org.apache.cassandra.io.sstable

Class IndexSummaryBuilder

java.lang.Object

org.apache.cassandra.io.sstable.IndexSummaryBuilder

All Implemented Interfaces:

java.lang.AutoCloseable

public class IndexSummaryBuilder
extends java.lang.Object
implements java.lang.AutoCloseable

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	IndexSummaryBuilder.ReadableBoundary Represents a boundary that is guaranteed fully readable in the summary, index file and data file.

Constructor Summary

Constructors

Constructor and Description
IndexSummaryBuilder(long expectedKeys, int minIndexInterval, int samplingLevel)

Method Summary

Modifier and Type	Method and Description
IndexSummary	build(IPartitioner partitioner)
IndexSummary	build(IPartitioner partitioner, IndexSummaryBuilder.ReadableBoundary boundary)
static int	calculateSamplingLevel(int currentSamplingLevel, int currentNumEntries, long targetNumEntries, int minIndexInterval, int maxIndexInterval)
void	close()
java.lang.Throwable	close(java.lang.Throwable accumulate)
static IndexSummary	downsample(IndexSummary existing, int newSamplingLevel, int minIndexInterval, IPartitioner partitioner) Downsamples an existing index summary to a new sampling level.
static int	entriesAtSamplingLevel(int samplingLevel, int maxSummarySize)
IndexSummaryBuilder.ReadableBoundary	getLastReadableBoundary()
void	markDataSynced(long upToPosition)
void	markIndexSynced(long upToPosition)
IndexSummaryBuilder	maybeAddEntry(DecoratedKey decoratedKey, long indexStart)
IndexSummaryBuilder	maybeAddEntry(DecoratedKey decoratedKey, long indexStart, long indexEnd, long dataEnd)
void	prepareToCommit()

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexSummaryBuilder

public IndexSummaryBuilder(long expectedKeys,
                           int minIndexInterval,
                           int samplingLevel)

Method Detail

markIndexSynced

public void markIndexSynced(long upToPosition)

markDataSynced

public void markDataSynced(long upToPosition)

getLastReadableBoundary

public IndexSummaryBuilder.ReadableBoundary getLastReadableBoundary()

maybeAddEntry

public IndexSummaryBuilder maybeAddEntry(DecoratedKey decoratedKey,
                                         long indexStart)
                                  throws java.io.IOException

Throws:

java.io.IOException

maybeAddEntry

public IndexSummaryBuilder maybeAddEntry(DecoratedKey decoratedKey,
                                         long indexStart,
                                         long indexEnd,
                                         long dataEnd)
                                  throws java.io.IOException

Parameters:

decoratedKey - the key for this record

indexStart - the position in the index file this record begins

indexEnd - the position in the index file we need to be able to read to (exclusive) to read this record

dataEnd - the position in the data file we need to be able to read to (exclusive) to read this record a value of 0 indicates we are not tracking readable boundaries

Throws:

java.io.IOException

prepareToCommit

public void prepareToCommit()

build

public IndexSummary build(IPartitioner partitioner)

build

public IndexSummary build(IPartitioner partitioner,
                          IndexSummaryBuilder.ReadableBoundary boundary)

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

close

public java.lang.Throwable close(java.lang.Throwable accumulate)

entriesAtSamplingLevel

public static int entriesAtSamplingLevel(int samplingLevel,
                                         int maxSummarySize)

calculateSamplingLevel

public static int calculateSamplingLevel(int currentSamplingLevel,
                                         int currentNumEntries,
                                         long targetNumEntries,
                                         int minIndexInterval,
                                         int maxIndexInterval)

downsample

public static IndexSummary downsample(IndexSummary existing,
                                      int newSamplingLevel,
                                      int minIndexInterval,
                                      IPartitioner partitioner)

Downsamples an existing index summary to a new sampling level.

Parameters:

existing - an existing IndexSummary

newSamplingLevel - the target level for the new IndexSummary. This must be less than the current sampling level for `existing`.

partitioner - the partitioner used for the index summary

Returns:

a new IndexSummary