1 /* 2 * Copyright (C) 2022 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.server.art; 18 19 import android.annotation.NonNull; 20 import android.annotation.Nullable; 21 22 import java.util.concurrent.ScheduledExecutorService; 23 import java.util.concurrent.ScheduledFuture; 24 import java.util.concurrent.TimeUnit; 25 import java.util.function.Supplier; 26 27 /** 28 * A class that executes commands with a minimum interval. 29 * 30 * @hide 31 */ 32 public class Debouncer { 33 @NonNull private Supplier<ScheduledExecutorService> mScheduledExecutorFactory; 34 private final long mIntervalMs; 35 @Nullable private ScheduledFuture<?> mCurrentTask = null; 36 Debouncer( long intervalMs, @NonNull Supplier<ScheduledExecutorService> scheduledExecutorFactory)37 public Debouncer( 38 long intervalMs, @NonNull Supplier<ScheduledExecutorService> scheduledExecutorFactory) { 39 mScheduledExecutorFactory = scheduledExecutorFactory; 40 mIntervalMs = intervalMs; 41 } 42 43 /** 44 * Runs the given command after the interval has passed. If another command comes in during 45 * this interval, the previous one will never run. 46 */ maybeRunAsync(@onNull Runnable command)47 synchronized public void maybeRunAsync(@NonNull Runnable command) { 48 if (mCurrentTask != null) { 49 mCurrentTask.cancel(false /* mayInterruptIfRunning */); 50 } 51 ScheduledExecutorService executor = mScheduledExecutorFactory.get(); 52 mCurrentTask = executor.schedule(command, mIntervalMs, TimeUnit.MILLISECONDS); 53 executor.shutdown(); 54 } 55 } 56