AbstractProcessorLight.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.coyote;
import java.io.IOException;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import org.apache.juli.logging.Log;
import org.apache.tomcat.util.net.AbstractEndpoint.Handler.SocketState;
import org.apache.tomcat.util.net.DispatchType;
import org.apache.tomcat.util.net.SocketEvent;
import org.apache.tomcat.util.net.SocketWrapperBase;
/**
* This is a light-weight abstract processor implementation that is intended as a basis for all Processor
* implementations from the light-weight upgrade processors to the HTTP/AJP processors.
*/
public abstract class AbstractProcessorLight implements Processor {
private Set<DispatchType> dispatches = new CopyOnWriteArraySet<>();
@Override
public SocketState process(SocketWrapperBase<?> socketWrapper, SocketEvent status) throws IOException {
SocketState state = SocketState.CLOSED;
Iterator<DispatchType> dispatches = null;
do {
if (dispatches != null) {
DispatchType nextDispatch = dispatches.next();
if (getLog().isTraceEnabled()) {
getLog().trace("Processing dispatch type: [" + nextDispatch + "]");
}
state = dispatch(nextDispatch.getSocketStatus());
if (!dispatches.hasNext()) {
state = checkForPipelinedData(state, socketWrapper);
}
} else if (status == SocketEvent.DISCONNECT) {
// Do nothing here, just wait for it to get recycled
} else if (isAsync() || isUpgrade() || state == SocketState.ASYNC_END) {
state = dispatch(status);
state = checkForPipelinedData(state, socketWrapper);
} else if (status == SocketEvent.OPEN_WRITE) {
// Extra write event likely after async, ignore
state = SocketState.LONG;
} else if (status == SocketEvent.OPEN_READ) {
state = service(socketWrapper);
} else if (status == SocketEvent.CONNECT_FAIL) {
logAccess(socketWrapper);
} else {
// Default to closing the socket if the SocketEvent passed in
// is not consistent with the current state of the Processor
state = SocketState.CLOSED;
}
if (getLog().isTraceEnabled()) {
getLog().trace(
"Socket: [" + socketWrapper + "], Status in: [" + status + "], State out: [" + state + "]");
}
/*
* If state is already CLOSED don't call asyncPostProcess() as that will likely change the the state to some
* other value causing processing to continue when it should cease. The AsyncStateMachine will be recycled
* as part of the Processor clean-up on CLOSED so it doesn't matter what state it is left in at this point.
*/
if (isAsync() && state != SocketState.CLOSED) {
state = asyncPostProcess();
if (getLog().isTraceEnabled()) {
getLog().trace(
"Socket: [" + socketWrapper + "], State after async post processing: [" + state + "]");
}
}
if (dispatches == null || !dispatches.hasNext()) {
// Only returns non-null iterator if there are
// dispatches to process.
dispatches = getIteratorAndClearDispatches();
}
} while (state == SocketState.ASYNC_END || dispatches != null && state != SocketState.CLOSED);
return state;
}
private SocketState checkForPipelinedData(SocketState inState, SocketWrapperBase<?> socketWrapper)
throws IOException {
if (inState == SocketState.OPEN) {
// There may be pipe-lined data to read. If the data isn't
// processed now, execution will exit this loop and call
// release() which will recycle the processor (and input
// buffer) deleting any pipe-lined data. To avoid this,
// process it now.
return service(socketWrapper);
} else {
return inState;
}
}
public void addDispatch(DispatchType dispatchType) {
synchronized (dispatches) {
dispatches.add(dispatchType);
}
}
public Iterator<DispatchType> getIteratorAndClearDispatches() {
// Note: Logic in AbstractProtocol depends on this method only returning
// a non-null value if the iterator is non-empty. i.e. it should never
// return an empty iterator.
Iterator<DispatchType> result;
synchronized (dispatches) {
// Synchronized as the generation of the iterator and the clearing
// of dispatches needs to be an atomic operation.
result = dispatches.iterator();
if (result.hasNext()) {
dispatches.clear();
} else {
result = null;
}
}
return result;
}
protected void clearDispatches() {
synchronized (dispatches) {
dispatches.clear();
}
}
/**
* Add an entry to the access log for a failed connection attempt.
*
* @param socketWrapper The connection to process
*
* @throws IOException If an I/O error occurs during the processing of the request
*/
protected void logAccess(SocketWrapperBase<?> socketWrapper) throws IOException {
// NO-OP by default
}
/**
* Service a 'standard' HTTP request. This method is called for both new requests and for requests that have
* partially read the HTTP request line or HTTP headers. Once the headers have been fully read this method is not
* called again until there is a new HTTP request to process. Note that the request type may change during
* processing which may result in one or more calls to {@link #dispatch(SocketEvent)}. Requests may be pipe-lined.
*
* @param socketWrapper The connection to process
*
* @return The state the caller should put the socket in when this method returns
*
* @throws IOException If an I/O error occurs during the processing of the request
*/
protected abstract SocketState service(SocketWrapperBase<?> socketWrapper) throws IOException;
/**
* Process an in-progress request that is not longer in standard HTTP mode. Uses currently include Servlet 3.0 Async
* and HTTP upgrade connections. Further uses may be added in the future. These will typically start as HTTP
* requests.
*
* @param status The event to process
*
* @return The state the caller should put the socket in when this method returns
*
* @throws IOException If an I/O error occurs during the processing of the request
*/
protected abstract SocketState dispatch(SocketEvent status) throws IOException;
/**
* Calls the post process of the async state machine.
*
* @return The state the caller should put the socket in when this method returns
*/
protected abstract SocketState asyncPostProcess();
/**
* @return the logger associated with this processor type
*/
protected abstract Log getLog();
}