/*
* 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 gobblin.util.io;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import com.codahale.metrics.Meter;
import com.google.common.base.Optional;
import lombok.Builder;
import lombok.extern.slf4j.Slf4j;
/**
* A {@link FilterOutputStream} that counts the bytes read from the underlying {@link OutputStream}.
*/
@Slf4j
public class MeteredOutputStream extends FilterOutputStream implements MeteredStream {
/**
* Find the lowest {@link MeteredOutputStream} in a chain of {@link FilterOutputStream}s.
*/
public static Optional<MeteredOutputStream> findWrappedMeteredOutputStream(OutputStream os) {
if (os instanceof FilterOutputStream) {
try {
Optional<MeteredOutputStream> meteredOutputStream =
findWrappedMeteredOutputStream(FilterStreamUnpacker.unpackFilterOutputStream((FilterOutputStream) os));
if (meteredOutputStream.isPresent()) {
return meteredOutputStream;
}
} catch (IllegalAccessException iae) {
log.warn("Cannot unpack input stream due to SecurityManager.", iae);
// Do nothing, we can't unpack the FilterInputStream due to security restrictions
}
}
if (os instanceof MeteredOutputStream) {
return Optional.of((MeteredOutputStream) os);
}
return Optional.absent();
}
BatchedMeterDecorator meter;
/**
* Builds a {@link MeteredOutputStream}.
* @param out The {@link OutputStream} to measure.
* @param meter A {@link Meter} to use for measuring the {@link OutputStream}. If null, a new {@link Meter} will be created.
* @param updateFrequency For performance, {@link MeteredInputStream} will batch {@link Meter} updates to this many bytes.
*/
@Builder
public MeteredOutputStream(OutputStream out, Meter meter, int updateFrequency) {
super(out);
this.meter = new BatchedMeterDecorator(meter == null ? new Meter() : meter, updateFrequency > 0 ? updateFrequency : 1000);
}
@Override
public void write(int b) throws IOException {
this.meter.mark();
this.out.write(b);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
this.meter.mark(len);
this.out.write(b, off, len);
}
@Override
public Meter getBytesProcessedMeter() {
return this.meter.getUnderlyingMeter();
}
}