/*
* 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();
state = dispatch(nextDispatch.getSocketStatus());
} 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);
if (state == 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.
state = service(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 {
// Default to closing the socket if the SocketEvent passed in
// is not consistent with the current state of the Processor
state = SocketState.CLOSED;
}
if (state != SocketState.CLOSED && isAsync()) {
state = asyncPostProcess();
}
if (getLog().isDebugEnabled()) {
getLog().debug("Socket: [" + socketWrapper +
"], Status in: [" + status +
"], State out: [" + 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;
}
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();
}
}
/**
* 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 socket state
*/
protected abstract SocketState dispatch(SocketEvent status);
protected abstract SocketState asyncPostProcess();
protected abstract Log getLog();
}