org.apache.drill.exec.physical.impl.scan.v3.schema

Class MutableTupleSchema

java.lang.Object

org.apache.drill.exec.physical.impl.scan.v3.schema.MutableTupleSchema

public class MutableTupleSchema
extends Object

A mutable form of a tuple schema. Allows insertions (at the wildcard position), and replacing columns (as the schema becomes resolved). Tracks implicit columns (those not filled in by the reader).

Does not implement the TupleMetadata interface because that interface has far more functionality than is needed here, and assumes that column order remains fixed (and hence columns can be addressed by position) which is not true for this class.

This class represents the top-level tuple (the row.) Maps are also dynamic, but provide a subset of resolution options: map fields cannot be implicit. They can, however, be defined, provided, discovered or missing. Map columns can start unresolved if the map comes from projection. A map itself can be resolved, but its members may be unresolved. New map members may only be added at the end (there is no equivalent of a wildcard position.)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MutableTupleSchema.ColumnHandle Holder for a column to allow inserting and replacing columns within the top-level project list.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<MutableTupleSchema.ColumnHandle>	columns
protected Map<String,MutableTupleSchema.ColumnHandle>	nameIndex

Constructor Summary

Constructors

Constructor and Description
MutableTupleSchema()

Method Summary

Modifier and Type	Method and Description
void	add(ColumnMetadata col)
void	addIndex(MutableTupleSchema.ColumnHandle holder)
List<MutableTupleSchema.ColumnHandle>	columns() Provide the list of partially-resolved columns.
void	copyFrom(TupleMetadata from)
MutableTupleSchema.ColumnHandle	find(String colName)
MutableTupleSchema.ColumnHandle	insert(ColumnMetadata col)
MutableTupleSchema.ColumnHandle	insert(int posn, ColumnMetadata col)
boolean	isEmpty()
boolean	isResolved()
void	moveIfExplicit(String colName) Move a column from its current position (which must be past the insert point) to the insert point.
ScanSchemaTracker.ProjectionType	projectionType()
void	replace(MutableTupleSchema.ColumnHandle col, ColumnMetadata resolved)
void	resolve(MutableTupleSchema.ColumnHandle col, ColumnMetadata resolved)
void	resolveImplicit(MutableTupleSchema.ColumnHandle col, ColumnMetadata resolved, ImplicitColumnMarker marker)
void	setInsertPoint(int insertPoint)
void	setProjectionType(ScanSchemaTracker.ProjectionType type)
int	size()
TupleMetadata	toSchema()
int	version()

Methods inherited from class java.lang.Object

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

Field Detail

columns

protected final List<MutableTupleSchema.ColumnHandle> columns

nameIndex

protected final Map<String,MutableTupleSchema.ColumnHandle> nameIndex

Constructor Detail

MutableTupleSchema

public MutableTupleSchema()

Method Detail

setProjectionType

public void setProjectionType(ScanSchemaTracker.ProjectionType type)

setInsertPoint

public void setInsertPoint(int insertPoint)

projectionType

public ScanSchemaTracker.ProjectionType projectionType()

size

public int size()

version

public int version()

columns

public List<MutableTupleSchema.ColumnHandle> columns()

Provide the list of partially-resolved columns. Primarily for the implicit column parser.

find

public MutableTupleSchema.ColumnHandle find(String colName)

copyFrom

public void copyFrom(TupleMetadata from)

add

public void add(ColumnMetadata col)

addIndex

public void addIndex(MutableTupleSchema.ColumnHandle holder)

insert

public MutableTupleSchema.ColumnHandle insert(int posn,
                                              ColumnMetadata col)

insert

public MutableTupleSchema.ColumnHandle insert(ColumnMetadata col)

moveIfExplicit

public void moveIfExplicit(String colName)

Move a column from its current position (which must be past the insert point) to the insert point. An index entry already exists. Special operation done when matching a provided schema to a projection list that includes a wildcard and explicitly projected columns. Works around unfortunate behavior in the planner.

isResolved

public boolean isResolved()

toSchema

public TupleMetadata toSchema()

resolveImplicit

public void resolveImplicit(MutableTupleSchema.ColumnHandle col,
                            ColumnMetadata resolved,
                            ImplicitColumnMarker marker)

replace

public void replace(MutableTupleSchema.ColumnHandle col,
                    ColumnMetadata resolved)

resolve

public void resolve(MutableTupleSchema.ColumnHandle col,
                    ColumnMetadata resolved)

isEmpty

public boolean isEmpty()