org.apache.marmotta.commons.sesame.tripletable

Class TripleTable<Triple extends org.openrdf.model.Statement>

java.lang.Object

org.apache.marmotta.commons.sesame.tripletable.TripleTable<Triple>

All Implemented Interfaces:

Serializable, Iterable<Triple>, Collection<Triple>, Set<Triple>

public class TripleTable<Triple extends org.openrdf.model.Statement>
extends Object
implements Set<Triple>, Serializable

A triple table that allows efficient in-memory operations over large collections of triples. This can be used as a simplified version of a Sesame in-memory repository (MemStore) using typical collection methods.

Author: Sebastian Schaffert

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TripleTable()
TripleTable(Collection<Triple> triples)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(Triple triple) Adds the specified element to this set if it is not already present (optional operation).
boolean	addAll(Collection<? extends Triple> c) Adds all of the elements in the specified collection to this set if they're not already present (optional operation).
void	clear() Removes all of the elements from this set (optional operation).
boolean	contains(Object o) Returns true if this set contains the specified element.
boolean	containsAll(Collection<?> c) Returns true if this set contains all of the elements of the specified collection.
boolean	equals(Object o)
int	hashCode()
boolean	isEmpty() Returns true if this set contains no elements.
Iterator<Triple>	iterator() Returns an iterator over the elements in this set.
Collection<org.openrdf.model.Resource>	listContextIDs()
Collection<Triple>	listTriples(org.openrdf.model.Resource subject, org.openrdf.model.URI property, org.openrdf.model.Value object, org.openrdf.model.Resource context, boolean wildcardContext) Return a subset of the triples matching the filter criteria.
boolean	remove(Object o) Removes the specified element from this set if it is present (optional operation).
boolean	removeAll(Collection<?> c) Removes from this set all of its elements that are contained in the specified collection (optional operation).
boolean	retainAll(Collection<?> c) Retains only the elements in this set that are contained in the specified collection (optional operation).
int	size() Returns the number of elements in this set (its cardinality).
Object[]	toArray() Returns an array containing all of the elements in this set.
<T> T[]	toArray(T[] a) Returns an array containing all of the elements in this set; the runtime type of the returned array is that of the specified array.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TripleTable

public TripleTable()

TripleTable

public TripleTable(Collection<Triple> triples)

Method Detail

size

public int size()

Returns the number of elements in this set (its cardinality). If this set contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Specified by:

size in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

size in interface Set<Triple extends org.openrdf.model.Statement>

Returns:

the number of elements in this set (its cardinality)

isEmpty

public boolean isEmpty()

Returns true if this set contains no elements.

Specified by:

isEmpty in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

isEmpty in interface Set<Triple extends org.openrdf.model.Statement>

Returns:

true if this set contains no elements

contains

public boolean contains(Object o)

Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an element e such that (o==null ? e==null : o.equals(e)).

Specified by:

contains in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

contains in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

o - element whose presence in this set is to be tested

Returns:

true if this set contains the specified element

Throws:

ClassCastException - if the type of the specified element is incompatible with this set (optional)

NullPointerException - if the specified element is null and this set does not permit null elements (optional)

iterator

public Iterator<Triple> iterator()

Returns an iterator over the elements in this set. The elements are returned in no particular order (unless this set is an instance of some class that provides a guarantee).

Specified by:

iterator in interface Iterable<Triple extends org.openrdf.model.Statement>

Specified by:

iterator in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

iterator in interface Set<Triple extends org.openrdf.model.Statement>

Returns:

an iterator over the elements in this set

toArray

public Object[] toArray()

Returns an array containing all of the elements in this set. If this set makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.

The returned array will be "safe" in that no references to it are maintained by this set. (In other words, this method must allocate a new array even if this set is backed by an array). The caller is thus free to modify the returned array.

This method acts as bridge between array-based and collection-based APIs.

Specified by:

toArray in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

toArray in interface Set<Triple extends org.openrdf.model.Statement>

Returns:

an array containing all the elements in this set

toArray

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

Returns an array containing all of the elements in this set; the runtime type of the returned array is that of the specified array. If the set fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this set.

If this set fits in the specified array with room to spare (i.e., the array has more elements than this set), the element in the array immediately following the end of the set is set to null. (This is useful in determining the length of this set only if the caller knows that this set does not contain any null elements.)

If this set makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.

Like the toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.

Suppose x is a set known to contain only strings. The following code can be used to dump the set into a newly allocated array of String:

     String[] y = x.toArray(new String[0]);

Note that toArray(new Object[0]) is identical in function to toArray().

Specified by:

toArray in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

toArray in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

a - the array into which the elements of this set are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.

Returns:

an array containing all the elements in this set

Throws:

ArrayStoreException - if the runtime type of the specified array is not a supertype of the runtime type of every element in this set

NullPointerException - if the specified array is null

add

public boolean add(Triple triple)

Adds the specified element to this set if it is not already present (optional operation). More formally, adds the specified element e to this set if the set contains no element e2 such that (e==null ? e2==null : e.equals(e2)). If this set already contains the element, the call leaves the set unchanged and returns false. In combination with the restriction on constructors, this ensures that sets never contain duplicate elements.

The stipulation above does not imply that sets must accept all elements; sets may refuse to add any particular element, including null, and throw an exception, as described in the specification for Collection.add. Individual set implementations should clearly document any restrictions on the elements that they may contain.

Specified by:

add in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

add in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

triple - element to be added to this set

Returns:

true if this set did not already contain the specified element

Throws:

UnsupportedOperationException - if the add operation is not supported by this set

ClassCastException - if the class of the specified element prevents it from being added to this set

NullPointerException - if the specified element is null and this set does not permit null elements

IllegalArgumentException - if some property of the specified element prevents it from being added to this set

remove

public boolean remove(Object o)

Removes the specified element from this set if it is present (optional operation). More formally, removes an element e such that (o==null ? e==null : o.equals(e)), if this set contains such an element. Returns true if this set contained the element (or equivalently, if this set changed as a result of the call). (This set will not contain the element once the call returns.)

Specified by:

remove in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

remove in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

o - object to be removed from this set, if present

Returns:

true if this set contained the specified element

Throws:

ClassCastException - if the type of the specified element is incompatible with this set (optional)

NullPointerException - if the specified element is null and this set does not permit null elements (optional)

UnsupportedOperationException - if the remove operation is not supported by this set

containsAll

public boolean containsAll(Collection<?> c)

Returns true if this set contains all of the elements of the specified collection. If the specified collection is also a set, this method returns true if it is a subset of this set.

Specified by:

containsAll in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

containsAll in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

c - collection to be checked for containment in this set

Returns:

true if this set contains all of the elements of the specified collection

Throws:

ClassCastException - if the types of one or more elements in the specified collection are incompatible with this set (optional)

NullPointerException - if the specified collection contains one or more null elements and this set does not permit null elements (optional), or if the specified collection is null

See Also:

contains(Object)

addAll

public boolean addAll(Collection<? extends Triple> c)

Adds all of the elements in the specified collection to this set if they're not already present (optional operation). If the specified collection is also a set, the addAll operation effectively modifies this set so that its value is the union of the two sets. The behavior of this operation is undefined if the specified collection is modified while the operation is in progress.

Specified by:

addAll in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

addAll in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

c - collection containing elements to be added to this set

Returns:

true if this set changed as a result of the call

Throws:

UnsupportedOperationException - if the addAll operation is not supported by this set

ClassCastException - if the class of an element of the specified collection prevents it from being added to this set

NullPointerException - if the specified collection contains one or more null elements and this set does not permit null elements, or if the specified collection is null

IllegalArgumentException - if some property of an element of the specified collection prevents it from being added to this set

See Also:

Set.add(Object)

retainAll

public boolean retainAll(Collection<?> c)

Retains only the elements in this set that are contained in the specified collection (optional operation). In other words, removes from this set all of its elements that are not contained in the specified collection. If the specified collection is also a set, this operation effectively modifies this set so that its value is the intersection of the two sets.

Specified by:

retainAll in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

retainAll in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

c - collection containing elements to be retained in this set

Returns:

true if this set changed as a result of the call

Throws:

UnsupportedOperationException - if the retainAll operation is not supported by this set

ClassCastException - if the class of an element of this set is incompatible with the specified collection (optional)

NullPointerException - if this set contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null

See Also:

remove(Object)

removeAll

public boolean removeAll(Collection<?> c)

Removes from this set all of its elements that are contained in the specified collection (optional operation). If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.

Specified by:

removeAll in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

removeAll in interface Set<Triple extends org.openrdf.model.Statement>

Parameters:

c - collection containing elements to be removed from this set

Returns:

true if this set changed as a result of the call

Throws:

UnsupportedOperationException - if the removeAll operation is not supported by this set

ClassCastException - if the class of an element of this set is incompatible with the specified collection (optional)

NullPointerException - if this set contains a null element and the specified collection does not permit null elements (optional), or if the specified collection is null

See Also:

remove(Object), contains(Object)

clear

public void clear()

Removes all of the elements from this set (optional operation). The set will be empty after this call returns.

Specified by:

clear in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

clear in interface Set<Triple extends org.openrdf.model.Statement>

Throws:

UnsupportedOperationException - if the clear method is not supported by this set

listTriples

public Collection<Triple> listTriples(org.openrdf.model.Resource subject,
                             org.openrdf.model.URI property,
                             org.openrdf.model.Value object,
                             org.openrdf.model.Resource context,
                             boolean wildcardContext)

Return a subset of the triples matching the filter criteria. Arguments with null value are treated as wildcards.

Parameters:

subject -

property -

object -

context -

wildcardContext -

Returns:

listContextIDs

public Collection<org.openrdf.model.Resource> listContextIDs()

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

equals in interface Set<Triple extends org.openrdf.model.Statement>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<Triple extends org.openrdf.model.Statement>

Specified by:

hashCode in interface Set<Triple extends org.openrdf.model.Statement>

Overrides:

hashCode in class Object