--- /dev/null
+package org.apache.lucene.util;
+
+/**
+ * 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.
+ */
+import java.io.IOException;
+
+import org.apache.lucene.store.DataInput;
+import org.apache.lucene.store.IndexOutput;
+
+public class ThrottledIndexOutput extends IndexOutput {
+ public static final int DEFAULT_MIN_WRITTEN_BYTES = 1024;
+ private final int bytesPerSecond;
+ private IndexOutput delegate;
+ private long flushDelayMillis;
+ private long closeDelayMillis;
+ private long seekDelayMillis;
+ private long pendingBytes;
+ private long minBytesWritten;
+ private long timeElapsed;
+ private final byte[] bytes = new byte[1];
+
+ public ThrottledIndexOutput newFromDelegate(IndexOutput output) {
+ return new ThrottledIndexOutput(bytesPerSecond, flushDelayMillis,
+ closeDelayMillis, seekDelayMillis, minBytesWritten, output);
+ }
+
+ public ThrottledIndexOutput(int bytesPerSecond, long delayInMillis,
+ IndexOutput delegate) {
+ this(bytesPerSecond, delayInMillis, delayInMillis, delayInMillis,
+ DEFAULT_MIN_WRITTEN_BYTES, delegate);
+ }
+
+ public ThrottledIndexOutput(int bytesPerSecond, long delays,
+ int minBytesWritten, IndexOutput delegate) {
+ this(bytesPerSecond, delays, delays, delays, minBytesWritten, delegate);
+ }
+
+ public static final int mBitsToBytes(int mbits) {
+ return mbits * 125000;
+ }
+
+ public ThrottledIndexOutput(int bytesPerSecond, long flushDelayMillis,
+ long closeDelayMillis, long seekDelayMillis, long minBytesWritten,
+ IndexOutput delegate) {
+ assert bytesPerSecond > 0;
+ this.delegate = delegate;
+ this.bytesPerSecond = bytesPerSecond;
+ this.flushDelayMillis = flushDelayMillis;
+ this.closeDelayMillis = closeDelayMillis;
+ this.seekDelayMillis = seekDelayMillis;
+ this.minBytesWritten = minBytesWritten;
+ }
+
+ @Override
+ public void flush() throws IOException {
+ sleep(flushDelayMillis);
+ delegate.flush();
+ }
+
+ @Override
+ public void close() throws IOException {
+ try {
+ sleep(closeDelayMillis + getDelay(true));
+ } finally {
+ delegate.close();
+ }
+ }
+
+ @Override
+ public long getFilePointer() {
+ return delegate.getFilePointer();
+ }
+
+ @Override
+ public void seek(long pos) throws IOException {
+ sleep(seekDelayMillis);
+ delegate.seek(pos);
+ }
+
+ @Override
+ public long length() throws IOException {
+ return delegate.length();
+ }
+
+ @Override
+ public void writeByte(byte b) throws IOException {
+ bytes[0] = b;
+ writeBytes(bytes, 0, 1);
+ }
+
+ @Override
+ public void writeBytes(byte[] b, int offset, int length) throws IOException {
+ final long before = System.nanoTime();
+ delegate.writeBytes(b, offset, length);
+ timeElapsed += System.nanoTime() - before;
+ pendingBytes += length;
+ sleep(getDelay(false));
+
+ }
+
+ protected long getDelay(boolean closing) {
+ if (pendingBytes > 0 && (closing || pendingBytes > minBytesWritten)) {
+ long actualBps = (timeElapsed / pendingBytes) * 1000000000l; // nano to sec
+ if (actualBps > bytesPerSecond) {
+ long expected = (pendingBytes * 1000l / bytesPerSecond) ;
+ final long delay = expected - (timeElapsed / 1000000l) ;
+ pendingBytes = 0;
+ timeElapsed = 0;
+ return delay;
+ }
+ }
+ return 0;
+
+ }
+
+ private static final void sleep(long ms) {
+ if (ms <= 0)
+ return;
+ try {
+ Thread.sleep(ms);
+ } catch (InterruptedException e) {
+ throw new ThreadInterruptedException(e);
+ }
+ }
+
+ @Override
+ public void setLength(long length) throws IOException {
+ delegate.setLength(length);
+ }
+
+ @Override
+ public void copyBytes(DataInput input, long numBytes) throws IOException {
+ delegate.copyBytes(input, numBytes);
+ }
+}