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
protected java.util.Set<Component>	components
boolean	compression
Descriptor	descriptor
DecoratedKey	first
DecoratedKey	last
CFMetaData	metadata
static int	TOMBSTONE_HISTOGRAM_BIN_SIZE
static int	TOMBSTONE_HISTOGRAM_SPOOL_SIZE
static int	TOMBSTONE_HISTOGRAM_TTL_ROUND_SECONDS

Constructor Summary

Constructors

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

Method Summary

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.
DecoratedKey	decorateKey(java.nio.ByteBuffer key)
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.
static java.util.Set<Component>	discoverComponentsFor(Descriptor desc)
protected long	estimateRowsFromIndex(RandomAccessReader ifile)
java.util.List<java.lang.String>	getAllFilePaths()
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.
IPartitioner	getPartitioner()
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

TOMBSTONE_HISTOGRAM_BIN_SIZE

public static final int TOMBSTONE_HISTOGRAM_BIN_SIZE

See Also:

Constant Field Values

TOMBSTONE_HISTOGRAM_SPOOL_SIZE

public static final int TOMBSTONE_HISTOGRAM_SPOOL_SIZE

See Also:

Constant Field Values

TOMBSTONE_HISTOGRAM_TTL_ROUND_SECONDS

public static final int TOMBSTONE_HISTOGRAM_TTL_ROUND_SECONDS

descriptor

public final Descriptor descriptor

components

protected final java.util.Set<Component> components

metadata

public final CFMetaData metadata

compression

public final boolean compression

first

public DecoratedKey first

last

public DecoratedKey last

Constructor Detail

SSTable

protected SSTable(Descriptor descriptor,
                  CFMetaData metadata)

SSTable

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

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

getPartitioner

public IPartitioner getPartitioner()

decorateKey

public DecoratedKey decorateKey(java.nio.ByteBuffer key)

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()

getAllFilePaths

public java.util.List<java.lang.String> getAllFilePaths()

tryComponentFromFilename

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

Returns:

Descriptor and Component pair. null if given file is not acceptable as SSTable component. 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.

discoverComponentsFor

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

estimateRowsFromIndex

protected long estimateRowsFromIndex(RandomAccessReader ifile)
                              throws java.io.IOException

Returns:

An estimate of the number of keys contained in the given index file.

Throws:

java.io.IOException

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