/*
* bitlet - Simple bittorrent library
* Copyright (C) 2008 Alessandro Bahgat Shehata, Daniele Castagna
*
* 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 org.bitlet.wetorrent.util.stream;
public class BandwidthLimiter {
private final static int CHUNK_SIZE = 256;
int bytesToChunk = 0;
long lastChunkSent = System.nanoTime();
int maximumRate = 24;
long nanosToWait = (1000000000l * CHUNK_SIZE) / (maximumRate * 1024l);
public synchronized void setMaximumRate(int maximumRate) throws IllegalArgumentException {
if (maximumRate < 1) {
throw new IllegalArgumentException("maximumRate must be grater than 0");
}
this.maximumRate = maximumRate;
nanosToWait = (1000000000l * CHUNK_SIZE) / (maximumRate * 1024l);
}
public synchronized void limitNextByte() {
limitNextBytes(1);
}
public synchronized void limitNextBytes(int len) {
bytesToChunk += len;
while (bytesToChunk > CHUNK_SIZE) { /* passed a chunk */
long now = System.nanoTime();
long missingNanos = nanosToWait - (now - lastChunkSent);
if (missingNanos > 0) {
try {
Thread.sleep(missingNanos / 1000000, (int) missingNanos % 1000000);
} catch (InterruptedException ex) {
}
}
bytesToChunk -= CHUNK_SIZE;
lastChunkSent = now + (missingNanos > 0 ? missingNanos : 0);
}
}
}