org.apache.kafka.clients.InFlightRequests Maven / Gradle / Ivy
/*
* 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.kafka.clients;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
/**
* The set of requests which have been sent or are being sent but haven't yet received a response
*/
final class InFlightRequests {
private final int maxInFlightRequestsPerConnection;
private final Map> requests = new HashMap<>();
/** Thread safe total number of in flight requests. */
private final AtomicInteger inFlightRequestCount = new AtomicInteger(0);
public InFlightRequests(int maxInFlightRequestsPerConnection) {
this.maxInFlightRequestsPerConnection = maxInFlightRequestsPerConnection;
}
/**
* Add the given request to the queue for the connection it was directed to
*/
public void add(NetworkClient.InFlightRequest request) {
String destination = request.destination;
Deque reqs = this.requests.get(destination);
if (reqs == null) {
reqs = new ArrayDeque<>();
this.requests.put(destination, reqs);
}
reqs.addFirst(request);
inFlightRequestCount.incrementAndGet();
}
/**
* Get the request queue for the given node
*/
private Deque requestQueue(String node) {
Deque reqs = requests.get(node);
if (reqs == null || reqs.isEmpty())
throw new IllegalStateException("There are no in-flight requests for node " + node);
return reqs;
}
/**
* Get the oldest request (the one that will be completed next) for the given node
*/
public NetworkClient.InFlightRequest completeNext(String node) {
NetworkClient.InFlightRequest inFlightRequest = requestQueue(node).pollLast();
inFlightRequestCount.decrementAndGet();
return inFlightRequest;
}
/**
* Get the last request we sent to the given node (but don't remove it from the queue)
* @param node The node id
*/
public NetworkClient.InFlightRequest lastSent(String node) {
return requestQueue(node).peekFirst();
}
/**
* Complete the last request that was sent to a particular node.
* @param node The node the request was sent to
* @return The request
*/
public NetworkClient.InFlightRequest completeLastSent(String node) {
NetworkClient.InFlightRequest inFlightRequest = requestQueue(node).pollFirst();
inFlightRequestCount.decrementAndGet();
return inFlightRequest;
}
/**
* Can we send more requests to this node?
*
* @param node Node in question
* @return true iff we have no requests still being sent to the given node
*/
public boolean canSendMore(String node) {
Deque queue = requests.get(node);
return queue == null || queue.isEmpty() ||
(queue.peekFirst().send.completed() && queue.size() < this.maxInFlightRequestsPerConnection);
}
/**
* Return the number of in-flight requests directed at the given node
* @param node The node
* @return The request count.
*/
public int count(String node) {
Deque queue = requests.get(node);
return queue == null ? 0 : queue.size();
}
/**
* Return true if there is no in-flight request directed at the given node and false otherwise
*/
public boolean isEmpty(String node) {
Deque queue = requests.get(node);
return queue == null || queue.isEmpty();
}
/**
* Count all in-flight requests for all nodes. This method is thread safe, but may lag the actual count.
*/
public int count() {
return inFlightRequestCount.get();
}
/**
* Return true if there is no in-flight request and false otherwise
*/
public boolean isEmpty() {
for (Deque deque : this.requests.values()) {
if (!deque.isEmpty())
return false;
}
return true;
}
/**
* Clear out all the in-flight requests for the given node and return them
*
* @param node The node
* @return All the in-flight requests for that node that have been removed
*/
public Iterable clearAll(String node) {
Deque reqs = requests.get(node);
if (reqs == null) {
return Collections.emptyList();
} else {
final Deque clearedRequests = requests.remove(node);
inFlightRequestCount.getAndAdd(-clearedRequests.size());
return () -> clearedRequests.descendingIterator();
}
}
private Boolean hasExpiredRequest(long now, Deque deque) {
for (NetworkClient.InFlightRequest request : deque) {
if (request.timeElapsedSinceSendMs(now) > request.requestTimeoutMs)
return true;
}
return false;
}
/**
* Returns a list of nodes with pending in-flight request, that need to be timed out
*
* @param now current time in milliseconds
* @return list of nodes
*/
public List nodesWithTimedOutRequests(long now) {
List nodeIds = new ArrayList<>();
for (Map.Entry> requestEntry : requests.entrySet()) {
String nodeId = requestEntry.getKey();
Deque deque = requestEntry.getValue();
if (hasExpiredRequest(now, deque))
nodeIds.add(nodeId);
}
return nodeIds;
}
}