| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * 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.android.tradefed.util; |
| |
| /** |
| * Data structure for holding a fixed size array that operates as a circular buffer, |
| * and tracks the total sum of all values in the array. |
| */ |
| public class CircularByteArray { |
| |
| private byte[] mArray; |
| private int mCurPos = 0; |
| private boolean mIsWrapped = false; |
| private long mSum = 0; |
| |
| public CircularByteArray(int size) { |
| mArray = new byte[size]; |
| } |
| |
| /** |
| * Adds a new value to array, replacing oldest value if necessary |
| * @param value |
| */ |
| public void add(byte value) { |
| if (mIsWrapped) { |
| // pop value and adjust total |
| mSum -= mArray[mCurPos]; |
| } |
| mArray[mCurPos] = value; |
| mCurPos++; |
| mSum += value; |
| if (mCurPos >= mArray.length) { |
| mIsWrapped = true; |
| mCurPos = 0; |
| } |
| } |
| |
| /** |
| * Get the number of elements stored |
| */ |
| public int size() { |
| if (mIsWrapped) { |
| return mArray.length; |
| } else { |
| return mCurPos; |
| } |
| } |
| |
| /** |
| * Gets the total value of all elements currently stored in array |
| */ |
| public long getSum() { |
| return mSum; |
| } |
| } |