javolution37.javolution.util

Class FastCollection<E>

java.lang.Object

javolution37.javolution.realtime.RealtimeObject

javolution37.javolution.util.FastCollection<E>

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>, Realtime

Direct Known Subclasses:

FastList, FastSet, FastTable

public abstract class FastCollection<E>
extends RealtimeObject
implements java.util.Collection<E>, java.io.Serializable

This class represents collections which can quickly be iterated over (forward or backward) in a thread-safe manner without creating new objects and without using iterators . For example:

     boolean search(Object item, FastCollection c) {
         for (Record r = c.head(), end = c.tail(); (r = r.getNext()) != end;) {
              if (item.equals(c.valueOf(r))) return true;
         }
         return false;
     }

Iterations are thread-safe as long as the record sequence iterated over is not structurally modified by another thread (objects can safely be append/prepend during iterations but not inserted/removed).

Users may provide a read-only view of any FastCollection instance using the unmodifiable() method (the view is thread-safe if iterations are thread-safe). For example:

     public class Polynomial {
         private final FastTable<Coefficient> _coefficients = new FastTable<Coefficient>();
         public List<Coefficient> getCoefficients() { // Read-only view. 
             return _coefficients.unmodifiable();
         }
     }

Finally, FastCollection may use custom comparators for element equality or ordering if the collection is ordered (e.g. FastTree).

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	FastCollection.Record This interface represents the collection records which can directly be iterated over.

Nested classes/interfaces inherited from class javolution37.javolution.realtime.RealtimeObject

RealtimeObject.Factory<T extends RealtimeObject>

Nested classes/interfaces inherited from interface javolution37.javolution.realtime.Realtime

Realtime.ObjectSpace

Method Summary

Modifier and Type	Method and Description
boolean	add(E value) Appends the specified value to the end of this collection (optional operation).
boolean	addAll(java.util.Collection<? extends E> c) Appends all of the values in the specified collection to the end of this collection, in the order that they are returned by the specified collection's iterator or the node order if the specified collection is a FastCollection.
void	clear() Removes all of the values from this collection (optional operation).
boolean	contains(java.lang.Object value) Indicates if this collection contains the specified value.
boolean	containsAll(java.util.Collection<?> c) Indicates if this collection contains all of the values of the specified collection.
abstract void	delete(FastCollection.Record record) Deletes the specified record from this collection.
boolean	equals(java.lang.Object obj) Compares the specified object with this collection for equality.
FastComparator	getValueComparator() Returns the value comparator for this collection (default FastComparator.DEFAULT).
int	hashCode() Returns the hash code for this collection (independent from the collection order; unless this collection is a list instance).
abstract FastCollection.Record	head() Returns the head record of this collection; it is the record such as head().getNext() holds the first collection value.
boolean	isEmpty() Indicates if this collection is empty.
java.util.Iterator<E>	iterator() Returns an iterator over the elements in this collection (allocated on the stack when executed in a PoolContext).
boolean	remove(java.lang.Object value) Removes the first occurrence in this collection of the specified value (optional operation).
boolean	removeAll(java.util.Collection<?> c) Removes from this collection all the values that are contained in the specified collection.
boolean	retainAll(java.util.Collection<?> c) Retains only the values in this collection that are contained in the specified collection.
FastCollection<E>	setValueComparator(FastComparator comparator) Sets the comparator to use for value equality or ordering if the collection is ordered (e.g.
abstract int	size() Returns the number of values in this collection.
abstract FastCollection.Record	tail() Returns the tail record of this collection; it is the record such as tail().getPrevious() holds the last collection value.
java.lang.Object[]	toArray() Returns a new array allocated on the heap containing all of the values in this collection in proper sequence.
<T> T[]	toArray(T[] array) Fills the specified array with the values of this collection in the proper sequence.
Text	toText() Returns the textual representation of this collection.
java.util.Collection<E>	unmodifiable() Returns the unmodifiable view associated to this collection.
abstract E	valueOf(FastCollection.Record record) Returns the collection value for the specified record.

Methods inherited from class javolution37.javolution.realtime.RealtimeObject

export, move, moveHeap, preserve, toString, unpreserve

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Method Detail

size

public abstract int size()

Returns the number of values in this collection.

Specified by:

size in interface java.util.Collection<E>

Returns:

the number of values.

head

public abstract FastCollection.Record head()

Returns the head record of this collection; it is the record such as head().getNext() holds the first collection value.

Returns:

the head record.

tail

public abstract FastCollection.Record tail()

Returns the tail record of this collection; it is the record such as tail().getPrevious() holds the last collection value.

Returns:

the tail record.

valueOf

public abstract E valueOf(FastCollection.Record record)

Returns the collection value for the specified record.

Parameters:

record - the record whose current value is returned.

Returns:

the current value.

delete

public abstract void delete(FastCollection.Record record)

Deletes the specified record from this collection.

Implementation must ensure that removing a record from the collection does not affect in any way the records preceding the record being removed (it might affect the next records though, e.g. in a list collection, the indices of the subsequent records will change).

Parameters:

record - the record to be removed.

Throws:

java.lang.UnsupportedOperationException - if not supported.

unmodifiable

public java.util.Collection<E> unmodifiable()

Returns the unmodifiable view associated to this collection. Attempts to modify the returned collection result in an UnsupportedOperationException being thrown. The view is typically part of the collection itself (created only once) and also an instance of FastCollection supporting direct iterations.

Returns:

the unmodifiable view over this collection.

iterator

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

Returns an iterator over the elements in this collection (allocated on the stack when executed in a PoolContext).

Specified by:

iterator in interface java.lang.Iterable<E>

Specified by:

iterator in interface java.util.Collection<E>

Returns:

an iterator over this collection's elements.

setValueComparator

public FastCollection<E> setValueComparator(FastComparator comparator)

Sets the comparator to use for value equality or ordering if the collection is ordered (e.g. FastTree).

Parameters:

comparator - the value comparator.

Returns:

this

getValueComparator

public FastComparator getValueComparator()

Returns the value comparator for this collection (default FastComparator.DEFAULT).

Returns:

the comparator to use for value equality (or ordering if the collection is ordered)

add

public boolean add(E value)

Appends the specified value to the end of this collection (optional operation).

Note: This default implementation always throws UnsupportedOperationException.

Specified by:

add in interface java.util.Collection<E>

Parameters:

value - the value to be appended to this collection.

Returns:

true (as per the general contract of the Collection.add method).

Throws:

java.lang.UnsupportedOperationException - if not supported.

remove

public boolean remove(java.lang.Object value)

Removes the first occurrence in this collection of the specified value (optional operation).

Specified by:

remove in interface java.util.Collection<E>

Parameters:

value - the value to be removed from this collection.

Returns:

true if this collection contained the specified value; false otherwise.

Throws:

java.lang.UnsupportedOperationException - if not supported.

clear

public void clear()

Removes all of the values from this collection (optional operation).

Specified by:

clear in interface java.util.Collection<E>

Throws:

java.lang.UnsupportedOperationException - if not supported.

isEmpty

public final boolean isEmpty()

Indicates if this collection is empty.

Specified by:

isEmpty in interface java.util.Collection<E>

Returns:

true if this collection contains no value; false otherwise.

contains

public boolean contains(java.lang.Object value)

Indicates if this collection contains the specified value.

Specified by:

contains in interface java.util.Collection<E>

Parameters:

value - the value whose presence in this collection is to be tested.

Returns:

true if this collection contains the specified value;false otherwise.

addAll

public boolean addAll(java.util.Collection<? extends E> c)

Appends all of the values in the specified collection to the end of this collection, in the order that they are returned by the specified collection's iterator or the node order if the specified collection is a FastCollection.

Specified by:

addAll in interface java.util.Collection<E>

Parameters:

c - collection whose values are to be added to this collection.

Returns:

true if this collection changed as a result of the call; false otherwise.

containsAll

public boolean containsAll(java.util.Collection<?> c)

Indicates if this collection contains all of the values of the specified collection.

Specified by:

containsAll in interface java.util.Collection<E>

Parameters:

c - collection to be checked for containment in this collection.

Returns:

true if this collection contains all of the values of the specified collection; false otherwise.

removeAll

public boolean removeAll(java.util.Collection<?> c)

Removes from this collection all the values that are contained in the specified collection.

Specified by:

removeAll in interface java.util.Collection<E>

Parameters:

c - collection that defines which values will be removed from this collection.

Returns:

true if this collection changed as a result of the call; false otherwise.

retainAll

public boolean retainAll(java.util.Collection<?> c)

Retains only the values in this collection that are contained in the specified collection.

Specified by:

retainAll in interface java.util.Collection<E>

Parameters:

c - collection that defines which values this set will retain.

Returns:

true if this collection changed as a result of the call; false otherwise.

toArray

public java.lang.Object[] toArray()

Returns a new array allocated on the heap containing all of the values in this collection in proper sequence.

Note: To avoid heap allocation toArray(Object[]) is recommended.

Specified by:

toArray in interface java.util.Collection<E>

Returns:

toArray(new Object[size()])

toArray

public <T> T[] toArray(T[] array)

Fills the specified array with the values of this collection in the proper sequence.

Note: Unlike standard Collection, this method does not try to resize the array using reflection (which might not be supported) if the array is too small. UnsupportedOperationException is raised if the specified array is too small for this collection.

Specified by:

toArray in interface java.util.Collection<E>

Parameters:

array - the array into which the values of this collection are to be stored.

Returns:

the specified array.

Throws:

java.lang.UnsupportedOperationException - if array.length < size()

toText

public Text toText()

Returns the textual representation of this collection.

Specified by:

toText in interface Realtime

Overrides:

toText in class RealtimeObject

Returns:

this collection textual representation.

equals

public boolean equals(java.lang.Object obj)

Compares the specified object with this collection for equality. Returns true if and only both collection contains the same values regardless of the order; unless this collection is a list instance in which case both collection must be list with the same order.

Specified by:

equals in interface java.util.Collection<E>

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to be compared for equality with this collection.

Returns:

true if the specified object is equal to this collection; false otherwise.

hashCode

public int hashCode()

Returns the hash code for this collection (independent from the collection order; unless this collection is a list instance).

Specified by:

hashCode in interface java.util.Collection<E>

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code for this collection.