com.ksc.metrics.MetricInputStreamEntity Maven / Gradle / Ivy
/*
* Copyright 2010-2016 ksyun.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://ksyun.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.ksc.metrics;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.InputStreamEntity;
import com.ksc.internal.MetricAware;
/**
* Used to help capture the throughput metrics.
*
* Note this class is only relevant
* when metric is enabled. Otherwise it should not even be involved in the call
* stack to minimize runtime overhead.
*/
public class MetricInputStreamEntity extends InputStreamEntity {
private final static int BUFFER_SIZE = 2048;
private final ByteThroughputHelper helper;
public MetricInputStreamEntity(ThroughputMetricType metricType,
InputStream instream, long length) {
super(instream, length);
helper = new ByteThroughputHelper(metricType);
}
public MetricInputStreamEntity(ThroughputMetricType metricType,
final InputStream instream, long length,
final ContentType contentType) {
super(instream, length, contentType);
helper = new ByteThroughputHelper(metricType);
}
@Override
public void writeTo(final OutputStream outstream) throws IOException {
if (outstream instanceof MetricAware) {
// hchar: There is currently no implementation of output stream that
// has metric gathering capability but there could be!
// So the code here is for future proof purposes.
MetricAware aware = (MetricAware)outstream;
if (aware.isMetricActivated()) {
// let the underlying output stream takes care of byte counting
super.writeTo(outstream);
return;
}
}
writeToWithMetrics(outstream);
}
/**
* Copied from {{@link InputStreamEntity#writeTo(OutputStream)} but modified
* to capture metrics for the output stream.
*/
private void writeToWithMetrics(final OutputStream outstream) throws IOException {
if (outstream == null) {
throw new IllegalArgumentException("Output stream may not be null");
}
final InputStream content = getContent();
final long length = getContentLength();
InputStream instream = content;
try {
byte[] buffer = new byte[BUFFER_SIZE];
int l;
if (length < 0) {
// consume until EOF
while ((l = instream.read(buffer)) != -1) {
long startNano = helper.startTiming();
outstream.write(buffer, 0, l);
helper.increment(l, startNano);
}
} else {
// consume no more than length
long remaining = length;
while (remaining > 0) {
l = instream.read(buffer, 0, (int)Math.min(BUFFER_SIZE, remaining));
if (l == -1) {
break;
}
long startNano = helper.startTiming();
outstream.write(buffer, 0, l);
helper.increment(l, startNano);
remaining -= l;
}
}
} finally {
helper.reportMetrics();
instream.close();
}
}
}