com.bigdata.rdf.internal.encoder

Interface IBindingSetEncoder

All Known Implementing Classes:

IVBindingSetEncoder, IVBindingSetEncoderWithIVCache, IVSolutionSetEncoder

public interface IBindingSetEncoder

Interface for encoding IBindingSets comprised of IVs. The interface is slightly more complicated than it otherwise would be due to (a) IVCache and (b) the need to vector operations.

Encoding schemes tend to rely on IVUtility to provide fast and efficient encode / decode. This is the same representation which is used in the statement indices.

The IVCache interface may be used to associate a materialized BigdataValue with an IV. In order to have efficient encode / decode of IVs which preserves the IVCache information, the encoding scheme also needs to store this association somewhere.

Encoders designed for the wire should store the IVCache association in an inline representation. Encoders designed for main memory (for example, vectored operations in hash joins) can use persistence capable data structures to store the IVCache association.

Version:

$Id$

Author:

Bryan Thompson

See Also:

IBindingSetDecoder

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	encodeSolution(IBindingSet bset) Encode the solution as an IV[], collecting updates for the internal IV to BigdataValue cache.
byte[]	encodeSolution(IBindingSet bset, boolean updateCache) Encode the solution as an IV[].
void	flush() Flush any updates.
boolean	isValueCache() Return true iff the IVCache associations are preserved by the encoder.
void	release() Release the state associated with the IVBindingSetEncoder.

Method Detail

isValueCache

boolean isValueCache()

Return true iff the IVCache associations are preserved by the encoder.

encodeSolution

byte[] encodeSolution(IBindingSet bset)

Encode the solution as an IV[], collecting updates for the internal IV to BigdataValue cache.

Parameters:

bset - The solution to be encoded.

Returns:

The encoded solution.

encodeSolution

byte[] encodeSolution(IBindingSet bset,
                    boolean updateCache)

Encode the solution as an IV[].

Note: The IVCache associations may be buffered by this method. Use flush() to vector any buffered associations.

Parameters:

bset - The solution to be encoded.

updateCache - When true, updates are accumulated for the IV to BigdataValue cache. You must still use flush() to vector the accumulated updates.

If you are only generating the encoding in order to resolve a key in a hash index, then you would use false since you do not need to maintain the IVCache association for the given IBindingSet.

Returns:

The encoded solution.

flush

void flush()

Flush any updates. This allows for vectored operations when updating the IVCache associations.

release

void release()

Release the state associated with the IVBindingSetEncoder.