1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.inputmethod.research; 18 19 import java.util.LinkedList; 20 21 /** 22 * Maintain a FIFO queue of LogUnits. 23 * 24 * This class provides an unbounded queue. This is useful when the user is aware that their actions 25 * are being recorded, such as when they are trying to reproduce a bug. In this case, there should 26 * not be artificial restrictions on how many events that can be saved. 27 */ 28 public class LogBuffer { 29 // TODO: Gracefully handle situations in which this LogBuffer is consuming too much memory. 30 // This may happen, for example, if the user has forgotten that data is being logged. 31 private final LinkedList<LogUnit> mLogUnits; 32 LogBuffer()33 public LogBuffer() { 34 mLogUnits = new LinkedList<LogUnit>(); 35 } 36 getLogUnits()37 protected LinkedList<LogUnit> getLogUnits() { 38 return mLogUnits; 39 } 40 clear()41 public void clear() { 42 mLogUnits.clear(); 43 } 44 shiftIn(final LogUnit logUnit)45 public void shiftIn(final LogUnit logUnit) { 46 mLogUnits.add(logUnit); 47 } 48 unshiftIn()49 public LogUnit unshiftIn() { 50 if (mLogUnits.isEmpty()) { 51 return null; 52 } 53 return mLogUnits.removeLast(); 54 } 55 peekLastLogUnit()56 public LogUnit peekLastLogUnit() { 57 if (mLogUnits.isEmpty()) { 58 return null; 59 } 60 return mLogUnits.peekLast(); 61 } 62 isEmpty()63 public boolean isEmpty() { 64 return mLogUnits.isEmpty(); 65 } 66 shiftOut()67 public LogUnit shiftOut() { 68 if (isEmpty()) { 69 return null; 70 } 71 return mLogUnits.removeFirst(); 72 } 73 } 74