Package org.eclipse.rdf4j.sail.nativerdf

Class ValueStore

java.lang.Object

org.eclipse.rdf4j.model.base.AbstractValueFactory

org.eclipse.rdf4j.model.impl.SimpleValueFactory

org.eclipse.rdf4j.sail.nativerdf.ValueStore

All Implemented Interfaces:

ValueFactory

@InternalUseOnly
public class ValueStore
extends SimpleValueFactory

File-based indexed storage and retrieval of RDF values. ValueStore maps RDF values to integer IDs and vice-versa.

Author:

Arjohn Kampman

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NAMESPACE_CACHE_SIZE	The default namespace cache size.
static final int	NAMESPACE_ID_CACHE_SIZE	The default namespace id cache size.
static final int	VALUE_CACHE_SIZE	The default value cache size.
static final int	VALUE_ID_CACHE_SIZE	The default value id cache size.

Constructor Summary

Constructors

Constructor	Description
ValueStore(File dataDir)
ValueStore(File dataDir, boolean forceSync)
ValueStore(File dataDir, boolean forceSync, int valueCacheSize, int valueIDCacheSize, int namespaceCacheSize, int namespaceIDCacheSize)

Method Summary

Modifier and Type	Method	Description
void	checkConsistency()	Checks that every value has exactly one ID.
void	clear()	Removes all values from the ValueStore.
void	close()	Closes the ValueStore, releasing any file references, etc.
NativeBNode	createBNode(String nodeID)	Creates a new blank node with the given node identifier.
NativeIRI	createIRI(String uri)	Creates a new IRI from the supplied string-representation.
NativeIRI	createIRI(String namespace, String localName)	Creates a new IRI from the supplied namespace and local name.
NativeLiteral	createLiteral(String value)	Creates a new literal with the supplied label.
NativeLiteral	createLiteral(String value, String language)	Creates a new literal with the supplied label and language attribute.
NativeLiteral	createLiteral(String value, IRI datatype)	Creates a new literal with the supplied label and datatype.
int	getID(Value value)	Gets the ID for the specified value.
<T extends NativeValue & IRI> T	getIRI(int id)	Gets the IRI for the specified ID.
NativeBNode	getNativeBNode(BNode bnode)	Creates a NativeBNode that is equal to the supplied bnode.
NativeLiteral	getNativeLiteral(Literal l)	Creates an NativeLiteral that is equal to the supplied literal.
NativeResource	getNativeResource(Resource resource)
NativeIRI	getNativeURI(IRI uri)	Creates a NativeURI that is equal to the supplied URI.
NativeValue	getNativeValue(Value value)
Lock	getReadLock()	Gets a read lock on this value store that can be used to prevent values from being removed while the lock is active.
<T extends NativeValue & Resource> T	getResource(int id)	Gets the Resource for the specified ID.
ValueStoreRevision	getRevision()
NativeValue	getValue(int id)	Gets the value for the specified ID.
static void	main(String[] args)
int	storeValue(Value value)	Stores the supplied value and returns the ID that has been assigned to it.
void	sync()	Synchronizes any changes that are cached in memory to disk.

Methods inherited from class org.eclipse.rdf4j.model.impl.SimpleValueFactory

createBNode, createFPLiteral, createFPLiteral, createIntegerLiteral, createIntegerLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createNumericLiteral, createNumericLiteral, createStatement, createStatement, createTriple, getInstance

Methods inherited from class org.eclipse.rdf4j.model.base.AbstractValueFactory

createLiteral, createLiteral, createLiteral, createLiteral

Methods inherited from class java.lang.Object

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

Field Details

VALUE_CACHE_SIZE

public static final int VALUE_CACHE_SIZE

The default value cache size.

See Also:

• Constant Field Values

VALUE_ID_CACHE_SIZE

public static final int VALUE_ID_CACHE_SIZE

The default value id cache size.

See Also:

• Constant Field Values

NAMESPACE_CACHE_SIZE

public static final int NAMESPACE_CACHE_SIZE

The default namespace cache size.

See Also:

• Constant Field Values

NAMESPACE_ID_CACHE_SIZE

public static final int NAMESPACE_ID_CACHE_SIZE

The default namespace id cache size.

See Also:

• Constant Field Values

Constructor Details

ValueStore

public ValueStore(File dataDir)
           throws IOException

Throws:

IOException

ValueStore

public ValueStore(File dataDir,
 boolean forceSync)
           throws IOException

Throws:

IOException

ValueStore

public ValueStore(File dataDir,
 boolean forceSync,
 int valueCacheSize,
 int valueIDCacheSize,
 int namespaceCacheSize,
 int namespaceIDCacheSize)
           throws IOException

Throws:

IOException

Method Details

getRevision

public ValueStoreRevision getRevision()

getReadLock

public Lock getReadLock()
                 throws InterruptedException

Gets a read lock on this value store that can be used to prevent values from being removed while the lock is active.

Throws:

InterruptedException

getValue

public NativeValue getValue(int id)
                     throws IOException

Gets the value for the specified ID.

Parameters:

id - A value ID.

Returns:

The value for the ID, or null no such value could be found.

Throws:

IOException - If an I/O error occurred.

getResource

public <T extends NativeValue & Resource> T getResource(int id)
                                                 throws IOException

Gets the Resource for the specified ID.

Parameters:

id - A value ID.

Returns:

The Resource for the ID, or null no such value could be found.

Throws:

IOException - If an I/O error occurred.

getIRI

public <T extends NativeValue & IRI> T getIRI(int id)
                                       throws IOException

Gets the IRI for the specified ID.

Parameters:

id - A value ID.

Returns:

The IRI for the ID, or null no such value could be found.

Throws:

IOException - If an I/O error occurred.

getID

public int getID(Value value)
          throws IOException

Gets the ID for the specified value.

Parameters:

value - A value.

Returns:

The ID for the specified value, or NativeValue.UNKNOWN_ID if no such ID could be found.

Throws:

IOException - If an I/O error occurred.

storeValue

public int storeValue(Value value)
               throws IOException

Stores the supplied value and returns the ID that has been assigned to it. In case the value was already present, the value will not be stored again and the ID of the existing value is returned.

Parameters:

value - The Value to store.

Returns:

The ID that has been assigned to the value.

Throws:

IOException - If an I/O error occurred.

clear

public void clear()
           throws IOException

Removes all values from the ValueStore.

Throws:

IOException - If an I/O error occurred.

sync

public void sync()
          throws IOException

Synchronizes any changes that are cached in memory to disk.

Throws:

IOException - If an I/O error occurred.

close

public void close()
           throws IOException

Closes the ValueStore, releasing any file references, etc. Once closed, the ValueStore can no longer be used.

Throws:

IOException - If an I/O error occurred.

checkConsistency

public void checkConsistency()
                      throws SailException,
IOException

Checks that every value has exactly one ID.

Throws:

IOException

SailException

createIRI

public NativeIRI createIRI(String uri)

Description copied from interface: ValueFactory

Creates a new IRI from the supplied string-representation.

Specified by:

createIRI in interface ValueFactory

Overrides:

createIRI in class SimpleValueFactory

Parameters:

uri - A string-representation of a IRI.

Returns:

An object representing the IRI.

createIRI

public NativeIRI createIRI(String namespace,
 String localName)

Description copied from interface: ValueFactory

Creates a new IRI from the supplied namespace and local name. Calling this method is funtionally equivalent to calling createIRI(namespace+localName), but allows the ValueFactory to reuse supplied namespace and local name strings whenever possible. Note that the values returned by IRI.getNamespace() and IRI.getLocalName() are not necessarily the same as the values that are supplied to this method.

Specified by:

createIRI in interface ValueFactory

Overrides:

createIRI in class SimpleValueFactory

Parameters:

namespace - The IRI's namespace.

localName - The IRI's local name.

createBNode

public NativeBNode createBNode(String nodeID)

Description copied from interface: ValueFactory

Creates a new blank node with the given node identifier.

Specified by:

createBNode in interface ValueFactory

Overrides:

createBNode in class SimpleValueFactory

Parameters:

nodeID - The blank node identifier.

Returns:

An object representing the blank node.

createLiteral

public NativeLiteral createLiteral(String value)

Description copied from interface: ValueFactory

Creates a new literal with the supplied label. The return value of Literal.getDatatype() for the returned object must be xsd:string.

Specified by:

createLiteral in interface ValueFactory

Overrides:

createLiteral in class SimpleValueFactory

Parameters:

value - The literal's label, must not be null.

Returns:

A literal for the specified value.

createLiteral

public NativeLiteral createLiteral(String value,
 String language)

Description copied from interface: ValueFactory

Creates a new literal with the supplied label and language attribute. The return value of Literal.getDatatype() for the returned object must be rdf:langString.

Specified by:

createLiteral in interface ValueFactory

Overrides:

createLiteral in class SimpleValueFactory

Parameters:

value - The literal's label, must not be null.

language - The literal's language attribute, must not be null.

Returns:

A literal for the specified value and language attribute.

createLiteral

public NativeLiteral createLiteral(String value,
 IRI datatype)

Description copied from interface: ValueFactory

Creates a new literal with the supplied label and datatype.

Specified by:

createLiteral in interface ValueFactory

Overrides:

createLiteral in class SimpleValueFactory

Parameters:

value - The literal's label, must not be null.

datatype - The literal's datatype. If it is null, the datatype xsd:string will be assigned to this literal.

Returns:

A literal for the specified value and type.

getNativeValue

public NativeValue getNativeValue(Value value)

getNativeResource

public NativeResource getNativeResource(Resource resource)

getNativeURI

public NativeIRI getNativeURI(IRI uri)

Creates a NativeURI that is equal to the supplied URI. This method returns the supplied URI itself if it is already a NativeURI that has been created by this ValueStore, which prevents unnecessary object creations.

Returns:

A NativeURI for the specified URI.

getNativeBNode

public NativeBNode getNativeBNode(BNode bnode)

Creates a NativeBNode that is equal to the supplied bnode. This method returns the supplied bnode itself if it is already a NativeBNode that has been created by this ValueStore, which prevents unnecessary object creations.

Returns:

A NativeBNode for the specified bnode.

getNativeLiteral

public NativeLiteral getNativeLiteral(Literal l)

Creates an NativeLiteral that is equal to the supplied literal. This method returns the supplied literal itself if it is already a NativeLiteral that has been created by this ValueStore, which prevents unnecessary object creations.

Returns:

A NativeLiteral for the specified literal.

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception