| /* |
| * Copyright 2019 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.server.timezonedetector; |
| |
| import android.annotation.IntRange; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.util.ArrayMap; |
| import android.util.Log; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.IndentingPrintWriter; |
| |
| /** |
| * A partial decorator for {@link ArrayMap} that records historic values for each mapping for |
| * debugging later with {@link #dump(IndentingPrintWriter)}. |
| * |
| * <p>This class is only intended for use in {@link TimeZoneDetectorStrategy} and |
| * {@link com.android.server.timedetector.TimeDetectorStrategy} so only provides the parts of the |
| * {@link ArrayMap} API needed. If it is ever extended to include deletion methods like |
| * {@link ArrayMap#remove(Object)} some thought would need to be given to the correct |
| * {@link ArrayMap#containsKey(Object)} behavior for the history. Like {@link ArrayMap}, it is not |
| * thread-safe. |
| * |
| * @param <K> the type of the key |
| * @param <V> the type of the value |
| */ |
| public final class ArrayMapWithHistory<K, V> { |
| private static final String TAG = "ArrayMapWithHistory"; |
| |
| /** The size the linked list against each value is allowed to grow to. */ |
| private final int mMaxHistorySize; |
| |
| @Nullable |
| private ArrayMap<K, ReferenceWithHistory<V>> mMap; |
| |
| /** |
| * Creates an instance that records, at most, the specified number of values against each key. |
| */ |
| public ArrayMapWithHistory(@IntRange(from = 1) int maxHistorySize) { |
| if (maxHistorySize < 1) { |
| throw new IllegalArgumentException("maxHistorySize < 1: " + maxHistorySize); |
| } |
| mMaxHistorySize = maxHistorySize; |
| } |
| |
| /** |
| * See {@link ArrayMap#put(K, V)}. |
| */ |
| @Nullable |
| public V put(@Nullable K key, @Nullable V value) { |
| if (mMap == null) { |
| mMap = new ArrayMap<>(); |
| } |
| |
| ReferenceWithHistory<V> valueHolder = mMap.get(key); |
| if (valueHolder == null) { |
| valueHolder = new ReferenceWithHistory<>(mMaxHistorySize); |
| mMap.put(key, valueHolder); |
| } else if (valueHolder.getHistoryCount() == 0) { |
| Log.w(TAG, "History for \"" + key + "\" was unexpectedly empty"); |
| } |
| |
| return valueHolder.set(value); |
| } |
| |
| /** |
| * See {@link ArrayMap#get(Object)}. |
| */ |
| @Nullable |
| public V get(@Nullable Object key) { |
| if (mMap == null) { |
| return null; |
| } |
| |
| ReferenceWithHistory<V> valueHolder = mMap.get(key); |
| if (valueHolder == null) { |
| return null; |
| } else if (valueHolder.getHistoryCount() == 0) { |
| Log.w(TAG, "History for \"" + key + "\" was unexpectedly empty"); |
| } |
| return valueHolder.get(); |
| } |
| |
| /** |
| * See {@link ArrayMap#size()}. |
| */ |
| public int size() { |
| return mMap == null ? 0 : mMap.size(); |
| } |
| |
| /** |
| * See {@link ArrayMap#keyAt(int)}. |
| */ |
| @Nullable |
| public K keyAt(int index) { |
| if (mMap == null) { |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| return mMap.keyAt(index); |
| } |
| |
| /** |
| * See {@link ArrayMap#valueAt(int)}. |
| */ |
| @Nullable |
| public V valueAt(int index) { |
| if (mMap == null) { |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| |
| ReferenceWithHistory<V> valueHolder = mMap.valueAt(index); |
| if (valueHolder == null || valueHolder.getHistoryCount() == 0) { |
| Log.w(TAG, "valueAt(" + index + ") was unexpectedly null or empty"); |
| return null; |
| } |
| return valueHolder.get(); |
| } |
| |
| /** |
| * Dumps the content of the map, including historic values, using the supplied writer. |
| */ |
| public void dump(@NonNull IndentingPrintWriter ipw) { |
| if (mMap == null) { |
| ipw.println("{Empty}"); |
| } else { |
| for (int i = 0; i < mMap.size(); i++) { |
| ipw.println("key idx: " + i + "=" + mMap.keyAt(i)); |
| ReferenceWithHistory<V> value = mMap.valueAt(i); |
| ipw.println("val idx: " + i + "=" + value); |
| ipw.increaseIndent(); |
| |
| ipw.println("Historic values=["); |
| ipw.increaseIndent(); |
| value.dump(ipw); |
| ipw.decreaseIndent(); |
| ipw.println("]"); |
| |
| ipw.decreaseIndent(); |
| } |
| } |
| ipw.flush(); |
| } |
| |
| /** |
| * Internal method intended for tests that returns the number of historic values associated with |
| * the supplied key currently. If there is no mapping for the key then {@code 0} is returned. |
| */ |
| @VisibleForTesting |
| public int getHistoryCountForKeyForTests(@Nullable K key) { |
| if (mMap == null) { |
| return 0; |
| } |
| |
| ReferenceWithHistory<V> valueHolder = mMap.get(key); |
| if (valueHolder == null) { |
| return 0; |
| } else if (valueHolder.getHistoryCount() == 0) { |
| Log.w(TAG, "getValuesSizeForKeyForTests(\"" + key + "\") was unexpectedly empty"); |
| return 0; |
| } else { |
| return valueHolder.getHistoryCount(); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "ArrayMapWithHistory{" |
| + "mHistorySize=" + mMaxHistorySize |
| + ", mMap=" + mMap |
| + '}'; |
| } |
| } |