public class ByteLinkedOpenHashSet extends AbstractByteSortedSet implements Serializable, Cloneable, Hash
Instances of this class use a hash table to represent a set. 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 sets 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.
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 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.
Hash,
HashCommon,
Serialized FormHash.Strategy<K>| Modifier and Type | Field and Description |
|---|---|
protected boolean |
containsNull
Whether this set contains the null key.
|
protected float |
f
The acceptable load factor.
|
protected int |
first
The index of the first entry in iteration order.
|
protected byte[] |
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 |
minN
We never resize below this threshold, which is the construction-time {#n}.
|
protected int |
n
The current table size.
|
protected int |
size
Number of entries in the set (including the null key, if present).
|
DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR| Constructor and Description |
|---|
ByteLinkedOpenHashSet()
Creates a new hash set with initial expected
Hash.DEFAULT_INITIAL_SIZE elements
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
ByteLinkedOpenHashSet(byte[] a)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor
copying the elements of an array. |
ByteLinkedOpenHashSet(byte[] a,
float f)
Creates a new hash set copying the elements of an array.
|
ByteLinkedOpenHashSet(byte[] 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. |
ByteLinkedOpenHashSet(byte[] a,
int offset,
int length,
float f)
Creates a new hash set and fills it with the elements of a given array.
|
ByteLinkedOpenHashSet(ByteCollection c)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given type-specific collection. |
ByteLinkedOpenHashSet(ByteCollection c,
float f)
Creates a new hash set copying a given type-specific collection.
|
ByteLinkedOpenHashSet(ByteIterator i)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator. |
ByteLinkedOpenHashSet(ByteIterator i,
float f)
Creates a new hash set using elements provided by a type-specific iterator.
|
ByteLinkedOpenHashSet(Collection<? extends Byte> c)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given collection. |
ByteLinkedOpenHashSet(Collection<? extends Byte> c,
float f)
Creates a new hash set copying a given collection.
|
ByteLinkedOpenHashSet(int expected)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
ByteLinkedOpenHashSet(int expected,
float f)
Creates a new hash set.
|
ByteLinkedOpenHashSet(Iterator<?> i)
Creates a new hash set with
Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator. |
ByteLinkedOpenHashSet(Iterator<?> i,
float f)
Creates a new hash set using elements provided by an iterator.
|
| Modifier and Type | Method and Description |
|---|---|
boolean |
add(byte k)
Ensures that this collection contains the specified element (optional operation).
|
boolean |
addAll(ByteCollection c)
Adds all elements of the given type-specific collection to this collection.
|
boolean |
addAll(Collection<? extends Byte> c) |
boolean |
addAndMoveToFirst(byte 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(byte 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() |
ByteLinkedOpenHashSet |
clone()
Returns a deep copy of this set.
|
ByteComparator |
comparator() |
boolean |
contains(byte k)
Returns
true if this collection contains the specified element. |
byte |
firstByte()
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 |
hashCode()
Returns a hash code for this set.
|
ByteSortedSet |
headSet(byte to)
Returns a view of the portion of this sorted set whose elements are strictly less than
toElement. |
boolean |
isEmpty() |
ByteListIterator |
iterator()
Returns a type-specific list iterator on the elements in this set, starting from the first element.
|
ByteListIterator |
iterator(byte from)
Returns a type-specific list iterator on the elements in this set, starting from a given element of the set.
|
byte |
lastByte()
Returns the last element of this set in iteration order.
|
protected void |
rehash(int newN)
Rehashes the set.
|
boolean |
remove(byte k)
Removes an element from this set.
|
byte |
removeFirstByte()
Removes the first key in iteration order.
|
byte |
removeLastByte()
Removes the the last key in iteration order.
|
protected void |
shiftKeys(int pos)
Shifts left entries with the specified hash code, starting at the specified position,
and empties the resulting free entry.
|
int |
size() |
ByteSortedSet |
subSet(byte from,
byte to)
Returns a view of the portion of this sorted set whose elements range from
fromElement, inclusive, to toElement, exclusive. |
ByteSortedSet |
tailSet(byte from)
Returns a view of the portion of this sorted set whose elements are greater than or equal to
fromElement. |
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.
|
equals, remadd, contains, containsAll, remove, removeAll, retainAll, toArray, toByteArray, toByteArray, toStringcontainsAll, removeAll, retainAll, toArray, toArrayfinalize, getClass, notify, notifyAll, wait, wait, waitfirst, headSet, last, subSet, tailSetcontainsAll, removeAll, removeIf, removeIf, retainAll, toArray, toByteArray, toByteArrayforEach, forEachspliteratorcontainsAll, equals, removeAll, retainAll, toArray, toArrayparallelStream, streamprotected transient byte[] key
protected transient int mask
protected transient boolean containsNull
protected transient int first
size is nonzero; otherwise, it contains -1.protected transient int last
size is nonzero; otherwise, it contains -1.protected transient long[] link
((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL).
The first entry contains predecessor -1, and the last entry
contains successor -1.protected transient int n
protected transient int maxFill
f.protected final transient int minN
protected int size
protected final float f
public ByteLinkedOpenHashSet(int expected,
float f)
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.public ByteLinkedOpenHashSet(int expected)
Hash.DEFAULT_LOAD_FACTOR as load factor.expected - the expected number of elements in the hash set.public ByteLinkedOpenHashSet()
Hash.DEFAULT_INITIAL_SIZE elements
and Hash.DEFAULT_LOAD_FACTOR as load factor.public ByteLinkedOpenHashSet(Collection<? extends Byte> c, float f)
c - a Collection to be copied into the new hash set.f - the load factor.public ByteLinkedOpenHashSet(Collection<? extends Byte> c)
Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given collection.c - a Collection to be copied into the new hash set.public ByteLinkedOpenHashSet(ByteCollection c, float f)
c - a type-specific collection to be copied into the new hash set.f - the load factor.public ByteLinkedOpenHashSet(ByteCollection c)
Hash.DEFAULT_LOAD_FACTOR as load factor
copying a given type-specific collection.c - a type-specific collection to be copied into the new hash set.public ByteLinkedOpenHashSet(ByteIterator i, float f)
i - a type-specific iterator whose elements will fill the set.f - the load factor.public ByteLinkedOpenHashSet(ByteIterator i)
Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by a type-specific iterator.i - a type-specific iterator whose elements will fill the set.public ByteLinkedOpenHashSet(Iterator<?> i, float f)
i - an iterator whose elements will fill the set.f - the load factor.public ByteLinkedOpenHashSet(Iterator<?> i)
Hash.DEFAULT_LOAD_FACTOR as load factor using elements provided by an iterator.i - an iterator whose elements will fill the set.public ByteLinkedOpenHashSet(byte[] a,
int offset,
int length,
float f)
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.public ByteLinkedOpenHashSet(byte[] a,
int offset,
int length)
Hash.DEFAULT_LOAD_FACTOR as load factor and fills it with the elements of a given array.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.public ByteLinkedOpenHashSet(byte[] a,
float f)
a - an array to be copied into the new hash set.f - the load factor.public ByteLinkedOpenHashSet(byte[] a)
Hash.DEFAULT_LOAD_FACTOR as load factor
copying the elements of an array.a - an array to be copied into the new hash set.public boolean addAll(ByteCollection c)
ByteCollectionaddAll in interface ByteCollectionaddAll in class AbstractByteCollectionc - a type-specific collection.true if this collection changed as a result of the call.Collection.addAll(Collection)public boolean addAll(Collection<? extends Byte> c)
addAll in interface Collection<Byte>addAll in interface Set<Byte>addAll in class AbstractCollection<Byte>public boolean add(byte k)
AbstractByteCollectionThis implementation always throws an UnsupportedOperationException.
add in interface ByteCollectionadd in class AbstractByteCollectionCollection.add(Object)protected final void shiftKeys(int pos)
pos - a starting position.public boolean remove(byte k)
AbstractByteSetNote that the corresponding method of a type-specific collection is rem().
This unfortunate situation is caused by the clash
with the similarly named index-based method in the List interface.
Delegates to the type-specific rem() method
implemented by type-specific abstract Collection superclass.
remove in interface ByteSetremove in class AbstractByteSetCollection.remove(Object)public boolean contains(byte k)
AbstractByteCollectiontrue if this collection contains the specified element.
This implementation iterates over the elements in the collection, looking for the specified element.
contains in interface ByteCollectioncontains in class AbstractByteCollectionCollection.contains(Object)public byte removeFirstByte()
NoSuchElementException - is this set is empty.public byte removeLastByte()
NoSuchElementException - is this set is empty.public boolean addAndMoveToFirst(byte k)
k - the key.public boolean addAndMoveToLast(byte k)
k - the key.public void clear()
clear in interface Collection<Byte>clear in interface Set<Byte>clear in class AbstractCollection<Byte>public int size()
size in interface Collection<Byte>size in interface Set<Byte>size in class AbstractCollection<Byte>public boolean isEmpty()
isEmpty in interface Collection<Byte>isEmpty in interface Set<Byte>isEmpty in class AbstractCollection<Byte>protected void fixPointers(int i)
link vector so that the given entry is removed.
This method will complete in constant time.i - the index of an entry.protected void fixPointers(int s,
int d)
link vector for a shift from s to d.
This method will complete in constant time.s - the source position.d - the destination position.public byte firstByte()
firstByte in interface ByteSortedSetSortedSet.first()public byte lastByte()
lastByte in interface ByteSortedSetSortedSet.last()public ByteSortedSet tailSet(byte from)
fromElement.
Note that this specification strengthens the one given in SortedSet.headSet(Object).
This implementation just throws an UnsupportedOperationException.
tailSet in interface ByteSortedSetSortedSet.tailSet(Object)public ByteSortedSet headSet(byte to)
toElement.
Note that this specification strengthens the one given in SortedSet.headSet(Object).
This implementation just throws an UnsupportedOperationException.
headSet in interface ByteSortedSetSortedSet.headSet(Object)public ByteSortedSet subSet(byte from, byte to)
fromElement, inclusive, to toElement, exclusive.
Note that this specification strengthens the one given in SortedSet.subSet(Object,Object).
This implementation just throws an UnsupportedOperationException.
subSet in interface ByteSortedSetSortedSet.subSet(Object,Object)public ByteComparator comparator()
Note that this specification strengthens the one given in SortedSet.comparator().
This implementation just returns null.
comparator in interface ByteSortedSetcomparator in interface SortedSet<Byte>public ByteListIterator iterator(byte from)
iterator in interface ByteSortedSetfrom - an element to start from.IllegalArgumentException - if from does not belong to the set.public ByteListIterator iterator()
iterator in interface ByteBidirectionalIterableiterator in interface ByteCollectioniterator in interface ByteIterableiterator in interface ByteSetiterator in interface ByteSortedSetiterator in interface Iterable<Byte>iterator in interface Collection<Byte>iterator in interface Set<Byte>iterator in class AbstractByteSortedSetIterable.iterator()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 set in a table of size
N.
size())
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.
n - the threshold for the trimming.trim()protected void rehash(int newN)
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.
newN - the new sizepublic ByteLinkedOpenHashSet clone()
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.
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.hashCode in interface Collection<Byte>hashCode in interface Set<Byte>hashCode in class AbstractByteSetCopyright © 2020. All rights reserved.