it.unimi.dsi.fastutil.chars
Class Char2BooleanOpenHashMap

java.lang.Object
  extended by it.unimi.dsi.fastutil.chars.AbstractChar2BooleanFunction
      extended by it.unimi.dsi.fastutil.chars.AbstractChar2BooleanMap
          extended by it.unimi.dsi.fastutil.chars.Char2BooleanOpenHashMap
All Implemented Interfaces:
Char2BooleanFunction, Char2BooleanMap, Function<java.lang.Character,java.lang.Boolean>, Hash, java.io.Serializable, java.lang.Cloneable, java.util.Map<java.lang.Character,java.lang.Boolean>

public class Char2BooleanOpenHashMap
extends AbstractChar2BooleanMap
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 enlarged as needed by doubling its size when new entries are created, but it is never made smaller (even on a clear()). A family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

Warning: The implementation of this class has significantly changed in fastutil 6.1.0. Please read the comments about this issue in the section “Faster Hash Tables” of the overview.

See Also:
Hash, HashCommon, Serialized Form

Nested Class Summary
 
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2BooleanMap
AbstractChar2BooleanMap.BasicEntry
 
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash
Hash.Strategy<K>
 
Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.chars.Char2BooleanMap
Char2BooleanMap.Entry, Char2BooleanMap.FastEntrySet
 
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
Char2BooleanOpenHashMap()
          Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.
Char2BooleanOpenHashMap(char[] k, boolean[] v)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.
Char2BooleanOpenHashMap(char[] k, boolean[] v, float f)
          Creates a new hash map using the elements of two parallel arrays.
Char2BooleanOpenHashMap(Char2BooleanMap m)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.
Char2BooleanOpenHashMap(Char2BooleanMap m, float f)
          Creates a new hash map copying a given type-specific one.
Char2BooleanOpenHashMap(int expected)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.
Char2BooleanOpenHashMap(int expected, float f)
          Creates a new hash map.
Char2BooleanOpenHashMap(java.util.Map<? extends java.lang.Character,? extends java.lang.Boolean> m)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.
Char2BooleanOpenHashMap(java.util.Map<? extends java.lang.Character,? extends java.lang.Boolean> m, float f)
          Creates a new hash map copying a given one.
 
Method Summary
 Char2BooleanMap.FastEntrySet char2BooleanEntrySet()
          Returns a type-specific set view of the mappings contained in this map.
 void clear()
          Removes all associations from this function (optional operation).
 Char2BooleanOpenHashMap clone()
          Returns a deep copy of this map.
 boolean containsKey(char k)
          Checks whether the given value is contained in AbstractChar2BooleanMap.keySet().
 boolean containsValue(boolean v)
          Checks whether the given value is contained in AbstractChar2BooleanMap.values().
 boolean get(char k)
          Returns the value to which the given key is mapped.
 java.lang.Boolean get(java.lang.Character ok)
           
 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()
           
 CharSet keySet()
          Returns a type-specific-set view of the keys of this map.
 java.lang.Boolean put(java.lang.Character ok, java.lang.Boolean ov)
          Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
 boolean put(char k, boolean v)
          Adds a pair to the map.
 boolean rehash()
          Deprecated. A no-op.
 boolean remove(char k)
          Removes the mapping with the given key.
 java.lang.Boolean remove(java.lang.Object ok)
          Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
 int size()
          Returns the intended number of keys in this function, or -1 if no such number exists.
 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.
 BooleanCollection values()
          Returns a type-specific-set view of the values of this map.
 
Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2BooleanMap
containsValue, entrySet, equals, putAll, toString
 
Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2BooleanFunction
containsKey, defaultReturnValue, defaultReturnValue, get
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface it.unimi.dsi.fastutil.chars.Char2BooleanFunction
defaultReturnValue, defaultReturnValue
 
Methods inherited from interface it.unimi.dsi.fastutil.Function
containsKey, get
 
Methods inherited from interface java.util.Map
containsKey, get
 

Constructor Detail

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(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 set.
f - the load factor.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(int expected)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.

Parameters:
expected - the expected number of elements in the hash map.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap()
Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.


Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(java.util.Map<? extends java.lang.Character,? extends java.lang.Boolean> m,
                               float f)
Creates a new hash map copying a given one.

Parameters:
m - a Map to be copied into the new hash map.
f - the load factor.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(java.util.Map<? extends java.lang.Character,? extends java.lang.Boolean> m)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.

Parameters:
m - a Map to be copied into the new hash map.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(Char2BooleanMap 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.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(Char2BooleanMap m)
Creates a new hash map with Hash.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.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(char[] k,
                               boolean[] 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 - if k and v have different lengths.

Char2BooleanOpenHashMap

public Char2BooleanOpenHashMap(char[] k,
                               boolean[] v)
Creates a new hash map with Hash.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 - if k and v have different lengths.
Method Detail

put

public boolean put(char k,
                   boolean v)
Description copied from interface: Char2BooleanFunction
Adds a pair to the map.

Specified by:
put in interface Char2BooleanFunction
Overrides:
put in class AbstractChar2BooleanFunction
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)

put

public java.lang.Boolean put(java.lang.Character ok,
                             java.lang.Boolean ov)
Description copied from class: AbstractChar2BooleanFunction
Delegates to the corresponding type-specific method, taking care of returning 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.

Specified by:
put in interface Function<java.lang.Character,java.lang.Boolean>
Specified by:
put in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
put in class AbstractChar2BooleanFunction
Parameters:
ok - the key.
ov - the value.
Returns:
the old value, or null if no value was present for the given key.
See Also:
Map.put(Object,Object)

remove

public boolean remove(char k)
Description copied from interface: Char2BooleanFunction
Removes the mapping with the given key.

Specified by:
remove in interface Char2BooleanFunction
Overrides:
remove in class AbstractChar2BooleanFunction
Returns:
the old value, or the default return value if no value was present for the given key.
See Also:
Function.remove(Object)

remove

public java.lang.Boolean remove(java.lang.Object ok)
Description copied from class: AbstractChar2BooleanFunction
Delegates to the corresponding type-specific method, taking care of returning 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.

Specified by:
remove in interface Function<java.lang.Character,java.lang.Boolean>
Specified by:
remove in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
remove in class AbstractChar2BooleanFunction
Returns:
the old value, or null if no value was present for the given key.
See Also:
Map.remove(Object)

get

public java.lang.Boolean get(java.lang.Character ok)

get

public boolean get(char k)
Description copied from interface: Char2BooleanFunction
Returns the value to which the given key is mapped.

Specified by:
get in interface Char2BooleanFunction
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: AbstractChar2BooleanMap
Checks whether the given value is contained in AbstractChar2BooleanMap.keySet().

Specified by:
containsKey in interface Char2BooleanFunction
Overrides:
containsKey in class AbstractChar2BooleanMap
See Also:
Function.containsKey(Object)

containsValue

public boolean containsValue(boolean v)
Description copied from class: AbstractChar2BooleanMap
Checks whether the given value is contained in AbstractChar2BooleanMap.values().

Specified by:
containsValue in interface Char2BooleanMap
Overrides:
containsValue in class AbstractChar2BooleanMap
See Also:
Map.containsValue(Object)

clear

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

Specified by:
clear in interface Function<java.lang.Character,java.lang.Boolean>
Specified by:
clear in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
clear in class AbstractChar2BooleanFunction
See Also:
Map.clear()

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

isEmpty

public boolean isEmpty()
Specified by:
isEmpty in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
isEmpty in class AbstractChar2BooleanMap

growthFactor

@Deprecated
public void growthFactor(int growthFactor)
Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

A no-op for backward compatibility.

Parameters:
growthFactor - unused.

growthFactor

@Deprecated
public int growthFactor()
Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

Gets the growth factor (2).

Returns:
the growth factor of this set, which is fixed (2).
See Also:
growthFactor(int)

char2BooleanEntrySet

public Char2BooleanMap.FastEntrySet char2BooleanEntrySet()
Description copied from interface: Char2BooleanMap
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 Char2BooleanMap.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).

Specified by:
char2BooleanEntrySet in interface Char2BooleanMap
Returns:
a type-specific set view of the mappings contained in this map.
See Also:
Char2BooleanMap.entrySet()

keySet

public CharSet keySet()
Description copied from class: AbstractChar2BooleanMap
Returns a type-specific-set view of the keys of this map.

The view is backed by the set returned by AbstractChar2BooleanMap.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 Char2BooleanMap
Specified by:
keySet in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
keySet in class AbstractChar2BooleanMap
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 BooleanCollection values()
Description copied from class: AbstractChar2BooleanMap
Returns a type-specific-set view of the values of this map.

The view is backed by the set returned by AbstractChar2BooleanMap.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 Char2BooleanMap
Specified by:
values in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
values in class AbstractChar2BooleanMap
Returns:
a set view of the values of this map; it may be safely cast to a type-specific interface.
See Also:
Map.values()

rehash

@Deprecated
public boolean rehash()
Deprecated. A no-op.

A no-op for backward compatibility. The kind of tables implemented by this class never need rehashing.

If you need to reduce the table size to fit exactly this set, use trim().

Returns:
true.
See Also:
trim()

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,size()) 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.

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 Char2BooleanOpenHashMap 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.

hashCode

public int hashCode()
Returns a hash code for this map. This method overrides the generic method provided by the superclass. Since 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.

Specified by:
hashCode in interface java.util.Map<java.lang.Character,java.lang.Boolean>
Overrides:
hashCode in class AbstractChar2BooleanMap
Returns:
a hash code for this map.