public class ArrayMap<K,V>
extends java.util.AbstractMap<K,V>
implements java.lang.Cloneable
ArrayMap is optimized for many-reads-few-write. In particular, it reallocates its array on any insertion or deletion.
ArrayMap also includes a series of static methods for managing the
Object array. These may be used in place of instantiating an
ArrayMap for clients that don't need a Map implementation.
Clients using these methods must be careful to store the returned
Object array on any mutator method. They also must provide their
own synchronization, if needed. When using these static methods,
clients can opt to search for objects by identity (via
getByIdentity()
) instead of equality, while the static
get()
method will try identity before equality. This
latter approach is extremely fast but still safe for retrieval of
Strings that have all been interned, especially if misses are
infrequent (since misses do require a scan using Object.equals()).
It's worth remembering that String constants are always interned,
as required by the language specification.
Constructor and Description |
---|
ArrayMap()
Creates an empty ArrayMap, preallocating nothing.
|
ArrayMap(int size)
Creates an ArrayMap, preallocating for a certain size.
|
ArrayMap(int size,
int increment)
Creates an ArrayMap, preallocating for a certain size.
|
Modifier and Type | Method and Description |
---|---|
void |
clear()
Removes all elements from the ArrayMap.
|
java.lang.Object |
clone()
Clones the map.
|
boolean |
containsKey(java.lang.Object key) |
boolean |
containsValue(java.lang.Object value) |
java.util.Set<java.util.Map.Entry<K,V>> |
entrySet() |
V |
get(java.lang.Object key) |
static java.lang.Object |
get(java.lang.Object[] array,
java.lang.Object key)
Gets the object stored with the given key.
|
static java.lang.Object |
getByEquality(java.lang.Object[] array,
java.lang.Object key)
Gets the object stored with the given key, using
only object equality.
|
V |
getByIdentity(java.lang.Object key) |
static java.lang.Object |
getByIdentity(java.lang.Object[] array,
java.lang.Object key)
Gets the object stored with the given key, using
only object identity.
|
K |
getKey(int index)
Returns the key at a specific index in the map.
|
static java.util.Enumeration<java.lang.Object> |
getKeys(java.lang.Object[] array)
Returns an Iterator of keys in the array.
|
V |
getValue(int index)
Returns the value at a specific index in the map.
|
static java.util.Enumeration<java.lang.Object> |
getValues(java.lang.Object[] array)
Returns an Iterator of values in the array.
|
java.util.Enumeration<K> |
keys()
Returns an enumeration of the keys in this map.
|
V |
put(K key,
V value) |
static java.lang.Object[] |
put(java.lang.Object[] array,
java.lang.Object key,
java.lang.Object value)
Adds the key/value pair to the array, returning a
new array if necessary.
|
V |
remove(java.lang.Object key) |
static java.lang.Object[] |
remove(java.lang.Object[] array,
java.lang.Object key)
Removes the value for the key from the array, returning a
new array if necessary.
|
static java.lang.Object[] |
remove(java.lang.Object[] array,
java.lang.Object key,
boolean reallocate)
Removes the value for the key from the array, returning a
new array if necessary.
|
int |
size() |
public ArrayMap()
public ArrayMap(int size)
size
- the number of elements to pre-allocate forpublic ArrayMap(int size, int increment)
size
- the number of elements to pre-allocate forincrement
- the number of additional elements to
allocate for when overruningpublic K getKey(int index)
public V getValue(int index)
public static java.lang.Object get(java.lang.Object[] array, java.lang.Object key)
public static java.lang.Object getByIdentity(java.lang.Object[] array, java.lang.Object key)
public static java.lang.Object getByEquality(java.lang.Object[] array, java.lang.Object key)
public static java.lang.Object[] put(java.lang.Object[] array, java.lang.Object key, java.lang.Object value)
public static java.lang.Object[] remove(java.lang.Object[] array, java.lang.Object key)
public static java.lang.Object[] remove(java.lang.Object[] array, java.lang.Object key, boolean reallocate)
public int size()
public boolean containsValue(java.lang.Object value)
public boolean containsKey(java.lang.Object key)
public java.util.Enumeration<K> keys()
public static java.util.Enumeration<java.lang.Object> getKeys(java.lang.Object[] array)
public static java.util.Enumeration<java.lang.Object> getValues(java.lang.Object[] array)
public java.lang.Object clone()
public V get(java.lang.Object key)
public V getByIdentity(java.lang.Object key)
public V remove(java.lang.Object key)