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-rw-r--r--core/java/android/util/ArrayMap.java123
-rw-r--r--core/java/android/util/ArraySet.java599
2 files changed, 659 insertions, 63 deletions
diff --git a/core/java/android/util/ArrayMap.java b/core/java/android/util/ArrayMap.java
index bb0a6e1..4bd9b37 100644
--- a/core/java/android/util/ArrayMap.java
+++ b/core/java/android/util/ArrayMap.java
@@ -206,6 +206,7 @@ public final class ArrayMap<K, V> implements Map<K, V> {
}
mSize = 0;
}
+
/**
* Create a new ArrayMap with the mappings from the given ArrayMap.
*/
@@ -216,7 +217,6 @@ public final class ArrayMap<K, V> implements Map<K, V> {
}
}
-
/**
* Make the array map empty. All storage is released.
*/
@@ -236,8 +236,8 @@ public final class ArrayMap<K, V> implements Map<K, V> {
*/
public void ensureCapacity(int minimumCapacity) {
if (mHashes.length < minimumCapacity) {
- int[] ohashes = mHashes;
- Object[] oarray = mArray;
+ final int[] ohashes = mHashes;
+ final Object[] oarray = mArray;
allocArrays(minimumCapacity);
if (mSize > 0) {
System.arraycopy(ohashes, 0, mHashes, 0, mSize);
@@ -493,6 +493,63 @@ public final class ArrayMap<K, V> implements Map<K, V> {
return mSize;
}
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation returns false if the object is not a map, or
+ * if the maps have different sizes. Otherwise, for each key in this map,
+ * values of both maps are compared. If the values for any key are not
+ * equal, the method returns false, otherwise it returns true.
+ */
+ @Override
+ public boolean equals(Object object) {
+ if (this == object) {
+ return true;
+ }
+ if (object instanceof Map) {
+ Map<?, ?> map = (Map<?, ?>) object;
+ if (size() != map.size()) {
+ return false;
+ }
+
+ try {
+ for (int i=0; i<mSize; i++) {
+ K key = keyAt(i);
+ V mine = valueAt(i);
+ Object theirs = map.get(key);
+ if (mine == null) {
+ if (theirs != null || !map.containsKey(key)) {
+ return false;
+ }
+ } else if (!mine.equals(theirs)) {
+ return false;
+ }
+ }
+ } catch (NullPointerException ignored) {
+ return false;
+ } catch (ClassCastException ignored) {
+ return false;
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public int hashCode() {
+ final int[] hashes = mHashes;
+ final Object[] array = mArray;
+ int result = 0;
+ for (int i = 0, v = 1, s = mSize; i < s; i++, v+=2) {
+ Object value = array[v];
+ result += hashes[i] ^ (value == null ? 0 : value.hashCode());
+ }
+ return result;
+ }
+
// ------------------------------------------------------------------------
// Interop with traditional Java containers. Not as efficient as using
// specialized collection APIs.
@@ -632,64 +689,4 @@ public final class ArrayMap<K, V> implements Map<K, V> {
public Collection<V> values() {
return getCollection().getValues();
}
-
- /**
- * {@inheritDoc}
- *
- * <p>This implementation returns false if the object is not a map, or
- * if the maps have different sizes. Otherwise, for each key in this map,
- * values of both maps are compared. If the values for any key are not
- * equal, the method returns false, otherwise it returns true.
- */
- @Override
- public boolean equals(Object object) {
- if (this == object) {
- return true;
- }
- if (object instanceof Map) {
- Map<?, ?> map = (Map<?, ?>) object;
- if (size() != map.size()) {
- return false;
- }
-
- try {
- for (int i=0; i<mSize; i++) {
- K key = keyAt(i);
- V mine = valueAt(i);
- Object theirs = map.get(key);
- if (mine == null) {
- if (theirs != null || !map.containsKey(key)) {
- return false;
- }
- } else if (!mine.equals(theirs)) {
- return false;
- }
- }
- } catch (NullPointerException ignored) {
- return false;
- } catch (ClassCastException ignored) {
- return false;
- }
- return true;
- }
- return false;
- }
-
- /**
- * {@inheritDoc}
- *
- * <p>This implementation sums a hashcode using all keys and values.
- */
- @Override
- public int hashCode() {
- int result = 0;
- for (int i=0; i<mSize; i++) {
- K key = keyAt(i);
- V value = valueAt(i);
- result += (key == null ? 0 : key.hashCode())
- ^ (value == null ? 0 : value.hashCode());
- }
- return result;
- }
-
}
diff --git a/core/java/android/util/ArraySet.java b/core/java/android/util/ArraySet.java
new file mode 100644
index 0000000..a84c47c
--- /dev/null
+++ b/core/java/android/util/ArraySet.java
@@ -0,0 +1,599 @@
+/*
+ * Copyright (C) 2013 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 java.lang.reflect.Array;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * ArraySet is a generic set data structure that is designed to be more memory efficient than a
+ * traditional {@link java.util.HashSet}. The design is very similar to
+ * {@link ArrayMap}, with all of the caveats described there. This implementation is
+ * separate from ArrayMap, however, so the Object array contains only one item for each
+ * entry in the set (instead of a pair for a mapping).
+ *
+ * <p>Note that this implementation is not intended to be appropriate for data structures
+ * that may contain large numbers of items. It is generally slower than a traditional
+ * HashSet, since lookups require a binary search and adds and removes require inserting
+ * and deleting entries in the array. For containers holding up to hundreds of items,
+ * the performance difference is not significant, less than 50%. For larger numbers of items
+ * this data structure should be avoided.</p>
+ *
+ * <p><b>Note:</b> unlike {@link java.util.HashSet}, this container does not support
+ * null values.</p>
+ *
+ * <p>Because this container is intended to better balance memory use, unlike most other
+ * standard Java containers it will shrink its array as items are removed from it. Currently
+ * you have no control over this shrinking -- if you set a capacity and then remove an
+ * item, it may reduce the capacity to better match the current size. In the future an
+ * explicitly call to set the capacity should turn off this aggressive shrinking behavior.</p>
+ *
+ * @hide
+ */
+public final class ArraySet<E> implements Collection<E>, Set<E> {
+ private static final boolean DEBUG = false;
+ private static final String TAG = "ArraySet";
+
+ /**
+ * The minimum amount by which the capacity of a ArraySet will increase.
+ * This is tuned to be relatively space-efficient.
+ */
+ private static final int BASE_SIZE = 4;
+
+ /**
+ * Maximum number of entries to have in array caches.
+ */
+ private static final int CACHE_SIZE = 10;
+
+ /**
+ * Caches of small array objects to avoid spamming garbage. The cache
+ * Object[] variable is a pointer to a linked list of array objects.
+ * The first entry in the array is a pointer to the next array in the
+ * list; the second entry is a pointer to the int[] hash code array for it.
+ */
+ static Object[] mBaseCache;
+ static int mBaseCacheSize;
+ static Object[] mTwiceBaseCache;
+ static int mTwiceBaseCacheSize;
+
+ int[] mHashes;
+ Object[] mArray;
+ int mSize;
+ MapCollections<E, E> mCollections;
+
+ private int indexOf(Object key, int hash) {
+ final int N = mSize;
+
+ // Important fast case: if nothing is in here, nothing to look for.
+ if (N == 0) {
+ return ~0;
+ }
+
+ int index = SparseArray.binarySearch(mHashes, N, hash);
+
+ // If the hash code wasn't found, then we have no entry for this key.
+ if (index < 0) {
+ return index;
+ }
+
+ // If the key at the returned index matches, that's what we want.
+ if (mArray[index].equals(key)) {
+ return index;
+ }
+
+ // Search for a matching key after the index.
+ int end;
+ for (end = index + 1; end < N && mHashes[end] == hash; end++) {
+ if (mArray[end].equals(key)) return end;
+ }
+
+ // Search for a matching key before the index.
+ for (int i = index - 1; i >= 0 && mHashes[i] == hash; i--) {
+ if (mArray[i].equals(key)) return i;
+ }
+
+ // Key not found -- return negative value indicating where a
+ // new entry for this key should go. We use the end of the
+ // hash chain to reduce the number of array entries that will
+ // need to be copied when inserting.
+ return ~end;
+ }
+
+ private void allocArrays(final int size) {
+ if (size == (BASE_SIZE*2)) {
+ synchronized (ArraySet.class) {
+ if (mTwiceBaseCache != null) {
+ final Object[] array = mTwiceBaseCache;
+ mArray = array;
+ mTwiceBaseCache = (Object[])array[0];
+ mHashes = (int[])array[1];
+ array[0] = array[1] = null;
+ mTwiceBaseCacheSize--;
+ if (DEBUG) Log.d(TAG, "Retrieving 2x cache " + mHashes
+ + " now have " + mTwiceBaseCacheSize + " entries");
+ return;
+ }
+ }
+ } else if (size == BASE_SIZE) {
+ synchronized (ArraySet.class) {
+ if (mBaseCache != null) {
+ final Object[] array = mBaseCache;
+ mArray = array;
+ mBaseCache = (Object[])array[0];
+ mHashes = (int[])array[1];
+ array[0] = array[1] = null;
+ mBaseCacheSize--;
+ if (DEBUG) Log.d(TAG, "Retrieving 1x cache " + mHashes
+ + " now have " + mBaseCacheSize + " entries");
+ return;
+ }
+ }
+ }
+
+ mHashes = new int[size];
+ mArray = new Object[size];
+ }
+
+ private static void freeArrays(final int[] hashes, final Object[] array, final int size) {
+ if (hashes.length == (BASE_SIZE*2)) {
+ synchronized (ArraySet.class) {
+ if (mTwiceBaseCacheSize < CACHE_SIZE) {
+ array[0] = mTwiceBaseCache;
+ array[1] = hashes;
+ for (int i=size-1; i>=2; i--) {
+ array[i] = null;
+ }
+ mTwiceBaseCache = array;
+ mTwiceBaseCacheSize++;
+ if (DEBUG) Log.d(TAG, "Storing 2x cache " + array
+ + " now have " + mTwiceBaseCacheSize + " entries");
+ }
+ }
+ } else if (hashes.length == BASE_SIZE) {
+ synchronized (ArraySet.class) {
+ if (mBaseCacheSize < CACHE_SIZE) {
+ array[0] = mBaseCache;
+ array[1] = hashes;
+ for (int i=size-1; i>=2; i--) {
+ array[i] = null;
+ }
+ mBaseCache = array;
+ mBaseCacheSize++;
+ if (DEBUG) Log.d(TAG, "Storing 1x cache " + array
+ + " now have " + mBaseCacheSize + " entries");
+ }
+ }
+ }
+ }
+
+ /**
+ * Create a new empty ArraySet. The default capacity of an array map is 0, and
+ * will grow once items are added to it.
+ */
+ public ArraySet() {
+ mHashes = SparseArray.EMPTY_INTS;
+ mArray = SparseArray.EMPTY_OBJECTS;
+ mSize = 0;
+ }
+
+ /**
+ * Create a new ArraySet with a given initial capacity.
+ */
+ public ArraySet(int capacity) {
+ if (capacity == 0) {
+ mHashes = SparseArray.EMPTY_INTS;
+ mArray = SparseArray.EMPTY_OBJECTS;
+ } else {
+ allocArrays(capacity);
+ }
+ mSize = 0;
+ }
+
+ /**
+ * Create a new ArraySet with the mappings from the given ArraySet.
+ */
+ public ArraySet(ArraySet set) {
+ this();
+ if (set != null) {
+ addAll(set);
+ }
+ }
+
+
+ /**
+ * Make the array map empty. All storage is released.
+ */
+ @Override
+ public void clear() {
+ if (mSize != 0) {
+ freeArrays(mHashes, mArray, mSize);
+ mHashes = SparseArray.EMPTY_INTS;
+ mArray = SparseArray.EMPTY_OBJECTS;
+ mSize = 0;
+ }
+ }
+
+ /**
+ * Ensure the array map can hold at least <var>minimumCapacity</var>
+ * items.
+ */
+ public void ensureCapacity(int minimumCapacity) {
+ if (mHashes.length < minimumCapacity) {
+ final int[] ohashes = mHashes;
+ final Object[] oarray = mArray;
+ allocArrays(minimumCapacity);
+ if (mSize > 0) {
+ System.arraycopy(ohashes, 0, mHashes, 0, mSize);
+ System.arraycopy(oarray, 0, mArray, 0, mSize);
+ }
+ freeArrays(ohashes, oarray, mSize);
+ }
+ }
+
+ /**
+ * Check whether a value exists in the set.
+ *
+ * @param key The value to search for.
+ * @return Returns true if the value exists, else false.
+ */
+ @Override
+ public boolean contains(Object key) {
+ return indexOf(key, key.hashCode()) >= 0;
+ }
+
+ /**
+ * Return the value at the given index in the array.
+ * @param index The desired index, must be between 0 and {@link #size()}-1.
+ * @return Returns the value stored at the given index.
+ */
+ public E valueAt(int index) {
+ return (E)mArray[index];
+ }
+
+ /**
+ * Return true if the array map contains no items.
+ */
+ @Override
+ public boolean isEmpty() {
+ return mSize <= 0;
+ }
+
+ /**
+ * Adds the specified object to this set. The set is not modified if it
+ * already contains the object.
+ *
+ * @param value the object to add.
+ * @return {@code true} if this set is modified, {@code false} otherwise.
+ * @throws ClassCastException
+ * when the class of the object is inappropriate for this set.
+ */
+ @Override
+ public boolean add(E value) {
+ final int hash = value.hashCode();
+ int index = indexOf(value, hash);
+ if (index >= 0) {
+ return false;
+ }
+
+ index = ~index;
+ if (mSize >= mHashes.length) {
+ final int n = mSize >= (BASE_SIZE*2) ? (mSize+(mSize>>1))
+ : (mSize >= BASE_SIZE ? (BASE_SIZE*2) : BASE_SIZE);
+
+ if (DEBUG) Log.d(TAG, "add: grow from " + mHashes.length + " to " + n);
+
+ final int[] ohashes = mHashes;
+ final Object[] oarray = mArray;
+ allocArrays(n);
+
+ if (mHashes.length > 0) {
+ if (DEBUG) Log.d(TAG, "add: copy 0-" + mSize + " to 0");
+ System.arraycopy(ohashes, 0, mHashes, 0, ohashes.length);
+ System.arraycopy(oarray, 0, mArray, 0, oarray.length);
+ }
+
+ freeArrays(ohashes, oarray, mSize);
+ }
+
+ if (index < mSize) {
+ if (DEBUG) Log.d(TAG, "add: move " + index + "-" + (mSize-index)
+ + " to " + (index+1));
+ System.arraycopy(mHashes, index, mHashes, index + 1, mSize - index);
+ System.arraycopy(mArray, index, mArray, index + 1, mSize - index);
+ }
+
+ mHashes[index] = hash;
+ mArray[index] = value;
+ mSize++;
+ return true;
+ }
+
+ /**
+ * Perform a {@link #add(Object)} of all values in <var>array</var>
+ * @param array The array whose contents are to be retrieved.
+ */
+ public void putAll(ArraySet<? extends E> array) {
+ final int N = array.mSize;
+ ensureCapacity(mSize + N);
+ if (mSize == 0) {
+ if (N > 0) {
+ System.arraycopy(array.mHashes, 0, mHashes, 0, N);
+ System.arraycopy(array.mArray, 0, mArray, 0, N);
+ mSize = N;
+ }
+ } else {
+ for (int i=0; i<N; i++) {
+ add(array.valueAt(i));
+ }
+ }
+ }
+
+ /**
+ * Removes the specified object from this set.
+ *
+ * @param object the object to remove.
+ * @return {@code true} if this set was modified, {@code false} otherwise.
+ */
+ @Override
+ public boolean remove(Object object) {
+ int index = indexOf(object, object.hashCode());
+ if (index >= 0) {
+ removeAt(index);
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Remove the key/value mapping at the given index.
+ * @param index The desired index, must be between 0 and {@link #size()}-1.
+ * @return Returns the value that was stored at this index.
+ */
+ public E removeAt(int index) {
+ final E old = (E)mArray[index];
+ if (mSize <= 1) {
+ // Now empty.
+ if (DEBUG) Log.d(TAG, "remove: shrink from " + mHashes.length + " to 0");
+ freeArrays(mHashes, mArray, mSize);
+ mHashes = SparseArray.EMPTY_INTS;
+ mArray = SparseArray.EMPTY_OBJECTS;
+ mSize = 0;
+ } else {
+ if (mHashes.length > (BASE_SIZE*2) && mSize < mHashes.length/3) {
+ // Shrunk enough to reduce size of arrays. We don't allow it to
+ // shrink smaller than (BASE_SIZE*2) to avoid flapping between
+ // that and BASE_SIZE.
+ final int n = mSize > (BASE_SIZE*2) ? (mSize + (mSize>>1)) : (BASE_SIZE*2);
+
+ if (DEBUG) Log.d(TAG, "remove: shrink from " + mHashes.length + " to " + n);
+
+ final int[] ohashes = mHashes;
+ final Object[] oarray = mArray;
+ allocArrays(n);
+
+ mSize--;
+ if (index > 0) {
+ if (DEBUG) Log.d(TAG, "remove: copy from 0-" + index + " to 0");
+ System.arraycopy(ohashes, 0, mHashes, 0, index);
+ System.arraycopy(oarray, 0, mArray, 0, index);
+ }
+ if (index < mSize) {
+ if (DEBUG) Log.d(TAG, "remove: copy from " + (index+1) + "-" + mSize
+ + " to " + index);
+ System.arraycopy(ohashes, index + 1, mHashes, index, mSize - index);
+ System.arraycopy(oarray, index + 1, mArray, index, mSize - index);
+ }
+ } else {
+ mSize--;
+ if (index < mSize) {
+ if (DEBUG) Log.d(TAG, "remove: move " + (index+1) + "-" + mSize
+ + " to " + index);
+ System.arraycopy(mHashes, index + 1, mHashes, index, mSize - index);
+ System.arraycopy(mArray, index + 1, mArray, index, mSize - index);
+ }
+ mArray[mSize] = null;
+ }
+ }
+ return old;
+ }
+
+ /**
+ * Return the number of items in this array map.
+ */
+ @Override
+ public int size() {
+ return mSize;
+ }
+
+ @Override
+ public Object[] toArray() {
+ Object[] result = new Object[mSize];
+ System.arraycopy(mArray, 0, result, 0, mSize);
+ return result;
+ }
+
+ @Override
+ public <T> T[] toArray(T[] array) {
+ if (array.length < mSize) {
+ @SuppressWarnings("unchecked") T[] newArray
+ = (T[]) Array.newInstance(array.getClass().getComponentType(), mSize);
+ array = newArray;
+ }
+ System.arraycopy(mArray, 0, array, 0, mSize);
+ if (array.length > mSize) {
+ array[mSize] = null;
+ }
+ return array;
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This implementation returns false if the object is not a set, or
+ * if the sets have different sizes. Otherwise, for each value in this
+ * set, it checks to make sure the value also exists in the other set.
+ * If any value doesn't exist, the method returns false; otherwise, it
+ * returns true.
+ */
+ @Override
+ public boolean equals(Object object) {
+ if (this == object) {
+ return true;
+ }
+ if (object instanceof Set) {
+ Set<?> set = (Set<?>) object;
+ if (size() != set.size()) {
+ return false;
+ }
+
+ try {
+ for (int i=0; i<mSize; i++) {
+ E mine = valueAt(i);
+ if (!set.contains(mine)) {
+ return false;
+ }
+ }
+ } catch (NullPointerException ignored) {
+ return false;
+ } catch (ClassCastException ignored) {
+ return false;
+ }
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public int hashCode() {
+ final int[] hashes = mHashes;
+ int result = 0;
+ for (int i = 0, s = mSize; i < s; i++) {
+ result += hashes[i];
+ }
+ return result;
+ }
+
+ // ------------------------------------------------------------------------
+ // Interop with traditional Java containers. Not as efficient as using
+ // specialized collection APIs.
+ // ------------------------------------------------------------------------
+
+ private MapCollections<E, E> getCollection() {
+ if (mCollections == null) {
+ mCollections = new MapCollections<E, E>() {
+ @Override
+ protected int colGetSize() {
+ return mSize;
+ }
+
+ @Override
+ protected Object colGetEntry(int index, int offset) {
+ return mArray[index];
+ }
+
+ @Override
+ protected int colIndexOfKey(Object key) {
+ return indexOf(key, key.hashCode());
+ }
+
+ @Override
+ protected int colIndexOfValue(Object value) {
+ return indexOf(value, value.hashCode());
+ }
+
+ @Override
+ protected Map<E, E> colGetMap() {
+ throw new UnsupportedOperationException("not a map");
+ }
+
+ @Override
+ protected void colPut(E key, E value) {
+ add(key);
+ }
+
+ @Override
+ protected E colSetValue(int index, E value) {
+ throw new UnsupportedOperationException("not a map");
+ }
+
+ @Override
+ protected void colRemoveAt(int index) {
+ removeAt(index);
+ }
+
+ @Override
+ protected void colClear() {
+ clear();
+ }
+ };
+ }
+ return mCollections;
+ }
+
+ @Override
+ public Iterator<E> iterator() {
+ return getCollection().getKeySet().iterator();
+ }
+
+ @Override
+ public boolean containsAll(Collection<?> collection) {
+ Iterator<?> it = collection.iterator();
+ while (it.hasNext()) {
+ if (!contains(it.next())) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ @Override
+ public boolean addAll(Collection<? extends E> collection) {
+ ensureCapacity(mSize + collection.size());
+ boolean added = false;
+ for (E value : collection) {
+ added |= add(value);
+ }
+ return added;
+ }
+
+ @Override
+ public boolean removeAll(Collection<?> collection) {
+ boolean removed = false;
+ for (Object value : collection) {
+ removed |= remove(value);
+ }
+ return removed;
+ }
+
+ @Override
+ public boolean retainAll(Collection<?> collection) {
+ boolean removed = false;
+ for (int i=mSize-1; i>=0; i--) {
+ if (!collection.contains(mArray[i])) {
+ removeAt(i);
+ removed = true;
+ }
+ }
+ return removed;
+ }
+}
generated by cgit v1.1 at 2025-08-17 14:13:52 +0000