CharLinkedOpenHashSet (fastutil 6.4.1 API)

java.lang.Object
- java.util.AbstractCollection<Character>
- - it.unimi.dsi.fastutil.chars.AbstractCharCollection
  - - it.unimi.dsi.fastutil.chars.AbstractCharSet
    - - it.unimi.dsi.fastutil.chars.AbstractCharSortedSet
      - it.unimi.dsi.fastutil.chars.CharLinkedOpenHashSet

All Implemented Interfaces:

CharCollection, CharIterable, CharSet, CharSortedSet, Hash, Serializable, Cloneable, Iterable<Character>, Collection<Character>, Set<Character>, SortedSet<Character>
```
public class CharLinkedOpenHashSet
extends AbstractCharSortedSet
implements Serializable, Cloneable, Hash
```
A type-specific linked hash set with with a fast, small-footprint implementation.
Instances of this class use a hash table to represent a set. 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.
Iterators generated by this set will enumerate elements in the same order in which they have been added to the set (addition of elements already present in the set does not change the iteration order). Note that this order has nothing in common with the natural order of the keys. The order is kept by means of a doubly linked list, represented via an array of longs parallel to the table.
This class implements the interface of a sorted set, so to allow easy access of the iteration order: for instance, you can get the first element in iteration order with AbstractCharSortedSet.first() without having to create an iterator; however, this class partially violates the SortedSet contract because all subset methods throw an exception and comparator() returns always null.
Additional methods, such as addAndMoveToFirst(), make it easy to use instances of this class as a cache (e.g., with LRU policy).
The iterators provided by this class are type-specific list iterators, and can be started at any element which is in the set (if the provided element is not in the set, a NoSuchElementException exception will be thrown). If, however, the provided element is not the first or last element in the set, the first access to the list index will require linear time, as in the worst case the entire set must be scanned in iteration order to retrieve the positional index of the starting element. If you use just the methods of a type-specific BidirectionalIterator, however, all operations will be performed in constant time.

See Also:
Hash, HashCommon, Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash
  Hash.Strategy<K>

Field Summary

Fields
Modifier and Type	Field and Description
`protected float`	`f` The acceptable load factor.
`protected int`	`first` The index of the first entry in iteration order.
`protected char[]`	`key` The array of keys.
`protected int`	`last` The index of the last entry in iteration order.
`protected long[]`	`link` For each entry, the next and the previous entry in iteration order, stored as `((prev & 0xFFFFFFFFL) << 32) \| (next & 0xFFFFFFFFL)`.
`protected int`	`mask` The mask for wrapping a position counter.
`protected int`	`maxFill` Threshold after which we rehash.
`protected int`	`n` The current table size.
`static long`	`serialVersionUID`
`protected int`	`size` Number of entries in the set.
`protected boolean[]`	`used` The array telling whether a position is used.

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 and Description
`CharLinkedOpenHashSet()` Creates a new hash set with initial expected `Hash.DEFAULT_INITIAL_SIZE` elements and `Hash.DEFAULT_LOAD_FACTOR` as load factor.
`CharLinkedOpenHashSet(char[] a)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor copying the elements of an array.
`CharLinkedOpenHashSet(char[] a, float f)` Creates a new hash set copying the elements of an array.
`CharLinkedOpenHashSet(char[] a, int offset, int length)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor and fills it with the elements of a given array.
`CharLinkedOpenHashSet(char[] a, int offset, int length, float f)` Creates a new hash set and fills it with the elements of a given array.
`CharLinkedOpenHashSet(CharCollection c)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor copying a given type-specific collection.
`CharLinkedOpenHashSet(CharCollection c, float f)` Creates a new hash set copying a given type-specific collection.
`CharLinkedOpenHashSet(CharIterator i)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor using elements provided by a type-specific iterator.
`CharLinkedOpenHashSet(CharIterator i, float f)` Creates a new hash set using elements provided by a type-specific iterator.
`CharLinkedOpenHashSet(Collection<? extends Character> c)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor copying a given collection.
`CharLinkedOpenHashSet(Collection<? extends Character> c, float f)` Creates a new hash set copying a given collection.
`CharLinkedOpenHashSet(int expected)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor.
`CharLinkedOpenHashSet(int expected, float f)` Creates a new hash set.
`CharLinkedOpenHashSet(Iterator<?> i)` Creates a new hash set with `Hash.DEFAULT_LOAD_FACTOR` as load factor using elements provided by an iterator.
`CharLinkedOpenHashSet(Iterator<?> i, float f)` Creates a new hash set using elements provided by an iterator.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`add(char k)`
`boolean`	`addAndMoveToFirst(char k)` Adds a key to the set; if the key is already present, it is moved to the first position of the iteration order.
`boolean`	`addAndMoveToLast(char k)` Adds a key to the set; if the key is already present, it is moved to the last position of the iteration order.
`void`	`clear()`
`CharLinkedOpenHashSet`	`clone()` Returns a deep copy of this set.
`CharComparator`	`comparator()` Returns the comparator associated with this sorted set, or null if it uses its elements' natural ordering.
`boolean`	`contains(char k)`
`char`	`firstChar()` Returns the first element of this set in iteration order.
`protected void`	`fixPointers(int i)` Modifies the `link` vector so that the given entry is removed.
`protected void`	`fixPointers(int s, int d)` Modifies the `link` vector for a shift from s to d.
`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 set.
`CharSortedSet`	`headSet(char to)`
`boolean`	`isEmpty()`
`CharListIterator`	`iterator()` Returns a type-specific iterator on the elements of this collection.
`CharListIterator`	`iterator(char from)` Returns a type-specific list iterator on the elements in this set, starting from a given element of the set.
`char`	`lastChar()` Returns the last element of this set in iteration order.
`boolean`	`rehash()` Deprecated. A no-op.
`protected void`	`rehash(int newN)` Resizes the set.
`boolean`	`remove(char k)` Removes an element from this set.
`char`	`removeFirstChar()` Removes the first key in iteration order.
`char`	`removeLastChar()` Removes the the last key in iteration order.
`protected int`	`shiftKeys(int pos)` Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.
`int`	`size()`
`CharSortedSet`	`subSet(char from, char to)`
`CharSortedSet`	`tailSet(char from)`
`boolean`	`trim()` Rehashes this set, making the table as small as possible.
`boolean`	`trim(int n)` Rehashes this set if the table is too large.

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharSortedSet
charIterator, first, headSet, last, subSet, tailSet

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharSet
equals, rem, remove

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharCollection
add, addAll, addAll, contains, containsAll, containsAll, rem, removeAll, removeAll, retainAll, retainAll, toArray, toArray, toArray, toCharArray, toCharArray, toString

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharCollection
addAll, containsAll, rem, removeAll, retainAll, toArray, toArray, toCharArray, toCharArray

Methods inherited from interface java.util.Set
add, addAll, contains, containsAll, equals, remove, removeAll, retainAll, toArray, toArray

- Field Detail
  - serialVersionUID
```
public static final long serialVersionUID
```
    See Also:
    Constant Field Values
  - key
```
protected transient char[] key
```
    The array of keys.
  - used
```
protected transient boolean[] used
```
    The array telling whether a position is used.
  - f
```
protected final float f
```
    The acceptable load factor.
  - n
```
protected transient int n
```
    The current table size.
  - maxFill
```
protected transient int maxFill
```
    Threshold after which we rehash. It must be the table size times f.
  - mask
```
protected transient int mask
```
    The mask for wrapping a position counter.
  - size
```
protected int size
```
    Number of entries in the set.
  - first
```
protected transient int first
```
    The index of the first entry in iteration order. It is valid iff size is nonzero; otherwise, it contains -1.
  - last
```
protected transient int last
```
    The index of the last entry in iteration order. It is valid iff size is nonzero; otherwise, it contains -1.
  - link
```
protected transient long[] link
```
    For each entry, the next and the previous entry in iteration order, stored as ((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL). The first entry contains predecessor -1, and the last entry contains successor -1.
- Constructor Detail
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(int expected,
                     float f)
```
    Creates a new hash set.
    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.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(int expected)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor.
    
    Parameters:
    expected - the expected number of elements in the hash set.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet()
```
    Creates a new hash set with initial expected Hash.DEFAULT_INITIAL_SIZE elements and Hash.DEFAULT_LOAD_FACTOR as load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(Collection<? extends Character> c,
                     float f)
```
    Creates a new hash set copying a given collection.
    
    Parameters:
    c - a Collection to be copied into the new hash set.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(Collection<? extends Character> c)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given collection.
    
    Parameters:
    c - a Collection to be copied into the new hash set.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(CharCollection c,
                     float f)
```
    Creates a new hash set copying a given type-specific collection.
    
    Parameters:
    c - a type-specific collection to be copied into the new hash set.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(CharCollection c)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific collection.
    
    Parameters:
    c - a type-specific collection to be copied into the new hash set.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(CharIterator i,
                     float f)
```
    Creates a new hash set using elements provided by a type-specific iterator.
    
    Parameters:
    i - a type-specific iterator whose elements will fill the set.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(CharIterator i)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.
    
    Parameters:
    i - a type-specific iterator whose elements will fill the set.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(Iterator<?> i,
                     float f)
```
    Creates a new hash set using elements provided by an iterator.
    
    Parameters:
    i - an iterator whose elements will fill the set.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(Iterator<?> i)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.
    
    Parameters:
    i - an iterator whose elements will fill the set.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(char[] a,
                     int offset,
                     int length,
                     float f)
```
    Creates a new hash set and fills it with the elements of a given array.
    
    Parameters:
    a - an array whose elements will be used to fill the set.
    offset - the first element to use.
    length - the number of elements to use.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(char[] a,
                     int offset,
                     int length)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor and fills it with the elements of a given array.
    
    Parameters:
    a - an array whose elements will be used to fill the set.
    offset - the first element to use.
    length - the number of elements to use.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(char[] a,
                     float f)
```
    Creates a new hash set copying the elements of an array.
    
    Parameters:
    a - an array to be copied into the new hash set.
    f - the load factor.
  - CharLinkedOpenHashSet
```
public CharLinkedOpenHashSet(char[] a)
```
    Creates a new hash set with Hash.DEFAULT_LOAD_FACTOR as load factor copying the elements of an array.
    
    Parameters:
    a - an array to be copied into the new hash set.
- Method Detail
  - add
```
public boolean add(char k)
```
    Specified by:
    
    add in interface CharCollection
    
    Overrides:
    
    add in class AbstractCharCollection
    
    See Also:
    Collection.add(Object)
  - shiftKeys
```
protected final int shiftKeys(int pos)
```
    Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.
    
    Parameters:
    pos - a starting position.
    
    Returns:
    the position cleared by the shifting process.
  - remove
```
public boolean remove(char k)
```
    Description copied from interface: CharSet
    
    Removes an element from this set.
    Note that the corresponding method of the type-specific collection is rem(). This unfortunate situation is caused by the clash with the similarly named index-based method in the List interface.
    
    Specified by:
    
    remove in interface CharSet
    
    Overrides:
    
    remove in class AbstractCharSet
    
    See Also:
    Collection.remove(Object)
  - contains
```
public boolean contains(char k)
```
    Specified by:
    
    contains in interface CharCollection
    
    Overrides:
    
    contains in class AbstractCharCollection
    
    See Also:
    Collection.contains(Object)
  - removeFirstChar
```
public char removeFirstChar()
```
    Removes the first key in iteration order.
    
    Returns:
    the first key.
    
    Throws:
    
    NoSuchElementException - is this set is empty.
  - removeLastChar
```
public char removeLastChar()
```
    Removes the the last key in iteration order.
    
    Returns:
    the last key.
    
    Throws:
    
    NoSuchElementException - is this set is empty.
  - addAndMoveToFirst
```
public boolean addAndMoveToFirst(char k)
```
    Adds a key to the set; if the key is already present, it is moved to the first position of the iteration order.
    
    Parameters:
    k - the key.
    
    Returns:
    true if the key was not present.
  - addAndMoveToLast
```
public boolean addAndMoveToLast(char k)
```
    Adds a key to the set; if the key is already present, it is moved to the last position of the iteration order.
    
    Parameters:
    k - the key.
    
    Returns:
    true if the key was not present.
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Collection<Character>
    
    Specified by:
    
    clear in interface Set<Character>
    
    Overrides:
    
    clear in class AbstractCollection<Character>
  - size
```
public int size()
```
    Specified by:
    
    size in interface Collection<Character>
    
    Specified by:
    
    size in interface Set<Character>
    
    Specified by:
    
    size in class AbstractCollection<Character>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Collection<Character>
    
    Specified by:
    
    isEmpty in interface Set<Character>
    
    Overrides:
    
    isEmpty in class AbstractCharCollection
  - 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)
  - fixPointers
```
protected void fixPointers(int i)
```
    Modifies the link vector so that the given entry is removed.
    If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.
    
    Parameters:
    i - the index of an entry.
  - fixPointers
```
protected void fixPointers(int s,
               int d)
```
    Modifies the link vector for a shift from s to d.
    If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.
    
    Parameters:
    s - the source position.
    d - the destination position.
  - firstChar
```
public char firstChar()
```
    Returns the first element of this set in iteration order.
    
    Specified by:
    
    firstChar in interface CharSortedSet
    
    Returns:
    the first element in iteration order.
    See Also:
    SortedSet.first()
  - lastChar
```
public char lastChar()
```
    Returns the last element of this set in iteration order.
    
    Specified by:
    
    lastChar in interface CharSortedSet
    
    Returns:
    the last element in iteration order.
    See Also:
    SortedSet.last()
  - tailSet
```
public CharSortedSet tailSet(char from)
```
    Specified by:
    
    tailSet in interface CharSortedSet
    
    See Also:
    SortedSet.tailSet(Object)
  - headSet
```
public CharSortedSet headSet(char to)
```
    Specified by:
    
    headSet in interface CharSortedSet
    
    See Also:
    SortedSet.headSet(Object)
  - subSet
```
public CharSortedSet subSet(char from,
                   char to)
```
    Specified by:
    
    subSet in interface CharSortedSet
    
    See Also:
    SortedSet.subSet(Object,Object)
  - comparator
```
public CharComparator comparator()
```
    Description copied from interface: CharSortedSet
    
    Returns the comparator associated with this sorted set, or null if it uses its elements' natural ordering.
    Note that this specification strengthens the one given in SortedSet.comparator().
    
    Specified by:
    
    comparator in interface CharSortedSet
    
    Specified by:
    
    comparator in interface SortedSet<Character>
    
    See Also:
    SortedSet.comparator()
  - iterator
```
public CharListIterator iterator(char from)
```
    Returns a type-specific list iterator on the elements in this set, starting from a given element of the set. Please see the class documentation for implementation details.
    
    Specified by:
    
    iterator in interface CharSortedSet
    
    Parameters:
    from - an element to start from.
    
    Returns:
    a type-specific list iterator starting at the given element.
    
    Throws:
    
    IllegalArgumentException - if from does not belong to the set.
  - iterator
```
public CharListIterator iterator()
```
    Description copied from interface: CharCollection
    
    Returns a type-specific iterator on the elements of this collection.
    Note that this specification strengthens the one given in Iterable.iterator(), which was already strengthened in the corresponding type-specific class, but was weakened by the fact that this interface extends Collection.
    
    Specified by:
    
    iterator in interface CharCollection
    
    Specified by:
    
    iterator in interface CharIterable
    
    Specified by:
    
    iterator in interface CharSet
    
    Specified by:
    
    iterator in interface CharSortedSet
    
    Specified by:
    
    iterator in interface Iterable<Character>
    
    Specified by:
    
    iterator in interface Collection<Character>
    
    Specified by:
    
    iterator in interface Set<Character>
    
    Specified by:
    
    iterator in class AbstractCharSortedSet
    
    Returns:
    a type-specific iterator on the elements of this collection.
  - 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 this set, 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 set.
    See Also:
    trim(int)
  - trim
```
public boolean trim(int n)
```
    Rehashes this set 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 set in a table of size N.
    This method is useful when reusing sets. Clearing a set leaves the table size untouched. If you are reusing a set 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 sets.
    
    Parameters:
    n - the threshold for the trimming.
    
    Returns:
    true if there was enough memory to trim the set.
    See Also:
    trim()
  - rehash
```
protected void rehash(int newN)
```
    Resizes the set.
    This method implements the basic rehashing strategy, and may be overriden by subclasses implementing different rehashing strategies (e.g., disk-based rehashing). However, you should not override this method unless you understand the internal workings of this class.
    
    Parameters:
    newN - the new size
  - clone
```
public CharLinkedOpenHashSet clone()
```
    Returns a deep copy of this set.
    This method performs a deep copy of this hash set; the data stored in the set, however, is not cloned. Note that this makes a difference only for object keys.
    
    Overrides:
    
    clone in class Object
    
    Returns:
    a deep copy of this set.
  - hashCode
```
public int hashCode()
```
    Returns a hash code for this set. 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 Collection<Character>
    
    Specified by:
    
    hashCode in interface Set<Character>
    
    Overrides:
    
    hashCode in class AbstractCharSet
    
    Returns:
    a hash code for this set.

Class CharLinkedOpenHashSet

Nested Class Summary

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Field Summary

Fields inherited from interface it.unimi.dsi.fastutil.Hash

Constructor Summary

Method Summary

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharSortedSet

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharSet

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractCharCollection

Methods inherited from class java.lang.Object

Methods inherited from interface it.unimi.dsi.fastutil.chars.CharCollection

Methods inherited from interface java.util.Set

Field Detail

serialVersionUID

key

used

f

n

maxFill

mask

size

first

last

link

Constructor Detail

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

CharLinkedOpenHashSet

Method Detail

add

shiftKeys

remove

contains

removeFirstChar

removeLastChar

addAndMoveToFirst

addAndMoveToLast

clear

size

isEmpty

growthFactor

growthFactor

fixPointers

fixPointers

firstChar

lastChar

tailSet

headSet

subSet

comparator

iterator

iterator

rehash

trim

trim

rehash

clone

hashCode