package io.dropwizard.metrics;
import org.HdrHistogram.Histogram;
import org.HdrHistogram.HistogramIterationValue;
import javax.annotation.Nonnull;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import static java.nio.charset.StandardCharsets.UTF_8;
final class HistogramSnapshot extends Snapshot {
private final Histogram histogram;
HistogramSnapshot(@Nonnull Histogram histogram) {
this.histogram = histogram;
}
@Override
public double getValue(double quantile) {
return histogram.getValueAtPercentile(quantile * 100.0);
}
@Override
public long[] getValues() {
long[] vals = new long[(int) histogram.getTotalCount()];
int i = 0;
for (HistogramIterationValue value : histogram.recordedValues()) {
long val = value.getValueIteratedTo();
for (int j = 0; j < value.getCountAddedInThisIterationStep(); j++) {
vals[i] = val;
i++;
}
}
if (i != vals.length) {
throw new IllegalStateException(
"Total count was " + histogram.getTotalCount() + " but iterating values produced " + vals.length);
}
return vals;
}
@Override
public int size() {
return (int) histogram.getTotalCount();
}
@Override
public long getMax() {
return histogram.getMaxValue();
}
@Override
public double getMean() {
return histogram.getMean();
}
@Override
public long getMin() {
return histogram.getMinValue();
}
@Override
public double getStdDev() {
return histogram.getStdDeviation();
}
@Override
public void dump(OutputStream output) {
PrintWriter p = null;
try {
p = new PrintWriter(new OutputStreamWriter(output, UTF_8));
for (HistogramIterationValue value : histogram.recordedValues()) {
for (int j = 0; j < value.getCountAddedInThisIterationStep(); j++) {
p.printf("%d%n", value.getValueIteratedTo());
}
}
} catch (Exception e) {
if(p != null) p.close();
e.printStackTrace();
}
}
}