Class Char2ObjectOpenHashMap<V>
- java.lang.Object
-
- it.unimi.dsi.fastutil.chars.AbstractChar2ObjectFunction<V>
-
- it.unimi.dsi.fastutil.chars.AbstractChar2ObjectMap<V>
-
- it.unimi.dsi.fastutil.chars.Char2ObjectOpenHashMap<V>
-
- All Implemented Interfaces:
Char2ObjectFunction<V>
,Char2ObjectMap<V>
,Function<java.lang.Character,V>
,Hash
,java.io.Serializable
,java.lang.Cloneable
,java.util.function.Function<java.lang.Character,V>
,java.util.function.IntFunction<V>
,java.util.Map<java.lang.Character,V>
public class Char2ObjectOpenHashMap<V> extends AbstractChar2ObjectMap<V> implements java.io.Serializable, java.lang.Cloneable, Hash
A type-specific hash map with a fast, small-footprint implementation.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, the table is never reduced to a size smaller than that at creation time: this approach makes it possible to create maps with a large capacity in which insertions and deletions do not cause immediately rehashing. Moreover, 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.Entries returned by the type-specific
Char2ObjectMap.entrySet()
method implement the suitable type-specificPair
interface; only values are mutable.- See Also:
Hash
,HashCommon
, Serialized Form
-
-
Nested Class Summary
-
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ObjectMap
AbstractChar2ObjectMap.BasicEntry<V>, AbstractChar2ObjectMap.BasicEntrySet<V>
-
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.chars.Char2ObjectMap
Char2ObjectMap.Entry<V>, Char2ObjectMap.FastEntrySet<V>
-
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash
Hash.Strategy<K>
-
-
Field Summary
-
Fields inherited from interface it.unimi.dsi.fastutil.Hash
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR
-
-
Constructor Summary
Constructors Constructor Description Char2ObjectOpenHashMap()
Creates a new hash map with initial expectedHash.DEFAULT_INITIAL_SIZE
entries andHash.DEFAULT_LOAD_FACTOR
as load factor.Char2ObjectOpenHashMap(char[] k, V[] v)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor using the elements of two parallel arrays.Char2ObjectOpenHashMap(char[] k, V[] v, float f)
Creates a new hash map using the elements of two parallel arrays.Char2ObjectOpenHashMap(int expected)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor.Char2ObjectOpenHashMap(int expected, float f)
Creates a new hash map.Char2ObjectOpenHashMap(Char2ObjectMap<V> m)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given type-specific one.Char2ObjectOpenHashMap(Char2ObjectMap<V> m, float f)
Creates a new hash map copying a given type-specific one.Char2ObjectOpenHashMap(java.util.Map<? extends java.lang.Character,? extends V> m)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given one.Char2ObjectOpenHashMap(java.util.Map<? extends java.lang.Character,? extends V> m, float f)
Creates a new hash map copying a given one.
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Char2ObjectMap.FastEntrySet<V>
char2ObjectEntrySet()
Returns a type-specific set view of the mappings contained in this map.void
clear()
Removes all of the mappings from this map (optional operation).Char2ObjectOpenHashMap<V>
clone()
Returns a deep copy of this map.V
compute(char k, java.util.function.BiFunction<? super java.lang.Character,? super V,? extends V> remappingFunction)
Attempts to compute a mapping for the specified key and its current mapped value (ornull
if there is no current mapping).V
computeIfAbsent(char key, Char2ObjectFunction<? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map, unless the key is not present in the given mapping function.V
computeIfAbsent(char k, java.util.function.IntFunction<? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map.V
computeIfPresent(char k, java.util.function.BiFunction<? super java.lang.Character,? super V,? extends V> remappingFunction)
If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.boolean
containsKey(char k)
Returns true if this function contains a mapping for the specified key.boolean
containsValue(java.lang.Object v)
void
ensureCapacity(int capacity)
Ensures that this map can hold a certain number of keys without rehashing.V
get(char k)
Returns the value to which the given key is mapped.V
getOrDefault(char k, V defaultValue)
Returns the value to which the specified key is mapped, or thedefaultValue
if this map contains no mapping for the key.int
hashCode()
Returns a hash code for this map.boolean
isEmpty()
CharSet
keySet()
Returns a type-specific-set view of the keys of this map.V
merge(char k, V v, java.util.function.BiFunction<? super V,? super V,? extends V> remappingFunction)
If the specified key is not already associated with a value, associates it with the givenvalue
.V
put(char k, V v)
Adds a pair to the map (optional operation).void
putAll(java.util.Map<? extends java.lang.Character,? extends V> m)
V
putIfAbsent(char k, V v)
If the specified key is not already associated with a value, associates it with the given value and returns the default return value, else returns the current value.V
remove(char k)
Removes the mapping with the given key (optional operation).boolean
remove(char k, java.lang.Object v)
Removes the entry for the specified key only if it is currently mapped to the specified value.V
replace(char k, V v)
Replaces the entry for the specified key only if it is currently mapped to some value.boolean
replace(char k, V oldValue, V v)
Replaces the entry for the specified key only if currently mapped to the specified value.int
size()
Returns the number of key/value mappings in this map.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.ObjectCollection<V>
values()
Returns a type-specific-set view of the values of this map.-
Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ObjectMap
equals, toString
-
Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ObjectFunction
defaultReturnValue, defaultReturnValue
-
Methods inherited from interface it.unimi.dsi.fastutil.chars.Char2ObjectFunction
andThenByte, andThenChar, andThenDouble, andThenFloat, andThenInt, andThenLong, andThenObject, andThenReference, andThenShort, apply, compose, composeByte, composeChar, composeDouble, composeFloat, composeInt, composeLong, composeObject, composeReference, composeShort
-
Methods inherited from interface it.unimi.dsi.fastutil.chars.Char2ObjectMap
computeIfAbsentPartial, containsKey, defaultReturnValue, defaultReturnValue, entrySet, forEach, get, getOrDefault, put, remove
-
-
-
-
Constructor Detail
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(int expected, float f)
Creates a new hash map.The actual table size will be the least power of two greater than
expected
/f
.- Parameters:
expected
- the expected number of elements in the hash map.f
- the load factor.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(int expected)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor.- Parameters:
expected
- the expected number of elements in the hash map.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap()
Creates a new hash map with initial expectedHash.DEFAULT_INITIAL_SIZE
entries andHash.DEFAULT_LOAD_FACTOR
as load factor.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(java.util.Map<? extends java.lang.Character,? extends V> m, float f)
Creates a new hash map copying a given one.- Parameters:
m
- aMap
to be copied into the new hash map.f
- the load factor.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(java.util.Map<? extends java.lang.Character,? extends V> m)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given one.- Parameters:
m
- aMap
to be copied into the new hash map.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(Char2ObjectMap<V> m, float f)
Creates a new hash map copying a given type-specific one.- Parameters:
m
- a type-specific map to be copied into the new hash map.f
- the load factor.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(Char2ObjectMap<V> m)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor copying a given type-specific one.- Parameters:
m
- a type-specific map to be copied into the new hash map.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(char[] k, V[] v, float f)
Creates a new hash map using the elements of two parallel arrays.- Parameters:
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.- Throws:
java.lang.IllegalArgumentException
- ifk
andv
have different lengths.
-
Char2ObjectOpenHashMap
public Char2ObjectOpenHashMap(char[] k, V[] v)
Creates a new hash map withHash.DEFAULT_LOAD_FACTOR
as load factor using the elements of two parallel arrays.- Parameters:
k
- the array of keys of the new hash map.v
- the array of corresponding values in the new hash map.- Throws:
java.lang.IllegalArgumentException
- ifk
andv
have different lengths.
-
-
Method Detail
-
ensureCapacity
public void ensureCapacity(int capacity)
Ensures that this map can hold a certain number of keys without rehashing.- Parameters:
capacity
- a number of keys; there will be no rehashing unless the map size exceeds this number.
-
putAll
public void putAll(java.util.Map<? extends java.lang.Character,? extends V> m)
Description copied from class:AbstractChar2ObjectMap
- Specified by:
putAll
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
putAll
in classAbstractChar2ObjectMap<V>
-
put
public V put(char k, V v)
Description copied from interface:Char2ObjectFunction
Adds a pair to the map (optional operation).- Specified by:
put
in interfaceChar2ObjectFunction<V>
- 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)
-
remove
public V remove(char k)
Description copied from interface:Char2ObjectFunction
Removes the mapping with the given key (optional operation).- Specified by:
remove
in interfaceChar2ObjectFunction<V>
- Parameters:
k
- the key.- Returns:
- the old value, or the default return value if no value was present for the given key.
- See Also:
Function.remove(Object)
-
get
public V get(char k)
Description copied from interface:Char2ObjectFunction
Returns the value to which the given key is mapped.- Specified by:
get
in interfaceChar2ObjectFunction<V>
- 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)
-
containsKey
public boolean containsKey(char k)
Description copied from class:AbstractChar2ObjectMap
Returns true if this function contains a mapping for the specified key.- Specified by:
containsKey
in interfaceChar2ObjectFunction<V>
- Specified by:
containsKey
in interfaceChar2ObjectMap<V>
- Overrides:
containsKey
in classAbstractChar2ObjectMap<V>
- Parameters:
k
- the key.- Returns:
- true if this function associates a value to
key
. - See Also:
Map.containsKey(Object)
-
containsValue
public boolean containsValue(java.lang.Object v)
Description copied from class:AbstractChar2ObjectMap
- Specified by:
containsValue
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
containsValue
in classAbstractChar2ObjectMap<V>
-
getOrDefault
public V getOrDefault(char k, V defaultValue)
Returns the value to which the specified key is mapped, or thedefaultValue
if this map contains no mapping for the key.- Specified by:
getOrDefault
in interfaceChar2ObjectFunction<V>
- Specified by:
getOrDefault
in interfaceChar2ObjectMap<V>
- Parameters:
k
- the key.defaultValue
- the default mapping of the key.- Returns:
- the value to which the specified key is mapped, or the
defaultValue
if this map contains no mapping for the key. - See Also:
Map.getOrDefault(Object, Object)
-
putIfAbsent
public V putIfAbsent(char k, V v)
If the specified key is not already associated with a value, associates it with the given value and returns the default return value, else returns the current value.- Specified by:
putIfAbsent
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is to be associated.v
- value to be associated with the specified key.- Returns:
- the previous value associated with the specified key, or the default return value if there was no mapping for the key.
- See Also:
Map.putIfAbsent(Object, Object)
-
remove
public boolean remove(char k, java.lang.Object v)
Removes the entry for the specified key only if it is currently mapped to the specified value.- Specified by:
remove
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is associated.v
- value expected to be associated with the specified key.- Returns:
true
if the value was removed.- See Also:
Map.remove(Object, Object)
-
replace
public boolean replace(char k, V oldValue, V v)
Replaces the entry for the specified key only if currently mapped to the specified value.- Specified by:
replace
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is associated.oldValue
- value expected to be associated with the specified key.v
- value to be associated with the specified key.- Returns:
true
if the value was replaced.- See Also:
Map.replace(Object, Object, Object)
-
replace
public V replace(char k, V v)
Replaces the entry for the specified key only if it is currently mapped to some value.- Specified by:
replace
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is associated.v
- value to be associated with the specified key.- Returns:
- the previous value associated with the specified key, or the default return value if there was no mapping for the key.
- See Also:
Map.replace(Object, Object)
-
computeIfAbsent
public V computeIfAbsent(char k, java.util.function.IntFunction<? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map.Note that contrarily to the default computeIfAbsent(), it is not possible to not add a value for a given key, since the
mappingFunction
cannot returnnull
. If such a behavior is needed, please use the corresponding nullable version.- Specified by:
computeIfAbsent
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is to be associated.mappingFunction
- the function to compute a value.- Returns:
- the current (existing or computed) value associated with the specified key.
- See Also:
Map.computeIfAbsent(Object, java.util.function.Function)
-
computeIfAbsent
public V computeIfAbsent(char key, Char2ObjectFunction<? extends V> mappingFunction)
If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map, unless the key is not present in the given mapping function.This version of computeIfAbsent() uses a type-specific version of
fastutil
'sFunction
. SinceFunction
has acontainsKey()
method, it is possible to avoid adding a key by havingcontainsKey()
returnfalse
for that key.- Specified by:
computeIfAbsent
in interfaceChar2ObjectMap<V>
- Parameters:
key
- key with which the specified value is to be associated.mappingFunction
- the function to compute a value.- Returns:
- the current (existing or computed) value associated with the specified key.
- See Also:
Map.computeIfAbsent(Object, java.util.function.Function)
-
computeIfPresent
public V computeIfPresent(char k, java.util.function.BiFunction<? super java.lang.Character,? super V,? extends V> remappingFunction)
If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.- Specified by:
computeIfPresent
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is to be associated.remappingFunction
- the function to compute a value.- Returns:
- the new value associated with the specified key, or the default return value if none.
- See Also:
Map.computeIfPresent(Object, java.util.function.BiFunction)
-
compute
public V compute(char k, java.util.function.BiFunction<? super java.lang.Character,? super V,? extends V> remappingFunction)
Attempts to compute a mapping for the specified key and its current mapped value (ornull
if there is no current mapping).If the function returns
null
, the mapping is removed (or remains absent if initially absent). If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.- Specified by:
compute
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the specified value is to be associated.remappingFunction
- the function to compute a value.- Returns:
- the new value associated with the specified key, or the default return value if none.
- See Also:
Map.compute(Object, java.util.function.BiFunction)
-
merge
public V merge(char k, V v, java.util.function.BiFunction<? super V,? super V,? extends V> remappingFunction)
If the specified key is not already associated with a value, associates it with the givenvalue
. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result isnull
.- Specified by:
merge
in interfaceChar2ObjectMap<V>
- Parameters:
k
- key with which the resulting value is to be associated.v
- the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.remappingFunction
- the function to recompute a value if present.- Returns:
- the new value associated with the specified key, or the default return value if no value is associated with the key.
- See Also:
Map.merge(Object, Object, java.util.function.BiFunction)
-
clear
public void clear()
Description copied from interface:Char2ObjectMap
Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
-
size
public int size()
Description copied from interface:Char2ObjectMap
Returns the number of key/value mappings in this map. If the map contains more thanInteger.MAX_VALUE
elements, returnsInteger.MAX_VALUE
.
-
isEmpty
public boolean isEmpty()
- Specified by:
isEmpty
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
isEmpty
in classAbstractChar2ObjectMap<V>
-
char2ObjectEntrySet
public Char2ObjectMap.FastEntrySet<V> char2ObjectEntrySet()
Description copied from interface:Char2ObjectMap
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
Map.entrySet()
so that it returns anObjectSet
of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).- Specified by:
char2ObjectEntrySet
in interfaceChar2ObjectMap<V>
- Returns:
- a type-specific set view of the mappings contained in this map.
- See Also:
Map.entrySet()
-
keySet
public CharSet keySet()
Description copied from class:AbstractChar2ObjectMap
Returns a type-specific-set view of the keys of this map.The view is backed by the set returned by
Map.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 interfaceChar2ObjectMap<V>
- Specified by:
keySet
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
keySet
in classAbstractChar2ObjectMap<V>
- 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 ObjectCollection<V> values()
Description copied from class:AbstractChar2ObjectMap
Returns a type-specific-set view of the values of this map.The view is backed by the set returned by
Map.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 interfaceChar2ObjectMap<V>
- Specified by:
values
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
values
in classAbstractChar2ObjectMap<V>
- Returns:
- a set view of the values of this map; it may be safely cast to a type-specific interface.
- See Also:
Map.values()
-
trim
public boolean trim()
Rehashes the map, making the table as small as possible.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.
- Returns:
- true if there was enough memory to trim the map.
- See Also:
trim(int)
-
trim
public boolean trim(int n)
Rehashes this map if the table is too large.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.
- Parameters:
n
- the threshold for the trimming.- Returns:
- true if there was enough memory to trim the map.
- See Also:
trim()
-
clone
public Char2ObjectOpenHashMap<V> 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.
- Returns:
- a deep copy of this map.
-
hashCode
public int hashCode()
Returns a hash code for this map. This method overrides the generic method provided by the superclass. Sinceequals()
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.- Specified by:
hashCode
in interfacejava.util.Map<java.lang.Character,V>
- Overrides:
hashCode
in classAbstractChar2ObjectMap<V>
- Returns:
- a hash code for this map.
-
-