org.apache.hadoop.hive.ql.exec.vector
Class VectorHashKeyWrapperBatch

java.lang.Object
  org.apache.hadoop.hive.ql.exec.vector.VectorHashKeyWrapperBatch

public class VectorHashKeyWrapperBatch
extends Object

Class for handling vectorized hash map key wrappers. It evaluates the key columns in a row batch in a vectorized fashion. This class stores additional information about keys needed to evaluate and output the key values.

Constructor Summary

VectorHashKeyWrapperBatch()

Method Summary

VectorHashKeyWrapper	allocateKeyWrapper()
static VectorHashKeyWrapperBatch	compileKeyWrapperBatch(VectorExpression[] keyExpressions) Prepares a VectorHashKeyWrapperBatch to work for a specific set of keys.
void	evaluateBatch(VectorizedRowBatch batch) Processes a batch: Evaluates each key vector expression. Copies out each key's primitive values into the key wrappers computes the hashcode of the key wrappers
int	getKeysFixedSize() Returns the compiled fixed size for the key wrappers.
int	getVariableSize(int batchSize)
VectorHashKeyWrapper[]	getVectorHashKeyWrappers() Accessor for the batch-sized array of key wrappers.
Object	getWritableKeyValue(VectorHashKeyWrapper kw, int i, VectorExpressionWriter keyOutputWriter) Get the row-mode writable object value of a key from a key wrapper

Methods inherited from class java.lang.Object

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

Constructor Detail

VectorHashKeyWrapperBatch

public VectorHashKeyWrapperBatch()

Method Detail

getKeysFixedSize

public int getKeysFixedSize()

Returns the compiled fixed size for the key wrappers.

Returns:

getVectorHashKeyWrappers

public VectorHashKeyWrapper[] getVectorHashKeyWrappers()

Accessor for the batch-sized array of key wrappers.

evaluateBatch

public void evaluateBatch(VectorizedRowBatch batch)
                   throws HiveException

Processes a batch:

• Evaluates each key vector expression.
• Copies out each key's primitive values into the key wrappers
• computes the hashcode of the key wrappers

Parameters:

batch -

Throws:

HiveException

compileKeyWrapperBatch

public static VectorHashKeyWrapperBatch compileKeyWrapperBatch(VectorExpression[] keyExpressions)
                                                        throws HiveException

Prepares a VectorHashKeyWrapperBatch to work for a specific set of keys. Computes the fast access lookup indices, preallocates all needed internal arrays. This step is done only once per query, not once per batch. The information computed now will be used to generate proper individual VectorKeyHashWrapper objects.

Throws:

HiveException

allocateKeyWrapper

public VectorHashKeyWrapper allocateKeyWrapper()

getWritableKeyValue

public Object getWritableKeyValue(VectorHashKeyWrapper kw,
                                  int i,
                                  VectorExpressionWriter keyOutputWriter)
                           throws HiveException

Get the row-mode writable object value of a key from a key wrapper

Parameters:

keyOutputWriter -

Throws:

HiveException

getVariableSize

public int getVariableSize(int batchSize)