org.apache.drill.exec.physical.resultSet.impl

Interface VectorState

All Known Implementing Classes:

ListState.ListVectorState, NullableVectorState, NullVectorState, NullVectorState.UnmanagedVectorState, RepeatedListState.RepeatedListVectorState, RepeatedVectorState, SingleVectorState, SingleVectorState.FixedWidthVectorState, SingleVectorState.IsSetVectorState, SingleVectorState.OffsetVectorState, SingleVectorState.SimpleVectorState, SingleVectorState.VariableWidthVectorState, TupleState.DictArrayVectorState, TupleState.DictVectorState, TupleState.MapVectorState, TupleState.SingleDictVectorState, UnionState.UnionVectorState

public interface VectorState

Handles batch and overflow operation for a (possibly compound) vector.

The data model is the following:

• Column model
  • Value vector itself
  • Column writer
  • Column schema
  • Column coordinator (this class)

The vector state coordinates events between the result set loader on the one side and the vectors, writers and schema on the other. For example:

 Result Set       Vector
   Loader   <-->  State   <-->    Vectors
 

Events from the row set loader deal with allocation, roll-over, harvesting completed batches and so on. Events from the writer, via the tuple model deal with adding columns and column overflow.

Method Summary

Modifier and Type	Method and Description
int	allocate(int cardinality) Allocate a new vector with the number of elements given.
void	close() Clear the vector(s) associated with this state.
void	dump(HierarchicalFormatter format)
void	harvestWithLookAhead() A batch is being harvested after an overflow.
boolean	isProjected() Report whether this column is projected (has materialized vectors), or is unprojected (has no materialized backing.)
void	rollover(int cardinality) A vector has overflowed.
void	startBatchWithLookAhead() A new batch is starting while an look-ahead vector exists.
<T extends ValueVector> T	vector() Underlying vector: the one presented to the consumer of the result set loader.

Method Detail

allocate

int allocate(int cardinality)

Allocate a new vector with the number of elements given. If the vector is an array, then the cardinality given is the number of arrays.

Parameters:

cardinality - number of elements desired in the allocated vector

Returns:

the number of bytes allocated

rollover

void rollover(int cardinality)

A vector has overflowed. Create a new look-ahead vector of the given cardinality, then copy the overflow values from the main vector to the look-ahead vector.

Parameters:

cardinality - the number of elements in the new vector. If this vector is an array, then this is the number of arrays

harvestWithLookAhead

void harvestWithLookAhead()

A batch is being harvested after an overflow. Put the full batch back into the main vector so it can be harvested.

startBatchWithLookAhead

void startBatchWithLookAhead()

A new batch is starting while an look-ahead vector exists. Move the look-ahead buffers into the main vector to prepare for writing the rest of the batch.

close

void close()

Clear the vector(s) associated with this state.

vector

<T extends ValueVector> T vector()

Underlying vector: the one presented to the consumer of the result set loader.

isProjected

boolean isProjected()

Report whether this column is projected (has materialized vectors), or is unprojected (has no materialized backing.)

Returns:

true if the column is projected to the output, false if not

dump

void dump(HierarchicalFormatter format)