Package org.apache.nemo.runtime.executor.data.metadata

Class FileMetadata<K extends java.io.Serializable>

java.lang.Object

org.apache.nemo.runtime.executor.data.metadata.FileMetadata<K>

Type Parameters:

K - the key type of its partitions.

Direct Known Subclasses:

LocalFileMetadata, RemoteFileMetadata

public abstract class FileMetadata<K extends java.io.Serializable>
extends java.lang.Object

This class represents a metadata for a Block. The writer and reader determine the status of a file block (such as accessibility, how many bytes are written, etc.) by using this metadata.

Constructor Summary

Constructors

Constructor	Description
FileMetadata()	Construct a new file metadata.
FileMetadata(java.util.List<PartitionMetadata<K>> partitionMetadataList)	Construct a file metadata with existing partition metadata.

Method Summary

Modifier and Type	Method	Description
abstract void	commitBlock()	Notifies that all writes are finished for the block corresponding to this metadata.
abstract void	deleteMetadata()	Deletes the metadata.
java.util.List<PartitionMetadata<K>>	getPartitionMetadataList()	Gets a list containing the partition metadata of corresponding block.
boolean	isCommitted()
protected void	setCommitted(boolean committed)	Set the commit value.
void	writePartitionMetadata(K key, int partitionSize)	Writes the metadata for a partition.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileMetadata

public FileMetadata()

Construct a new file metadata.

FileMetadata

public FileMetadata(java.util.List<PartitionMetadata<K>> partitionMetadataList)

Construct a file metadata with existing partition metadata.

Parameters:

partitionMetadataList - the partition metadata list.

Method Detail

writePartitionMetadata

public final void writePartitionMetadata(K key,
                                         int partitionSize)
                                  throws java.io.IOException

Writes the metadata for a partition.

Parameters:

key - the key of the partition.

partitionSize - the size of the partition.

Throws:

java.io.IOException - if fail to append the partition metadata.

getPartitionMetadataList

public final java.util.List<PartitionMetadata<K>> getPartitionMetadataList()

Gets a list containing the partition metadata of corresponding block.

Returns:

the list containing the partition metadata.

deleteMetadata

public abstract void deleteMetadata()
                             throws java.io.IOException

Deletes the metadata.

Throws:

java.io.IOException - if fail to delete.

commitBlock

public abstract void commitBlock()
                          throws java.io.IOException

Notifies that all writes are finished for the block corresponding to this metadata.

Throws:

java.io.IOException - if fail to commit.

setCommitted

protected final void setCommitted(boolean committed)

Set the commit value.

Parameters:

committed - whether this block is committed or not.

isCommitted

public final boolean isCommitted()

Returns:

whether this file is committed or not.