org.apache.cassandra.io.sstable

Class SSTable

java.lang.Object

org.apache.cassandra.io.sstable.SSTable

Direct Known Subclasses:

SSTableReader, SSTableWriter

public abstract class SSTable
extends java.lang.Object

This class is built on top of the SequenceFile. It stores data on disk in sorted fashion. However the sorting is upto the application. This class expects keys to be handed to it in sorted order. A separate index file is maintained as well, containing the SSTable keys and the offset into the SSTable at which they are found. Every 1/indexInterval key is read into memory when the SSTable is opened. Finally, a bloom filter file is also kept for the keys in each SSTable.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	COMPONENT_DATA
static java.lang.String	COMPONENT_DIGEST
static java.lang.String	COMPONENT_FILTER
static java.lang.String	COMPONENT_INDEX
static java.lang.String	COMPONENT_STATS
protected java.util.Set<Component>	components
boolean	compression
Descriptor	descriptor
DecoratedKey	first
DecoratedKey	last
static java.util.Comparator<SSTableReader>	maxTimestampComparator
CFMetaData	metadata
IPartitioner	partitioner
static java.util.Comparator<SSTableReader>	sstableComparator
static com.google.common.collect.Ordering<SSTableReader>	sstableOrdering
static java.lang.String	TEMPFILE_MARKER
static int	TOMBSTONE_HISTOGRAM_BIN_SIZE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SSTable(Descriptor descriptor, CFMetaData metadata, IPartitioner partitioner)
protected	SSTable(Descriptor descriptor, java.util.Set<Component> components, CFMetaData metadata, IPartitioner partitioner)

Method Summary

Methods

Modifier and Type	Method and Description
void	addComponents(java.util.Collection<Component> newComponents) Registers new custom components.
protected static void	appendTOC(Descriptor descriptor, java.util.Collection<Component> components) Appends new component names to the TOC component.
long	bytesOnDisk()
static java.util.Set<Component>	componentsFor(Descriptor desc) Discovers existing components for the descriptor.
static boolean	delete(Descriptor desc, java.util.Set<Component> components) We use a ReferenceQueue to manage deleting files that have been compacted and for which no more SSTable references exist.
java.lang.String	getColumnFamilyName()
java.lang.String	getFilename()
java.lang.String	getIndexFilename()
java.lang.String	getKeyspaceName()
static DecoratedKey	getMinimalKey(DecoratedKey key) If the given @param key occupies only part of a larger buffer, allocate a new buffer that is only as large as necessary.
static long	getTotalBytes(java.lang.Iterable<SSTableReader> sstables)
protected static java.util.Set<Component>	readTOC(Descriptor descriptor) Reads the list of components from the TOC component.
java.lang.String	toString()
static Pair<Descriptor,Component>	tryComponentFromFilename(java.io.File dir, java.lang.String name)

Methods inherited from class java.lang.Object

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

Field Detail

COMPONENT_DATA

public static final java.lang.String COMPONENT_DATA

COMPONENT_INDEX

public static final java.lang.String COMPONENT_INDEX

COMPONENT_FILTER

public static final java.lang.String COMPONENT_FILTER

COMPONENT_STATS

public static final java.lang.String COMPONENT_STATS

COMPONENT_DIGEST

public static final java.lang.String COMPONENT_DIGEST

TEMPFILE_MARKER

public static final java.lang.String TEMPFILE_MARKER

See Also:

Constant Field Values

TOMBSTONE_HISTOGRAM_BIN_SIZE

public static final int TOMBSTONE_HISTOGRAM_BIN_SIZE

See Also:

Constant Field Values

maxTimestampComparator

public static final java.util.Comparator<SSTableReader> maxTimestampComparator

descriptor

public final Descriptor descriptor

components

protected final java.util.Set<Component> components

metadata

public final CFMetaData metadata

partitioner

public final IPartitioner partitioner

compression

public final boolean compression

first

public DecoratedKey first

last

public DecoratedKey last

sstableComparator

public static final java.util.Comparator<SSTableReader> sstableComparator

sstableOrdering

public static final com.google.common.collect.Ordering<SSTableReader> sstableOrdering

Constructor Detail

SSTable

protected SSTable(Descriptor descriptor,
       CFMetaData metadata,
       IPartitioner partitioner)

SSTable

protected SSTable(Descriptor descriptor,
       java.util.Set<Component> components,
       CFMetaData metadata,
       IPartitioner partitioner)

Method Detail

delete

public static boolean delete(Descriptor desc,
             java.util.Set<Component> components)

We use a ReferenceQueue to manage deleting files that have been compacted and for which no more SSTable references exist. But this is not guaranteed to run for each such file because of the semantics of the JVM gc. So, we write a marker to `compactedFilename` when a file is compacted; if such a marker exists on startup, the file should be removed. This method will also remove SSTables that are marked as temporary.

Returns:

true if the file was deleted

getMinimalKey

public static DecoratedKey getMinimalKey(DecoratedKey key)

If the given @param key occupies only part of a larger buffer, allocate a new buffer that is only as large as necessary.

getFilename

public java.lang.String getFilename()

getIndexFilename

public java.lang.String getIndexFilename()

getColumnFamilyName

public java.lang.String getColumnFamilyName()

getKeyspaceName

public java.lang.String getKeyspaceName()

tryComponentFromFilename

public static Pair<Descriptor,Component> tryComponentFromFilename(java.io.File dir,
                                                  java.lang.String name)

Returns:

A Descriptor,Component pair. If component is of unknown type, returns CUSTOM component.

componentsFor

public static java.util.Set<Component> componentsFor(Descriptor desc)

Discovers existing components for the descriptor. Slow: only intended for use outside the critical path.

getTotalBytes

public static long getTotalBytes(java.lang.Iterable<SSTableReader> sstables)

bytesOnDisk

public long bytesOnDisk()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

readTOC

protected static java.util.Set<Component> readTOC(Descriptor descriptor)
                                           throws java.io.IOException

Reads the list of components from the TOC component.

Returns:

set of components found in the TOC

Throws:

java.io.IOException

appendTOC

protected static void appendTOC(Descriptor descriptor,
             java.util.Collection<Component> components)

Appends new component names to the TOC component.

addComponents

public void addComponents(java.util.Collection<Component> newComponents)

Registers new custom components. Used by custom compaction strategies. Adding a component for the second time is a no-op. Don't remove this - this method is a part of the public API, intended for use by custom compaction strategies.

Parameters:

newComponents - collection of components to be added