io.reactivex.netty.contexts.ContextAttributeStorageHelper Maven / Gradle / Ivy
/*
* Copyright 2014 Netflix, Inc.
*
* 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.reactivex.netty.contexts;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.AttributeKey;
import java.util.concurrent.ConcurrentHashMap;
/**
* A utility class to store {@link ContextsContainer} instances as channel attributes.
*
* @author Nitesh Kant
*/
public final class ContextAttributeStorageHelper {
public static final String CONTAINER_ATTRIBUTE_KEY_NAME = "rxnetty_contexts_container";
/**
* Why is this a ConcurrentHashMap?
* This will always be updated from within a Channel handler, which makes sure that this is always updated by a
* single thread. However, for protocols which have multiple concurrent requests per connection (SPDY, HTTP2, etc)
* this may not be true if the requests are potentially processed parallely. So, this is just a safety net.
*/
public static final AttributeKey> CONTAINERS_ATTRIBUTE_KEY =
AttributeKey.valueOf(CONTAINER_ATTRIBUTE_KEY_NAME);
private ContextAttributeStorageHelper() {
}
public static void setContainer(ChannelHandlerContext ctx, String requestId, ContextsContainer container) {
if (null == ctx) {
throw new IllegalArgumentException("Context can not be null.");
}
if (null == requestId) {
throw new IllegalArgumentException("Request id can not be null.");
}
if (null == container) {
throw new IllegalArgumentException("Context container can not be null.");
}
ConcurrentHashMap containers = ctx.channel().attr(CONTAINERS_ATTRIBUTE_KEY).get();
if (null == containers) {
containers = new ConcurrentHashMap();
ctx.channel().attr(CONTAINERS_ATTRIBUTE_KEY).set(containers);
}
containers.put(requestId, container);
}
public static ContextsContainer getContainer(ChannelHandlerContext ctx, String requestId) {
if (null == ctx) {
throw new IllegalArgumentException("Context can not be null.");
}
if (null == requestId) {
throw new IllegalArgumentException("Request id can not be null.");
}
ConcurrentHashMap containers = ctx.channel().attr(CONTAINERS_ATTRIBUTE_KEY).get();
if (null != containers) {
return containers.get(requestId);
}
return null;
}
}