org.apache.flink.core.fs

Class AbstractMultiFSDataInputStream

java.lang.Object

java.io.InputStream

org.apache.flink.core.fs.FSDataInputStream

org.apache.flink.core.fs.AbstractMultiFSDataInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

@Internal
public abstract class AbstractMultiFSDataInputStream
extends FSDataInputStream

Abstract base class for wrappers over multiple FSDataInputStream, which gives a contiguous view on all inner streams and makes them look like a single stream, in which we can read, seek, etc.

Field Summary

Fields

Modifier and Type	Field and Description
protected FSDataInputStream	delegate Inner stream for the currently accessed segment of the virtual global stream.
protected long	totalAvailable Total available bytes in the virtual global stream.
protected long	totalPos Position in the virtual global stream.

Constructor Summary

Constructors

Constructor and Description
AbstractMultiFSDataInputStream()

Method Summary

Modifier and Type	Method and Description
void	close()
long	getPos() Gets the current position in the input stream.
protected abstract FSDataInputStream	getSeekedStreamForOffset(long globalStreamOffset) Delivers a the right stream for the given global stream offset.
int	read()
void	seek(long desired) Seek to the given offset from the start of the file.
long	skip(long n)

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, read, reset

Methods inherited from class java.lang.Object

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

Field Detail

delegate

protected FSDataInputStream delegate

Inner stream for the currently accessed segment of the virtual global stream.

totalPos

protected long totalPos

Position in the virtual global stream.

totalAvailable

protected long totalAvailable

Total available bytes in the virtual global stream.

Constructor Detail

AbstractMultiFSDataInputStream

public AbstractMultiFSDataInputStream()

Method Detail

seek

public void seek(long desired)
          throws IOException

Description copied from class: FSDataInputStream

Seek to the given offset from the start of the file. The next read() will be from that location. Can't seek past the end of the stream.

Specified by:

seek in class FSDataInputStream

Parameters:

desired - the desired offset

Throws:

IOException - Thrown if an error occurred while seeking inside the input stream.

getPos

public long getPos()
            throws IOException

Description copied from class: FSDataInputStream

Gets the current position in the input stream.

Specified by:

getPos in class FSDataInputStream

Returns:

current position in the input stream

Throws:

IOException - Thrown if an I/O error occurred in the underlying stream implementation while accessing the stream's position.

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

getSeekedStreamForOffset

protected abstract FSDataInputStream getSeekedStreamForOffset(long globalStreamOffset)
                                                       throws IOException

Delivers a the right stream for the given global stream offset. The returned stream is already seeked to the right local offset that correctly reflects the global offset.

Parameters:

globalStreamOffset - the global offset to which we seek

Returns:

a sub-stream, seeked to the correct local offset w.r.t. the global offset.

Throws:

IOException