org.openrdf.sail.nativerdf

Class ValueStore

java.lang.Object

org.openrdf.model.impl.ValueFactoryBase

org.openrdf.sail.nativerdf.ValueStore

All Implemented Interfaces:

ValueFactory

public class ValueStore
extends ValueFactoryBase

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 and Description
static int	NAMESPACE_CACHE_SIZE The default namespace cache size: 64.
static int	NAMESPACE_ID_CACHE_SIZE The default namespace id cache size: 32.
static int	VALUE_CACHE_SIZE The default value cache size: 512.
static int	VALUE_ID_CACHE_SIZE The default value id cache size: 128.

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Removes all values from the ValueStore.
void	close() Closes the ValueStore, releasing any file references, etc.
NativeBNode	createBNode(String nodeID)
NativeLiteral	createLiteral(String value)
NativeLiteral	createLiteral(String value, String language)
NativeLiteral	createLiteral(String value, URI datatype)
Statement	createStatement(Resource subject, URI predicate, Value object)
Statement	createStatement(Resource subject, URI predicate, Value object, Resource context)
NativeURI	createURI(String uri)
NativeURI	createURI(String namespace, String localName)
int	getID(Value value) Gets the ID for the specified value.
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)
NativeURI	getNativeURI(URI 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.
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.openrdf.model.impl.ValueFactoryBase

createBNode, createFPLiteral, createIntegerLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createLiteral, createNumericLiteral, initBNodeParams

Methods inherited from class java.lang.Object

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

Field Detail

VALUE_CACHE_SIZE

public static final int VALUE_CACHE_SIZE

The default value cache size: 512.

See Also:

Constant Field Values

VALUE_ID_CACHE_SIZE

public static final int VALUE_ID_CACHE_SIZE

The default value id cache size: 128.

See Also:

Constant Field Values

NAMESPACE_CACHE_SIZE

public static final int NAMESPACE_CACHE_SIZE

The default namespace cache size: 64.

See Also:

Constant Field Values

NAMESPACE_ID_CACHE_SIZE

public static final int NAMESPACE_ID_CACHE_SIZE

The default namespace id cache size: 32.

See Also:

Constant Field Values

Constructor Detail

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 Detail

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.

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.

createURI

public NativeURI createURI(String uri)

createURI

public NativeURI createURI(String namespace,
                  String localName)

createBNode

public NativeBNode createBNode(String nodeID)

createLiteral

public NativeLiteral createLiteral(String value)

createLiteral

public NativeLiteral createLiteral(String value,
                          String language)

createLiteral

public NativeLiteral createLiteral(String value,
                          URI datatype)

createStatement

public Statement createStatement(Resource subject,
                        URI predicate,
                        Value object)

createStatement

public Statement createStatement(Resource subject,
                        URI predicate,
                        Value object,
                        Resource context)

getNativeValue

public NativeValue getNativeValue(Value value)

getNativeResource

public NativeResource getNativeResource(Resource resource)

getNativeURI

public NativeURI getNativeURI(URI 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