/*
* Copyright 1999-2011 Alibaba Group Holding Ltd.
*
* Licensed 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 com.alibaba.druid.util;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLongArray;
public class Histogram {
private final long[] ranges;
private final AtomicLongArray rangeCounters;
public Histogram(long... ranges){
this.ranges = ranges;
this.rangeCounters = new AtomicLongArray(ranges.length + 1);
}
public static Histogram makeHistogram(int rangeCount) {
long[] rangeValues = new long[rangeCount];
for (int i = 0; i < rangeValues.length; ++i) {
rangeValues[i] = (long) Math.pow(10, i);
}
return new Histogram(rangeValues);
}
public Histogram(TimeUnit timeUnit, long... ranges){
this.ranges = new long[ranges.length];
for (int i = 0; i < ranges.length; i++) {
this.ranges[i] = TimeUnit.MILLISECONDS.convert(ranges[i], timeUnit);
}
rangeCounters = new AtomicLongArray(ranges.length + 1);
}
public void reset() {
for (int i = 0; i < rangeCounters.length(); i++) {
rangeCounters.set(i, 0);
}
}
public void record(long millis) {
int index = rangeCounters.length() - 1;
for (int i = 0; i < ranges.length; ++i) {
if (millis < ranges[i]) {
index = i;
break;
}
}
rangeCounters.incrementAndGet(index);
}
public long get(int index) {
return rangeCounters.get(index);
}
public long[] toArray() {
long[] array = new long[rangeCounters.length()];
for (int i = 0; i < rangeCounters.length(); i++) {
array[i] = rangeCounters.get(i);
}
return array;
}
public long[] getRanges() {
return ranges;
}
public long getValue(int index) {
return rangeCounters.get(index);
}
public long getSum() {
long sum = 0;
for (int i = 0; i < rangeCounters.length(); ++i) {
sum += rangeCounters.get(i);
}
return sum;
}
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append('[');
for (int i = 0; i < rangeCounters.length(); ++i) {
if (i != 0) {
buf.append(',');
}
buf.append(rangeCounters.get(i));
}
buf.append(']');
return buf.toString();
}
}