org.elasticsearch.http.HttpPipeliningAggregator Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.http;
import org.elasticsearch.core.Tuple;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.PriorityQueue;
public class HttpPipeliningAggregator {
private final int maxEventsHeld;
private final PriorityQueue> outboundHoldingQueue;
/*
* The current read and write sequence numbers. Read sequence numbers are attached to requests in the order they are read from the
* channel, and then transferred to responses. A response is not written to the channel context until its sequence number matches the
* current write sequence, implying that all preceding messages have been written.
*/
private int readSequence;
private int writeSequence;
public HttpPipeliningAggregator(int maxEventsHeld) {
this.maxEventsHeld = maxEventsHeld;
this.outboundHoldingQueue = new PriorityQueue<>(1, Comparator.comparing(Tuple::v1));
}
public HttpPipelinedRequest read(final HttpRequest request) {
return new HttpPipelinedRequest(readSequence++, request);
}
public List> write(final HttpPipelinedResponse response, Listener listener) {
if (outboundHoldingQueue.size() < maxEventsHeld) {
ArrayList> readyResponses = new ArrayList<>();
outboundHoldingQueue.add(new Tuple<>(response, listener));
while (outboundHoldingQueue.isEmpty() == false) {
/*
* Since the response with the lowest sequence number is the top of the priority queue, we know if its sequence
* number does not match the current write sequence number then we have not processed all preceding responses yet.
*/
final Tuple top = outboundHoldingQueue.peek();
if (top.v1().getSequence() != writeSequence) {
break;
}
outboundHoldingQueue.poll();
readyResponses.add(top);
writeSequence++;
}
return readyResponses;
} else {
int eventCount = outboundHoldingQueue.size() + 1;
throw new IllegalStateException("Too many pipelined events [" + eventCount + "]. Max events allowed [" + maxEventsHeld + "].");
}
}
public List> removeAllInflightResponses() {
ArrayList> responses = new ArrayList<>(outboundHoldingQueue);
outboundHoldingQueue.clear();
return responses;
}
}