mobios.index
Class AbstractIndex

java.lang.Object
  mobios.index.AbstractIndex

All Implemented Interfaces:

Serializable, Index

Direct Known Subclasses:

VPIndex

public abstract class AbstractIndex
extends Object
implements Index

The primary interface for a distance-based index. Through AbstractIndex, the user can build a database index, or read a pre-built index from a file, and then do the search.

Version:

2006.07.24

Author:

Rui Mao, Willard

See Also:

Serialized Form

Constructor Summary

AbstractIndex(File mobiosDataDir, String fileName, List<? extends IndexObject> data, Metric metric, Level debugLevel)
The constructor in common use.

Method Summary

void	close() Closes anything used internally that needs to be closed.
void	destroy() Deletes the index from the file, and also release it from memory.
List<IndexObject>	getAllPoints() Returns all the data points in the index
Metric	getMetric()
void	initAndOpenOIOM(File dir, boolean readOnly) Initializes and opens the ObjectIOManager for this index.
void	preLoad(int level) When a lot of queries are to be answered, for the sake of performance, it is a good idea to have the top levels of the index tree reside in memory.
int	size()

Methods inherited from class java.lang.Object

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

Methods inherited from interface mobios.index.Index

getOIOM, getRootAddress, search

Constructor Detail

AbstractIndex

public AbstractIndex(File mobiosDataDir,
                     String fileName,
                     List<? extends IndexObject> data,
                     Metric metric,
                     Level debugLevel)

The constructor in common use. Initializes the directory to store index files, opens up the ObjectIOManager, and defines the metric and debug level to use when building an index.

Parameters:

fileName -

data -

metric -

debugLevel -

Method Detail

initAndOpenOIOM

public void initAndOpenOIOM(File dir,
                            boolean readOnly)

Initializes and opens the ObjectIOManager for this index.

Parameters:

readOnly -

getMetric

public Metric getMetric()

Specified by:

getMetric in interface Index

Returns:

the metric used to build the index.

size

public int size()

Specified by:

size in interface Index

Returns:

the total number of data objects contained in the index.

preLoad

public void preLoad(int level)

Description copied from interface: Index

When a lot of queries are to be answered, for the sake of performance, it is a good idea to have the top levels of the index tree reside in memory. This method loads the top levels into memory.

Specified by:

preLoad in interface Index

Parameters:

level - number of levels, from the root, to be pre-loaded into memory.

getAllPoints

public List<IndexObject> getAllPoints()

Description copied from interface: Index

Returns all the data points in the index

Specified by:

getAllPoints in interface Index

close

public void close()
           throws IOException

Description copied from interface: Index

Closes anything used internally that needs to be closed. It is a good idea to close it when it is no longer in use.

Specified by:

close in interface Index

Throws:

IOException

destroy

public void destroy()
             throws IOException

Description copied from interface: Index

Deletes the index from the file, and also release it from memory. This method should only be called when the index will never be used again!

Specified by:

destroy in interface Index

Throws:

IOException