/**
* Copyright 2016 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 com.netflix.hystrix.contrib.requests.stream;
import com.netflix.config.DynamicIntProperty;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.hystrix.contrib.sample.stream.HystrixSampleSseServlet;
import com.netflix.hystrix.metric.HystrixRequestEvents;
import com.netflix.hystrix.metric.HystrixRequestEventsStream;
import com.netflix.hystrix.serial.SerialHystrixRequestEvents;
import rx.Observable;
import rx.functions.Func1;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Servlet that writes SSE JSON every time a request is made
*/
public class HystrixRequestEventsSseServlet extends HystrixSampleSseServlet {
private static final long serialVersionUID = 6389353893099737870L;
/* used to track number of connections and throttle */
private static AtomicInteger concurrentConnections = new AtomicInteger(0);
private static DynamicIntProperty maxConcurrentConnections =
DynamicPropertyFactory.getInstance().getIntProperty("hystrix.config.stream.maxConcurrentConnections", 5);
public HystrixRequestEventsSseServlet() {
this(HystrixRequestEventsStream.getInstance().observe(), DEFAULT_PAUSE_POLLER_THREAD_DELAY_IN_MS);
}
/* package-private */ HystrixRequestEventsSseServlet(Observable<HystrixRequestEvents> sampleStream, int pausePollerThreadDelayInMs) {
super(sampleStream.map(new Func1<HystrixRequestEvents, String>() {
@Override
public String call(HystrixRequestEvents requestEvents) {
return SerialHystrixRequestEvents.toJsonString(requestEvents);
}
}), pausePollerThreadDelayInMs);
}
@Override
protected int getMaxNumberConcurrentConnectionsAllowed() {
return maxConcurrentConnections.get();
}
@Override
protected int getNumberCurrentConnections() {
return concurrentConnections.get();
}
@Override
protected int incrementAndGetCurrentConcurrentConnections() {
return concurrentConnections.incrementAndGet();
}
@Override
protected void decrementCurrentConcurrentConnections() {
concurrentConnections.decrementAndGet();
}
}