org.apache.asterix.metadata.api

Interface IValueExtractor<T>

All Known Implementing Classes:

DatasetNameValueExtractor, DatatypeNameValueExtractor, MetadataEntityValueExtractor, NestedDatatypeNameValueExtractor, TupleCopyValueExtractor

public interface IValueExtractor<T>

Extracts an object of type T from a given tuple. Implementations of this interface are used for extracting specific fields of metadata records within the metadata node. The intention is to have a single transactional search procedure than can deliver different objects based on the type of value extractor passed to the search procedure.

Method Summary

Methods

Modifier and Type	Method and Description
T	getValue(JobId jobId, org.apache.hyracks.dataflow.common.data.accessors.ITupleReference tuple) Extracts an object of type T from a given tuple.

Method Detail

getValue

T getValue(JobId jobId,
         org.apache.hyracks.dataflow.common.data.accessors.ITupleReference tuple)
           throws MetadataException,
                  org.apache.hyracks.api.exceptions.HyracksDataException,
                  IOException

Extracts an object of type T from a given tuple.

Parameters:

jobId - A globally unique transaction id.

tuple - Tuple from which an object shall be extracted.

Returns:

New object of type T.

Throws:

MetadataException

org.apache.hyracks.api.exceptions.HyracksDataException

IOException