1 files changed, 245 insertions, 0 deletions
diff --git a/core/java/android/util/SparseBooleanArray.java b/core/java/android/util/SparseBooleanArray.java
new file mode 100644
index 000000000000..f7799dee6ef7
--- /dev/null
+++ b/core/java/android/util/SparseBooleanArray.java
@@ -0,0 +1,245 @@
+/*
+ * Copyright (C) 2006 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;
+
+/**
+ * SparseBooleanArrays map integers to booleans.
+ * Unlike a normal array of booleans
+ * there can be gaps in the indices.  It is intended to be more efficient
+ * than using a HashMap to map Integers to Booleans.
+ */
+public class SparseBooleanArray {
+    /**
+     * Creates a new SparseBooleanArray containing no mappings.
+     */
+    public SparseBooleanArray() {
+        this(10);
+    }
+
+    /**
+     * Creates a new SparseBooleanArray containing no mappings that will not
+     * require any additional memory allocation to store the specified
+     * number of mappings.
+     */
+    public SparseBooleanArray(int initialCapacity) {
+        initialCapacity = ArrayUtils.idealIntArraySize(initialCapacity);
+
+        mKeys = new int[initialCapacity];
+        mValues = new boolean[initialCapacity];
+        mSize = 0;
+    }
+
+    /**
+     * Gets the boolean mapped from the specified key, or <code>false</code>
+     * if no such mapping has been made.
+     */
+    public boolean get(int key) {
+        return get(key, false);
+    }
+
+    /**
+     * Gets the boolean mapped from the specified key, or the specified value
+     * if no such mapping has been made.
+     */
+    public boolean get(int key, boolean valueIfKeyNotFound) {
+        int i = binarySearch(mKeys, 0, mSize, key);
+
+        if (i < 0) {
+            return valueIfKeyNotFound;
+        } else {
+            return mValues[i];
+        }
+    }
+
+    /**
+     * Removes the mapping from the specified key, if there was any.
+     */
+    public void delete(int key) {
+        int i = binarySearch(mKeys, 0, mSize, key);
+
+        if (i >= 0) {
+            System.arraycopy(mKeys, i + 1, mKeys, i, mSize - (i + 1));
+            System.arraycopy(mValues, i + 1, mValues, i, mSize - (i + 1));
+            mSize--;
+        }
+    }
+
+    /**
+     * Adds a mapping from the specified key to the specified value,
+     * replacing the previous mapping from the specified key if there
+     * was one.
+     */
+    public void put(int key, boolean value) {
+        int i = binarySearch(mKeys, 0, mSize, key);
+
+        if (i >= 0) {
+            mValues[i] = value;
+        } else {
+            i = ~i;
+
+            if (mSize >= mKeys.length) {
+                int n = ArrayUtils.idealIntArraySize(mSize + 1);
+
+                int[] nkeys = new int[n];
+                boolean[] nvalues = new boolean[n];
+
+                // Log.e("SparseBooleanArray", "grow " + mKeys.length + " to " + n);
+                System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
+                System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
+
+                mKeys = nkeys;
+                mValues = nvalues;
+            }
+
+            if (mSize - i != 0) {
+                // Log.e("SparseBooleanArray", "move " + (mSize - i));
+                System.arraycopy(mKeys, i, mKeys, i + 1, mSize - i);
+                System.arraycopy(mValues, i, mValues, i + 1, mSize - i);
+            }
+
+            mKeys[i] = key;
+            mValues[i] = value;
+            mSize++;
+        }
+    }
+
+    /**
+     * Returns the number of key-value mappings that this SparseBooleanArray
+     * currently stores.
+     */
+    public int size() {
+        return mSize;
+    }
+
+    /**
+     * Given an index in the range <code>0...size()-1</code>, returns
+     * the key from the <code>index</code>th key-value mapping that this
+     * SparseBooleanArray stores.  
+     */
+    public int keyAt(int index) {
+        return mKeys[index];
+    }
+    
+    /**
+     * Given an index in the range <code>0...size()-1</code>, returns
+     * the value from the <code>index</code>th key-value mapping that this
+     * SparseBooleanArray stores.  
+     */
+    public boolean valueAt(int index) {
+        return mValues[index];
+    }
+
+    /**
+     * Returns the index for which {@link #keyAt} would return the
+     * specified key, or a negative number if the specified
+     * key is not mapped.
+     */
+    public int indexOfKey(int key) {
+        return binarySearch(mKeys, 0, mSize, key);
+    }
+
+    /**
+     * Returns an index for which {@link #valueAt} would return the
+     * specified key, or a negative number if no keys map to the
+     * specified value.
+     * Beware that this is a linear search, unlike lookups by key,
+     * and that multiple keys can map to the same value and this will
+     * find only one of them.
+     */
+    public int indexOfValue(boolean value) {
+        for (int i = 0; i < mSize; i++)
+            if (mValues[i] == value)
+                return i;
+
+        return -1;
+    }
+
+    /**
+     * Removes all key-value mappings from this SparseBooleanArray.
+     */
+    public void clear() {
+        mSize = 0;
+    }
+
+    /**
+     * Puts a key/value pair into the array, optimizing for the case where
+     * the key is greater than all existing keys in the array.
+     */
+    public void append(int key, boolean value) {
+        if (mSize != 0 && key <= mKeys[mSize - 1]) {
+            put(key, value);
+            return;
+        }
+
+        int pos = mSize;
+        if (pos >= mKeys.length) {
+            int n = ArrayUtils.idealIntArraySize(pos + 1);
+
+            int[] nkeys = new int[n];
+            boolean[] nvalues = new boolean[n];
+
+            // Log.e("SparseBooleanArray", "grow " + mKeys.length + " to " + n);
+            System.arraycopy(mKeys, 0, nkeys, 0, mKeys.length);
+            System.arraycopy(mValues, 0, nvalues, 0, mValues.length);
+
+            mKeys = nkeys;
+            mValues = nvalues;
+        }
+
+        mKeys[pos] = key;
+        mValues[pos] = value;
+        mSize = pos + 1;
+    }
+    
+    private static int binarySearch(int[] a, int start, int len, int key) {
+        int high = start + len, low = start - 1, guess;
+
+        while (high - low > 1) {
+            guess = (high + low) / 2;
+
+            if (a[guess] < key)
+                low = guess;
+            else
+                high = guess;
+        }
+
+        if (high == start + len)
+            return ~(start + len);
+        else if (a[high] == key)
+            return high;
+        else
+            return ~high;
+    }
+
+    private void checkIntegrity() {
+        for (int i = 1; i < mSize; i++) {
+            if (mKeys[i] <= mKeys[i - 1]) {
+                for (int j = 0; j < mSize; j++) {
+                    Log.e("FAIL", j + ": " + mKeys[j] + " -> " + mValues[j]);
+                }
+
+                throw new RuntimeException();
+            }
+        }
+    }
+
+    private int[] mKeys;
+    private boolean[] mValues;
+    private int mSize;
+}