Package org.apache.druid.frame.file

Class FrameFileFooter

java.lang.Object

org.apache.druid.frame.file.FrameFileFooter

public class FrameFileFooter
extends Object

Encapsulation for ƒrame file footer related operations. The footer must be wrapped in a memory object (the memory can be physical or mmaped). Some verifications are also done on the footer to see if it is not corrupted. The schema for footer is as described by FrameFile.

Constructor Summary

Constructors

Constructor	Description
FrameFileFooter(org.apache.datasketches.memory.Memory footerMemory, long frameFileLength)

Method Summary

Modifier and Type	Method	Description
long	getFrameEndPosition(int frameNumber)	Get the last byte for the frame specified.
int	getNumFrames()
int	getNumPartitions()
int	getPartitionStartFrame(int partition)	First frame of a given partition.

Methods inherited from class java.lang.Object

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

Constructor Detail

FrameFileFooter

public FrameFileFooter(org.apache.datasketches.memory.Memory footerMemory,
                       long frameFileLength)
                throws IOE

Throws:

IOE

Method Detail

getPartitionStartFrame

public int getPartitionStartFrame(int partition)

First frame of a given partition. Partitions beyond getNumPartitions() are treated as empty: if provided, this method returns getNumFrames().

getFrameEndPosition

public long getFrameEndPosition(int frameNumber)

Get the last byte for the frame specified. The byte number is offsetted from the frame file start and is exclusive.

Parameters:

frameNumber - the id of the frame to get the end position for

Returns:

a long exclusive index representing the frame end

getNumFrames

public int getNumFrames()

getNumPartitions

public int getNumPartitions()