/*
* Copyright 2013 <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
* Licensed 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.ocpsoft.rewrite.servlet.impl;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;
import javax.servlet.ServletContext;
import org.ocpsoft.common.services.NonEnriching;
import org.ocpsoft.common.services.ServiceLoader;
import org.ocpsoft.common.util.Iterators;
import org.ocpsoft.logging.Logger;
import org.ocpsoft.rewrite.config.Configuration;
import org.ocpsoft.rewrite.config.ConfigurationLoader;
import org.ocpsoft.rewrite.config.Operation;
import org.ocpsoft.rewrite.config.Rule;
import org.ocpsoft.rewrite.context.RewriteState;
import org.ocpsoft.rewrite.event.InboundRewrite;
import org.ocpsoft.rewrite.event.OutboundRewrite;
import org.ocpsoft.rewrite.exception.RewriteException;
import org.ocpsoft.rewrite.param.DefaultParameterValueStore;
import org.ocpsoft.rewrite.param.Parameter;
import org.ocpsoft.rewrite.param.ParameterStore;
import org.ocpsoft.rewrite.param.ParameterValueStore;
import org.ocpsoft.rewrite.servlet.event.BaseRewrite.ServletRewriteFlow;
import org.ocpsoft.rewrite.servlet.http.HttpRewriteProvider;
import org.ocpsoft.rewrite.servlet.http.event.HttpServletRewrite;
import org.ocpsoft.rewrite.spi.RuleCacheProvider;
import org.ocpsoft.rewrite.util.ParameterUtils;
import org.ocpsoft.rewrite.util.ServiceLogger;
/**
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
*/
/**
* @author <a href="mailto:lincolnbaxter@gmail.com">Lincoln Baxter, III</a>
*
*/
public class DefaultHttpRewriteProvider extends HttpRewriteProvider implements NonEnriching
{
private static Logger log = Logger.getLogger(DefaultHttpRewriteProvider.class);
private volatile ConfigurationLoader loader;
private volatile List<RuleCacheProvider> ruleCacheProviders;
@Override
@SuppressWarnings("unchecked")
public void init(ServletContext context)
{
if (loader == null)
synchronized (this)
{
if (loader == null)
loader = ConfigurationLoader.create(context);
}
if (ruleCacheProviders == null)
synchronized (this)
{
ruleCacheProviders = Iterators
.asList(ServiceLoader.load(RuleCacheProvider.class));
ServiceLogger.logLoadedServices(log, RuleCacheProvider.class, ruleCacheProviders);
}
loader.loadConfiguration(context);
}
@Override
public void rewriteHttp(final HttpServletRewrite event)
{
if (event instanceof InboundRewrite)
rewriteInbound(event);
else if (event instanceof OutboundRewrite)
rewriteOutbound(event);
else
throw new RewriteException("Unknown Rewrite event type [" + event.getClass().getName()
+ "] - was neither an inbound nor outbound Rewrite.");
}
private void rewriteInbound(final HttpServletRewrite event)
{
ServletContext servletContext = event.getServletContext();
if (loader == null)
{
synchronized (servletContext)
{
if (loader == null)
loader = ConfigurationLoader.create(servletContext);
}
}
Configuration compiledConfiguration = loader.loadConfiguration(servletContext);
List<Rule> rules = compiledConfiguration.getRules();
final EvaluationContextImpl context = new EvaluationContextImpl();
Object cacheKey = null;
for (int i = 0; i < ruleCacheProviders.size(); i++)
{
RuleCacheProvider provider = ruleCacheProviders.get(i);
cacheKey = provider.createKey(event, context);
final List<Rule> list = provider.get(cacheKey);
if (list != null && !list.isEmpty())
{
if (log.isDebugEnabled())
log.debug("Using cached ruleset for event [" + event + "] from provider [" + provider + "].");
for (int j = 0; j < list.size(); j++)
{
Rule rule = list.get(j);
event.getEvaluatedRules().add(rule);
context.clear();
DefaultParameterValueStore values = new DefaultParameterValueStore();
context.put(ParameterValueStore.class, values);
context.setState(RewriteState.EVALUATING);
if (rule.evaluate(event, context))
{
if (handleBindings(event, context, values))
{
context.setState(RewriteState.PERFORMING);
if (log.isDebugEnabled())
log.debug("Rule [" + rule + "] matched and will be performed.");
List<Operation> preOperations = context.getPreOperations();
for (int k = 0; k < preOperations.size(); k++)
{
preOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
rule.perform(event, context);
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
List<Operation> postOperations = context.getPostOperations();
for (int k = 0; k < postOperations.size(); k++)
{
postOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
}
}
else
{
event.getEvaluatedRules().remove(rule);
break;
}
}
}
}
/*
* Highly optimized loop - for performance reasons. Think before you change this!
*/
List<Rule> cacheable = new ArrayList<Rule>();
for (int i = 0; i < rules.size(); i++)
{
Rule rule = rules.get(i);
event.getEvaluatedRules().add(rule);
context.clear();
DefaultParameterValueStore values = new DefaultParameterValueStore();
context.put(ParameterValueStore.class, values);
context.setState(RewriteState.EVALUATING);
if (rule.evaluate(event, context))
{
if (handleBindings(event, context, values))
{
context.setState(RewriteState.PERFORMING);
if (log.isDebugEnabled())
log.debug("Rule [" + rule + "] matched and will be performed.");
cacheable.add(rule);
List<Operation> preOperations = context.getPreOperations();
for (int k = 0; k < preOperations.size(); k++)
{
preOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
rule.perform(event, context);
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
List<Operation> postOperations = context.getPostOperations();
for (int k = 0; k < postOperations.size(); k++)
{
postOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
}
}
else
{
event.getEvaluatedRules().remove(rule);
}
}
if (!cacheable.isEmpty())
{
for (int i = 0; i < ruleCacheProviders.size(); i++)
{
ruleCacheProviders.get(i).put(cacheKey, cacheable);
}
}
}
private void rewriteOutbound(HttpServletRewrite event)
{
ServletContext servletContext = event.getServletContext();
if (loader == null)
{
synchronized (servletContext)
{
if (loader == null)
loader = ConfigurationLoader.create(servletContext);
}
}
Configuration compiledConfiguration = loader.loadConfiguration(servletContext);
List<Rule> rules = compiledConfiguration.getRules();
final EvaluationContextImpl context = new EvaluationContextImpl();
Object cacheKey = null;
for (int i = ruleCacheProviders.size() - 1; i >= 0; i--)
{
RuleCacheProvider provider = ruleCacheProviders.get(i);
cacheKey = provider.createKey(event, context);
final List<Rule> list = provider.get(cacheKey);
if (list != null && !list.isEmpty())
{
if (log.isDebugEnabled())
log.debug("Using cached ruleset for event [" + event + "] from provider [" + provider + "].");
for (int j = list.size() - 1; j >= 0; j--)
{
Rule rule = list.get(j);
event.getEvaluatedRules().add(rule);
context.clear();
DefaultParameterValueStore values = new DefaultParameterValueStore();
context.put(ParameterValueStore.class, values);
context.setState(RewriteState.EVALUATING);
if (rule.evaluate(event, context))
{
if (handleBindings(event, context, values))
{
context.setState(RewriteState.PERFORMING);
if (log.isDebugEnabled())
log.debug("Rule [" + rule + "] matched and will be performed.");
List<Operation> preOperations = context.getPreOperations();
for (int k = 0; k < preOperations.size(); k++)
{
preOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
rule.perform(event, context);
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
List<Operation> postOperations = context.getPostOperations();
for (int k = 0; k < postOperations.size(); k++)
{
postOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
return;
}
}
}
else
{
event.getEvaluatedRules().remove(rule);
break;
}
}
}
}
/*
* Highly optimized loop - for performance reasons. Think before you change this!
*/
List<Rule> cacheable = new ArrayList<Rule>();
for (int i = rules.size() - 1; i >= 0; i--)
{
Rule rule = rules.get(i);
event.getEvaluatedRules().add(rule);
context.clear();
DefaultParameterValueStore values = new DefaultParameterValueStore();
context.put(ParameterValueStore.class, values);
context.setState(RewriteState.EVALUATING);
if (rule.evaluate(event, context))
{
if (handleBindings(event, context, values))
{
context.setState(RewriteState.PERFORMING);
if (log.isDebugEnabled())
log.debug("Rule [" + rule + "] matched and will be performed.");
cacheable.add(rule);
List<Operation> preOperations = context.getPreOperations();
for (int k = 0; k < preOperations.size(); k++)
{
preOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
rule.perform(event, context);
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
List<Operation> postOperations = context.getPostOperations();
for (int k = 0; k < postOperations.size(); k++)
{
postOperations.get(k).perform(event, context);
}
if (event.getFlow().is(ServletRewriteFlow.HANDLED))
{
break;
}
}
}
else {
event.getEvaluatedRules().remove(rule);
}
}
if (!cacheable.isEmpty())
{
for (int i = ruleCacheProviders.size() - 1; i >= 0; i--)
{
ruleCacheProviders.get(i).put(cacheKey, cacheable);
}
}
}
private boolean handleBindings(final HttpServletRewrite event, final EvaluationContextImpl context,
DefaultParameterValueStore values)
{
boolean result = true;
ParameterStore store = (ParameterStore) context.get(ParameterStore.class);
for (Entry<String, Parameter<?>> entry : store)
{
Parameter<?> parameter = entry.getValue();
String value = values.retrieve(parameter);
if (!ParameterUtils.enqueueSubmission(event, context, parameter, value))
{
result = false;
break;
}
}
return result;
}
@Override
public void shutdown(ServletContext context)
{}
@Override
public int priority()
{
return 0;
}
}