1 files changed, 98 insertions, 0 deletions
diff --git a/core/java/android/util/SparseSetArray.java b/core/java/android/util/SparseSetArray.java
new file mode 100644
index 000000000000..d100f12ed026
--- /dev/null
+++ b/core/java/android/util/SparseSetArray.java
@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2018 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;
+
+/**
+ * A sparse array of ArraySets, which is suitable to hold userid->packages association.
+ *
+ * @hide
+ */
+public class SparseSetArray<T> {
+    private final SparseArray<ArraySet<T>> mData = new SparseArray<>();
+
+    public SparseSetArray() {
+    }
+
+    /**
+     * Add a value at index n.
+     * @return FALSE when the value already existed at the given index, TRUE otherwise.
+     */
+    public boolean add(int n, T value) {
+        ArraySet<T> set = mData.get(n);
+        if (set == null) {
+            set = new ArraySet<>();
+            mData.put(n, set);
+        }
+        if (set.contains(value)) {
+            return true;
+        }
+        set.add(value);
+        return false;
+    }
+
+    /**
+     * @return whether a value exists at index n.
+     */
+    public boolean contains(int n, T value) {
+        final ArraySet<T> set = mData.get(n);
+        if (set == null) {
+            return false;
+        }
+        return set.contains(value);
+    }
+
+    /**
+     * Remove a value from index n.
+     * @return TRUE when the value existed at the given index and removed, FALSE otherwise.
+     */
+    public boolean remove(int n, T value) {
+        final ArraySet<T> set = mData.get(n);
+        if (set == null) {
+            return false;
+        }
+        final boolean ret = set.remove(value);
+        if (set.size() == 0) {
+            mData.remove(n);
+        }
+        return ret;
+    }
+
+    /**
+     * Remove all values from index n.
+     */
+    public void remove(int n) {
+        mData.remove(n);
+    }
+    public int size() {
+        return mData.size();
+    }
+
+    public int keyAt(int index) {
+        return mData.keyAt(index);
+    }
+
+    public int sizeAt(int index) {
+        final ArraySet<T> set = mData.valueAt(index);
+        if (set == null) {
+            return 0;
+        }
+        return set.size();
+    }
+
+    public T valueAt(int intIndex, int valueIndex) {
+        return mData.valueAt(intIndex).valueAt(valueIndex);
+    }
+}