edu.snu.coral.runtime.executor.data.metadata

Class FileMetadata<K extends Serializable>

java.lang.Object

edu.snu.coral.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 Serializable>
extends 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 and Description
FileMetadata() Construct a new file metadata.
FileMetadata(List<PartitionMetadata<K>> partitionMetadataList) Construct a file metadata with existing partition metadata.

Method Summary

Modifier and Type	Method and Description
abstract void	commitBlock() Notifies that all writes are finished for the block corresponding to this metadata.
abstract void	deleteMetadata() Deletes the metadata.
Iterable<PartitionMetadata<K>>	getPartitionMetadataIterable() Gets a iterable containing the partition metadata of corresponding block.
protected void	setCommitted(boolean committed) Set the commit value.
void	writePartitionMetadata(K key, int partitionSize, long elementsTotal) 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(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,
                                         long elementsTotal)
                                  throws IOException

Writes the metadata for a partition.

Parameters:

key - the key of the partition.

partitionSize - the size of the partition.

elementsTotal - the number of elements in the partition.

Throws:

IOException - if fail to append the partition metadata.

getPartitionMetadataIterable

public final Iterable<PartitionMetadata<K>> getPartitionMetadataIterable()
                                                                  throws IOException

Gets a iterable containing the partition metadata of corresponding block.

Returns:

the iterable containing the partition metadata.

Throws:

IOException - if fail to get the iterable.

deleteMetadata

public abstract void deleteMetadata()
                             throws IOException

Deletes the metadata.

Throws:

IOException - if fail to delete.

commitBlock

public abstract void commitBlock()
                          throws IOException

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

Throws:

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.