/**
* 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.hadoop.gateway.filter.rewrite.impl;
import org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriteEnvironment;
import org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriteFlowDescriptor;
import org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriteStepDescriptor;
import org.apache.hadoop.gateway.filter.rewrite.api.UrlRewriteStepFlow;
import org.apache.hadoop.gateway.filter.rewrite.i18n.UrlRewriteMessages;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteContext;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteStepProcessor;
import org.apache.hadoop.gateway.filter.rewrite.spi.UrlRewriteStepStatus;
import org.apache.hadoop.gateway.i18n.messages.MessagesFactory;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class UrlRewriteStepProcessorHolder implements UrlRewriteStepProcessor {
private static final UrlRewriteMessages LOG = MessagesFactory.get( UrlRewriteMessages.class );
private boolean isCondition;
private UrlRewriteStepDescriptor descriptor;
private UrlRewriteStepProcessor processor;
private List<UrlRewriteStepProcessorHolder> childProcessors;
@Override
public String getType() {
return "system";
}
public boolean isCondition() {
return isCondition;
}
public boolean isAction() {
return !isCondition;
}
@Override
@SuppressWarnings( "unchecked" )
public void initialize( UrlRewriteEnvironment environment, UrlRewriteStepDescriptor descriptor ) throws Exception {
UrlRewriteStepProcessor processor = UrlRewriteStepProcessorFactory.create( descriptor );
processor.initialize( environment, descriptor );
initialize( environment, descriptor, processor );
}
// For unit testing.
@SuppressWarnings("unchecked")
void initialize( UrlRewriteEnvironment environment, UrlRewriteStepDescriptor descriptor, UrlRewriteStepProcessor processor ) throws Exception {
this.descriptor = descriptor;
this.processor = processor;
this.isCondition = descriptor instanceof UrlRewriteFlowDescriptor;
this.childProcessors = new ArrayList<UrlRewriteStepProcessorHolder>();
if( isCondition ) {
UrlRewriteFlowDescriptor flowDescriptor = (UrlRewriteFlowDescriptor)descriptor;
List<UrlRewriteStepDescriptor> stepList = flowDescriptor.steps();
if( stepList != null && !stepList.isEmpty() ) {
Iterator<UrlRewriteStepDescriptor> stepIterator = stepList.iterator();
while( stepIterator.hasNext() ) {
UrlRewriteStepDescriptor stepDescriptor = stepIterator.next();
UrlRewriteStepProcessorHolder stepProcessor = new UrlRewriteStepProcessorHolder();
stepProcessor.initialize( environment, stepDescriptor );
childProcessors.add( stepProcessor );
}
}
}
}
// For unit testing.
UrlRewriteStepDescriptor getDescriptor() {
return descriptor;
}
// For unit testing.
UrlRewriteStepProcessor getProcessor() {
return processor;
}
@Override
public UrlRewriteStepStatus process( UrlRewriteContext context ) throws Exception {
UrlRewriteStepStatus status = UrlRewriteStepStatus.SUCCESS;
// If initialization failed then fail processing
if( processor != null ) {
status = processor.process( context );
if( UrlRewriteStepStatus.SUCCESS == status &&
descriptor instanceof UrlRewriteFlowDescriptor &&
!childProcessors.isEmpty() ) {
UrlRewriteFlowDescriptor flowDescriptor = (UrlRewriteFlowDescriptor)descriptor;
UrlRewriteStepFlow flow = flowDescriptor.flow();
if( flow == null ) {
flow = UrlRewriteStepFlow.AND;
}
switch( flow ) {
case ALL:
return processAllFlow( context );
case AND:
return processAndFlow( context );
case OR:
return processOrFlow( context );
}
}
}
return status;
}
private UrlRewriteStepStatus processAllFlow( UrlRewriteContext context ) throws Exception {
UrlRewriteStepProcessorState state = new UrlRewriteStepProcessorState( childProcessors.iterator() );
UrlRewriteStepStatus stepStatus = UrlRewriteStepStatus.SUCCESS;
UrlRewriteStepProcessorHolder step;
while( state.hasNext() ) {
while( state.hasNextCondition() ) {
step = state.nextCondition( stepStatus );
stepStatus = step.process( context );
if( stepStatus == UrlRewriteStepStatus.FINISHED ) {
return stepStatus;
}
}
stepStatus = processActions( context, state );
if( stepStatus == UrlRewriteStepStatus.FINISHED ) {
return stepStatus;
}
}
return UrlRewriteStepStatus.SUCCESS;
}
// All conditions proceeding a set of one or more actions must succeed for the actions to be executed.
private UrlRewriteStepStatus processAndFlow( UrlRewriteContext context ) throws Exception {
UrlRewriteStepProcessorState state = new UrlRewriteStepProcessorState( childProcessors.iterator() );
UrlRewriteStepStatus stepStatus = UrlRewriteStepStatus.SUCCESS;
UrlRewriteStepProcessorHolder step;
while( state.hasNext() ) {
while( state.hasNextCondition() ) {
step = state.nextCondition( stepStatus );
stepStatus = step.process( context );
if( !( stepStatus == UrlRewriteStepStatus.SUCCESS ) ) {
return stepStatus;
}
}
stepStatus = processActions( context, state );
if( !( stepStatus == UrlRewriteStepStatus.SUCCESS ) ) {
return stepStatus;
}
}
return UrlRewriteStepStatus.SUCCESS;
}
// At least one condition proceeding a set of one or more actions must succedd for the actions to be executed.
private UrlRewriteStepStatus processOrFlow( UrlRewriteContext context ) throws Exception {
UrlRewriteStepProcessorState state = new UrlRewriteStepProcessorState( childProcessors.iterator() );
UrlRewriteStepStatus status = UrlRewriteStepStatus.SUCCESS;
UrlRewriteStepProcessorHolder step;
while( state.hasNext() ) {
UrlRewriteStepStatus flowStatus = UrlRewriteStepStatus.FAILURE;
while( state.hasNextCondition() ) {
step = state.nextCondition( status );
if( flowStatus == UrlRewriteStepStatus.FAILURE ) {
status = step.process( context );
switch( status ) {
case SUCCESS:
flowStatus = UrlRewriteStepStatus.SUCCESS;
continue;
case FINISHED:
return status;
}
}
}
status = processActions( context, state );
if( status != UrlRewriteStepStatus.SUCCESS ) {
return status;
}
}
return UrlRewriteStepStatus.SUCCESS;
}
private UrlRewriteStepStatus processActions( UrlRewriteContext context, UrlRewriteStepProcessorState state )
throws Exception {
UrlRewriteStepStatus flowStatus = UrlRewriteStepStatus.SUCCESS;
while( state.hasNextAction() ) {
if( flowStatus == UrlRewriteStepStatus.SUCCESS ) {
UrlRewriteStepStatus stepStatus = UrlRewriteStepStatus.SUCCESS;
UrlRewriteStepProcessorHolder step = state.nextAction( stepStatus );
stepStatus = step.process( context );
switch( stepStatus ) {
case FAILURE:
flowStatus = UrlRewriteStepStatus.FAILURE;
continue;
case FINISHED:
return stepStatus;
}
}
}
return flowStatus;
}
@Override
public void destroy() throws Exception {
destroy( processor );
if( descriptor instanceof UrlRewriteFlowDescriptor ) {
for( UrlRewriteStepProcessorHolder childProcessor : childProcessors ) {
destroy( childProcessor );
}
}
}
public void destroy( UrlRewriteStepProcessor processor ) {
if( processor != null ) {
try {
processor.destroy();
} catch( Exception e ) {
// Maybe it makes sense to throw exception
LOG.failedToDestroyRewriteStepProcessor( e );
}
}
}
}