Package org.apache.drill.exec.vector.complex

Class DictVector

java.lang.Object

org.apache.drill.exec.vector.complex.AbstractContainerVector

org.apache.drill.exec.vector.complex.AbstractMapVector

org.apache.drill.exec.vector.complex.AbstractRepeatedMapVector

org.apache.drill.exec.vector.complex.DictVector

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<ValueVector>, ContainerVectorLike, RepeatedValueVector, ValueVector

public final class DictVector
extends AbstractRepeatedMapVector

A ValueVector holding key-value pairs.

This vector is essentially a RepeatedMapVector but with constraints: it may have 2 children only, named FIELD_KEY_NAME and FIELD_VALUE_NAME. The FIELD_KEY_NAME can be of primitive type only and its values should not be null, while the other, FIELD_VALUE_NAME, field can be either of primitive or complex type. Value field can hold null values.

This vector has it's own FieldReader and FieldWriter to ensure data is read and written correctly. In addition, the reader is responsible for getting a value for a given key.

Additionally, Object representation is changed in DictVector.Accessor.getObject(int) to represent it as JsonStringHashMap with appropriate key and value types.

(The structure corresponds to Java's notion of Map).

See Also:

• reader corresponding to the vector
• writer corresponding to the vector

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	DictVector.Accessor
class	DictVector.Mutator

Nested classes/interfaces inherited from interface org.apache.drill.exec.vector.complex.RepeatedValueVector

RepeatedValueVector.RepeatedAccessor, RepeatedValueVector.RepeatedMutator

Field Summary

Fields

Modifier and Type	Field	Description
static final String	FIELD_KEY_NAME
static final String	FIELD_VALUE_NAME
static final List<String>	fieldNames
static final TypeProtos.MajorType	TYPE

Fields inherited from class org.apache.drill.exec.vector.complex.AbstractRepeatedMapVector

emptyPopulator, offsets

Fields inherited from class org.apache.drill.exec.vector.complex.AbstractContainerVector

allocator, callBack, field

Fields inherited from interface org.apache.drill.exec.vector.complex.RepeatedValueVector

DEFAULT_REPEAT_PER_RECORD

Fields inherited from interface org.apache.drill.exec.vector.ValueVector

BITS_VECTOR_NAME, MAX_BUFFER_SIZE, MAX_ROW_COUNT, MIN_ROW_COUNT, OFFSETS_VECTOR_NAME, VALUES_VECTOR_NAME

Constructor Summary

Constructors

Constructor	Description
DictVector(MaterializedField field, BufferAllocator allocator, CallBack callBack)
DictVector(MaterializedField field, BufferAllocator allocator, CallBack callBack, TypeProtos.MajorType keyType, TypeProtos.MajorType valueType)

Method Summary

Modifier and Type	Method	Description
void	exchange(ValueVector other)	Exchange state with another value vector of the same type.
DictVector.Accessor	getAccessor()	Returns an accessor that is used to read from this vector instance.
ValueVector	getChild(String name)	Returns a ValueVector corresponding to the given field name if exists or null.
<T extends ValueVector> T	getChild(String name, Class<T> clazz)	Returns a ValueVector instance of subtype of corresponding to the given field name if exists or null.
protected Collection<String>	getChildFieldNames()	Returns a sequence of field names in the order that they show up in the schema.
VectorWithOrdinal	getChildVectorWithOrdinal(String name)	Returns a vector with its corresponding ordinal mapping if field exists or null.
ValueVector	getKeys()
TypeProtos.MajorType	getKeyType()
DictVector.Mutator	getMutator()	Returns an mutator that is used to write to this vector instance.
SingleDictReaderImpl	getReader()	Returns a field reader that supports reading values from this vector.
TransferPair	getTransferPair(String ref, BufferAllocator allocator)
TransferPair	getTransferPair(BufferAllocator allocator)	Returns a transfer pair, creating a new target vector of the same type.
ValueVector	getValues()
TypeProtos.MajorType	getValueType()
boolean	isValueNullable()
TransferPair	makeTransferPair(DictVector to)
TransferPair	makeTransferPair(ValueVector to)	Returns a new transfer pair that is used to transfer underlying buffers into the target vector.
void	putChild(String name, ValueVector vector)	Inserts the vector with the given name if it does not exist else replaces it with the new value.
void	transferTo(DictVector target)

Methods inherited from class org.apache.drill.exec.vector.complex.AbstractRepeatedMapVector

addOrGetVector, allocateNew, allocateNewSafe, allocateOffsetsNew, clear, close, collectLedgers, copyEntry, copyFromSafe, fieldNameIterator, getAllocatedSize, getBuffers, getBufferSize, getBufferSizeFor, getDataVector, getMetadata, getOffsetVector, getPayloadByteCount, getPrimitiveVectors, getTransferPairToSingleMap, getValueCapacity, load, setInitialCapacity, toNullable

Methods inherited from class org.apache.drill.exec.vector.complex.AbstractMapVector

addOrGet, getChildByOrdinal, getChildren, iterator, putVector, size

Methods inherited from class org.apache.drill.exec.vector.complex.AbstractContainerVector

allocateNew, getAllocator, getField, supportsDirectRead, typeify

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.complex.ContainerVectorLike

size

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Methods inherited from interface org.apache.drill.exec.vector.ValueVector

allocateNew, getAllocator, getField

Field Details

TYPE

public static final TypeProtos.MajorType TYPE

FIELD_KEY_NAME

public static final String FIELD_KEY_NAME

See Also:

• Constant Field Values

FIELD_VALUE_NAME

public static final String FIELD_VALUE_NAME

See Also:

• Constant Field Values

fieldNames

public static final List<String> fieldNames

Constructor Details

DictVector

public DictVector(MaterializedField field,
 BufferAllocator allocator,
 CallBack callBack)

DictVector

public DictVector(MaterializedField field,
 BufferAllocator allocator,
 CallBack callBack,
 TypeProtos.MajorType keyType,
 TypeProtos.MajorType valueType)

Method Details

getReader

public SingleDictReaderImpl getReader()

Description copied from interface: ValueVector

Returns a field reader that supports reading values from this vector.

getChildFieldNames

protected Collection<String> getChildFieldNames()

Description copied from class: AbstractContainerVector

Returns a sequence of field names in the order that they show up in the schema.

Overrides:

getChildFieldNames in class AbstractContainerVector

transferTo

public void transferTo(DictVector target)

makeTransferPair

public TransferPair makeTransferPair(DictVector to)

getTransferPair

public TransferPair getTransferPair(BufferAllocator allocator)

Description copied from interface: ValueVector

Returns a transfer pair, creating a new target vector of the same type.

makeTransferPair

public TransferPair makeTransferPair(ValueVector to)

Description copied from interface: ValueVector

Returns a new transfer pair that is used to transfer underlying buffers into the target vector.

getTransferPair

public TransferPair getTransferPair(String ref,
 BufferAllocator allocator)

putChild

public void putChild(String name,
 ValueVector vector)

Inserts the vector with the given name if it does not exist else replaces it with the new value. If the vector is replaced, old and new type are expected to be equal. Validates that the name is either FIELD_KEY_NAME or FIELD_VALUE_NAME and that key is of primitive type.

Overrides:

putChild in class AbstractMapVector

Parameters:

name - field name

vector - vector to be added

Throws:

DrillRuntimeException - if name is not equal to FIELD_KEY_NAME or FIELD_VALUE_NAME or if name.equals(FIELD_KEY_NAME) and vector is of repeated or complex type.

getChild

public ValueVector getChild(String name)

Returns a ValueVector corresponding to the given field name if exists or null. Expects either FIELD_KEY_NAME or FIELD_VALUE_NAME.

Overrides:

getChild in class AbstractContainerVector

Parameters:

name - field's name

exchange

public void exchange(ValueVector other)

Description copied from interface: ValueVector

Exchange state with another value vector of the same type. Used to implement look-ahead writers.

Specified by:

exchange in interface ValueVector

Overrides:

exchange in class AbstractRepeatedMapVector

getChildVectorWithOrdinal

public VectorWithOrdinal getChildVectorWithOrdinal(String name)

Description copied from class: AbstractMapVector

Returns a vector with its corresponding ordinal mapping if field exists or null.

Overrides:

getChildVectorWithOrdinal in class AbstractMapVector

getChild

public <T extends ValueVector> T getChild(String name,
 Class<T> clazz)

Description copied from class: AbstractMapVector

Returns a ValueVector instance of subtype of corresponding to the given field name if exists or null.

Overrides:

getChild in class AbstractMapVector

getAccessor

public DictVector.Accessor getAccessor()

Description copied from interface: ValueVector

Returns an accessor that is used to read from this vector instance.

Specified by:

getAccessor in interface RepeatedValueVector

Specified by:

getAccessor in interface ValueVector

Specified by:

getAccessor in class AbstractRepeatedMapVector

getMutator

public DictVector.Mutator getMutator()

Description copied from interface: ValueVector

Returns an mutator that is used to write to this vector instance.

getKeys

public ValueVector getKeys()

getValues

public ValueVector getValues()

getKeyType

public TypeProtos.MajorType getKeyType()

getValueType

public TypeProtos.MajorType getValueType()

isValueNullable

public boolean isValueNullable()