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

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

Constructor Summary

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

Method Summary

long	bytesOnDisk()
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()
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.
java.lang.String	getTableName()
static long	getTotalBytes(java.lang.Iterable<SSTableReader> sstables)
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

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)
                      throws java.io.IOException

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

Throws:

java.io.IOException

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()

getColumnFamilyName

public java.lang.String getColumnFamilyName()

getTableName

public java.lang.String getTableName()

tryComponentFromFilename

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

Returns:

A Descriptor,Component pair, or null if not a valid sstable component.

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