CompressedSegment (apache-cassandra API)

java.lang.Object
- org.apache.cassandra.db.commitlog.CommitLogSegment
- - org.apache.cassandra.db.commitlog.FileDirectSegment
  - - org.apache.cassandra.db.commitlog.CompressedSegment

```
public class CompressedSegment
extends FileDirectSegment
```
Compressed commit log segment. Provides an in-memory buffer for the mutation threads. On sync compresses the written section of the buffer and writes it to the destination channel. The format of the compressed commit log is as follows: - standard commit log header (as written by CommitLogDescriptor.writeHeader(ByteBuffer, CommitLogDescriptor)) - a series of 'sync segments' that are written every time the commit log is sync()'ed -- a sync section header, see CommitLogSegment.writeSyncMarker(long, ByteBuffer, int, int, int) -- total plain text length for this section -- a block of compressed data

- Nested Class Summary
  
  Nested Classes
  Modifier and Type Class Description
  
  protected static class CompressedSegment.CompressedSegmentBuilder
  - Nested classes/interfaces inherited from class org.apache.cassandra.db.commitlog.CommitLogSegment
    CommitLogSegment.Allocation, CommitLogSegment.Builder, CommitLogSegment.CDCState, CommitLogSegment.CommitLogSegmentFileComparator
- Field Summary
  - Fields inherited from class org.apache.cassandra.db.commitlog.CommitLogSegment
    descriptor, ENTRY_OVERHEAD_SIZE, id, manager
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  long onDiskSize()
  - Methods inherited from class org.apache.cassandra.db.commitlog.FileDirectSegment
    flush, internalClose
  - Methods inherited from class org.apache.cassandra.db.commitlog.CommitLogSegment
    additionalHeaderParameters, contains, contentSize, coverInMap, createBuffer, dirtyString, getCDCFile, getCDCIndexFile, getCDCState, getCurrentCommitLogPosition, getDirtyTableIds, getName, getPath, isStillAllocating, isUnused, markClean, setCDCState, toString, writeCDCIndexFile, writeSyncMarker
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - onDiskSize
```
public long onDiskSize()
```
    Specified by:
    
    onDiskSize in class CommitLogSegment