org.apache.cassandra.io.sstable
Class IndexHelper

java.lang.Object
  org.apache.cassandra.io.sstable.IndexHelper

public class IndexHelper
extends java.lang.Object

Provides helper to serialize, deserialize and use column indexes.

Nested Class Summary

static class

IndexHelper.IndexInfo

Constructor Summary

IndexHelper()

Method Summary

static Filter	defreezeBloomFilter(FileDataInput file, boolean usesOldBloomFilter)
static Filter	defreezeBloomFilter(FileDataInput file, long maxSize, boolean useOldBuffer) De-freeze the bloom filter.
static java.util.ArrayList<IndexHelper.IndexInfo>	deserializeIndex(FileDataInput in) Deserialize the index into a structure and return it
static java.util.Comparator<IndexHelper.IndexInfo>	getComparator(AbstractType nameComparator, boolean reversed)
static int	indexFor(java.nio.ByteBuffer name, java.util.List<IndexHelper.IndexInfo> indexList, AbstractType comparator, boolean reversed) The index of the IndexInfo in which a scan starting with @name should begin.
static void	skipBloomFilter(java.io.DataInput in) Skip the bloom filter
static void	skipIndex(java.io.DataInput in) Skip the index

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexHelper

public IndexHelper()

Method Detail

skipBloomFilter

public static void skipBloomFilter(java.io.DataInput in)
                            throws java.io.IOException

Skip the bloom filter

Parameters:

in - the data input from which the bloom filter should be skipped

Throws:

java.io.IOException

skipIndex

public static void skipIndex(java.io.DataInput in)
                      throws java.io.IOException

Skip the index

Parameters:

in - the data input from which the index should be skipped

Throws:

java.io.IOException - if an I/O error occurs.

deserializeIndex

public static java.util.ArrayList<IndexHelper.IndexInfo> deserializeIndex(FileDataInput in)
                                                                   throws java.io.IOException

Deserialize the index into a structure and return it

Parameters:

in - - input source

Returns:

ArrayList - list of de-serialized indexes

Throws:

java.io.IOException - if an I/O error occurs.

defreezeBloomFilter

public static Filter defreezeBloomFilter(FileDataInput file,
                                         boolean usesOldBloomFilter)
                                  throws java.io.IOException

Throws:

java.io.IOException

defreezeBloomFilter

public static Filter defreezeBloomFilter(FileDataInput file,
                                         long maxSize,
                                         boolean useOldBuffer)
                                  throws java.io.IOException

De-freeze the bloom filter.

Parameters:

file - - source file

maxSize - - sanity check: if filter claimes to be larger than this it is bogus

useOldBuffer - - do we need to reuse old buffer?

Returns:

bloom filter summarizing the column information

Throws:

java.io.IOException - if an I/O error occurs. Guarantees that file's current position will be just after the bloom filter, even if the filter cannot be deserialized, UNLESS EOFException is thrown.

indexFor

public static int indexFor(java.nio.ByteBuffer name,
                           java.util.List<IndexHelper.IndexInfo> indexList,
                           AbstractType comparator,
                           boolean reversed)

The index of the IndexInfo in which a scan starting with @name should begin.

Parameters:

name - name of the index

indexList - list of the indexInfo objects

comparator - comparator type

reversed - is name reversed

Returns:

int index

getComparator

public static java.util.Comparator<IndexHelper.IndexInfo> getComparator(AbstractType nameComparator,
                                                                        boolean reversed)