Package org.apache.flink.formats.avro

Class AvroInputFormat<E>

java.lang.Object

org.apache.flink.api.common.io.RichInputFormat<OT,FileInputSplit>

org.apache.flink.api.common.io.FileInputFormat<E>

org.apache.flink.formats.avro.AvroInputFormat<E>

Type Parameters:

E - the type of the result Avro record. If you specify GenericRecord then the result will be returned as a GenericRecord, so you do not have to know the schema ahead of time.

All Implemented Interfaces:

Serializable, CheckpointableInputFormat<FileInputSplit,Tuple2<Long,Long>>, InputFormat<E,FileInputSplit>, ResultTypeQueryable<E>, InputSplitSource<FileInputSplit>

public class AvroInputFormat<E>
extends FileInputFormat<E>
implements ResultTypeQueryable<E>, CheckpointableInputFormat<FileInputSplit,Tuple2<Long,Long>>

Provides a FileInputFormat for Avro records.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.api.common.io.FileInputFormat

FileInputFormat.FileBaseStatistics, FileInputFormat.InputSplitOpenThread

Field Summary

Fields inherited from class org.apache.flink.api.common.io.FileInputFormat

currentSplit, enumerateNestedFiles, INFLATER_INPUT_STREAM_FACTORIES, minSplitSize, numSplits, openTimeout, READ_WHOLE_SPLIT_FLAG, splitLength, splitStart, stream, unsplittable

Constructor Summary

Constructors

Constructor	Description
AvroInputFormat(Path filePath, Class<E> type)

Method Summary

Modifier and Type	Method	Description
Tuple2<Long,Long>	getCurrentState()	Returns the split currently being read, along with its current state.
TypeInformation<E>	getProducedType()	Gets the data type (as a TypeInformation) produced by this function or input format.
long	getRecordsReadFromBlock()
E	nextRecord(E reuseValue)	Reads the next record from the input.
void	open(FileInputSplit split)	Opens an input stream to the file defined in the input format.
boolean	reachedEnd()	Method used to check if the end of the input is reached.
void	reopen(FileInputSplit split, Tuple2<Long,Long> state)	Restores the state of a parallel instance reading from an InputFormat.
void	setReuseAvroValue(boolean reuseAvroValue)	Sets the flag whether to reuse the Avro value instance for all records.
void	setUnsplittable(boolean unsplittable)	If set, the InputFormat will only read entire files.

Methods inherited from class org.apache.flink.api.common.io.FileInputFormat

acceptFile, close, configure, createInputSplits, decorateInputStream, extractFileExtension, getFilePaths, getFileStats, getFileStats, getInflaterInputStreamFactory, getInputSplitAssigner, getMinSplitSize, getNestedFileEnumeration, getNumSplits, getOpenTimeout, getSplitLength, getSplitStart, getStatistics, getSupportedCompressionFormats, registerInflaterInputStreamFactory, setFilePath, setFilePath, setFilePaths, setFilePaths, setFilesFilter, setMinSplitSize, setNestedFileEnumeration, setNumSplits, setOpenTimeout, testForUnsplittable, toString

Methods inherited from class org.apache.flink.api.common.io.RichInputFormat

closeInputFormat, getRuntimeContext, openInputFormat, setRuntimeContext

Methods inherited from class java.lang.Object

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

Constructor Detail

AvroInputFormat

public AvroInputFormat(Path filePath,
                       Class<E> type)

Method Detail

setReuseAvroValue

public void setReuseAvroValue(boolean reuseAvroValue)

Sets the flag whether to reuse the Avro value instance for all records. By default, the input format reuses the Avro value.

Parameters:

reuseAvroValue - True, if the input format should reuse the Avro value instance, false otherwise.

setUnsplittable

public void setUnsplittable(boolean unsplittable)

If set, the InputFormat will only read entire files.

getProducedType

public TypeInformation<E> getProducedType()

Description copied from interface: ResultTypeQueryable

Gets the data type (as a TypeInformation) produced by this function or input format.

Specified by:

getProducedType in interface ResultTypeQueryable<E>

Returns:

The data type produced by this function or input format.

open

public void open(FileInputSplit split)
          throws IOException

Description copied from class: FileInputFormat

Opens an input stream to the file defined in the input format. The stream is positioned at the beginning of the given split.

The stream is actually opened in an asynchronous thread to make sure any interruptions to the thread working on the input format do not reach the file system.

Specified by:

open in interface InputFormat<E,FileInputSplit>

Overrides:

open in class FileInputFormat<E>

Parameters:

split - The split to be opened.

Throws:

IOException - Thrown, if the spit could not be opened due to an I/O problem.

reachedEnd

public boolean reachedEnd()
                   throws IOException

Description copied from interface: InputFormat

Method used to check if the end of the input is reached.

When this method is called, the input format it guaranteed to be opened.

Specified by:

reachedEnd in interface InputFormat<E,FileInputSplit>

Returns:

True if the end is reached, otherwise false.

Throws:

IOException - Thrown, if an I/O error occurred.

getRecordsReadFromBlock

public long getRecordsReadFromBlock()

nextRecord

public E nextRecord(E reuseValue)
             throws IOException

Description copied from interface: InputFormat

Reads the next record from the input.

When this method is called, the input format it guaranteed to be opened.

Specified by:

nextRecord in interface InputFormat<E,FileInputSplit>

Parameters:

reuseValue - Object that may be reused.

Returns:

Read record.

Throws:

IOException - Thrown, if an I/O error occurred.

getCurrentState

public Tuple2<Long,Long> getCurrentState()
                                        throws IOException

Description copied from interface: CheckpointableInputFormat

Returns the split currently being read, along with its current state. This will be used to restore the state of the reading channel when recovering from a task failure. In the case of a simple text file, the state can correspond to the last read offset in the split.

Specified by:

getCurrentState in interface CheckpointableInputFormat<FileInputSplit,Tuple2<Long,Long>>

Returns:

The state of the channel.

Throws:

IOException - Thrown if the creation of the state object failed.

reopen

public void reopen(FileInputSplit split,
                   Tuple2<Long,Long> state)
            throws IOException

Description copied from interface: CheckpointableInputFormat

Restores the state of a parallel instance reading from an InputFormat. This is necessary when recovering from a task failure. When this method is called, the input format it guaranteed to be configured.

NOTE: The caller has to make sure that the provided split is the one to whom the state belongs.

Specified by:

reopen in interface CheckpointableInputFormat<FileInputSplit,Tuple2<Long,Long>>

Parameters:

split - The split to be opened.

state - The state from which to start from. This can contain the offset, but also other data, depending on the input format.

Throws:

IOException