org.apache.drill.exec.physical.resultSet.model.single

Class SimpleReaderBuilder

java.lang.Object

org.apache.drill.exec.physical.resultSet.model.ReaderBuilder

org.apache.drill.exec.physical.resultSet.model.single.SimpleReaderBuilder

public class SimpleReaderBuilder
extends ReaderBuilder

Builds a set of readers for a single (non-hyper) batch. Single batches are indexed directly or via a simple indirection vector.

Derived classes handle the details of the various kinds of readers. Today there is a single subclass that builds (test-time) RowSet objects. The idea, however, is that we may eventually want to create a "result set reader" for use in internal operators, in parallel to the "result set loader". The result set reader would handle a stream of incoming batches. The extant RowSet class handles just one batch (the batch that is returned from a test.)

Readers are built recursively by walking the tree that defines a row's structure. For a classic relational tuple, the tree has just a root and a set of primitives. But, once we add array (repeated), variant (LIST, UNION) and tuple (MAP) columns, the tree grows quite complex.

Method Summary

Modifier and Type	Method and Description
static RowSetReaderImpl	build(BatchAccessor batch)
static RowSetReaderImpl	build(VectorContainer container, ReaderIndex rowIndex)
static RowSetReaderImpl	build(VectorContainer container, TupleMetadata schema, ReaderIndex rowIndex)
List<AbstractObjectReader>	buildContainerChildren(VectorContainer container, MetadataProvider mdProvider)
protected List<AbstractObjectReader>	buildMapMembers(AbstractMapVector mapVector, MetadataProvider provider)
protected AbstractObjectReader	buildVectorReader(ValueVector vector, MetadataProvider.VectorDescrip descrip)
static ReaderIndex	readerIndex(BatchAccessor batch)

Methods inherited from class org.apache.drill.exec.physical.resultSet.model.ReaderBuilder

buildReader, buildScalarReader

Methods inherited from class java.lang.Object

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

Method Detail

build

public static RowSetReaderImpl build(VectorContainer container,
                                     TupleMetadata schema,
                                     ReaderIndex rowIndex)

build

public static RowSetReaderImpl build(VectorContainer container,
                                     ReaderIndex rowIndex)

build

public static RowSetReaderImpl build(BatchAccessor batch)

readerIndex

public static ReaderIndex readerIndex(BatchAccessor batch)

buildContainerChildren

public List<AbstractObjectReader> buildContainerChildren(VectorContainer container,
                                                         MetadataProvider mdProvider)

buildVectorReader

protected AbstractObjectReader buildVectorReader(ValueVector vector,
                                                 MetadataProvider.VectorDescrip descrip)

buildMapMembers

protected List<AbstractObjectReader> buildMapMembers(AbstractMapVector mapVector,
                                                     MetadataProvider provider)