LongSparseArray

extends Object
implements Cloneable

java.lang.Object
↳	android.util.LongSparseArray<E>

Class Overview

SparseArray mapping longs to Objects. Unlike a normal array of Objects, there can be gaps in the indices. It is intended to be more memory efficient than using a HashMap to map Longs to Objects, both because it avoids auto-boxing keys and its data structure doesn't rely on an extra entry object for each mapping.

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%.

To help with performance, the container includes an optimization when removing keys: instead of compacting its array immediately, it leaves the removed entry marked as deleted. The entry can then be re-used for the same key, or compacted later in a single garbage collection step of all removed entries. This garbage collection will need to be performed at any time the array needs to be grown or the the map size or entry values are retrieved.

It is possible to iterate over the items in this container using keyAt(int) and valueAt(int). Iterating over the keys using keyAt(int) 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 valueAt(int).

Summary

Public Constructors
	LongSparseArray() Creates a new LongSparseArray containing no mappings.
	LongSparseArray(int initialCapacity) Creates a new LongSparseArray containing no mappings that will not require any additional memory allocation to store the specified number of mappings.

Public Methods
void	append(long key, E value) Puts a key/value pair into the array, optimizing for the case where the key is greater than all existing keys in the array.
void	clear() Removes all key-value mappings from this LongSparseArray.
LongSparseArray<E>	clone() Creates and returns a copy of this `Object`.
void	delete(long key) Removes the mapping from the specified key, if there was any.
E	get(long key, E valueIfKeyNotFound) Gets the Object mapped from the specified key, or the specified Object if no such mapping has been made.
E	get(long key) Gets the Object mapped from the specified key, or `null` if no such mapping has been made.
int	indexOfKey(long key) Returns the index for which `keyAt(int)` would return the specified key, or a negative number if the specified key is not mapped.
int	indexOfValue(E value) Returns an index for which `valueAt(int)` would return the specified key, or a negative number if no keys map to the specified value.
long	keyAt(int index) Given an index in the range `0...size()-1`, returns the key from the `index`th key-value mapping that this LongSparseArray stores.
void	put(long key, E value) Adds a mapping from the specified key to the specified value, replacing the previous mapping from the specified key if there was one.
void	remove(long key) Alias for `delete(long)`.
void	removeAt(int index) Removes the mapping at the specified index.
void	setValueAt(int index, E value) Given an index in the range `0...size()-1`, sets a new value for the `index`th key-value mapping that this LongSparseArray stores.
int	size() Returns the number of key-value mappings that this LongSparseArray currently stores.
String	toString() Returns a string containing a concise, human-readable description of this object. This implementation composes a string by iterating over its mappings.
E	valueAt(int index) Given an index in the range `0...size()-1`, returns the value from the `index`th key-value mapping that this LongSparseArray stores.

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Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Results

Interfaces

Classes

Enums

Exceptions

LongSparseArray

Class Overview

Summary

Public Constructors

public LongSparseArray ()

public LongSparseArray (int initialCapacity)

Public Methods

public void append (long key, E value)

public void clear ()

public LongSparseArray<E> clone ()

Returns

public void delete (long key)

public E get (long key, E valueIfKeyNotFound)

public E get (long key)

public int indexOfKey (long key)

public int indexOfValue (E value)

public long keyAt (int index)

public void put (long key, E value)

public void remove (long key)

public void removeAt (int index)

public void setValueAt (int index, E value)

public int size ()

public String toString ()

Returns

public E valueAt (int index)