com.bigdata.rdf.model
Class BNodeContextFactory

java.lang.Object
  com.bigdata.rdf.model.BNodeContextFactory

All Implemented Interfaces:

BigdataValueFactory, ValueFactory

public class BNodeContextFactory
extends Object
implements BigdataValueFactory

Class provides a document-scoped context for generating blank node identifiers (IDs). This class is intended for use to generate blank node identifiers (IDs) for a source document within a shared prefix. When that prefix is mapped onto the term2id index, all blank nodes for the same source document will tend to be mapped onto the same index partition (this is more efficient since the ordered writes are more local). The prefix itself is a UUID, which is how we ensure that blank nodes generated for different sources are understood as distinct blank nodes by the database (this is required).

Note: All BigdataValue instances are in fact created by the delegate instances created by this class and by the delegate will appear to have been created by the same factory. This is intentional - it makes the instances reusable by the base factory.

Note: nextID() is NOT thread-safe, but different documents that are being passed concurrently will have a distinct instance of this factory and processing a single document is generally single-threaded.

Version:

$Id: BNodeContextFactory.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

Method Summary

BigdataBNode	asValue(BNode v) Strongly typed for BNodes.
BigdataLiteral	asValue(Literal v) Strongly typed for Literals.
BigdataResource	asValue(Resource v) Strongly typed for Resources.
BigdataURI	asValue(URI v) Strongly typed for URIs.
BigdataValue	asValue(Value v) Converts a Value into a BigdataValue.
BigdataBNodeImpl	createBNode()
BigdataBNodeImpl	createBNode(String id)
BigdataLiteralImpl	createLiteral(boolean arg0)
BigdataLiteralImpl	createLiteral(byte arg0)
BigdataLiteralImpl	createLiteral(double arg0)
BigdataLiteralImpl	createLiteral(float arg0)
BigdataLiteralImpl	createLiteral(int arg0)
BigdataLiteralImpl	createLiteral(long arg0)
BigdataLiteralImpl	createLiteral(short arg0)
BigdataLiteralImpl	createLiteral(String label)
BigdataLiteralImpl	createLiteral(String label, String language)
BigdataLiteralImpl	createLiteral(String label, URI datatype)
BigdataLiteralImpl	createLiteral(XMLGregorianCalendar arg0)
BigdataStatementImpl	createStatement(Resource s, URI p, Value o) Create a statement whose StatementEnum is NOT specified.
BigdataStatementImpl	createStatement(Resource s, URI p, Value o, Resource c) Create a statement whose StatementEnum is NOT specified.
BigdataStatementImpl	createStatement(Resource s, URI p, Value o, Resource c, StatementEnum type) Create a statement (core impl).
BigdataURIImpl	createURI(String uriString)
BigdataURIImpl	createURI(String namespace, String localName)
BigdataValueSerializer<BigdataValue>	getValueSerializer() An object that can efficiently (de-)serialize Values using this ValueFactory.
BigdataValueFactory	newBNodeContext() Recursive contexts are not available (should not be necessary, right?)
protected String	nextID() A globally unique blank node identifier (ID) created with prefix shared by all blank nodes whose identifers are generated by this class.

Methods inherited from class java.lang.Object

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

Method Detail

nextID

protected String nextID()

A globally unique blank node identifier (ID) created with prefix shared by all blank nodes whose identifers are generated by this class.

createBNode

public BigdataBNodeImpl createBNode()

Specified by:

createBNode in interface BigdataValueFactory

Specified by:

createBNode in interface ValueFactory

asValue

public BigdataValue asValue(Value v)

Description copied from interface: BigdataValueFactory

Converts a Value into a BigdataValue. If the value is already a BigdataValue and it was allocated by this BigdataValueFactoryImpl then it is returned unchanged. Otherwise a new BigdataValue will be creating using the same data as the given value and the term identifier on the new BigdataValue will be initialized to IRawTripleStore.NULL.

All BigdataValues created by a BigdataValueFactoryImpl internally store a transient reference to the BigdataValueFactoryImpl. This reference is used to decide if a BigdataValue MIGHT have been created by a different lexicon (term identifiers generated by different lexicons CAN NOT be used interchangably). This has the effect of protecting against incorrect use of the term identifier with a database backed by a different lexicon while allowing reuse of the BigdataValues when possible.

Specified by:

asValue in interface BigdataValueFactory

Parameters:

v - The value.

Returns:

A BigdataValue with the same data. If the value is null then null is returned.

createBNode

public BigdataBNodeImpl createBNode(String id)

Specified by:

createBNode in interface BigdataValueFactory

Specified by:

createBNode in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(boolean arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(byte arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(double arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(float arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(int arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(long arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(short arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(String label,
                                        String language)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(String label,
                                        URI datatype)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(String label)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createLiteral

public BigdataLiteralImpl createLiteral(XMLGregorianCalendar arg0)

Specified by:

createLiteral in interface BigdataValueFactory

Specified by:

createLiteral in interface ValueFactory

createStatement

public BigdataStatementImpl createStatement(Resource s,
                                            URI p,
                                            Value o)

Description copied from interface: BigdataValueFactory

Create a statement whose StatementEnum is NOT specified.

Specified by:

createStatement in interface BigdataValueFactory

Specified by:

createStatement in interface ValueFactory

createStatement

public BigdataStatementImpl createStatement(Resource s,
                                            URI p,
                                            Value o,
                                            Resource c)

Description copied from interface: BigdataValueFactory

Create a statement whose StatementEnum is NOT specified.

Specified by:

createStatement in interface BigdataValueFactory

Specified by:

createStatement in interface ValueFactory

createStatement

public BigdataStatementImpl createStatement(Resource s,
                                            URI p,
                                            Value o,
                                            Resource c,
                                            StatementEnum type)

Description copied from interface: BigdataValueFactory

Create a statement (core impl). The s,p,o, and the optional c arguments will be normalized to this BigdataValueFactory using BigdataValueFactory.asValue(Value).

Specified by:

createStatement in interface BigdataValueFactory

Parameters:

s - The subject.

p - The predicate.

o - The object.

c - The context (optional). Note: When non-null and statement identifiers are enabled, then this will be a blank node whose term identifier is the statement identifier.

type - The statement type (optional).

createURI

public BigdataURIImpl createURI(String namespace,
                                String localName)

Specified by:

createURI in interface BigdataValueFactory

Specified by:

createURI in interface ValueFactory

createURI

public BigdataURIImpl createURI(String uriString)

Specified by:

createURI in interface BigdataValueFactory

Specified by:

createURI in interface ValueFactory

getValueSerializer

public BigdataValueSerializer<BigdataValue> getValueSerializer()

Description copied from interface: BigdataValueFactory

An object that can efficiently (de-)serialize Values using this ValueFactory. When the values are de-serialized they will have a reference to this BigdataValueFactoryImpl. That reference can be used to identify when two BigdataValues MIGHT be from different lexicons.

Specified by:

getValueSerializer in interface BigdataValueFactory

Returns:

newBNodeContext

public BigdataValueFactory newBNodeContext()

Recursive contexts are not available (should not be necessary, right?)

Specified by:

newBNodeContext in interface BigdataValueFactory

See Also:

BNodeContextFactory

asValue

public BigdataResource asValue(Resource v)

Description copied from interface: BigdataValueFactory

Strongly typed for Resources.

Specified by:

asValue in interface BigdataValueFactory

asValue

public BigdataURI asValue(URI v)

Description copied from interface: BigdataValueFactory

Strongly typed for URIs.

Specified by:

asValue in interface BigdataValueFactory

asValue

public BigdataLiteral asValue(Literal v)

Description copied from interface: BigdataValueFactory

Strongly typed for Literals.

Specified by:

asValue in interface BigdataValueFactory

asValue

public BigdataBNode asValue(BNode v)

Description copied from interface: BigdataValueFactory

Strongly typed for BNodes.

Specified by:

asValue in interface BigdataValueFactory