it.unimi.dsi.fastutil.objects
Class Reference2IntArrayMap<K>

java.lang.Object
  extended by it.unimi.dsi.fastutil.objects.AbstractReference2IntFunction<K>
      extended by it.unimi.dsi.fastutil.objects.AbstractReference2IntMap<K>
          extended by it.unimi.dsi.fastutil.objects.Reference2IntArrayMap<K>
All Implemented Interfaces:
Function<K,java.lang.Integer>, Reference2IntFunction<K>, Reference2IntMap<K>, java.io.Serializable, java.lang.Cloneable, java.util.Map<K,java.lang.Integer>

public class Reference2IntArrayMap<K>
extends AbstractReference2IntMap<K>
implements java.io.Serializable, java.lang.Cloneable

A simple, brute-force implementation of a map based on two parallel backing arrays.

The main purpose of this implementation is that of wrapping cleanly the brute-force approach to the storage of a very small number of pairs: just put them into two parallel arrays and scan linearly to find an item.

See Also:
Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntMap
AbstractReference2IntMap.BasicEntry<K>
 
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.objects.Reference2IntMap
Reference2IntMap.Entry<K>, Reference2IntMap.FastEntrySet<K>
 
Constructor Summary
Reference2IntArrayMap()
          Creates a new empty array map.
Reference2IntArrayMap(int capacity)
          Creates a new empty array map of given capacity.
Reference2IntArrayMap(java.lang.Object[] key, int[] value)
          Creates a new empty array map with given key and value backing arrays.
Reference2IntArrayMap(java.lang.Object[] key, int[] value, int size)
          Creates a new array map with given key and value backing arrays, using the given number of elements.
Reference2IntArrayMap(Reference2IntMap<K> m)
          Creates a new empty array map copying the entries of a given map.
 
Method Summary
 void clear()
          Removes all associations from this function (optional operation).
 java.lang.Object clone()
          Returns a deep copy of this map.
 boolean containsKey(java.lang.Object k)
          Checks whether the given value is contained in AbstractReference2IntMap.keySet().
 boolean containsValue(int v)
          Checks whether the given value is contained in AbstractReference2IntMap.values().
 int getInt(java.lang.Object k)
          Returns the value to which the given key is mapped.
 boolean isEmpty()
           
 ReferenceSet<K> keySet()
          Returns a type-specific-set view of the keys of this map.
 int put(K k, int v)
          Adds a pair to the map.
 Reference2IntMap.FastEntrySet<K> reference2IntEntrySet()
          Returns a type-specific set view of the mappings contained in this map.
 int removeInt(java.lang.Object k)
          Removes the mapping with the given key.
 int size()
          Returns the intended number of keys in this function, or -1 if no such number exists.
 IntCollection values()
          Returns a type-specific-set view of the values of this map.
 
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntMap
containsValue, entrySet, equals, hashCode, putAll, toString
 
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReference2IntFunction
defaultReturnValue, defaultReturnValue, get, put, remove
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface it.unimi.dsi.fastutil.objects.Reference2IntFunction
defaultReturnValue, defaultReturnValue
 
Methods inherited from interface it.unimi.dsi.fastutil.Function
get, put, remove
 
Methods inherited from interface java.util.Map
get, put, remove
 

Constructor Detail

Reference2IntArrayMap

public Reference2IntArrayMap(java.lang.Object[] key,
                             int[] value)
Creates a new empty array map with given key and value backing arrays.

Parameters:
key - the key array.
value - the value array (it must have the same length as key).

Reference2IntArrayMap

public Reference2IntArrayMap()
Creates a new empty array map.


Reference2IntArrayMap

public Reference2IntArrayMap(int capacity)
Creates a new empty array map of given capacity.

Parameters:
capacity - the initial capacity.

Reference2IntArrayMap

public Reference2IntArrayMap(Reference2IntMap<K> m)
Creates a new empty array map copying the entries of a given map.

Parameters:
m - a map.

Reference2IntArrayMap

public Reference2IntArrayMap(java.lang.Object[] key,
                             int[] value,
                             int size)
Creates a new array map with given key and value backing arrays, using the given number of elements.

Parameters:
key - the key array.
value - the value array (it must have the same length as key).
size - the number of valid elements in key and value.
Method Detail

reference2IntEntrySet

public Reference2IntMap.FastEntrySet<K> reference2IntEntrySet()
Description copied from interface: Reference2IntMap
Returns a type-specific set view of the mappings contained in this map.

This method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Reference2IntMap.entrySet() so that it returns an ObjectSet of objects of type Reference2IntMap.Entry (the latter makes it possible to access keys and values with type-specific methods).

Specified by:
reference2IntEntrySet in interface Reference2IntMap<K>
Returns:
a type-specific set view of the mappings contained in this map.
See Also:
Reference2IntMap.entrySet()

getInt

public int getInt(java.lang.Object k)
Description copied from interface: Reference2IntFunction
Returns the value to which the given key is mapped.

Specified by:
getInt in interface Reference2IntFunction<K>
Parameters:
k - the key.
Returns:
the corresponding value, or the default return value if no value was present for the given key.
See Also:
Function.get(Object)

size

public int size()
Description copied from interface: Function
Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.

Specified by:
size in interface Function<K,java.lang.Integer>
Specified by:
size in interface java.util.Map<K,java.lang.Integer>
Returns:
the intended number of keys in this function, or -1 if that number is not available.

clear

public void clear()
Description copied from interface: Function
Removes all associations from this function (optional operation).

Specified by:
clear in interface Function<K,java.lang.Integer>
Specified by:
clear in interface java.util.Map<K,java.lang.Integer>
Overrides:
clear in class AbstractReference2IntFunction<K>
See Also:
Map.clear()

containsKey

public boolean containsKey(java.lang.Object k)
Description copied from class: AbstractReference2IntMap
Checks whether the given value is contained in AbstractReference2IntMap.keySet().

Specified by:
containsKey in interface Function<K,java.lang.Integer>
Specified by:
containsKey in interface java.util.Map<K,java.lang.Integer>
Overrides:
containsKey in class AbstractReference2IntMap<K>
Parameters:
k - the key.
Returns:
true if this function associates a value to key.
See Also:
Map.containsKey(Object)

containsValue

public boolean containsValue(int v)
Description copied from class: AbstractReference2IntMap
Checks whether the given value is contained in AbstractReference2IntMap.values().

Specified by:
containsValue in interface Reference2IntMap<K>
Overrides:
containsValue in class AbstractReference2IntMap<K>
See Also:
Map.containsValue(Object)

isEmpty

public boolean isEmpty()
Specified by:
isEmpty in interface java.util.Map<K,java.lang.Integer>
Overrides:
isEmpty in class AbstractReference2IntMap<K>

put

public int put(K k,
               int v)
Description copied from interface: Reference2IntFunction
Adds a pair to the map.

Specified by:
put in interface Reference2IntFunction<K>
Overrides:
put in class AbstractReference2IntFunction<K>
Parameters:
k - the key.
v - the value.
Returns:
the old value, or the default return value if no value was present for the given key.
See Also:
Function.put(Object,Object)

removeInt

public int removeInt(java.lang.Object k)
Description copied from interface: Reference2IntFunction
Removes the mapping with the given key.

Specified by:
removeInt in interface Reference2IntFunction<K>
Overrides:
removeInt in class AbstractReference2IntFunction<K>
Returns:
the old value, or the default return value if no value was present for the given key.
See Also:
Function.remove(Object)

keySet

public ReferenceSet<K> keySet()
Description copied from class: AbstractReference2IntMap
Returns a type-specific-set view of the keys of this map.

The view is backed by the set returned by AbstractReference2IntMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

Specified by:
keySet in interface Reference2IntMap<K>
Specified by:
keySet in interface java.util.Map<K,java.lang.Integer>
Overrides:
keySet in class AbstractReference2IntMap<K>
Returns:
a set view of the keys of this map; it may be safely cast to a type-specific interface.
See Also:
Map.keySet()

values

public IntCollection values()
Description copied from class: AbstractReference2IntMap
Returns a type-specific-set view of the values of this map.

The view is backed by the set returned by AbstractReference2IntMap.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

Specified by:
values in interface Reference2IntMap<K>
Specified by:
values in interface java.util.Map<K,java.lang.Integer>
Overrides:
values in class AbstractReference2IntMap<K>
Returns:
a set view of the values of this map; it may be safely cast to a type-specific interface.
See Also:
Map.values()

clone

public java.lang.Object clone()
Returns a deep copy of this map.

This method performs a deep copy of this hash map; the data stored in the map, however, is not cloned. Note that this makes a difference only for object keys.

Overrides:
clone in class java.lang.Object
Returns:
a deep copy of this map.