com.bigdata.rdf.internal.impl.bnode

Class SidIV<V extends BigdataBNode>

java.lang.Object

com.bigdata.rdf.internal.impl.AbstractIV<V,T>

com.bigdata.rdf.internal.impl.AbstractInlineIV<V,ISPO>

com.bigdata.rdf.internal.impl.bnode.SidIV<V>

All Implemented Interfaces:

IV<V,ISPO>, IVCache<V,ISPO>, Serializable, Comparable<IV>, org.openrdf.model.BNode, org.openrdf.model.Resource, org.openrdf.model.Value

public class SidIV<V extends BigdataBNode>
extends AbstractInlineIV<V,ISPO>
implements Serializable, org.openrdf.model.BNode

Internal value representing an inline statement identifier. Uses the ISPO supplied in the ctor as the inline value. The #asValue(BigdataValueFactory, ILexiconConfiguration) method returns a BigdataBNode that is used to represent the sid in serialization formats (such as the custom RDF/XML extension for sids). The bnode is guaranteed to always have the same bnode id for a given inlined SPO. This is accomplished using the byte[] key encoding for the spo along with the BigInteger class.

This internal value has a VTE of VTE.STATEMENT. It is encoded into the statement indices by directly encoding the spo using SPOKeyOrder.encodeKey(IKeyBuilder, ISPO) via the SPOKeyOrder.SPO key order. Thus when decoded from the statement indices, the spo associated with this sid is materialized directly from the sid itself. See IVUtility.decode(byte[]). The spo decoded from the sid IV will be marked as explicit (only explicit statements have sids) and this SidIV will be attached to it. This completely eliminates the need for a reverse index from sid->spo, as the spo is encoded inline into the SidIV itself. This replaces the TermId model for representing sids.

See Also:

Serialized Form

Field Summary

Fields inherited from class com.bigdata.rdf.internal.impl.AbstractIV

flags

Constructor Summary

Constructors

Constructor and Description
SidIV(ISPO spo) Ctor with internal value spo specified.

Method Summary

Methods

Modifier and Type	Method and Description
int	_compareTo(IV o) Compare two IVs having the same intrinsic datatype.
V	asValue(LexiconRelation lex) Returns the bnode representation of this IV, useful for serialization formats such as RDF/XML.
int	byteLength() Return the byte length for the byte[] encoded representation of this internal value.
IV<V,ISPO>	clone(boolean clearCache) Return a copy of this IV.
IKeyBuilder	encode(IKeyBuilder keyBuilder) Encode this internal value into the supplied key builder.
boolean	equals(Object o) Two SidIV are equal if their (s,p,o) IVs are equal.
String	getID() Implements BNode.getID().
ISPO	getInlineValue() Returns the inline spo.
int	hashCode() Return a hash code based on the value of the point in the value space.
boolean	needsMaterialization() Does not need materialization to answer BNode interface methods.
String	stringValue() Implements Value.stringValue().
static byte	toFlags() Return the flags byte for a SidIV.
String	toString()

Methods inherited from class com.bigdata.rdf.internal.impl.AbstractInlineIV

isInline

Methods inherited from class com.bigdata.rdf.internal.impl.AbstractIV

compareTo, flags, getDTE, getDTE, getDTEX, getInternalValueTypeEnum, getValue, getValueCache, getVTE, getVTE, hasValue, isBigNumeric, isBNode, isExtension, isExtension, isFixedNumeric, isFloatingPointNumeric, isInline, isLiteral, isNullIV, isNumeric, isResource, isSignedNumeric, isStatement, isUnsignedNumeric, isURI, isVocabulary, setValue, toFlags

Methods inherited from class java.lang.Object

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

Constructor Detail

SidIV

public SidIV(ISPO spo)

Ctor with internal value spo specified.

Method Detail

clone

public IV<V,ISPO> clone(boolean clearCache)

Description copied from interface: IVCache

Return a copy of this IV.

Note: This method exists to defeat the hard reference from the IV to the cached BigdataValue in order to avoid a memory leak when the IV is used as the key in a weak value cache whose value is the BigdataValue. Therefore, certain IV implementations MAY return this when they are used for limited collections. The vocabulary IVs are the primary example. For the same reason, we do not need to recursively break the link from the IV to the BigdataValue for IVs which embed other IVs.

Specified by:

clone in interface IVCache<V extends BigdataBNode,ISPO>

Parameters:

clearCache - When true the cached reference (if any) will NOT be set on the copy.

Returns:

The copy.

See Also:

(Thread-local cache combined with unbounded thread pools causes effective memory leak)

toFlags

public static final byte toFlags()

Return the flags byte for a SidIV.

getInlineValue

public ISPO getInlineValue()
                    throws UnsupportedOperationException

Returns the inline spo.

Specified by:

getInlineValue in interface IV<V extends BigdataBNode,ISPO>

Returns:

The Object.

Throws:

UnsupportedOperationException - unless the RDF value is inline.

asValue

public V asValue(LexiconRelation lex)

Returns the bnode representation of this IV, useful for serialization formats such as RDF/XML. See #bnodeId().

Specified by:

asValue in interface IVCache<V extends BigdataBNode,ISPO>

Parameters:

lex - The lexicon relation (this is required in order to access the BigdataValueFactory for the namespace associated with lexicon when we materialize an inline IV).

Returns:

The corresponding BigdataValue.

byteLength

public int byteLength()

Return the byte length for the byte[] encoded representation of this internal value. Depends on the byte length of the encoded inline spo.

Specified by:

byteLength in interface IV<V extends BigdataBNode,ISPO>

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Description copied from class: AbstractIV

Return a hash code based on the value of the point in the value space.

Note: The IV implementations typically DO NOT return hash codes that are consistent with BigdataValue#hashCode(). Therefore you MUST NOT mix IVs and BigdataValues in the keys of a map or the values of a set.

Specified by:

hashCode in interface org.openrdf.model.BNode

Specified by:

hashCode in class AbstractIV<V extends BigdataBNode,ISPO>

getID

public String getID()

Implements BNode.getID().

This implementation uses the BigInteger class to create a unique blank node ID based on the unsigned byte[] key of the inline SPO.

Specified by:

getID in interface org.openrdf.model.BNode

equals

public boolean equals(Object o)

Two SidIV are equal if their (s,p,o) IVs are equal.

Specified by:

equals in interface org.openrdf.model.BNode

Specified by:

equals in class AbstractIV<V extends BigdataBNode,ISPO>

_compareTo

public int _compareTo(IV o)

Description copied from class: AbstractIV

Compare two IVs having the same intrinsic datatype.

Specified by:

_compareTo in class AbstractIV<V extends BigdataBNode,ISPO>

encode

public IKeyBuilder encode(IKeyBuilder keyBuilder)

Encode this internal value into the supplied key builder. Emits the flags, following by the encoded byte[] representing the spo, in SPO key order.

Encode the IV as an unsigned byte[].

Specified by:

encode in interface IV<V extends BigdataBNode,ISPO>

Overrides:

encode in class AbstractIV<V extends BigdataBNode,ISPO>

Parameters:

keyBuilder - The object used to encode the IV.

Returns:

the key builder

stringValue

public String stringValue()

Implements Value.stringValue().

Specified by:

stringValue in interface org.openrdf.model.Value

needsMaterialization

public boolean needsMaterialization()

Does not need materialization to answer BNode interface methods.

Specified by:

needsMaterialization in interface IV<V extends BigdataBNode,ISPO>