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

Class AbstractScalarReader.NullReader

java.lang.Object

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

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

All Implemented Interfaces:

ColumnReader, ReaderEvents, ScalarReader

Enclosing class:

AbstractScalarReader

public static class AbstractScalarReader.NullReader
extends AbstractScalarReader

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.drill.exec.vector.accessor.reader.AbstractScalarReader

AbstractScalarReader.NullReader, AbstractScalarReader.ScalarObjectReader

Field Summary

Fields

Modifier and Type	Field	Description
protected final ColumnMetadata	schema

Fields inherited from class org.apache.drill.exec.vector.accessor.reader.AbstractScalarReader

nullStateReader, vectorIndex

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	NullReader(ColumnMetadata schema)

Method Summary

Modifier and Type	Method	Description
void	bindBuffer()
void	bindIndex(ColumnReaderIndex rowIndex)
boolean	isNull()	Determine if this value is null.
ColumnMetadata	schema()
ValueType	valueType()	Describe the type of the value.

Methods inherited from class org.apache.drill.exec.vector.accessor.reader.AbstractScalarReader

bindNullState, conversionError, extendedType, getAsString, getBoolean, getBytes, getDate, getDecimal, getDouble, getFloat, getInt, getLong, getObject, getPeriod, getString, getTime, getTimestamp, getValue, nullReader, nullStateReader, reposition, type

Methods inherited from class java.lang.Object

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

Field Details

schema

protected final ColumnMetadata schema

Constructor Details

NullReader

protected NullReader(ColumnMetadata schema)

Method Details

valueType

public ValueType valueType()

Description copied from interface: ScalarReader

Describe the type of the value. This is a compression of the value vector type: it describes which method will return the vector value.

Returns:

the value type which indicates which get method is valid for the column

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</tt.>
• 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

Overrides:

isNull in class AbstractScalarReader

Returns:

true if this value is null; false otherwise

bindIndex

public void bindIndex(ColumnReaderIndex rowIndex)

Specified by:

bindIndex in interface ReaderEvents

Overrides:

bindIndex in class AbstractScalarReader

schema

public ColumnMetadata schema()

bindBuffer

public void bindBuffer()