org.apache.drill.exec.store.mapr.db.json

Class RestrictedJsonRecordReader

java.lang.Object

org.apache.drill.exec.store.AbstractRecordReader

org.apache.drill.exec.store.mapr.db.json.MaprDBJsonRecordReader

org.apache.drill.exec.store.mapr.db.json.RestrictedJsonRecordReader

All Implemented Interfaces:

AutoCloseable, RecordReader

public class RestrictedJsonRecordReader
extends MaprDBJsonRecordReader

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.drill.exec.store.mapr.db.json.MaprDBJsonRecordReader

MaprDBJsonRecordReader.SchemaState

Field Summary

Fields inherited from class org.apache.drill.exec.store.mapr.db.json.MaprDBJsonRecordReader

condition, documentWriter, formatPlugin, ID_ONLY_PROJECTION, lastDocument, lastDocumentReader, maxRecordsToRead, subScanSpec, table, valueWriter, vectorWriter, vectorWriterMutator

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

DEFAULT_TEXT_COLS_TO_READ

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

ALLOCATOR_INITIAL_RESERVATION, ALLOCATOR_MAX_RESERVATION

Constructor Summary

Constructors

Constructor and Description
RestrictedJsonRecordReader(MapRDBSubScanSpec subScanSpec, MapRDBFormatPlugin formatPlugin, List<SchemaPath> projectedColumns, FragmentContext context, int maxRecordsToRead, TupleMetadata schema)

Method Summary

Modifier and Type	Method and Description
boolean	hasNext() Check if the reader may have potentially more data to be read in subsequent iterations.
int	next() Increments this record reader forward, writing via the provided output mutator into the output batch.
void	readToInitSchema()
void	setup(OperatorContext context, OutputMutator output) Configure the RecordReader with the provided schema and the record batch that should be written to.

Methods inherited from class org.apache.drill.exec.store.mapr.db.json.MaprDBJsonRecordReader

close, getIdOnly, getIgnoreSchemaChange, getScannedFields, getTable, includesIdField, nextDocument, nextDocumentReader, toString, transformColumns

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

allocate, getColumns, getDefaultColumnsToRead, isSkipQuery, isStarQuery, setColumns

Methods inherited from class java.lang.Object

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

Constructor Detail

RestrictedJsonRecordReader

public RestrictedJsonRecordReader(MapRDBSubScanSpec subScanSpec,
                                  MapRDBFormatPlugin formatPlugin,
                                  List<SchemaPath> projectedColumns,
                                  FragmentContext context,
                                  int maxRecordsToRead,
                                  TupleMetadata schema)

Method Detail

readToInitSchema

public void readToInitSchema()

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

Overrides:

setup in class MaprDBJsonRecordReader

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

Overrides:

next in class MaprDBJsonRecordReader

Returns:

The number of additional records added to the output.

hasNext

public boolean hasNext()

Description copied from interface: RecordReader

Check if the reader may have potentially more data to be read in subsequent iterations. Certain types of readers such as repeatable readers can be invoked multiple times, so this method will allow ScanBatch to check with the reader before closing it.

Specified by:

hasNext in interface RecordReader

Overrides:

hasNext in class AbstractRecordReader

Returns:

return true if there could potentially be more reads, false otherwise