org.apache.drill.exec.store.hbase

Class HBaseRecordReader

java.lang.Object

org.apache.drill.exec.store.AbstractRecordReader

org.apache.drill.exec.store.hbase.HBaseRecordReader

All Implemented Interfaces:

AutoCloseable, DrillHBaseConstants, RecordReader

public class HBaseRecordReader
extends AbstractRecordReader
implements DrillHBaseConstants

Field Summary

Fields inherited from class org.apache.drill.exec.store.AbstractRecordReader

DEFAULT_TEXT_COLS_TO_READ

Fields inherited from interface org.apache.drill.exec.store.hbase.DrillHBaseConstants

COLUMN_FAMILY_TYPE, COLUMN_TYPE, HBASE_ZOOKEEPER_PORT, ROW_KEY, ROW_KEY_PATH, ROW_KEY_TYPE, SYS_STORE_PROVIDER_HBASE_CONFIG, SYS_STORE_PROVIDER_HBASE_TABLE

Fields inherited from interface org.apache.drill.exec.store.RecordReader

ALLOCATOR_INITIAL_RESERVATION, ALLOCATOR_MAX_RESERVATION

Constructor Summary

Constructors

Constructor and Description
HBaseRecordReader(org.apache.hadoop.hbase.client.Connection connection, HBaseSubScan.HBaseSubScanSpec subScanSpec, List<SchemaPath> projectedColumns)

Method Summary

Modifier and Type	Method and Description
void	close()
int	next() Increments this record reader forward, writing via the provided output mutator into the output batch.
void	setup(OperatorContext context, OutputMutator output) Configure the RecordReader with the provided schema and the record batch that should be written to.
String	toString()
protected Collection<SchemaPath>	transformColumns(Collection<SchemaPath> columns) Provides the projected columns information to the Hbase Scan instance.

Methods inherited from class org.apache.drill.exec.store.AbstractRecordReader

allocate, getColumns, getDefaultColumnsToRead, hasNext, isSkipQuery, isStarQuery, setColumns

Methods inherited from class java.lang.Object

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

Constructor Detail

HBaseRecordReader

public HBaseRecordReader(org.apache.hadoop.hbase.client.Connection connection,
                         HBaseSubScan.HBaseSubScanSpec subScanSpec,
                         List<SchemaPath> projectedColumns)

Method Detail

transformColumns

protected Collection<SchemaPath> transformColumns(Collection<SchemaPath> columns)

Provides the projected columns information to the Hbase Scan instance. If the projected columns list contains a column family and also a column in the column family, only the column family is passed to the Scan instance. For example, if the projection list is {cf1, cf1.col1, cf2.col1} then we only pass {cf1, cf2.col1} to the Scan instance.

Overrides:

transformColumns in class AbstractRecordReader

Parameters:

columns - collection of projected columns

Returns:

collection of projected column family names

setup

public void setup(OperatorContext context,
                  OutputMutator output)
           throws ExecutionSetupException

Description copied from interface: RecordReader

Configure the RecordReader with the provided schema and the record batch that should be written to.

Specified by:

setup in interface RecordReader

Parameters:

context - operator context for the reader

output - The place where output for a particular scan should be written. The record reader is responsible for mutating the set of schema values for that particular record.

Throws:

ExecutionSetupException

next

public int next()

Description copied from interface: RecordReader

Increments this record reader forward, writing via the provided output mutator into the output batch.

Specified by:

next in interface RecordReader

Returns:

The number of additional records added to the output.

close

public void close()

Specified by:

close in interface AutoCloseable

toString

public String toString()

Overrides:

toString in class AbstractRecordReader