done inline, or still pending)
*/
public <A> CompletionState write(ByteBuffer[] srcs, int offset, int length,
BlockingMode block, long timeout, TimeUnit unit, A attachment,
CompletionCheck check, CompletionHandler<Long, ? super A> handler) {
throw new UnsupportedOperationException();
}
// --------------------------------------------------------- Utility methods
protected static int transfer(byte[] from, int offset, int length, ByteBuffer to) {
int max = Math.min(length, to.remaining());
if (max > 0) {
to.put(from, offset, max);
}
return max;
}
protected static int transfer(ByteBuffer from, ByteBuffer to) {
int max = Math.min(from.remaining(), to.remaining());
if (max > 0) {
int fromLimit = from.limit();
from.limit(from.position() + max);
to.put(from);
from.limit(fromLimit);
}
return max;
}
}