/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.index.snapshots.blobstore;
import org.apache.lucene.store.RateLimiter;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Rate limiting wrapper for InputStream
*/
public class RateLimitingInputStream extends FilterInputStream {
private final RateLimiter rateLimiter;
private final Listener listener;
private long bytesSinceLastRateLimit;
public interface Listener {
void onPause(long nanos);
}
public RateLimitingInputStream(InputStream delegate, RateLimiter rateLimiter, Listener listener) {
super(delegate);
this.rateLimiter = rateLimiter;
this.listener = listener;
}
private void maybePause(int bytes) throws IOException {
bytesSinceLastRateLimit += bytes;
if (bytesSinceLastRateLimit >= rateLimiter.getMinPauseCheckBytes()) {
long pause = rateLimiter.pause(bytesSinceLastRateLimit);
bytesSinceLastRateLimit = 0;
if (pause > 0) {
listener.onPause(pause);
}
}
}
@Override
public int read() throws IOException {
int b = super.read();
maybePause(1);
return b;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int n = super.read(b, off, len);
if (n > 0) {
maybePause(n);
}
return n;
}
}