Implementing app standby quotas for alarms
Adding a quota mechanism for deferring alarms based on their standby
buckets.
Number of times an app can receive alarms in an hour is now capped by a
maximum depending on their standby bucket, with the frequency getting
more restricted as the buckets move higher.
Restricting presubmit test to only run when AlarmManagerService changed,
as some tests can take a while to complete.
Test: atest android.util.LongArrayQueueTest
atest CtsAlarmManagerTestCases:AppStandbyTests
atest FrameworksMockingServicesTests:AlarmManagerServiceTest
Bug: 122974477
Change-Id: Icbd5bbb8aeef91b543d09acee553fd0aa3a23f30
diff --git a/core/java/android/util/LongArrayQueue.java b/core/java/android/util/LongArrayQueue.java
new file mode 100644
index 0000000..d5f0484
--- /dev/null
+++ b/core/java/android/util/LongArrayQueue.java
@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 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 android.util;
+
+import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.GrowingArrayUtils;
+
+import libcore.util.EmptyArray;
+
+import java.util.NoSuchElementException;
+
+/**
+ * A lightweight implementation for a queue with long values.
+ * Additionally supports getting an element with a specified position from the head of the queue.
+ * The queue grows in size if needed to accommodate new elements.
+ *
+ * @hide
+ */
+public class LongArrayQueue {
+
+ private long[] mValues;
+ private int mSize;
+ private int mHead;
+ private int mTail;
+
+ /**
+ * Initializes a queue with the given starting capacity.
+ *
+ * @param initialCapacity the capacity.
+ */
+ public LongArrayQueue(int initialCapacity) {
+ if (initialCapacity == 0) {
+ mValues = EmptyArray.LONG;
+ } else {
+ mValues = ArrayUtils.newUnpaddedLongArray(initialCapacity);
+ }
+ mSize = 0;
+ mHead = mTail = 0;
+ }
+
+ /**
+ * Initializes a queue with default starting capacity.
+ */
+ public LongArrayQueue() {
+ this(16);
+ }
+
+ private void grow() {
+ if (mSize < mValues.length) {
+ throw new IllegalStateException("Queue not full yet!");
+ }
+ final int newSize = GrowingArrayUtils.growSize(mSize);
+ final long[] newArray = ArrayUtils.newUnpaddedLongArray(newSize);
+ final int r = mValues.length - mHead; // Number of elements on and to the right of head.
+ System.arraycopy(mValues, mHead, newArray, 0, r);
+ System.arraycopy(mValues, 0, newArray, r, mHead);
+ mValues = newArray;
+ mHead = 0;
+ mTail = mSize;
+ }
+
+ /**
+ * Returns the number of elements in the queue.
+ */
+ public int size() {
+ return mSize;
+ }
+
+ /**
+ * Removes all elements from this queue.
+ */
+ public void clear() {
+ mSize = 0;
+ mHead = mTail = 0;
+ }
+
+ /**
+ * Adds a value to the tail of the queue.
+ *
+ * @param value the value to be added.
+ */
+ public void addLast(long value) {
+ if (mSize == mValues.length) {
+ grow();
+ }
+ mValues[mTail] = value;
+ mTail = (mTail + 1) % mValues.length;
+ mSize++;
+ }
+
+ /**
+ * Removes an element from the head of the queue.
+ *
+ * @return the element at the head of the queue.
+ * @throws NoSuchElementException if the queue is empty.
+ */
+ public long removeFirst() {
+ if (mSize == 0) {
+ throw new NoSuchElementException("Queue is empty!");
+ }
+ final long ret = mValues[mHead];
+ mHead = (mHead + 1) % mValues.length;
+ mSize--;
+ return ret;
+ }
+
+ /**
+ * Returns the element at the given position from the head of the queue, where 0 represents the
+ * head of the queue.
+ *
+ * @param position the position from the head of the queue.
+ * @return the element found at the given position.
+ * @throws IndexOutOfBoundsException if {@code position} < {@code 0} or
+ * {@code position} >= {@link #size()}
+ */
+ public long get(int position) {
+ if (position < 0 || position >= mSize) {
+ throw new IndexOutOfBoundsException("Index " + position
+ + " not valid for a queue of size " + mSize);
+ }
+ final int index = (mHead + position) % mValues.length;
+ return mValues[index];
+ }
+
+ /**
+ * Returns the element at the head of the queue, without removing it.
+ *
+ * @return the element at the head of the queue.
+ * @throws NoSuchElementException if the queue is empty
+ */
+ public long peekFirst() {
+ if (mSize == 0) {
+ throw new NoSuchElementException("Queue is empty!");
+ }
+ return mValues[mHead];
+ }
+
+ /**
+ * Returns the element at the tail of the queue.
+ *
+ * @return the element at the tail of the queue.
+ * @throws NoSuchElementException if the queue is empty.
+ */
+ public long peekLast() {
+ if (mSize == 0) {
+ throw new NoSuchElementException("Queue is empty!");
+ }
+ final int index = (mTail == 0) ? mValues.length - 1 : mTail - 1;
+ return mValues[index];
+ }
+}