Package org.apache.cassandra.io.compress

Class CompressionMetadata

java.lang.Object

org.apache.cassandra.utils.concurrent.SharedCloseableImpl

org.apache.cassandra.utils.concurrent.WrappedSharedCloseable

org.apache.cassandra.io.compress.CompressionMetadata

All Implemented Interfaces:

java.lang.AutoCloseable, SharedCloseable

public class CompressionMetadata
extends WrappedSharedCloseable

Holds metadata about compressed file TODO extract interface ICompressionMetadata which will just provide non-resource properties

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CompressionMetadata.Chunk	Holds offset and length of the file chunk
static class	CompressionMetadata.Writer

Field Summary

Fields

Modifier and Type	Field	Description
File	chunksIndexFile
long	compressedFileLength
long	dataLength
CompressionParams	parameters

Constructor Summary

Constructors

Constructor	Description
CompressionMetadata(File chunksIndexFile, CompressionParams parameters, Memory chunkOffsets, long chunkOffsetsSize, long dataLength, long compressedFileLength)

Method Summary

Modifier and Type	Method	Description
void	addTo(Ref.IdentityCollection identities)
CompressionMetadata.Chunk	chunkFor(long position)	Get a chunk of compressed data (offset, length) corresponding to given position
int	chunkLength()
ICompressor	compressor()
CompressionMetadata.Chunk[]	getChunksForSections(java.util.Collection<SSTableReader.PartitionPositionBounds> sections)
long	getDataOffsetForChunkOffset(long chunkOffset)
long	getTotalSizeForSections(java.util.Collection<SSTableReader.PartitionPositionBounds> sections)
int	maxCompressedLength()
long	offHeapSize()	Returns the amount of memory in bytes used off heap.
static CompressionMetadata	open(File chunksIndexFile, long compressedLength, boolean hasMaxCompressedSize)
CompressionMetadata	sharedCopy()

Methods inherited from class org.apache.cassandra.utils.concurrent.SharedCloseableImpl

close, close, isCleanedUp

Methods inherited from class java.lang.Object

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

Field Detail

dataLength

public final long dataLength

compressedFileLength

public final long compressedFileLength

chunksIndexFile

public final File chunksIndexFile

parameters

public final CompressionParams parameters

Constructor Detail

CompressionMetadata

public CompressionMetadata(File chunksIndexFile,
                           CompressionParams parameters,
                           Memory chunkOffsets,
                           long chunkOffsetsSize,
                           long dataLength,
                           long compressedFileLength)

Method Detail

open

public static CompressionMetadata open(File chunksIndexFile,
                                       long compressedLength,
                                       boolean hasMaxCompressedSize)

compressor

public ICompressor compressor()

chunkLength

public int chunkLength()

maxCompressedLength

public int maxCompressedLength()

offHeapSize

public long offHeapSize()

Returns the amount of memory in bytes used off heap.

Returns:

the amount of memory in bytes used off heap

addTo

public void addTo(Ref.IdentityCollection identities)

Specified by:

addTo in interface SharedCloseable

Overrides:

addTo in class SharedCloseableImpl

sharedCopy

public CompressionMetadata sharedCopy()

Returns:

a new instance of the object representing the same state and backed by the same underlying resources. Coordinates with the original (and other instances) when the underlying resource should be closed. Throws an exception if the shared resource has already been closed.

chunkFor

public CompressionMetadata.Chunk chunkFor(long position)

Get a chunk of compressed data (offset, length) corresponding to given position

Parameters:

position - Position in the file.

Returns:

pair of chunk offset and length.

getDataOffsetForChunkOffset

public long getDataOffsetForChunkOffset(long chunkOffset)

getTotalSizeForSections

public long getTotalSizeForSections(java.util.Collection<SSTableReader.PartitionPositionBounds> sections)

Parameters:

sections - Collection of sections in uncompressed file. Should not contain sections that overlap each other.

Returns:

Total chunk size in bytes for given sections including checksum.

getChunksForSections

public CompressionMetadata.Chunk[] getChunksForSections(java.util.Collection<SSTableReader.PartitionPositionBounds> sections)

Parameters:

sections - Collection of sections in uncompressed file

Returns:

Array of chunks which corresponds to given sections of uncompressed file, sorted by chunk offset