org.apache.drill.exec.vector.accessor.writer

Class DictEntryWriter

java.lang.Object

org.apache.drill.exec.vector.accessor.writer.AbstractTupleWriter

org.apache.drill.exec.vector.accessor.writer.DictEntryWriter

All Implemented Interfaces:

ColumnWriter, TupleWriter, WriterEvents, WriterPosition

public class DictEntryWriter
extends AbstractTupleWriter

Writer for a Dict entry. The entry is a special kind of tuple.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DictEntryWriter.DictEntryObjectWriter

Nested classes/interfaces inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractTupleWriter

AbstractTupleWriter.TupleObjectWriter, AbstractTupleWriter.TupleWriterListener

Nested classes/interfaces inherited from interface org.apache.drill.exec.vector.accessor.TupleWriter

TupleWriter.UndefinedColumnException

Nested classes/interfaces inherited from interface org.apache.drill.exec.vector.accessor.writer.WriterEvents

WriterEvents.ColumnWriterListener, WriterEvents.State

Field Summary

Fields inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractTupleWriter

childIndex, listener, logger, state, tupleSchema, vectorIndex, writers

Constructor Summary

Constructors

Constructor and Description
DictEntryWriter(ColumnMetadata schema, List<AbstractObjectWriter> writers)

Method Summary

Modifier and Type	Method and Description
void	bindIndex(ColumnWriterIndex index) Bind the writer to a writer index.
static DictEntryWriter.DictEntryObjectWriter	buildDictEntryWriter(ColumnMetadata schema, List<AbstractObjectWriter> keyValueWriters, DictVector vector)
boolean	isProjected() Whether this writer is projected (is backed by a materialized vector), or is unprojected (is just a dummy writer.) In most cases, clients can ignore whether the column is projected and just write to the writer.
ColumnMetadata	schema() Returns the schema of the column associated with this writer.
void	setObject(Object value) Generic technique to write data as a generic Java object.

Methods inherited from class org.apache.drill.exec.vector.accessor.writer.AbstractTupleWriter

addColumn, addColumn, addColumnWriter, array, array, bindIndex, bindListener, bindListener, column, column, copy, dict, dict, dump, endArrayValue, endWrite, isProjected, lastWriteIndex, listener, nullable, postRollover, preRollover, restartRow, rowStartIndex, saveRow, scalar, scalar, set, setNull, size, startRow, startWrite, tuple, tuple, tupleSchema, type, type, type, variant, variant, writeIndex

Methods inherited from class java.lang.Object

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

Constructor Detail

DictEntryWriter

public DictEntryWriter(ColumnMetadata schema,
                       List<AbstractObjectWriter> writers)

Method Detail

buildDictEntryWriter

public static DictEntryWriter.DictEntryObjectWriter buildDictEntryWriter(ColumnMetadata schema,
                                                                         List<AbstractObjectWriter> keyValueWriters,
                                                                         DictVector vector)

bindIndex

public void bindIndex(ColumnWriterIndex index)

Description copied from interface: WriterEvents

Bind the writer to a writer index.

Specified by:

bindIndex in interface WriterEvents

Overrides:

bindIndex in class AbstractTupleWriter

Parameters:

index - the writer index (top level or nested for arrays)

isProjected

public boolean isProjected()

Description copied from interface: ColumnWriter

Whether this writer is projected (is backed by a materialized vector), or is unprojected (is just a dummy writer.) In most cases, clients can ignore whether the column is projected and just write to the writer. This flag handles those special cases where it is helpful to know if the column is projected or not.

Specified by:

isProjected in interface ColumnWriter

Overrides:

isProjected in class AbstractTupleWriter

schema

public ColumnMetadata schema()

Description copied from interface: ColumnWriter

Returns the schema of the column associated with this writer.

Returns:

schema for this writer's column

setObject

public void setObject(Object value)

Description copied from interface: ColumnWriter

Generic technique to write data as a generic Java object. The type of the object must match the target writer. Primarily for testing.

• Scalar: The type of the Java object must match the type of the target vector. String or byte[] can be used for Varchar vectors.
• Array: Write the array given an array of values. The object must be a Java array. The type of the array must match the type of element in the repeated vector. That is, if the vector is a Repeated Int, provide an int[] array.
• Tuple (map or row): The Java object must be an array of objects in which the members of the array have a 1:1 correspondence with the members of the tuple in the order defined by the writer metadata. That is, if the map is (Int, Varchar), provide a Object[] array like this: {10, "fred"}.
• Union: Uses the Java object type to determine the type of the backing vector. Creates a vector of the required type if needed.

Specified by:

setObject in interface ColumnWriter

Overrides:

setObject in class AbstractTupleWriter

Parameters:

value - value to write to the vector. The Java type of the object indicates the Drill storage type