| /* |
| * 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 android.compat.annotation.UnsupportedAppUsage; |
| |
| import com.android.internal.util.ArrayUtils; |
| |
| import libcore.util.EmptyArray; |
| |
| import java.util.Collection; |
| import java.util.ConcurrentModificationException; |
| import java.util.Map; |
| import java.util.Set; |
| |
| /** |
| * ArrayMap is a generic key->value mapping data structure that is |
| * designed to be more memory efficient than a traditional {@link java.util.HashMap}. |
| * It keeps its mappings in an array data structure -- an integer array of hash |
| * codes for each item, and an Object array of the key/value pairs. This allows it to |
| * avoid having to create an extra object for every entry put in to the map, and it |
| * also tries to control the growth of the size of these arrays more aggressively |
| * (since growing them only requires copying the entries in the array, not rebuilding |
| * a hash map). |
| * |
| * <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 |
| * HashMap, 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%.</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 |
| * explicit call to set the capacity should turn off this aggressive shrinking behavior.</p> |
| */ |
| public final class ArrayMap<K, V> implements Map<K, V> { |
| private static final boolean DEBUG = false; |
| private static final String TAG = "ArrayMap"; |
| |
| /** |
| * Attempt to spot concurrent modifications to this data structure. |
| * |
| * It's best-effort, but any time we can throw something more diagnostic than an |
| * ArrayIndexOutOfBoundsException deep in the ArrayMap internals it's going to |
| * save a lot of development time. |
| * |
| * Good times to look for CME include after any allocArrays() call and at the end of |
| * functions that change mSize (put/remove/clear). |
| */ |
| private static final boolean CONCURRENT_MODIFICATION_EXCEPTIONS = true; |
| |
| /** |
| * The minimum amount by which the capacity of a ArrayMap 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. |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| private static final int CACHE_SIZE = 10; |
| |
| /** |
| * Special hash array value that indicates the container is immutable. |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| static final int[] EMPTY_IMMUTABLE_INTS = new int[0]; |
| |
| /** |
| * @hide Special immutable empty ArrayMap. |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Use your own singleton empty map. |
| public static final ArrayMap EMPTY = new ArrayMap<>(-1); |
| |
| /** |
| * 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. |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| static Object[] mBaseCache; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| static int mBaseCacheSize; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| static Object[] mTwiceBaseCache; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| static int mTwiceBaseCacheSize; |
| |
| final boolean mIdentityHashCode; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Hashes are an implementation detail. Use public key/value API. |
| int[] mHashes; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Storage is an implementation detail. Use public key/value API. |
| Object[] mArray; |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Use size() |
| int mSize; |
| MapCollections<K, V> mCollections; |
| |
| private static int binarySearchHashes(int[] hashes, int N, int hash) { |
| try { |
| return ContainerHelpers.binarySearch(hashes, N, hash); |
| } catch (ArrayIndexOutOfBoundsException e) { |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS) { |
| throw new ConcurrentModificationException(); |
| } else { |
| throw e; // the cache is poisoned at this point, there's not much we can do |
| } |
| } |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Hashes are an implementation detail. Use indexOfKey(Object). |
| 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 = binarySearchHashes(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 (key.equals(mArray[index<<1])) { |
| return index; |
| } |
| |
| // Search for a matching key after the index. |
| int end; |
| for (end = index + 1; end < N && mHashes[end] == hash; end++) { |
| if (key.equals(mArray[end << 1])) return end; |
| } |
| |
| // Search for a matching key before the index. |
| for (int i = index - 1; i >= 0 && mHashes[i] == hash; i--) { |
| if (key.equals(mArray[i << 1])) 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; |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Use indexOf(null) |
| int indexOfNull() { |
| final int N = mSize; |
| |
| // Important fast case: if nothing is in here, nothing to look for. |
| if (N == 0) { |
| return ~0; |
| } |
| |
| int index = binarySearchHashes(mHashes, N, 0); |
| |
| // 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 (null == mArray[index<<1]) { |
| return index; |
| } |
| |
| // Search for a matching key after the index. |
| int end; |
| for (end = index + 1; end < N && mHashes[end] == 0; end++) { |
| if (null == mArray[end << 1]) return end; |
| } |
| |
| // Search for a matching key before the index. |
| for (int i = index - 1; i >= 0 && mHashes[i] == 0; i--) { |
| if (null == mArray[i << 1]) 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; |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| private void allocArrays(final int size) { |
| if (mHashes == EMPTY_IMMUTABLE_INTS) { |
| throw new UnsupportedOperationException("ArrayMap is immutable"); |
| } |
| if (size == (BASE_SIZE*2)) { |
| synchronized (ArrayMap.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 (ArrayMap.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<<1]; |
| } |
| |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Allocations are an implementation detail. |
| private static void freeArrays(final int[] hashes, final Object[] array, final int size) { |
| if (hashes.length == (BASE_SIZE*2)) { |
| synchronized (ArrayMap.class) { |
| if (mTwiceBaseCacheSize < CACHE_SIZE) { |
| array[0] = mTwiceBaseCache; |
| array[1] = hashes; |
| for (int i=(size<<1)-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 (ArrayMap.class) { |
| if (mBaseCacheSize < CACHE_SIZE) { |
| array[0] = mBaseCache; |
| array[1] = hashes; |
| for (int i=(size<<1)-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 ArrayMap. The default capacity of an array map is 0, and |
| * will grow once items are added to it. |
| */ |
| public ArrayMap() { |
| this(0, false); |
| } |
| |
| /** |
| * Create a new ArrayMap with a given initial capacity. |
| */ |
| public ArrayMap(int capacity) { |
| this(capacity, false); |
| } |
| |
| /** {@hide} */ |
| public ArrayMap(int capacity, boolean identityHashCode) { |
| mIdentityHashCode = identityHashCode; |
| |
| // If this is immutable, use the sentinal EMPTY_IMMUTABLE_INTS |
| // instance instead of the usual EmptyArray.INT. The reference |
| // is checked later to see if the array is allowed to grow. |
| if (capacity < 0) { |
| mHashes = EMPTY_IMMUTABLE_INTS; |
| mArray = EmptyArray.OBJECT; |
| } else if (capacity == 0) { |
| mHashes = EmptyArray.INT; |
| mArray = EmptyArray.OBJECT; |
| } else { |
| allocArrays(capacity); |
| } |
| mSize = 0; |
| } |
| |
| /** |
| * Create a new ArrayMap with the mappings from the given ArrayMap. |
| */ |
| public ArrayMap(ArrayMap<K, V> map) { |
| this(); |
| if (map != null) { |
| putAll(map); |
| } |
| } |
| |
| /** |
| * Make the array map empty. All storage is released. |
| */ |
| @Override |
| public void clear() { |
| if (mSize > 0) { |
| final int[] ohashes = mHashes; |
| final Object[] oarray = mArray; |
| final int osize = mSize; |
| mHashes = EmptyArray.INT; |
| mArray = EmptyArray.OBJECT; |
| mSize = 0; |
| freeArrays(ohashes, oarray, osize); |
| } |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS && mSize > 0) { |
| throw new ConcurrentModificationException(); |
| } |
| } |
| |
| /** |
| * @hide |
| * Like {@link #clear}, but doesn't reduce the capacity of the ArrayMap. |
| */ |
| public void erase() { |
| if (mSize > 0) { |
| final int N = mSize<<1; |
| final Object[] array = mArray; |
| for (int i=0; i<N; i++) { |
| array[i] = null; |
| } |
| mSize = 0; |
| } |
| } |
| |
| /** |
| * Ensure the array map can hold at least <var>minimumCapacity</var> |
| * items. |
| */ |
| public void ensureCapacity(int minimumCapacity) { |
| final int osize = mSize; |
| if (mHashes.length < minimumCapacity) { |
| final int[] ohashes = mHashes; |
| final Object[] oarray = mArray; |
| allocArrays(minimumCapacity); |
| if (mSize > 0) { |
| System.arraycopy(ohashes, 0, mHashes, 0, osize); |
| System.arraycopy(oarray, 0, mArray, 0, osize<<1); |
| } |
| freeArrays(ohashes, oarray, osize); |
| } |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS && mSize != osize) { |
| throw new ConcurrentModificationException(); |
| } |
| } |
| |
| /** |
| * Check whether a key exists in the array. |
| * |
| * @param key The key to search for. |
| * @return Returns true if the key exists, else false. |
| */ |
| @Override |
| public boolean containsKey(Object key) { |
| return indexOfKey(key) >= 0; |
| } |
| |
| /** |
| * Returns the index of a key in the set. |
| * |
| * @param key The key to search for. |
| * @return Returns the index of the key if it exists, else a negative integer. |
| */ |
| public int indexOfKey(Object key) { |
| return key == null ? indexOfNull() |
| : indexOf(key, mIdentityHashCode ? System.identityHashCode(key) : key.hashCode()); |
| } |
| |
| /** |
| * Returns an index for which {@link #valueAt} would return the |
| * specified value, 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(Object value) { |
| final int N = mSize*2; |
| final Object[] array = mArray; |
| if (value == null) { |
| for (int i=1; i<N; i+=2) { |
| if (array[i] == null) { |
| return i>>1; |
| } |
| } |
| } else { |
| for (int i=1; i<N; i+=2) { |
| if (value.equals(array[i])) { |
| return i>>1; |
| } |
| } |
| } |
| return -1; |
| } |
| |
| /** |
| * Check whether a value exists in the array. This requires a linear search |
| * through the entire array. |
| * |
| * @param value The value to search for. |
| * @return Returns true if the value exists, else false. |
| */ |
| @Override |
| public boolean containsValue(Object value) { |
| return indexOfValue(value) >= 0; |
| } |
| |
| /** |
| * Retrieve a value from the array. |
| * @param key The key of the value to retrieve. |
| * @return Returns the value associated with the given key, |
| * or null if there is no such key. |
| */ |
| @Override |
| public V get(Object key) { |
| final int index = indexOfKey(key); |
| return index >= 0 ? (V)mArray[(index<<1)+1] : null; |
| } |
| |
| /** |
| * Return the key at the given index in the array. |
| * |
| * <p>For indices outside of the range <code>0...size()-1</code>, the behavior is undefined for |
| * apps targeting {@link android.os.Build.VERSION_CODES#P} and earlier, and an |
| * {@link ArrayIndexOutOfBoundsException} is thrown for apps targeting |
| * {@link android.os.Build.VERSION_CODES#Q} and later.</p> |
| * |
| * @param index The desired index, must be between 0 and {@link #size()}-1. |
| * @return Returns the key stored at the given index. |
| */ |
| public K keyAt(int index) { |
| if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) { |
| // The array might be slightly bigger than mSize, in which case, indexing won't fail. |
| // Check if exception should be thrown outside of the critical path. |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| return (K)mArray[index << 1]; |
| } |
| |
| /** |
| * Return the value at the given index in the array. |
| * |
| * <p>For indices outside of the range <code>0...size()-1</code>, the behavior is undefined for |
| * apps targeting {@link android.os.Build.VERSION_CODES#P} and earlier, and an |
| * {@link ArrayIndexOutOfBoundsException} is thrown for apps targeting |
| * {@link android.os.Build.VERSION_CODES#Q} and later.</p> |
| * |
| * @param index The desired index, must be between 0 and {@link #size()}-1. |
| * @return Returns the value stored at the given index. |
| */ |
| public V valueAt(int index) { |
| if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) { |
| // The array might be slightly bigger than mSize, in which case, indexing won't fail. |
| // Check if exception should be thrown outside of the critical path. |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| return (V)mArray[(index << 1) + 1]; |
| } |
| |
| /** |
| * Set the value at a given index in the array. |
| * |
| * <p>For indices outside of the range <code>0...size()-1</code>, the behavior is undefined for |
| * apps targeting {@link android.os.Build.VERSION_CODES#P} and earlier, and an |
| * {@link ArrayIndexOutOfBoundsException} is thrown for apps targeting |
| * {@link android.os.Build.VERSION_CODES#Q} and later.</p> |
| * |
| * @param index The desired index, must be between 0 and {@link #size()}-1. |
| * @param value The new value to store at this index. |
| * @return Returns the previous value at the given index. |
| */ |
| public V setValueAt(int index, V value) { |
| if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) { |
| // The array might be slightly bigger than mSize, in which case, indexing won't fail. |
| // Check if exception should be thrown outside of the critical path. |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| index = (index << 1) + 1; |
| V old = (V)mArray[index]; |
| mArray[index] = value; |
| return old; |
| } |
| |
| /** |
| * Return true if the array map contains no items. |
| */ |
| @Override |
| public boolean isEmpty() { |
| return mSize <= 0; |
| } |
| |
| /** |
| * Add a new value to the array map. |
| * @param key The key under which to store the value. If |
| * this key already exists in the array, its value will be replaced. |
| * @param value The value to store for the given key. |
| * @return Returns the old value that was stored for the given key, or null if there |
| * was no such key. |
| */ |
| @Override |
| public V put(K key, V value) { |
| final int osize = mSize; |
| final int hash; |
| int index; |
| if (key == null) { |
| hash = 0; |
| index = indexOfNull(); |
| } else { |
| hash = mIdentityHashCode ? System.identityHashCode(key) : key.hashCode(); |
| index = indexOf(key, hash); |
| } |
| if (index >= 0) { |
| index = (index<<1) + 1; |
| final V old = (V)mArray[index]; |
| mArray[index] = value; |
| return old; |
| } |
| |
| index = ~index; |
| if (osize >= mHashes.length) { |
| final int n = osize >= (BASE_SIZE*2) ? (osize+(osize>>1)) |
| : (osize >= BASE_SIZE ? (BASE_SIZE*2) : BASE_SIZE); |
| |
| if (DEBUG) Log.d(TAG, "put: grow from " + mHashes.length + " to " + n); |
| |
| final int[] ohashes = mHashes; |
| final Object[] oarray = mArray; |
| allocArrays(n); |
| |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS && osize != mSize) { |
| throw new ConcurrentModificationException(); |
| } |
| |
| if (mHashes.length > 0) { |
| if (DEBUG) Log.d(TAG, "put: copy 0-" + osize + " to 0"); |
| System.arraycopy(ohashes, 0, mHashes, 0, ohashes.length); |
| System.arraycopy(oarray, 0, mArray, 0, oarray.length); |
| } |
| |
| freeArrays(ohashes, oarray, osize); |
| } |
| |
| if (index < osize) { |
| if (DEBUG) Log.d(TAG, "put: move " + index + "-" + (osize-index) |
| + " to " + (index+1)); |
| System.arraycopy(mHashes, index, mHashes, index + 1, osize - index); |
| System.arraycopy(mArray, index << 1, mArray, (index + 1) << 1, (mSize - index) << 1); |
| } |
| |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS) { |
| if (osize != mSize || index >= mHashes.length) { |
| throw new ConcurrentModificationException(); |
| } |
| } |
| mHashes[index] = hash; |
| mArray[index<<1] = key; |
| mArray[(index<<1)+1] = value; |
| mSize++; |
| return null; |
| } |
| |
| /** |
| * Special fast path for appending items to the end of the array without validation. |
| * The array must already be large enough to contain the item. |
| * @hide |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = 28) // Storage is an implementation detail. Use put(K, V). |
| public void append(K key, V value) { |
| int index = mSize; |
| final int hash = key == null ? 0 |
| : (mIdentityHashCode ? System.identityHashCode(key) : key.hashCode()); |
| if (index >= mHashes.length) { |
| throw new IllegalStateException("Array is full"); |
| } |
| if (index > 0 && mHashes[index-1] > hash) { |
| RuntimeException e = new RuntimeException("here"); |
| e.fillInStackTrace(); |
| Log.w(TAG, "New hash " + hash |
| + " is before end of array hash " + mHashes[index-1] |
| + " at index " + index + " key " + key, e); |
| put(key, value); |
| return; |
| } |
| mSize = index+1; |
| mHashes[index] = hash; |
| index <<= 1; |
| mArray[index] = key; |
| mArray[index+1] = value; |
| } |
| |
| /** |
| * The use of the {@link #append} function can result in invalid array maps, in particular |
| * an array map where the same key appears multiple times. This function verifies that |
| * the array map is valid, throwing IllegalArgumentException if a problem is found. The |
| * main use for this method is validating an array map after unpacking from an IPC, to |
| * protect against malicious callers. |
| * @hide |
| */ |
| public void validate() { |
| final int N = mSize; |
| if (N <= 1) { |
| // There can't be dups. |
| return; |
| } |
| int basehash = mHashes[0]; |
| int basei = 0; |
| for (int i=1; i<N; i++) { |
| int hash = mHashes[i]; |
| if (hash != basehash) { |
| basehash = hash; |
| basei = i; |
| continue; |
| } |
| // We are in a run of entries with the same hash code. Go backwards through |
| // the array to see if any keys are the same. |
| final Object cur = mArray[i<<1]; |
| for (int j=i-1; j>=basei; j--) { |
| final Object prev = mArray[j<<1]; |
| if (cur == prev) { |
| throw new IllegalArgumentException("Duplicate key in ArrayMap: " + cur); |
| } |
| if (cur != null && prev != null && cur.equals(prev)) { |
| throw new IllegalArgumentException("Duplicate key in ArrayMap: " + cur); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Perform a {@link #put(Object, Object)} of all key/value pairs in <var>array</var> |
| * @param array The array whose contents are to be retrieved. |
| */ |
| public void putAll(ArrayMap<? extends K, ? extends V> 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<<1); |
| mSize = N; |
| } |
| } else { |
| for (int i=0; i<N; i++) { |
| put(array.keyAt(i), array.valueAt(i)); |
| } |
| } |
| } |
| |
| /** |
| * Remove an existing key from the array map. |
| * @param key The key of the mapping to remove. |
| * @return Returns the value that was stored under the key, or null if there |
| * was no such key. |
| */ |
| @Override |
| public V remove(Object key) { |
| final int index = indexOfKey(key); |
| if (index >= 0) { |
| return removeAt(index); |
| } |
| |
| return null; |
| } |
| |
| /** |
| * Remove the key/value mapping at the given index. |
| * |
| * <p>For indices outside of the range <code>0...size()-1</code>, the behavior is undefined for |
| * apps targeting {@link android.os.Build.VERSION_CODES#P} and earlier, and an |
| * {@link ArrayIndexOutOfBoundsException} is thrown for apps targeting |
| * {@link android.os.Build.VERSION_CODES#Q} and later.</p> |
| * |
| * @param index The desired index, must be between 0 and {@link #size()}-1. |
| * @return Returns the value that was stored at this index. |
| */ |
| public V removeAt(int index) { |
| if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) { |
| // The array might be slightly bigger than mSize, in which case, indexing won't fail. |
| // Check if exception should be thrown outside of the critical path. |
| throw new ArrayIndexOutOfBoundsException(index); |
| } |
| |
| final Object old = mArray[(index << 1) + 1]; |
| final int osize = mSize; |
| final int nsize; |
| if (osize <= 1) { |
| // Now empty. |
| if (DEBUG) Log.d(TAG, "remove: shrink from " + mHashes.length + " to 0"); |
| final int[] ohashes = mHashes; |
| final Object[] oarray = mArray; |
| mHashes = EmptyArray.INT; |
| mArray = EmptyArray.OBJECT; |
| freeArrays(ohashes, oarray, osize); |
| nsize = 0; |
| } else { |
| nsize = osize - 1; |
| 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 = osize > (BASE_SIZE*2) ? (osize + (osize>>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); |
| |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS && osize != mSize) { |
| throw new ConcurrentModificationException(); |
| } |
| |
| 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 << 1); |
| } |
| if (index < nsize) { |
| if (DEBUG) Log.d(TAG, "remove: copy from " + (index+1) + "-" + nsize |
| + " to " + index); |
| System.arraycopy(ohashes, index + 1, mHashes, index, nsize - index); |
| System.arraycopy(oarray, (index + 1) << 1, mArray, index << 1, |
| (nsize - index) << 1); |
| } |
| } else { |
| if (index < nsize) { |
| if (DEBUG) Log.d(TAG, "remove: move " + (index+1) + "-" + nsize |
| + " to " + index); |
| System.arraycopy(mHashes, index + 1, mHashes, index, nsize - index); |
| System.arraycopy(mArray, (index + 1) << 1, mArray, index << 1, |
| (nsize - index) << 1); |
| } |
| mArray[nsize << 1] = null; |
| mArray[(nsize << 1) + 1] = null; |
| } |
| } |
| if (CONCURRENT_MODIFICATION_EXCEPTIONS && osize != mSize) { |
| throw new ConcurrentModificationException(); |
| } |
| mSize = nsize; |
| return (V)old; |
| } |
| |
| /** |
| * Return the number of items in this array map. |
| */ |
| @Override |
| public int size() { |
| 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; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * <p>This implementation composes a string by iterating over its mappings. If |
| * this map contains itself as a key or a value, the string "(this Map)" |
| * will appear in its place. |
| */ |
| @Override |
| public String toString() { |
| if (isEmpty()) { |
| return "{}"; |
| } |
| |
| StringBuilder buffer = new StringBuilder(mSize * 28); |
| buffer.append('{'); |
| for (int i=0; i<mSize; i++) { |
| if (i > 0) { |
| buffer.append(", "); |
| } |
| Object key = keyAt(i); |
| if (key != this) { |
| buffer.append(key); |
| } else { |
| buffer.append("(this Map)"); |
| } |
| buffer.append('='); |
| Object value = valueAt(i); |
| if (value != this) { |
| buffer.append(ArrayUtils.deepToString(value)); |
| } else { |
| buffer.append("(this Map)"); |
| } |
| } |
| buffer.append('}'); |
| return buffer.toString(); |
| } |
| |
| // ------------------------------------------------------------------------ |
| // Interop with traditional Java containers. Not as efficient as using |
| // specialized collection APIs. |
| // ------------------------------------------------------------------------ |
| |
| private MapCollections<K, V> getCollection() { |
| if (mCollections == null) { |
| mCollections = new MapCollections<K, V>() { |
| @Override |
| protected int colGetSize() { |
| return mSize; |
| } |
| |
| @Override |
| protected Object colGetEntry(int index, int offset) { |
| return mArray[(index<<1) + offset]; |
| } |
| |
| @Override |
| protected int colIndexOfKey(Object key) { |
| return indexOfKey(key); |
| } |
| |
| @Override |
| protected int colIndexOfValue(Object value) { |
| return indexOfValue(value); |
| } |
| |
| @Override |
| protected Map<K, V> colGetMap() { |
| return ArrayMap.this; |
| } |
| |
| @Override |
| protected void colPut(K key, V value) { |
| put(key, value); |
| } |
| |
| @Override |
| protected V colSetValue(int index, V value) { |
| return setValueAt(index, value); |
| } |
| |
| @Override |
| protected void colRemoveAt(int index) { |
| removeAt(index); |
| } |
| |
| @Override |
| protected void colClear() { |
| clear(); |
| } |
| }; |
| } |
| return mCollections; |
| } |
| |
| /** |
| * Determine if the array map contains all of the keys in the given collection. |
| * @param collection The collection whose contents are to be checked against. |
| * @return Returns true if this array map contains a key for every entry |
| * in <var>collection</var>, else returns false. |
| */ |
| public boolean containsAll(Collection<?> collection) { |
| return MapCollections.containsAllHelper(this, collection); |
| } |
| |
| /** |
| * Perform a {@link #put(Object, Object)} of all key/value pairs in <var>map</var> |
| * @param map The map whose contents are to be retrieved. |
| */ |
| @Override |
| public void putAll(Map<? extends K, ? extends V> map) { |
| ensureCapacity(mSize + map.size()); |
| for (Map.Entry<? extends K, ? extends V> entry : map.entrySet()) { |
| put(entry.getKey(), entry.getValue()); |
| } |
| } |
| |
| /** |
| * Remove all keys in the array map that exist in the given collection. |
| * @param collection The collection whose contents are to be used to remove keys. |
| * @return Returns true if any keys were removed from the array map, else false. |
| */ |
| public boolean removeAll(Collection<?> collection) { |
| return MapCollections.removeAllHelper(this, collection); |
| } |
| |
| /** |
| * Remove all keys in the array map that do <b>not</b> exist in the given collection. |
| * @param collection The collection whose contents are to be used to determine which |
| * keys to keep. |
| * @return Returns true if any keys were removed from the array map, else false. |
| */ |
| public boolean retainAll(Collection<?> collection) { |
| return MapCollections.retainAllHelper(this, collection); |
| } |
| |
| /** |
| * Return a {@link java.util.Set} for iterating over and interacting with all mappings |
| * in the array map. |
| * |
| * <p><b>Note:</b> this is a very inefficient way to access the array contents, it |
| * requires generating a number of temporary objects and allocates additional state |
| * information associated with the container that will remain for the life of the container.</p> |
| * |
| * <p><b>Note:</b></p> the semantics of this |
| * Set are subtly different than that of a {@link java.util.HashMap}: most important, |
| * the {@link java.util.Map.Entry Map.Entry} object returned by its iterator is a single |
| * object that exists for the entire iterator, so you can <b>not</b> hold on to it |
| * after calling {@link java.util.Iterator#next() Iterator.next}.</p> |
| */ |
| @Override |
| public Set<Map.Entry<K, V>> entrySet() { |
| return getCollection().getEntrySet(); |
| } |
| |
| /** |
| * Return a {@link java.util.Set} for iterating over and interacting with all keys |
| * in the array map. |
| * |
| * <p><b>Note:</b> this is a fairly inefficient way to access the array contents, it |
| * requires generating a number of temporary objects and allocates additional state |
| * information associated with the container that will remain for the life of the container.</p> |
| */ |
| @Override |
| public Set<K> keySet() { |
| return getCollection().getKeySet(); |
| } |
| |
| /** |
| * Return a {@link java.util.Collection} for iterating over and interacting with all values |
| * in the array map. |
| * |
| * <p><b>Note:</b> this is a fairly inefficient way to access the array contents, it |
| * requires generating a number of temporary objects and allocates additional state |
| * information associated with the container that will remain for the life of the container.</p> |
| */ |
| @Override |
| public Collection<V> values() { |
| return getCollection().getValues(); |
| } |
| } |