SSTable (apache-cassandra API)

java.lang.Object
- org.apache.cassandra.io.sstable.SSTable

Direct Known Subclasses:

BigTableZeroCopyWriter, 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`
`protected TableMetadataRef`	`metadata`
`protected DiskOptimizationStrategy`	`optimizationStrategy`
`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, java.util.Set<Component> components, TableMetadataRef metadata, DiskOptimizationStrategy optimizationStrategy)`

Method Summary

All Methods Static Methods Instance Methods Concrete 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.
`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)`
`static long`	`estimateRowsFromIndex(RandomAccessReader ifile, Descriptor descriptor)`
`java.util.List<java.lang.String>`	`getAllFilePaths()`
`AbstractBounds<Token>`	`getBounds()`
`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()`
`TableMetadata`	`metadata()`
`protected static java.util.Set<Component>`	`readTOC(Descriptor descriptor)` Reads the list of components from the TOC component.
`protected static java.util.Set<Component>`	`readTOC(Descriptor descriptor, boolean skipMissing)` Reads the list of components from the TOC component.
`java.lang.String`	`toString()`
`static Pair<Descriptor,Component>`	`tryComponentFromFilename(java.io.File file)` Parse a sstable filename into both a `Descriptor` and `Component` object.
`static Descriptor`	`tryDescriptorFromFilename(java.io.File file)` Parse a sstable filename into a `Descriptor` object.
`static void`	`validateRepairedMetadata(long repairedAt, java.util.UUID pendingRepair, boolean isTransient)`

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
```
  - compression
```
public final boolean compression
```
  - first
```
public DecoratedKey first
```
  - last
```
public DecoratedKey last
```
  - optimizationStrategy
```
protected final DiskOptimizationStrategy optimizationStrategy
```
  - metadata
```
protected final TableMetadataRef metadata
```
- Constructor Detail
  - SSTable
```
protected SSTable(Descriptor descriptor,
                  java.util.Set<Component> components,
                  TableMetadataRef metadata,
                  DiskOptimizationStrategy optimizationStrategy)
```
- 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
  - metadata
```
public TableMetadata metadata()
```
  - 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 file)
```
    Parse a sstable filename into both a Descriptor and Component object.
    
    Parameters:
    
    file - the filename to parse.
    
    Returns:
    
    a pair of the Descriptor and Component corresponding to file if it corresponds to a valid and supported sstable filename, null otherwise. Note that components of an unknown type will be returned as CUSTOM ones.
  - tryDescriptorFromFilename
```
public static Descriptor tryDescriptorFromFilename(java.io.File file)
```
    Parse a sstable filename into a Descriptor object.
    Note that this method ignores the component part of the filename; if this is not what you want, use tryComponentFromFilename(java.io.File) instead.
    
    Parameters:
    
    file - the filename to parse.
    
    Returns:
    
    the Descriptor corresponding to file if it corresponds to a valid and supported sstable filename, null otherwise.
  - 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
```
public static long estimateRowsFromIndex(RandomAccessReader ifile,
                                         Descriptor descriptor)
                                  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
  - readTOC
```
protected static java.util.Set<Component> readTOC(Descriptor descriptor,
                                                  boolean skipMissing)
                                           throws java.io.IOException
```
    Reads the list of components from the TOC component.
    
    Parameters:
    
    skipMissing, - skip adding the component to the returned set if the corresponding file is missing.
    
    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
  - getBounds
```
public AbstractBounds<Token> getBounds()
```
  - validateRepairedMetadata
```
public static void validateRepairedMetadata(long repairedAt,
                                            java.util.UUID pendingRepair,
                                            boolean isTransient)
```

Class SSTable

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TOMBSTONE_HISTOGRAM_BIN_SIZE

TOMBSTONE_HISTOGRAM_SPOOL_SIZE

TOMBSTONE_HISTOGRAM_TTL_ROUND_SECONDS

descriptor

components

compression

first

last

optimizationStrategy

metadata

Constructor Detail

SSTable

Method Detail

delete

metadata

getPartitioner

decorateKey

getMinimalKey

getFilename

getIndexFilename

getColumnFamilyName

getKeyspaceName

getAllFilePaths

tryComponentFromFilename

tryDescriptorFromFilename

componentsFor

discoverComponentsFor

estimateRowsFromIndex

bytesOnDisk

toString

readTOC

readTOC

appendTOC

addComponents

getBounds

validateRepairedMetadata