org.apache.paimon.fs

Class PositionOutputStream

java.lang.Object

java.io.OutputStream

org.apache.paimon.fs.PositionOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

AsyncPositionOutputStream, LocalFileIO.LocalPositionOutputStream, PositionOutputStreamWrapper

@Public
public abstract class PositionOutputStream
extends OutputStream

PositionOutputStream provides position methods.

Since:

0.4.0

Constructor Summary

Constructors

Constructor and Description
PositionOutputStream()

Method Summary

Modifier and Type	Method and Description
abstract void	close() Closes the output stream.
abstract void	flush() Flushes the stream, writing any data currently buffered in stream implementation to the proper output stream.
abstract long	getPos() Gets the position of the stream (non-negative), defined as the number of bytes from the beginning of the file to the current writing position.
abstract void	write(byte[] b) Writes b.length bytes from the specified byte array to this output stream.
abstract void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this output stream.

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Constructor Detail

PositionOutputStream

public PositionOutputStream()

Method Detail

getPos

public abstract long getPos()
                     throws IOException

Gets the position of the stream (non-negative), defined as the number of bytes from the beginning of the file to the current writing position. The position corresponds to the zero-based index of the next byte that will be written.

This method must report accurately report the current position of the stream. Various components of the high-availability and recovery logic rely on the accurate

Returns:

The current position in the stream, defined as the number of bytes from the beginning of the file to the current writing position.

Throws:

IOException - Thrown if an I/O error occurs while obtaining the position from the stream implementation.

write

public abstract void write(byte[] b)
                    throws IOException

Writes b.length bytes from the specified byte array to this output stream. The general contract for write(b) is that it should have exactly the same effect as the call write(b, 0, b.length).

Overrides:

write in class OutputStream

Throws:

IOException

write

public abstract void write(byte[] b,
                           int off,
                           int len)
                    throws IOException

Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

Overrides:

write in class OutputStream

Throws:

IOException

flush

public abstract void flush()
                    throws IOException

Flushes the stream, writing any data currently buffered in stream implementation to the proper output stream. After this method has been called, the stream implementation must not hold onto any buffered data any more.

Implementation note: This overrides the method defined in OutputStream as abstract to force implementations of the PositionOutputStream to implement this method directly.

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - Thrown if an I/O error occurs while flushing the stream.

close

public abstract void close()
                    throws IOException

Closes the output stream. After this method returns, the implementation must guarantee that all data written to the stream is persistent/visible.

The above implies that the method must block until persistence can be guaranteed. For example for distributed replicated file systems, the method must block until the replication quorum has been reached. If the calling thread is interrupted in the process, it must fail with an IOException to indicate that persistence cannot be guaranteed.

If this method throws an exception, the data in the stream cannot be assumed to be persistent.

Implementation note: This overrides the method defined in OutputStream as abstract to force implementations of the PositionOutputStream to implement this method directly.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException - Thrown, if an error occurred while closing the stream or guaranteeing that the data is persistent.