org.apache.flink.runtime.checkpoint.MinMaxAvgStats Maven / Gradle / Ivy
/*
* 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 org.apache.flink.runtime.checkpoint;
import java.io.Serializable;
/**
* Helper for keeping track of min/max/average summaries.
*/
public class MinMaxAvgStats implements Serializable {
private static final long serialVersionUID = 1769601903483446707L;
/** Current min value. */
private long min;
/** Current max value. */
private long max;
/** Sum of all added values. */
private long sum;
/** Count of added values. */
private long count;
MinMaxAvgStats() {
}
private MinMaxAvgStats(long min, long max, long sum, long count) {
this.min = min;
this.max = max;
this.sum = sum;
this.count = count;
}
/**
* Adds the value to the stats if it is >= 0.
*
* @param value Value to add for min/max/avg stats..
*/
void add(long value) {
if (value >= 0) {
if (count > 0) {
min = Math.min(min, value);
max = Math.max(max, value);
} else {
min = value;
max = value;
}
count++;
sum += value;
}
}
/**
* Returns a snapshot of the current state.
*
* @return A snapshot of the current state.
*/
MinMaxAvgStats createSnapshot() {
return new MinMaxAvgStats(min, max, sum, count);
}
/**
* Returns the minimum seen value.
*
* @return The current minimum value.
*/
public long getMinimum() {
return min;
}
/**
* Returns the maximum seen value.
*
* @return The current maximum value.
*/
public long getMaximum() {
return max;
}
/**
* Returns the sum of all seen values.
*
* @return Sum of all values.
*/
public long getSum() {
return sum;
}
/**
* Returns the count of all seen values.
*
* @return Count of all values.
*/
public long getCount() {
return count;
}
/**
* Calculates the average over all seen values.
*
* @return Average over all seen values.
*/
public long getAverage() {
if (count == 0) {
return 0;
} else {
return sum / count;
}
}
}