org.apache.flink.core.io

Class PostVersionedIOReadableWritable

java.lang.Object

org.apache.flink.core.io.VersionedIOReadableWritable

org.apache.flink.core.io.PostVersionedIOReadableWritable

All Implemented Interfaces:

IOReadableWritable, Versioned

@Internal
public abstract class PostVersionedIOReadableWritable
extends VersionedIOReadableWritable

A VersionedIOReadableWritable which allows to differentiate whether the previous data was versioned with a VersionedIOReadableWritable. This can be used if previously written data was not versioned, and is to be migrated to a versioned format.

Constructor Summary

Constructors

Constructor and Description
PostVersionedIOReadableWritable()

Method Summary

Modifier and Type	Method and Description
void	read(DataInputView in) We do not support reading from a DataInputView, because it does not support pushing back already read bytes.
protected abstract void	read(DataInputView in, boolean wasVersioned) Read from the provided in.
void	read(InputStream inputStream) This read attempts to first identify if the input view contains the special VERSIONED_IDENTIFIER by reading and buffering the first few bytes.
void	write(DataOutputView out) Writes the object's internal data to the given data output view.

Methods inherited from class org.apache.flink.core.io.VersionedIOReadableWritable

getCompatibleVersions, getReadVersion

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.core.io.Versioned

getVersion

Constructor Detail

PostVersionedIOReadableWritable

public PostVersionedIOReadableWritable()

Method Detail

read

protected abstract void read(DataInputView in,
                             boolean wasVersioned)
                      throws IOException

Read from the provided in. A flag wasVersioned can be used to determine whether or not the data to read was previously written by a VersionedIOReadableWritable.

Throws:

IOException

write

public void write(DataOutputView out)
           throws IOException

Description copied from interface: IOReadableWritable

Writes the object's internal data to the given data output view.

Specified by:

write in interface IOReadableWritable

Overrides:

write in class VersionedIOReadableWritable

Parameters:

out - the output view to receive the data.

Throws:

IOException - thrown if any error occurs while writing to the output stream

read

public final void read(InputStream inputStream)
                throws IOException

This read attempts to first identify if the input view contains the special VERSIONED_IDENTIFIER by reading and buffering the first few bytes. If identified to be versioned, the usual version resolution read path in VersionedIOReadableWritable.read(DataInputView) is invoked. Otherwise, we "reset" the input stream by pushing back the read buffered bytes into the stream.

Throws:

IOException

read

public final void read(DataInputView in)
                throws IOException

We do not support reading from a DataInputView, because it does not support pushing back already read bytes.

Specified by:

read in interface IOReadableWritable

Overrides:

read in class VersionedIOReadableWritable

Parameters:

in - the input view to read the data from

Throws:

IOException - thrown if any error occurs while reading from the input stream