com.carrotsearch.hppc

Class CharHashSet

java.lang.Object

com.carrotsearch.hppc.CharHashSet

All Implemented Interfaces:

CharCollection, CharContainer, CharLookupContainer, CharSet, Preallocable, java.lang.Cloneable, java.lang.Iterable<CharCursor>

Direct Known Subclasses:

CharScatterSet

@Generated(date="2015-05-07T09:33:03+0200",
           value="KTypeHashSet.java")
public class CharHashSet
extends java.lang.Object
implements CharLookupContainer, CharSet, Preallocable, java.lang.Cloneable

A hash set of chars, implemented using using open addressing with linear probing for collision resolution.

Note: read about important differences between hash and scatter sets.

See Also:

CharScatterSet, HPPC interfaces diagram

Field Summary

Fields

Modifier and Type	Field and Description
char[]	keys The hash array holding keys.

Constructor Summary

Constructors

Constructor and Description
CharHashSet() New instance with sane defaults.
CharHashSet(CharContainer container) New instance copying elements from another CharContainer.
CharHashSet(int expectedElements) New instance with sane defaults.
CharHashSet(int expectedElements, double loadFactor) New instance with sane defaults.
CharHashSet(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer) New instance with the provided defaults.

Method Summary

Modifier and Type	Method and Description
boolean	add(char key) Adds k to the set.
int	addAll(char... elements) Adds all elements from the given list (vararg) to this set.
int	addAll(CharContainer container) Adds all elements from the given CharContainer to this set.
int	addAll(java.lang.Iterable<? extends CharCursor> iterable) Adds all elements from the given iterable to this set.
void	clear() Removes all elements from this collection.
CharHashSet	clone()
boolean	contains(char key) Lookup a given element in the container.
void	ensureCapacity(int expectedElements) Ensure this container can hold at least the given number of elements without resizing its buffers.
boolean	equals(java.lang.Object obj)
<T extends CharPredicate> T	forEach(T predicate) Applies a predicate to container elements as long, as the predicate returns true.
<T extends CharProcedure> T	forEach(T procedure) Applies a procedure to all container elements.
static CharHashSet	from(char... elements) Create a set from a variable number of arguments or an array of char.
int	hashCode()
boolean	indexExists(int index)
char	indexGet(int index) Returns the exact value of the existing key.
void	indexInsert(int index, char key) Inserts a key for an index that is not present in the set.
int	indexOf(char key) Returns a logical "index" of a given key that can be used to speed up follow-up logic in certain scenarios (conditional logic).
char	indexReplace(int index, char equivalentKey) Replaces the existing equivalent key with the given one and returns any previous value stored for that key.
boolean	isEmpty() Shortcut for size() == 0.
java.util.Iterator<CharCursor>	iterator() Returns an iterator to a cursor traversing the collection.
void	release() Removes all elements from the collection and additionally releases any internal buffers.
boolean	remove(char key) An alias for the (preferred) removeAll(char).
int	removeAll(char key) Removes all occurrences of e from this collection.
int	removeAll(CharLookupContainer c) Default implementation uses a predicate for removal.
int	removeAll(CharPredicate predicate) Removes all elements in this collection for which the given predicate returns true.
int	retainAll(CharLookupContainer c) Default implementation uses a predicate for retaining.
int	retainAll(CharPredicate predicate) Default implementation redirects to CharCollection.removeAll(CharPredicate) and negates the predicate.
int	size() Return the current number of elements in this container.
char[]	toArray() Default implementation of copying to an array.
java.lang.String	toString() Convert the contents of this container to a human-friendly string.
java.lang.String	visualizeKeyDistribution(int characters) Visually depict the distribution of keys.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.carrotsearch.hppc.CharCollection

removeAll, retainAll, retainAll

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

keys

public char[] keys

The hash array holding keys.

Constructor Detail

CharHashSet

public CharHashSet()

New instance with sane defaults.

See Also:

CharHashSet(int, double, HashOrderMixingStrategy)

CharHashSet

public CharHashSet(int expectedElements)

New instance with sane defaults.

See Also:

CharHashSet(int, double, HashOrderMixingStrategy)

CharHashSet

public CharHashSet(int expectedElements,
                   double loadFactor)

New instance with sane defaults.

See Also:

CharHashSet(int, double, HashOrderMixingStrategy)

CharHashSet

public CharHashSet(int expectedElements,
                   double loadFactor,
                   HashOrderMixingStrategy orderMixer)

New instance with the provided defaults.

Parameters:

expectedElements - The expected number of elements guaranteed not to cause a rehash (inclusive).

loadFactor - The load factor for internal buffers. Insane load factors (zero, full capacity) are rejected by verifyLoadFactor(double).

orderMixer - Hash key order mixing strategy. See HashOrderMixing for predefined implementations. Use constant mixers only if you understand the potential consequences.

CharHashSet

public CharHashSet(CharContainer container)

New instance copying elements from another CharContainer.

Method Detail

add

public boolean add(char key)

Adds k to the set.

Specified by:

add in interface CharSet

Returns:

Returns true if this element was not part of the set before. Returns false if an equal element is part of the set, and replaces the existing equal element with the argument (if keys are object types).

addAll

public final int addAll(char... elements)

Adds all elements from the given list (vararg) to this set.

Returns:

Returns the number of elements actually added as a result of this call (not previously present in the set).

addAll

public int addAll(CharContainer container)

Adds all elements from the given CharContainer to this set.

Returns:

Returns the number of elements actually added as a result of this call (not previously present in the set).

addAll

public int addAll(java.lang.Iterable<? extends CharCursor> iterable)

Adds all elements from the given iterable to this set.

Returns:

Returns the number of elements actually added as a result of this call (not previously present in the set).

toArray

public char[] toArray()

Default implementation of copying to an array.

Specified by:

toArray in interface CharContainer

remove

public boolean remove(char key)

An alias for the (preferred) removeAll(char).

removeAll

public int removeAll(char key)

Removes all occurrences of e from this collection.

Specified by:

removeAll in interface CharCollection

Parameters:

key - Element to be removed from this collection, if present.

Returns:

The number of removed elements as a result of this call.

removeAll

public int removeAll(CharPredicate predicate)

Removes all elements in this collection for which the given predicate returns true.

Specified by:

removeAll in interface CharCollection

Returns:

Returns the number of removed elements.

contains

public boolean contains(char key)

Lookup a given element in the container. This operation has no speed guarantees (may be linear with respect to the size of this container).

Specified by:

contains in interface CharContainer

Specified by:

contains in interface CharLookupContainer

Returns:

Returns true if this container has an element equal to e.

clear

public void clear()

Removes all elements from this collection.

Specified by:

clear in interface CharCollection

See Also:

CharCollection.release()

release

public void release()

Removes all elements from the collection and additionally releases any internal buffers. Typically, if the object is to be reused, a simple CharCollection.clear() should be a better alternative since it'll avoid reallocation.

Specified by:

release in interface CharCollection

See Also:

CharCollection.clear()

isEmpty

public boolean isEmpty()

Shortcut for size() == 0.

Specified by:

isEmpty in interface CharContainer

ensureCapacity

public void ensureCapacity(int expectedElements)

Ensure this container can hold at least the given number of elements without resizing its buffers.

Specified by:

ensureCapacity in interface Preallocable

Parameters:

expectedElements - The total number of elements, inclusive.

size

public int size()

Return the current number of elements in this container. The time for calculating the container's size may take O(n) time, although implementing classes should try to maintain the current size and return in constant time.

Specified by:

size in interface CharContainer

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

clone

public CharHashSet clone()

Overrides:

clone in class java.lang.Object

iterator

public java.util.Iterator<CharCursor> iterator()

Returns an iterator to a cursor traversing the collection. The order of traversal is not defined. More than one cursor may be active at a time. The behavior of iterators is undefined if structural changes are made to the underlying collection.

The iterator is implemented as a cursor and it returns the same cursor instance on every call to Iterator.next() (to avoid boxing of primitive types). To read the current list's value (or index in the list) use the cursor's public fields. An example is shown below.

 for (CharCursor<char> c : container) {
   System.out.println("index=" + c.index + " value=" + c.value);
 }
 

Specified by:

iterator in interface CharContainer

Specified by:

iterator in interface java.lang.Iterable<CharCursor>

forEach

public <T extends CharProcedure> T forEach(T procedure)

Applies a procedure to all container elements. Returns the argument (any subclass of CharProcedure. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example (IntContainer):

 int count = container.forEach(new IntProcedure() {
   int count; // this is a field declaration in an anonymous class.
 
   public void apply(int value) {
     count++;
   }
 }).count;
 

Specified by:

forEach in interface CharContainer

forEach

public <T extends CharPredicate> T forEach(T predicate)

Applies a predicate to container elements as long, as the predicate returns true. The iteration is interrupted otherwise.

Specified by:

forEach in interface CharContainer

from

public static CharHashSet from(char... elements)

Create a set from a variable number of arguments or an array of char. The elements are copied from the argument to the internal buffer.

indexOf

public int indexOf(char key)

Returns a logical "index" of a given key that can be used to speed up follow-up logic in certain scenarios (conditional logic). The semantics of "indexes" are not strictly defined. Indexes may (and typically won't be) contiguous. The index is valid only between modifications (it will not be affected by read-only operations).

Parameters:

key - The key to locate in the set.

Returns:

A non-negative value of the logical "index" of the key in the set or a negative value if the key did not exist.

See Also:

indexExists(int), indexGet(int), indexInsert(int, char), indexReplace(int, char)

indexExists

public boolean indexExists(int index)

Parameters:

index - The index of a given key, as returned from indexOf(char).

Returns:

Returns true if the index corresponds to an existing key or false otherwise. This is equivalent to checking whether the index is a positive value (existing keys) or a negative value (non-existing keys).

See Also:

indexOf(char)

indexGet

public char indexGet(int index)

Returns the exact value of the existing key. This method makes sense for sets of objects which define custom key-equality relationship.

Parameters:

index - The index of an existing key.

Returns:

Returns the equivalent key currently stored in the set.

Throws:

java.lang.AssertionError - If assertions are enabled and the index does not correspond to an existing key.

See Also:

indexOf(char)

indexReplace

public char indexReplace(int index,
                         char equivalentKey)

Replaces the existing equivalent key with the given one and returns any previous value stored for that key.

Parameters:

index - The index of an existing key.

equivalentKey - The key to put in the set as a replacement. Must be equivalent to the key currently stored at the provided index.

Returns:

Returns the previous key stored in the set.

Throws:

java.lang.AssertionError - If assertions are enabled and the index does not correspond to an existing key.

See Also:

indexOf(char)

indexInsert

public void indexInsert(int index,
                        char key)

Inserts a key for an index that is not present in the set. This method may help in avoiding double recalculation of the key's hash.

Parameters:

index - The index of a previously non-existing key, as returned from indexOf(char).

Throws:

java.lang.AssertionError - If assertions are enabled and the index does not correspond to an existing key.

See Also:

indexOf(char)

visualizeKeyDistribution

public java.lang.String visualizeKeyDistribution(int characters)

Description copied from interface: CharSet

Visually depict the distribution of keys.

Specified by:

visualizeKeyDistribution in interface CharSet

Parameters:

characters - The number of characters to "squeeze" the entire buffer into.

Returns:

Returns a sequence of characters where '.' depicts an empty fragment of the internal buffer and 'X' depicts full or nearly full capacity within the buffer's range and anything between 1 and 9 is between.

removeAll

public int removeAll(CharLookupContainer c)

Default implementation uses a predicate for removal.

Specified by:

removeAll in interface CharCollection

Returns:

Returns the number of removed elements.

retainAll

public int retainAll(CharLookupContainer c)

Default implementation uses a predicate for retaining.

Specified by:

retainAll in interface CharCollection

Returns:

Returns the number of removed elements.

retainAll

public int retainAll(CharPredicate predicate)

Default implementation redirects to CharCollection.removeAll(CharPredicate) and negates the predicate.

Specified by:

retainAll in interface CharCollection

Returns:

Returns the number of removed elements.

toString

public java.lang.String toString()

Convert the contents of this container to a human-friendly string.

Overrides:

toString in class java.lang.Object