com.bigdata.rdf.lexicon

Class RDFFullTextIndexTupleSerializer

java.lang.Object

com.bigdata.btree.DefaultTupleSerializer<ITermDocKey,ITermDocVal>

com.bigdata.rdf.lexicon.RDFFullTextIndexTupleSerializer

All Implemented Interfaces:

ITupleSerializer<ITermDocKey,ITermDocVal>, IKeyBuilderFactory, Externalizable, Serializable

public class RDFFullTextIndexTupleSerializer
extends DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Replaces the FullTextIndexTupleSerializer to support IVs as document identifiers.

Since IVs have a variable length encoding we have to indicate the length of the IV either in the key or the value of the ITuple . I've put this information into the value side of the tuple in order to keep the key format simpler.

Note: The RDF database does not make use of the "field" concept in the keys of the full text index. The fieldId will always be reported as -1.

Version:

$Id$

Author:

Bryan Thompson

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
RDFFullTextIndexTupleSerializer() De-serialization constructor.
RDFFullTextIndexTupleSerializer(IKeyBuilderFactory keyBuilderFactory, IRabaCoder leafKeysCoder, IRabaCoder leafValsCoder, boolean fieldsEnabled)

Method Summary

Methods

Modifier and Type	Method and Description
ITermDocRecord	deserialize(ITuple tuple) De-serializes an object from the value stored in the tuple (ignores the key stored in the tuple).
protected ITermDocKey	deserialize(ITuple tuple, boolean keyOnly)
ITermDocKey	deserializeKey(ITuple tuple) This is an unsupported operation.
void	readExternal(ObjectInput in)
byte[]	serializeKey(Object obj) Serialize a facet of an object's state that places the object into the total sort order for the index.
byte[]	serializeVal(ITermDocVal obj) Serializes the object as a byte[] using Java default serialization.
void	writeExternal(ObjectOutput out)

Methods inherited from class com.bigdata.btree.DefaultTupleSerializer

getDefaultKeyBuilderFactory, getDefaultLeafKeysCoder, getDefaultValuesCoder, getKeyBuilder, getLeafKeysCoder, getLeafValuesCoder, getPrimaryKeyBuilder, newInstance, setLeafKeysCoder, setLeafValuesCoder, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

RDFFullTextIndexTupleSerializer

public RDFFullTextIndexTupleSerializer()

De-serialization constructor.

RDFFullTextIndexTupleSerializer

public RDFFullTextIndexTupleSerializer(IKeyBuilderFactory keyBuilderFactory,
                               IRabaCoder leafKeysCoder,
                               IRabaCoder leafValsCoder,
                               boolean fieldsEnabled)

Parameters:

keyBuilderFactory - This factory governs the Unicode collation order that will be imposed on the indexed tokens.

leafKeysCoder - The coder used for the leaf keys (prefix coding is fine).

leafValsCoder - The coder used for the leaf values (custom coding may provide tighter representations of the ITermDocVal s in the index entries).

fieldsEnabled - When true the fieldId will be included as a component in the generated key. When false it will not be present in the generated key.

Method Detail

serializeKey

public byte[] serializeKey(Object obj)

Description copied from interface: ITupleSerializer

Serialize a facet of an object's state that places the object into the total sort order for the index. This method is automatically applied by IAutoboxBTree.insert(Object, Object) and friends to convert the key object into an unsigned variable length byte[].

Note: This handles the conversion between an object and the unsigned variable length byte[] representation of that object which determines its place within the total index order. Since this transform imposes the total order of the index, different techniques are applied here than are applied to the serialization of the index values.

Specified by:

serializeKey in interface ITupleSerializer<ITermDocKey,ITermDocVal>

Overrides:

serializeKey in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Parameters:

obj - A object (MAY NOT be null).

Returns:

An unsigned byte[] which places the object into the total sort order for the index and never null ( null keys are not allowed into an index).

serializeVal

public byte[] serializeVal(ITermDocVal obj)

Description copied from class: DefaultTupleSerializer

Serializes the object as a byte[] using Java default serialization.

Specified by:

serializeVal in interface ITupleSerializer<ITermDocKey,ITermDocVal>

Overrides:

serializeVal in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Parameters:

obj - The object to be serialized (MAY be null).

Returns:

The serialized representation of the object as a byte[] -or- null if the reference is null.

deserializeKey

public ITermDocKey deserializeKey(ITuple tuple)

Description copied from class: DefaultTupleSerializer

This is an unsupported operation. Additional information is required to either decode the internal unsigned byte[] keys or to extract the key from the de-serialized value (if it is being stored in that value). You can either write your own ITupleSerializer or you can specialize this one so that it can de-serialize your keys using whichever approach makes the most sense for your data.

Specified by:

deserializeKey in interface ITupleSerializer<ITermDocKey,ITermDocVal>

Overrides:

deserializeKey in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

deserialize

public ITermDocRecord deserialize(ITuple tuple)

Description copied from class: DefaultTupleSerializer

De-serializes an object from the value stored in the tuple (ignores the key stored in the tuple).

Specified by:

deserialize in interface ITupleSerializer<ITermDocKey,ITermDocVal>

Overrides:

deserialize in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Parameters:

tuple - The tuple.

Returns:

The de-serialized object.

deserialize

protected ITermDocKey deserialize(ITuple tuple,
                      boolean keyOnly)

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class DefaultTupleSerializer<ITermDocKey,ITermDocVal>

Throws:

IOException