org.apache.drill.exec.record.metadata

Class VariantSchema

java.lang.Object

org.apache.drill.exec.record.metadata.VariantSchema

All Implemented Interfaces:

VariantMetadata

public class VariantSchema
extends Object
implements VariantMetadata

Constructor Summary

Constructors

Constructor and Description
VariantSchema()

Method Summary

Modifier and Type	Method and Description
void	addList(VariantColumnMetadata listCol)
void	addMap(MapColumnMetadata mapCol)
void	addType(ColumnMetadata col) Add a column for any supported type to the variant.
ColumnMetadata	addType(MaterializedField field)
ColumnMetadata	addType(TypeProtos.MinorType type) Add any supported type to the variant.
void	becomeSimple()
protected void	bind(VariantColumnMetadata parent)
VariantSchema	cloneEmpty()
VariantSchema	copy()
boolean	hasType(TypeProtos.MinorType type) Determine if the given type is a member of the variant.
boolean	isEquivalent(VariantSchema other)
boolean	isSimple()
boolean	isSingleType() A list is defined as a list of variants at the metadata layer.
ColumnMetadata	listSubtype() Lists are odd creatures: they contain a union if they have more than one subtype, but are like a nullable repeated type if they contain only one type.
ColumnMetadata	member(TypeProtos.MinorType type) Retrieve the virtual column for a given type.
static ColumnMetadata	memberMetadata(TypeProtos.MinorType type)
Collection<ColumnMetadata>	members()
ColumnMetadata	parent() Return the column that defines this variant structure
int	size() Returns the number of types in the variant.
String	toString()
Collection<TypeProtos.MinorType>	types() Returns the list of types which are members of this variant.

Methods inherited from class java.lang.Object

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

Constructor Detail

VariantSchema

public VariantSchema()

Method Detail

bind

protected void bind(VariantColumnMetadata parent)

memberMetadata

public static ColumnMetadata memberMetadata(TypeProtos.MinorType type)

addType

public ColumnMetadata addType(TypeProtos.MinorType type)

Description copied from interface: VariantMetadata

Add any supported type to the variant.

At present, the union vector does not support the decimal types. This class does not reject such types; but they will cause a runtime exception when code asks the union vector for these types.

Specified by:

addType in interface VariantMetadata

Parameters:

type - type to add

Returns:

the "virtual" column for that type

addType

public void addType(ColumnMetadata col)

Description copied from interface: VariantMetadata

Add a column for any supported type to the variant. Use this to add structure to a list or map member.

Specified by:

addType in interface VariantMetadata

Parameters:

col - column to add. The column must have the correct mode. The column's type is used as the type key

size

public int size()

Description copied from interface: VariantMetadata

Returns the number of types in the variant.

Specified by:

size in interface VariantMetadata

Returns:

the number of types in the variant

hasType

public boolean hasType(TypeProtos.MinorType type)

Description copied from interface: VariantMetadata

Determine if the given type is a member of the variant.

Specified by:

hasType in interface VariantMetadata

Parameters:

type - type to check

Returns:

true if the type is a member, false if not

member

public ColumnMetadata member(TypeProtos.MinorType type)

Description copied from interface: VariantMetadata

Retrieve the virtual column for a given type.

Specified by:

member in interface VariantMetadata

Parameters:

type - the type key

Returns:

the virtual column, or null if the type is not a member of the variant

parent

public ColumnMetadata parent()

Description copied from interface: VariantMetadata

Return the column that defines this variant structure

Specified by:

parent in interface VariantMetadata

Returns:

the column that returns this variant structure from its variantSchema() method

types

public Collection<TypeProtos.MinorType> types()

Description copied from interface: VariantMetadata

Returns the list of types which are members of this variant.

Specified by:

types in interface VariantMetadata

Returns:

the list of types

members

public Collection<ColumnMetadata> members()

Specified by:

members in interface VariantMetadata

addMap

public void addMap(MapColumnMetadata mapCol)

addList

public void addList(VariantColumnMetadata listCol)

addType

public ColumnMetadata addType(MaterializedField field)

isSingleType

public boolean isSingleType()

Description copied from interface: VariantMetadata

A list is defined as a list of variants at the metadata layer. But, in implementation, a list will do special processing if the variant (union) contains only one type.

Specified by:

isSingleType in interface VariantMetadata

Returns:

true if this variant contains only one type, false if the variant contains 0, 2 or more types

listSubtype

public ColumnMetadata listSubtype()

Description copied from interface: VariantMetadata

Lists are odd creatures: they contain a union if they have more than one subtype, but are like a nullable repeated type if they contain only one type. This method returns the type of the array: either the single type (if VariantMetadata.isSingleType() is true) or a reference to the synthetic union column nested inside the list.

Specified by:

listSubtype in interface VariantMetadata

Returns:

the metadata for the implicit column within the list

becomeSimple

public void becomeSimple()

Specified by:

becomeSimple in interface VariantMetadata

isSimple

public boolean isSimple()

Specified by:

isSimple in interface VariantMetadata

toString

public String toString()

Overrides:

toString in class Object

cloneEmpty

public VariantSchema cloneEmpty()

copy

public VariantSchema copy()

isEquivalent

public boolean isEquivalent(VariantSchema other)