org.apache.drill.exec.store.easy.text.compliant

Class CompliantTextRecordReader

java.lang.Object

org.apache.drill.exec.store.AbstractRecordReader

org.apache.drill.exec.store.easy.text.compliant.CompliantTextRecordReader

All Implemented Interfaces:

AutoCloseable, RecordReader

public class CompliantTextRecordReader
extends AbstractRecordReader

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.RecordReader

ALLOCATOR_INITIAL_RESERVATION, ALLOCATOR_MAX_RESERVATION

Constructor Summary

Constructors

Constructor and Description
CompliantTextRecordReader(org.apache.hadoop.mapred.FileSplit split, DrillFileSystem dfs, FragmentContext context, TextParsingSettings settings, List<SchemaPath> columns)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Cleanup state once we are finished processing all the records.
protected List<SchemaPath>	getDefaultColumnsToRead() Returns list of default columns to read to replace empty list of columns.
boolean	isStarQuery()
int	next() Generates the next record batch
void	setup(OperatorContext context, OutputMutator outputMutator) Performs the initial setup required for the record reader.

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

allocate, getColumns, isSkipQuery, setColumns, toString, transformColumns

Methods inherited from class java.lang.Object

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

Constructor Detail

CompliantTextRecordReader

public CompliantTextRecordReader(org.apache.hadoop.mapred.FileSplit split,
                         DrillFileSystem dfs,
                         FragmentContext context,
                         TextParsingSettings settings,
                         List<SchemaPath> columns)

Method Detail

isStarQuery

public boolean isStarQuery()

Overrides:

isStarQuery in class AbstractRecordReader

getDefaultColumnsToRead

protected List<SchemaPath> getDefaultColumnsToRead()

Returns list of default columns to read to replace empty list of columns. For text files without headers returns "columns[0]". Text files with headers do not support columns syntax, so when header extraction is enabled, returns fake named column "_DEFAULT_COL_TO_READ_".

Overrides:

getDefaultColumnsToRead in class AbstractRecordReader

Returns:

list of default columns to read

setup

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

Performs the initial setup required for the record reader. Initializes the input stream, handling of the output record batch and the actual reader to be used.

Parameters:

context - operator context from which buffer's will be allocated and managed

outputMutator - Used to create the schema in the output record batch

Throws:

ExecutionSetupException

next

public int next()

Generates the next record batch

Returns:

number of records in the batch

close

public void close()

Cleanup state once we are finished processing all the records. This would internally close the input stream we are reading from.