io.undertow.server.handlers.cache.CacheHandler Maven / Gradle / Ivy
Go to download
This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* 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 io.undertow.server.handlers.cache;
import io.undertow.Handlers;
import io.undertow.server.ConduitWrapper;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.ResponseCodeHandler;
import io.undertow.server.handlers.encoding.AllowedContentEncodings;
import io.undertow.util.ConduitFactory;
import org.xnio.conduits.StreamSinkConduit;
import static io.undertow.util.Headers.CONTENT_LENGTH;
/**
*
* Handler that attaches a cache to the exchange, a handler can query this cache to see if the
* cache has a cached copy of the content, and if so have the cache serve this content automatically.
*
*
* @author Stuart Douglas
*/
public class CacheHandler implements HttpHandler {
private final DirectBufferCache cache;
private volatile HttpHandler next = ResponseCodeHandler.HANDLE_404;
public CacheHandler(final DirectBufferCache cache, final HttpHandler next) {
this.cache = cache;
this.next = next;
}
public CacheHandler(final DirectBufferCache cache) {
this.cache = cache;
}
@Override
public void handleRequest(final HttpServerExchange exchange) throws Exception {
final ResponseCache responseCache = new ResponseCache(cache, exchange);
exchange.putAttachment(ResponseCache.ATTACHMENT_KEY, responseCache);
exchange.addResponseWrapper(new ConduitWrapper() {
@Override
public StreamSinkConduit wrap(final ConduitFactory factory, final HttpServerExchange exchange) {
if(!responseCache.isResponseCachable()) {
return factory.create();
}
final AllowedContentEncodings contentEncodings = exchange.getAttachment(AllowedContentEncodings.ATTACHMENT_KEY);
if(contentEncodings != null) {
if(!contentEncodings.isIdentity()) {
//we can't cache content encoded responses, as we have no idea how big they will end up being
return factory.create();
}
}
String lengthString = exchange.getResponseHeaders().getFirst(CONTENT_LENGTH);
if(lengthString == null) {
//we don't cache chunked requests
return factory.create();
}
int length = Integer.parseInt(lengthString);
final CachedHttpRequest key = new CachedHttpRequest(exchange);
final DirectBufferCache.CacheEntry entry = cache.add(key, length);
if (entry == null || entry.buffers().length == 0 || !entry.claimEnable()) {
return factory.create();
}
if (!entry.reference()) {
entry.disable();
return factory.create();
}
return new ResponseCachingStreamSinkConduit(factory.create(), entry, length);
}
});
next.handleRequest(exchange);
}
public HttpHandler getNext() {
return next;
}
public CacheHandler setNext(final HttpHandler next) {
Handlers.handlerNotNull(next);
this.next = next;
return this;
}
}