org.apache.flink.api.common.io

Class DelimitedInputFormat<OT>

java.lang.Object

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

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

org.apache.flink.api.common.io.DelimitedInputFormat<OT>

All Implemented Interfaces:

Serializable, CheckpointableInputFormat<FileInputSplit,Long>, InputFormat<OT,FileInputSplit>, InputSplitSource<FileInputSplit>

Direct Known Subclasses:

GenericCsvInputFormat

@Public
public abstract class DelimitedInputFormat<OT>
extends FileInputFormat<OT>
implements CheckpointableInputFormat<FileInputSplit,Long>

Base implementation for input formats that split the input at a delimiter into records. The parsing of the record bytes into the record has to be implemented in the readRecord(Object, byte[], int, int) method.

The default delimiter is the newline character '\n'.

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

Modifier and Type	Field and Description
protected static String	RECORD_DELIMITER The configuration key to set the record delimiter.

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

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

Constructor Summary

Constructors

Modifier	Constructor and Description
	DelimitedInputFormat()
protected	DelimitedInputFormat(Path filePath)

Method Summary

Modifier and Type	Method and Description
void	close() Closes the input by releasing all buffers and closing the file input stream.
void	configure(Configuration parameters) Configures this input format by reading the path to the file from the configuration andge the string that defines the record delimiter.
int	getBufferSize()
Long	getCurrentState() Returns the split currently being read, along with its current state.
byte[]	getDelimiter()
int	getLineLengthLimit()
int	getNumLineSamples()
FileInputFormat.FileBaseStatistics	getStatistics(BaseStatistics cachedStats) Obtains basic file statistics containing only file size.
protected static void	loadGlobalConfigParams()
OT	nextRecord(OT record) Reads the next record from the input.
void	open(FileInputSplit split) Opens the given input split.
boolean	reachedEnd() Checks whether the current split is at its end.
protected boolean	readLine()
abstract OT	readRecord(OT reuse, byte[] bytes, int offset, int numBytes) This function parses the given byte array which represents a serialized record.
void	reopen(FileInputSplit split, Long state) Restores the state of a parallel instance reading from an InputFormat.
void	setBufferSize(int bufferSize)
void	setDelimiter(byte[] delimiter)
void	setDelimiter(char delimiter)
void	setDelimiter(String delimiter)
void	setLineLengthLimit(int lineLengthLimit)
void	setNumLineSamples(int numLineSamples)

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

acceptFile, createInputSplits, decorateInputStream, extractFileExtension, getFilePath, getFileStats, getInflaterInputStreamFactory, getInputSplitAssigner, getMinSplitSize, getNestedFileEnumeration, getNumSplits, getOpenTimeout, getSplitLength, getSplitStart, registerInflaterInputStreamFactory, setFilePath, setFilePath, 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

Field Detail

RECORD_DELIMITER

protected static final String RECORD_DELIMITER

The configuration key to set the record delimiter.

See Also:

Constant Field Values

Constructor Detail

DelimitedInputFormat

public DelimitedInputFormat()

DelimitedInputFormat

protected DelimitedInputFormat(Path filePath)

Method Detail

loadGlobalConfigParams

protected static void loadGlobalConfigParams()

getDelimiter

public byte[] getDelimiter()

setDelimiter

public void setDelimiter(byte[] delimiter)

setDelimiter

public void setDelimiter(char delimiter)

setDelimiter

public void setDelimiter(String delimiter)

getLineLengthLimit

public int getLineLengthLimit()

setLineLengthLimit

public void setLineLengthLimit(int lineLengthLimit)

getBufferSize

public int getBufferSize()

setBufferSize

public void setBufferSize(int bufferSize)

getNumLineSamples

public int getNumLineSamples()

setNumLineSamples

public void setNumLineSamples(int numLineSamples)

readRecord

public abstract OT readRecord(OT reuse,
                              byte[] bytes,
                              int offset,
                              int numBytes)
                       throws IOException

This function parses the given byte array which represents a serialized record. The function returns a valid record or throws an IOException.

Parameters:

reuse - An optionally reusable object.

bytes - Binary data of serialized records.

offset - The offset where to start to read the record data.

numBytes - The number of bytes that can be read starting at the offset position.

Returns:

Returns the read record if it was successfully deserialized.

Throws:

IOException - if the record could not be read.

configure

public void configure(Configuration parameters)

Configures this input format by reading the path to the file from the configuration andge the string that defines the record delimiter.

Specified by:

configure in interface InputFormat<OT,FileInputSplit>

Overrides:

configure in class FileInputFormat<OT>

Parameters:

parameters - The configuration object to read the parameters from.

See Also:

InputFormat.configure(org.apache.flink.configuration.Configuration)

getStatistics

public FileInputFormat.FileBaseStatistics getStatistics(BaseStatistics cachedStats)
                                                 throws IOException

Description copied from class: FileInputFormat

Obtains basic file statistics containing only file size. If the input is a directory, then the size is the sum of all contained files.

Specified by:

getStatistics in interface InputFormat<OT,FileInputSplit>

Overrides:

getStatistics in class FileInputFormat<OT>

Parameters:

cachedStats - The statistics that were cached. May be null.

Returns:

The base statistics for the input, or null, if not available.

Throws:

IOException

See Also:

InputFormat.getStatistics(org.apache.flink.api.common.io.statistics.BaseStatistics)

open

public void open(FileInputSplit split)
          throws IOException

Opens the given input split. This method opens the input stream to the specified file, allocates read buffers and positions the stream at the correct position, making sure that any partial record at the beginning is skipped.

Specified by:

open in interface InputFormat<OT,FileInputSplit>

Overrides:

open in class FileInputFormat<OT>

Parameters:

split - The input split to open.

Throws:

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

See Also:

FileInputFormat.open(org.apache.flink.core.fs.FileInputSplit)

reachedEnd

public boolean reachedEnd()

Checks whether the current split is at its end.

Specified by:

reachedEnd in interface InputFormat<OT,FileInputSplit>

Returns:

True, if the split is at its end, false otherwise.

nextRecord

public OT nextRecord(OT record)
              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<OT,FileInputSplit>

Parameters:

record - Object that may be reused.

Returns:

Read record.

Throws:

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

close

public void close()
           throws IOException

Closes the input by releasing all buffers and closing the file input stream.

Specified by:

close in interface InputFormat<OT,FileInputSplit>

Overrides:

close in class FileInputFormat<OT>

Throws:

IOException - Thrown, if the closing of the file stream causes an I/O error.

readLine

protected final boolean readLine()
                          throws IOException

Throws:

IOException

getCurrentState

@PublicEvolving
public 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,Long>

Returns:

The state of the channel.

Throws:

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

reopen

@PublicEvolving
public void reopen(FileInputSplit split,
                                   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,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