public class Object2CharOpenCustomHashMap<K> extends AbstractObject2CharMap<K> implements Serializable, Cloneable, Hash
Instances of this class use a hash table to represent a map. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is emptied below one fourth of the load factor, it is halved in size. However, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration process.
Note that clear()
does not modify the hash table size.
Rather, a family of trimming
methods lets you control the size of the table; this is particularly useful
if you reuse instances of this class.
Hash
,
HashCommon
,
Serialized FormAbstractObject2CharMap.BasicEntry<K>
Hash.Strategy<K>
Object2CharMap.Entry<K>, Object2CharMap.FastEntrySet<K>
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
Constructor and Description |
---|
Object2CharOpenCustomHashMap(Hash.Strategy<K> strategy)
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2CharOpenCustomHashMap(int expected,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map.
|
Object2CharOpenCustomHashMap(int expected,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2CharOpenCustomHashMap(K[] k,
char[] v,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map using the elements of two parallel arrays.
|
Object2CharOpenCustomHashMap(K[] k,
char[] v,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Object2CharOpenCustomHashMap(Map<? extends K,? extends Character> m,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map copying a given one.
|
Object2CharOpenCustomHashMap(Map<? extends K,? extends Character> m,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Object2CharOpenCustomHashMap(Object2CharMap<K> m,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map copying a given type-specific one.
|
Object2CharOpenCustomHashMap(Object2CharMap<K> m,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
Modifier and Type | Method and Description |
---|---|
void |
clear()
Removes all associations from this function (optional operation).
|
Object2CharOpenCustomHashMap<K> |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(Object k)
Checks whether the given value is contained in
AbstractObject2CharMap.keySet() . |
boolean |
containsValue(char v)
Checks whether the given value is contained in
AbstractObject2CharMap.values() . |
char |
getChar(Object k)
Returns the value to which the given key is mapped.
|
int |
growthFactor()
Deprecated.
Since
fastutil 6.1.0, hash tables are doubled when they are too full. |
void |
growthFactor(int growthFactor)
Deprecated.
Since
fastutil 6.1.0, hash tables are doubled when they are too full. |
int |
hashCode()
Returns a hash code for this map.
|
boolean |
isEmpty() |
ObjectSet<K> |
keySet()
Returns a type-specific-set view of the keys of this map.
|
Object2CharMap.FastEntrySet<K> |
object2CharEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
char |
put(K k,
char v)
Adds a pair to the map.
|
Character |
put(K ok,
Character ov)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
void |
putAll(Map<? extends K,? extends Character> m)
Puts all pairs in the given map.
|
boolean |
rehash()
Deprecated.
A no-op.
|
Character |
remove(Object ok)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
char |
removeChar(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.
|
Hash.Strategy<K> |
strategy()
Returns the hashing strategy.
|
boolean |
trim()
Rehashes the map, making the table as small as possible.
|
boolean |
trim(int n)
Rehashes this map if the table is too large.
|
CharCollection |
values()
Returns a type-specific-set view of the values of this map.
|
containsValue, entrySet, equals, toString
defaultReturnValue, defaultReturnValue, get
defaultReturnValue, defaultReturnValue
public Object2CharOpenCustomHashMap(int expected, float f, Hash.Strategy<K> strategy)
The actual table size will be the least power of two greater than expected
/f
.
expected
- the expected number of elements in the hash set.f
- the load factor.strategy
- the strategy.public Object2CharOpenCustomHashMap(int expected, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor.expected
- the expected number of elements in the hash map.strategy
- the strategy.public Object2CharOpenCustomHashMap(Hash.Strategy<K> strategy)
Hash.DEFAULT_INITIAL_SIZE
entries
and Hash.DEFAULT_LOAD_FACTOR
as load factor.strategy
- the strategy.public Object2CharOpenCustomHashMap(Map<? extends K,? extends Character> m, float f, Hash.Strategy<K> strategy)
m
- a Map
to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Object2CharOpenCustomHashMap(Map<? extends K,? extends Character> m, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor copying a given one.m
- a Map
to be copied into the new hash map.strategy
- the strategy.public Object2CharOpenCustomHashMap(Object2CharMap<K> m, float f, Hash.Strategy<K> strategy)
m
- a type-specific map to be copied into the new hash map.f
- the load factor.strategy
- the strategy.public Object2CharOpenCustomHashMap(Object2CharMap<K> m, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor copying a given type-specific one.m
- a type-specific map to be copied into the new hash map.strategy
- the strategy.public Object2CharOpenCustomHashMap(K[] k, char[] v, float f, Hash.Strategy<K> strategy)
k
- the array of keys of the new hash map.v
- the array of corresponding values in the new hash map.f
- the load factor.strategy
- the strategy.IllegalArgumentException
- if k
and v
have different lengths.public Object2CharOpenCustomHashMap(K[] k, char[] v, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR
as load factor using the elements of two parallel arrays.k
- the array of keys of the new hash map.v
- the array of corresponding values in the new hash map.strategy
- the strategy.IllegalArgumentException
- if k
and v
have different lengths.public Hash.Strategy<K> strategy()
public void putAll(Map<? extends K,? extends Character> m)
public char put(K k, char v)
Object2CharFunction
put
in interface Object2CharFunction<K>
put
in class AbstractObject2CharFunction<K>
k
- the key.v
- the value.Function.put(Object,Object)
public Character put(K ok, Character ov)
AbstractObject2CharFunction
null
on a missing key.
This method must check whether the provided key is in the map using containsKey()
. Thus,
it probes the map twice. Implementors of subclasses should override it with a more efficient method.
put
in interface Function<K,Character>
put
in interface Map<K,Character>
put
in class AbstractObject2CharFunction<K>
ok
- the key.ov
- the value.null
if no value was present for the given key.Map.put(Object,Object)
public char removeChar(Object k)
Object2CharFunction
removeChar
in interface Object2CharFunction<K>
removeChar
in class AbstractObject2CharFunction<K>
k
- the key.Function.remove(Object)
public Character remove(Object ok)
AbstractObject2CharFunction
null
on a missing key.
This method must check whether the provided key is in the map using containsKey()
. Thus,
it probes the map twice. Implementors of subclasses should override it with a more efficient method.
public char getChar(Object k)
Object2CharFunction
getChar
in interface Object2CharFunction<K>
k
- the key.Function.get(Object)
public boolean containsKey(Object k)
AbstractObject2CharMap
AbstractObject2CharMap.keySet()
.containsKey
in interface Function<K,Character>
containsKey
in interface Map<K,Character>
containsKey
in class AbstractObject2CharMap<K>
k
- the key.key
.Map.containsKey(Object)
public boolean containsValue(char v)
AbstractObject2CharMap
AbstractObject2CharMap.values()
.containsValue
in interface Object2CharMap<K>
containsValue
in class AbstractObject2CharMap<K>
Map.containsValue(Object)
public void clear()
Function
public int size()
Function
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.
public boolean isEmpty()
@Deprecated public void growthFactor(int growthFactor)
fastutil
6.1.0, hash tables are doubled when they are too full.growthFactor
- unused.@Deprecated public int growthFactor()
fastutil
6.1.0, hash tables are doubled when they are too full.growthFactor(int)
public Object2CharMap.FastEntrySet<K> object2CharEntrySet()
Object2CharMap
This method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Object2CharMap.entrySet()
so that it returns an ObjectSet
of objects of type Map.Entry
(the latter makes it possible to
access keys and values with type-specific methods).
object2CharEntrySet
in interface Object2CharMap<K>
Object2CharMap.entrySet()
public ObjectSet<K> keySet()
AbstractObject2CharMap
The view is backed by the set returned by AbstractObject2CharMap.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.
keySet
in interface Object2CharMap<K>
keySet
in interface Map<K,Character>
keySet
in class AbstractObject2CharMap<K>
Map.keySet()
public CharCollection values()
AbstractObject2CharMap
The view is backed by the set returned by AbstractObject2CharMap.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.
values
in interface Object2CharMap<K>
values
in interface Map<K,Character>
values
in class AbstractObject2CharMap<K>
Map.values()
@Deprecated public boolean rehash()
If you need to reduce the table size to fit exactly
this set, use trim()
.
trim()
public boolean trim()
This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.
If the table size is already the minimum possible, this method does nothing.
trim(int)
public boolean trim(int n)
Let N be the smallest table size that can hold
max(n,
entries, still satisfying the load factor. If the current
table size is smaller than or equal to N, this method does
nothing. Otherwise, it rehashes this map in a table of size
N.
size()
)
This method is useful when reusing maps. Clearing a map leaves the table size untouched. If you are reusing a map many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient maps.
n
- the threshold for the trimming.trim()
public Object2CharOpenCustomHashMap<K> clone()
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.
public int hashCode()
equals()
is not overriden, it is important
that the value returned by this method is the same value as
the one returned by the overriden method.