| /** |
| * Copyright 2016 Yahoo Inc. |
| * |
| * 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 org.apache.bookkeeper.mledger.util; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| import java.util.Arrays; |
| import java.util.concurrent.atomic.LongAdder; |
| |
| /** |
| * Create stats buckets to have frequency distribution of samples. |
| * |
| */ |
| public class StatsBuckets { |
| private final long[] boundaries; |
| private final LongAdder sumCounter; |
| private final LongAdder[] buckets; |
| |
| private final long[] values; |
| private long count = 0; |
| private long sum = 0; |
| |
| public StatsBuckets(long... boundaries) { |
| checkArgument(boundaries.length > 0); |
| checkArgument(isSorted(boundaries), "Boundaries array must be sorted"); |
| this.boundaries = boundaries; |
| this.sumCounter = new LongAdder(); |
| this.buckets = new LongAdder[boundaries.length + 1]; |
| |
| for (int i = 0; i < buckets.length; i++) { |
| buckets[i] = new LongAdder(); |
| } |
| |
| this.values = new long[buckets.length]; |
| } |
| |
| public void addValue(long value) { |
| int idx = Arrays.binarySearch(boundaries, value); |
| if (idx < 0) { |
| // If the precise value is not found, binary search is returning the negated insertion point |
| idx = ~idx; |
| } |
| |
| buckets[idx].increment(); |
| sumCounter.add(value); |
| } |
| |
| public void refresh() { |
| long count = 0; |
| sum = sumCounter.sumThenReset(); |
| |
| for (int i = 0; i < buckets.length; i++) { |
| long value = buckets[i].sumThenReset(); |
| count += value; |
| values[i] = value; |
| } |
| |
| this.count = count; |
| } |
| |
| public long[] getBuckets() { |
| return values; |
| } |
| |
| public long getCount() { |
| return count; |
| } |
| |
| public long getSum() { |
| return sum; |
| } |
| |
| public double getAvg() { |
| return sum / (double) count; |
| } |
| |
| private boolean isSorted(long[] array) { |
| long previous = Long.MIN_VALUE; |
| |
| for (long value : array) { |
| if (value < previous) { |
| return false; |
| } |
| |
| previous = value; |
| } |
| |
| return true; |
| } |
| } |