com.bigdata.btree

Class FixedLengthPrefixSplits

java.lang.Object

com.bigdata.btree.FixedLengthPrefixSplits

All Implemented Interfaces:

ISimpleSplitHandler, Externalizable, Serializable

Direct Known Subclasses:

BlobsIndexSplitHandler

public class FixedLengthPrefixSplits
extends Object
implements ISimpleSplitHandler, Serializable, Externalizable

Imposes constraint that the key before the separatorKey must differ in the first N bytes from the key after the separator key.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.log4j.Logger	log

Constructor Summary

Constructors

Constructor and Description
FixedLengthPrefixSplits(int nbytes)

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	getSeparatorKey(IndexSegment seg, int fromIndex, int toIndex, int splitAt) Linear search for the first successor of the keyAt(splitAt) which differs in the first N bytes.
void	readExternal(ObjectInput in)
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final transient org.apache.log4j.Logger log

Constructor Detail

FixedLengthPrefixSplits

public FixedLengthPrefixSplits(int nbytes)

Method Detail

getSeparatorKey

public byte[] getSeparatorKey(IndexSegment seg,
                     int fromIndex,
                     int toIndex,
                     int splitAt)

Linear search for the first successor of the keyAt(splitAt) which differs in the first N bytes.

Specified by:

getSeparatorKey in interface ISimpleSplitHandler

Parameters:

seg - The IndexSegment containing the data to be split.

fromIndex - The index of the first tuple which may be considered (inclusive lower bound).

toIndex - The index of the last tuple which may be considered (exclusive upper bound).

splitAt - The index of the recommended separator key.

Returns:

The desired separator key. If no acceptable separator key could be found or constructed then return null.

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException