org.datavec.api.records.reader

Interface RecordReader

All Superinterfaces:

AutoCloseable, Closeable, Configurable, Serializable

All Known Subinterfaces:

SequenceRecordReader

All Known Implementing Classes:

BaseRecordReader, CollectionRecordReader, CollectionSequenceRecordReader, ComposableRecordReader, CSVNLinesSequenceRecordReader, CSVRecordReader, CSVRegexRecordReader, CSVSequenceRecordReader, FileRecordReader, InMemoryRecordReader, InMemorySequenceRecordReader, JacksonRecordReader, LibSvmRecordReader, LineRecordReader, ListStringRecordReader, MatlabRecordReader, RegexLineRecordReader, RegexSequenceRecordReader, SVMLightRecordReader, TransformProcessRecordReader, TransformProcessSequenceRecordReader

public interface RecordReader
extends Closeable, Serializable, Configurable

Record reader

Author:

Adam Gibson

Field Summary

Fields

Modifier and Type	Field and Description
static String	APPEND_LABEL
static String	LABELS
static String	NAME_SPACE

Method Summary

Modifier and Type	Method and Description
boolean	batchesSupported() This method returns true, if next(int) signature is supported by this RecordReader implementation.
List<String>	getLabels() List of label strings
List<RecordListener>	getListeners() Get the record listeners for this record reader.
boolean	hasNext() Whether there are anymore records
void	initialize(Configuration conf, InputSplit split) Called once at initialization.
void	initialize(InputSplit split) Called once at initialization.
List<Record>	loadFromMetaData(List<RecordMetaData> recordMetaDatas) Load multiple records from the given a list of RecordMetaData instances
Record	loadFromMetaData(RecordMetaData recordMetaData) Load a single record from the given RecordMetaData instance Note: that for data that isn't splittable (i.e., text data that needs to be scanned/split), it is more efficient to load multiple records at once using loadFromMetaData(List)
List<Writable>	next() Get the next record
List<Writable>	next(int num) This method will be used, if batchesSupported() returns true.
Record	nextRecord() Similar to next(), but returns a Record object, that may include metadata such as the source of the data
List<Writable>	record(URI uri, DataInputStream dataInputStream) Load the record from the given DataInputStream Unlike next() the internal state of the RecordReader is not modified Implementations of this method should not close the DataInputStream
void	reset() Reset record reader iterator
void	setListeners(Collection<RecordListener> listeners) Set the record listeners for this record reader.
void	setListeners(RecordListener... listeners) Set the record listeners for this record reader.

Methods inherited from interface java.io.Closeable

close

Methods inherited from interface org.datavec.api.conf.Configurable

getConf, setConf

Field Detail

NAME_SPACE

static final String NAME_SPACE

APPEND_LABEL

static final String APPEND_LABEL

LABELS

static final String LABELS

Method Detail

initialize

void initialize(InputSplit split)
         throws IOException,
                InterruptedException

Called once at initialization.

Parameters:

split - the split that defines the range of records to read

Throws:

IOException

InterruptedException

initialize

void initialize(Configuration conf,
                InputSplit split)
         throws IOException,
                InterruptedException

Called once at initialization.

Parameters:

conf - a configuration for initialization

split - the split that defines the range of records to read

Throws:

IOException

InterruptedException

batchesSupported

boolean batchesSupported()

This method returns true, if next(int) signature is supported by this RecordReader implementation.

Returns:

next

List<Writable> next(int num)

This method will be used, if batchesSupported() returns true.

Parameters:

num -

Returns:

next

List<Writable> next()

Get the next record

Returns:

hasNext

boolean hasNext()

Whether there are anymore records

Returns:

getLabels

List<String> getLabels()

List of label strings

Returns:

reset

void reset()

Reset record reader iterator

record

List<Writable> record(URI uri,
                      DataInputStream dataInputStream)
               throws IOException

Load the record from the given DataInputStream Unlike next() the internal state of the RecordReader is not modified Implementations of this method should not close the DataInputStream

Throws:

IOException - if error occurs during reading from the input stream

nextRecord

Record nextRecord()

Similar to next(), but returns a Record object, that may include metadata such as the source of the data

Returns:

next record

loadFromMetaData

Record loadFromMetaData(RecordMetaData recordMetaData)
                 throws IOException

Load a single record from the given RecordMetaData instance
Note: that for data that isn't splittable (i.e., text data that needs to be scanned/split), it is more efficient to load multiple records at once using loadFromMetaData(List)

Parameters:

recordMetaData - Metadata for the record that we want to load from

Returns:

Single record for the given RecordMetaData instance

Throws:

IOException - If I/O error occurs during loading

loadFromMetaData

List<Record> loadFromMetaData(List<RecordMetaData> recordMetaDatas)
                       throws IOException

Load multiple records from the given a list of RecordMetaData instances

Parameters:

recordMetaDatas - Metadata for the records that we want to load from

Returns:

Multiple records for the given RecordMetaData instances

Throws:

IOException - If I/O error occurs during loading

getListeners

List<RecordListener> getListeners()

Get the record listeners for this record reader.

setListeners

void setListeners(RecordListener... listeners)

Set the record listeners for this record reader.

setListeners

void setListeners(Collection<RecordListener> listeners)

Set the record listeners for this record reader.