core/java/android/util/LongSparseLongArray.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2007 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;

 /**
  * Map of {@code long} to {@code long}. Unlike a normal array of longs, there
  * can be gaps in the indices. It is intended to be more memory efficient than using a
  * {@code HashMap}, both because it avoids
  * auto-boxing keys and values and its data structure doesn't rely on an extra entry object
  * for each mapping.
  *
  * <p>Note that this container keeps its mappings in an array data structure,
  * using a binary search to find keys.  The 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>It is possible to iterate over the items in this container using
  * {@link #keyAt(int)} and {@link #valueAt(int)}. Iterating over the keys using
  * <code>keyAt(int)</code> with ascending values of the index will return the
  * keys in ascending order, or the values corresponding to the keys in ascending
  * order in the case of <code>valueAt(int)</code>.</p>
  *
  * @hide
  */
 public class LongSparseLongArray implements Cloneable {
     private long[] mKeys;
     private long[] mValues;
     private int mSize;

     /**
      * Creates a new SparseLongArray containing no mappings.
      */
     public LongSparseLongArray() {
         this(10);
     }

     /**
      * Creates a new SparseLongArray containing no mappings that will not
      * require any additional memory allocation to store the specified
      * number of mappings.  If you supply an initial capacity of 0, the
      * sparse array will be initialized with a light-weight representation
      * not requiring any additional array allocations.
      */
     public LongSparseLongArray(int initialCapacity) {
         if (initialCapacity == 0) {
             mKeys = EmptyArray.LONG;
             mValues = EmptyArray.LONG;
         } else {
             mKeys = ArrayUtils.newUnpaddedLongArray(initialCapacity);
             mValues = new long[mKeys.length];
         }
         mSize = 0;
     }

     @Override
     public LongSparseLongArray clone() {
         LongSparseLongArray clone = null;
         try {
             clone = (LongSparseLongArray) super.clone();
             clone.mKeys = mKeys.clone();
             clone.mValues = mValues.clone();
         } catch (CloneNotSupportedException cnse) {
             /* ignore */
         }
         return clone;
     }

     /**
      * Gets the long mapped from the specified key, or <code>0</code>
      * if no such mapping has been made.
      */
     public long get(long key) {
         return get(key, 0);
     }

     /**
      * Gets the long mapped from the specified key, or the specified value
      * if no such mapping has been made.
      */
     public long get(long key, long valueIfKeyNotFound) {
         int i = ContainerHelpers.binarySearch(mKeys, 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(long key) {
         int i = ContainerHelpers.binarySearch(mKeys, mSize, key);

         if (i >= 0) {
             removeAt(i);
         }
     }

     /**
      * Removes the mapping at the given index.
      */
     public void removeAt(int index) {
         System.arraycopy(mKeys, index + 1, mKeys, index, mSize - (index + 1));
         System.arraycopy(mValues, index + 1, mValues, index, mSize - (index + 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(long key, long value) {
         int i = ContainerHelpers.binarySearch(mKeys, mSize, key);

         if (i >= 0) {
             mValues[i] = value;
         } else {
             i = ~i;

             mKeys = GrowingArrayUtils.insert(mKeys, mSize, i, key);
             mValues = GrowingArrayUtils.insert(mValues, mSize, i, value);
             mSize++;
         }
     }

     /**
      * Returns the number of key-value mappings that this SparseIntArray
      * 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
      * SparseLongArray stores.
      *
      * <p>The keys corresponding to indices in ascending order are guaranteed to
      * be in ascending order, e.g., <code>keyAt(0)</code> will return the
      * smallest key and <code>keyAt(size()-1)</code> will return the largest
      * key.</p>
      */
     public long 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
      * SparseLongArray stores.
      *
      * <p>The values corresponding to indices in ascending order are guaranteed
      * to be associated with keys in ascending order, e.g.,
      * <code>valueAt(0)</code> will return the value associated with the
      * smallest key and <code>valueAt(size()-1)</code> will return the value
      * associated with the largest key.</p>
      */
     public long 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(long key) {
         return ContainerHelpers.binarySearch(mKeys, 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(long value) {
         for (int i = 0; i < mSize; i++)
             if (mValues[i] == value)
                 return i;

         return -1;
     }

     /**
      * Removes all key-value mappings from this SparseIntArray.
      */
     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(long key, long value) {
         if (mSize != 0 && key <= mKeys[mSize - 1]) {
             put(key, value);
             return;
         }

         mKeys = GrowingArrayUtils.append(mKeys, mSize, key);
         mValues = GrowingArrayUtils.append(mValues, mSize, value);
         mSize++;
     }

     /**
      * {@inheritDoc}
      *
      * <p>This implementation composes a string by iterating over its mappings.
      */
     @Override
     public String toString() {
         if (size() <= 0) {
             return "{}";
         }

         StringBuilder buffer = new StringBuilder(mSize * 28);
         buffer.append('{');
         for (int i=0; i<mSize; i++) {
             if (i > 0) {
                 buffer.append(", ");
             }
             long key = keyAt(i);
             buffer.append(key);
             buffer.append('=');
             long value = valueAt(i);
             buffer.append(value);
         }
         buffer.append('}');
         return buffer.toString();
     }
 }
	/*
	* Copyright (C) 2007 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;

	/**
	* Map of {@code long} to {@code long}. Unlike a normal array of longs, there
	* can be gaps in the indices. It is intended to be more memory efficient than using a
	* {@code HashMap}, both because it avoids
	* auto-boxing keys and values and its data structure doesn't rely on an extra entry object
	* for each mapping.
	*
	* <p>Note that this container keeps its mappings in an array data structure,
	* using a binary search to find keys. The 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>It is possible to iterate over the items in this container using
	* {@link #keyAt(int)} and {@link #valueAt(int)}. Iterating over the keys using
	* <code>keyAt(int)</code> with ascending values of the index will return the
	* keys in ascending order, or the values corresponding to the keys in ascending
	* order in the case of <code>valueAt(int)</code>.</p>
	*
	* @hide
	*/
	public class LongSparseLongArray implements Cloneable {
	private long[] mKeys;
	private long[] mValues;
	private int mSize;

	/**
	* Creates a new SparseLongArray containing no mappings.
	*/
	public LongSparseLongArray() {
	this(10);
	}

	/**
	* Creates a new SparseLongArray containing no mappings that will not
	* require any additional memory allocation to store the specified
	* number of mappings. If you supply an initial capacity of 0, the
	* sparse array will be initialized with a light-weight representation
	* not requiring any additional array allocations.
	*/
	public LongSparseLongArray(int initialCapacity) {
	if (initialCapacity == 0) {
	mKeys = EmptyArray.LONG;
	mValues = EmptyArray.LONG;
	} else {
	mKeys = ArrayUtils.newUnpaddedLongArray(initialCapacity);
	mValues = new long[mKeys.length];
	}
	mSize = 0;
	}

	@Override
	public LongSparseLongArray clone() {
	LongSparseLongArray clone = null;
	try {
	clone = (LongSparseLongArray) super.clone();
	clone.mKeys = mKeys.clone();
	clone.mValues = mValues.clone();
	} catch (CloneNotSupportedException cnse) {
	/* ignore */
	}
	return clone;
	}

	/**
	* Gets the long mapped from the specified key, or <code>0</code>
	* if no such mapping has been made.
	*/
	public long get(long key) {
	return get(key, 0);
	}

	/**
	* Gets the long mapped from the specified key, or the specified value
	* if no such mapping has been made.
	*/
	public long get(long key, long valueIfKeyNotFound) {
	int i = ContainerHelpers.binarySearch(mKeys, 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(long key) {
	int i = ContainerHelpers.binarySearch(mKeys, mSize, key);

	if (i >= 0) {
	removeAt(i);
	}
	}

	/**
	* Removes the mapping at the given index.
	*/
	public void removeAt(int index) {
	System.arraycopy(mKeys, index + 1, mKeys, index, mSize - (index + 1));
	System.arraycopy(mValues, index + 1, mValues, index, mSize - (index + 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(long key, long value) {
	int i = ContainerHelpers.binarySearch(mKeys, mSize, key);

	if (i >= 0) {
	mValues[i] = value;
	} else {
	i = ~i;

	mKeys = GrowingArrayUtils.insert(mKeys, mSize, i, key);
	mValues = GrowingArrayUtils.insert(mValues, mSize, i, value);
	mSize++;
	}
	}

	/**
	* Returns the number of key-value mappings that this SparseIntArray
	* 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
	* SparseLongArray stores.
	*
	* <p>The keys corresponding to indices in ascending order are guaranteed to
	* be in ascending order, e.g., <code>keyAt(0)</code> will return the
	* smallest key and <code>keyAt(size()-1)</code> will return the largest
	* key.</p>
	*/
	public long 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
	* SparseLongArray stores.
	*
	* <p>The values corresponding to indices in ascending order are guaranteed
	* to be associated with keys in ascending order, e.g.,
	* <code>valueAt(0)</code> will return the value associated with the
	* smallest key and <code>valueAt(size()-1)</code> will return the value
	* associated with the largest key.</p>
	*/
	public long 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(long key) {
	return ContainerHelpers.binarySearch(mKeys, 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(long value) {
	for (int i = 0; i < mSize; i++)
	if (mValues[i] == value)
	return i;

	return -1;
	}

	/**
	* Removes all key-value mappings from this SparseIntArray.
	*/
	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(long key, long value) {
	if (mSize != 0 && key <= mKeys[mSize - 1]) {
	put(key, value);
	return;
	}

	mKeys = GrowingArrayUtils.append(mKeys, mSize, key);
	mValues = GrowingArrayUtils.append(mValues, mSize, value);
	mSize++;
	}

	/**
	* {@inheritDoc}
	*
	* <p>This implementation composes a string by iterating over its mappings.
	*/
	@Override
	public String toString() {
	if (size() <= 0) {
	return "{}";
	}

	StringBuilder buffer = new StringBuilder(mSize * 28);
	buffer.append('{');
	for (int i=0; i<mSize; i++) {
	if (i > 0) {
	buffer.append(", ");
	}
	long key = keyAt(i);
	buffer.append(key);
	buffer.append('=');
	long value = valueAt(i);
	buffer.append(value);
	}
	buffer.append('}');
	return buffer.toString();
	}
	}