org.apache.drill.exec.vector.accessor.reader

Class AbstractObjectReader

java.lang.Object

org.apache.drill.exec.vector.accessor.reader.AbstractObjectReader

All Implemented Interfaces:

ColumnReader, ObjectReader

Direct Known Subclasses:

AbstractScalarReader.ScalarObjectReader, AbstractTupleReader.TupleObjectReader, ArrayReaderImpl.ArrayObjectReader, UnionReaderImpl.UnionObjectReader

public abstract class AbstractObjectReader
extends Object
implements ObjectReader

Constructor Summary

Constructors

Constructor and Description
AbstractObjectReader()

Method Summary

Modifier and Type	Method and Description
ArrayReader	array()
DictReader	dict()
abstract ReaderEvents	events()
boolean	isNull() Determine if this value is null.
abstract ColumnReader	reader() Gets the reader as a generic type, for dynamic programming.
ScalarReader	scalar()
ColumnMetadata	schema()
TupleReader	tuple()
ObjectType	type() The type of this reader.
VariantReader	variant()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.drill.exec.vector.accessor.ColumnReader

getAsString, getObject

Constructor Detail

AbstractObjectReader

public AbstractObjectReader()

Method Detail

schema

public ColumnMetadata schema()

Specified by:

schema in interface ColumnReader

scalar

public ScalarReader scalar()

Specified by:

scalar in interface ObjectReader

tuple

public TupleReader tuple()

Specified by:

tuple in interface ObjectReader

array

public ArrayReader array()

Specified by:

array in interface ObjectReader

dict

public DictReader dict()

Specified by:

dict in interface ObjectReader

events

public abstract ReaderEvents events()

reader

public abstract ColumnReader reader()

Description copied from interface: ObjectReader

Gets the reader as a generic type, for dynamic programming.

Specified by:

reader in interface ObjectReader

Returns:

the untyped reader

variant

public VariantReader variant()

Specified by:

variant in interface ObjectReader

isNull

public boolean isNull()

Description copied from interface: ColumnReader

Determine if this value is null.

• Nullable scalar: determine if the value is null.
• Non-nullable scalar: always returns false.
• Arrays: always returns false
• Lists: determine if the list for the current row is null. In a list, an array entry can be null, empty, or can contain items. In repeated types, the array itself is never null. If the array is null, then it implicitly has no entries.
• Map or Repeated Map: Always returns false.
• Map inside a union, or in a list that contains a union, the tuple itself can be null.
• Union: Determine if the current value is null. Null values have no type and no associated reader.

Specified by:

isNull in interface ColumnReader

Returns:

true if this value is null; false otherwise

type

public ObjectType type()

Description copied from interface: ColumnReader

The type of this reader.

Specified by:

type in interface ColumnReader

Returns:

type of reader