org.terrier.structures

Class IndexUtil

java.lang.Object

org.terrier.structures.IndexUtil

public class IndexUtil
extends Object

Class with handy utilities for use on an Index.

Since:

3.0

Constructor Summary

Constructors

Constructor and Description
IndexUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static void	close(Object o) Check to see if an object is closeable, and if so, close it.
static void	configure(Index index, Object o) Configures an object with the index, if the object implements IndexConfigurable
static boolean	copyStructure(Index sourceIndex, Index destIndex, String sourceStructureName, String destinationStructureName) Copies an index structure from one index to another.
static void	deleteIndex(String path, String prefix) Delete an existing index
static boolean	deleteStructure(Index index, String structureName) Delete the named structure from the specified index.
static void	forceReloadStructure(Index index, String structureName) Forces a structure to be reloaded, by removing it from the index's structure cache
static void	forceStructure(Index index, String structureName, Object structure) Force the specified object into the structure cache of the specified object, as the given structure name
static String[]	getStructures(Index index) Returns a list of the structures in the given index
static boolean	isStructureOpen(IndexOnDisk index, String structureName) Checks the underlying structurecache of the specificed index to see if the named index structure is there.
static void	main(String[] args) Has some handy utilities for printing various index structures to System.out.
static void	printDocumentIndex(Index index, String structureName) Print the contents of the document index
static void	printMetaIndex(Index index, String structureName) Print the contents of the meta index
static void	renameIndex(String srcPath, String srcPrefix, String dstPath, String dstPrefix) Move an index from one location to another
static boolean	renameIndexStructure(Index index, String sourceStructureName, String destinationStructureName) Rename a structure within a given index.
static IndexOnDisk	reOpenIndex(Index index)
static IndexOnDisk	reOpenIndex(IndexOnDisk index) Reopen an existing index

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexUtil

public IndexUtil()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Has some handy utilities for printing various index structures to System.out.

• --printbitfile - print the bit file with the specified name
• --printbitentry - print one entry in a bit posting index.
• --printlex - print the entire lexicon
• --printdocument - print the document index
• --printlist - print the named list (e.g. document index)
• --printmeta - print the meta index

Throws:

Exception

forceStructure

public static void forceStructure(Index index,
                  String structureName,
                  Object structure)

Force the specified object into the structure cache of the specified object, as the given structure name

Parameters:

index - Index to operate on

structureName - which structure name to use

structure - which object to put into the structure cache

forceReloadStructure

public static void forceReloadStructure(Index index,
                        String structureName)

Forces a structure to be reloaded, by removing it from the index's structure cache

reOpenIndex

public static IndexOnDisk reOpenIndex(Index index)
                               throws IOException

Throws:

IOException

reOpenIndex

public static IndexOnDisk reOpenIndex(IndexOnDisk index)
                               throws IOException

Reopen an existing index

Throws:

IOException

getStructures

public static String[] getStructures(Index index)

Returns a list of the structures in the given index

renameIndex

public static void renameIndex(String srcPath,
               String srcPrefix,
               String dstPath,
               String dstPrefix)
                        throws IOException

Move an index from one location to another

Throws:

IOException

deleteIndex

public static void deleteIndex(String path,
               String prefix)
                        throws IOException

Delete an existing index

Throws:

IOException

printDocumentIndex

public static void printDocumentIndex(Index index,
                      String structureName)
                               throws IOException

Print the contents of the document index

Throws:

IOException

deleteStructure

public static boolean deleteStructure(Index index,
                      String structureName)
                               throws IOException

Delete the named structure from the specified index. Deletes files as well.

Parameters:

index - - index to operate on

structureName - name of structure to delete

Returns:

true if structure was found and deleted, false otherwise

Throws:

IOException

isStructureOpen

public static boolean isStructureOpen(IndexOnDisk index,
                      String structureName)

Checks the underlying structurecache of the specificed index to see if the named index structure is there.

Parameters:

index - index to examine

structureName - what structure

Returns:

true if the structure cache contains the item

copyStructure

public static boolean copyStructure(Index sourceIndex,
                    Index destIndex,
                    String sourceStructureName,
                    String destinationStructureName)
                             throws IOException

Copies an index structure from one index to another.

Parameters:

sourceIndex -

destIndex -

sourceStructureName -

destinationStructureName -

Throws:

IOException - if an IO problem occurs

printMetaIndex

public static void printMetaIndex(Index index,
                  String structureName)
                           throws IOException

Print the contents of the meta index

Throws:

IOException

renameIndexStructure

public static boolean renameIndexStructure(Index index,
                           String sourceStructureName,
                           String destinationStructureName)
                                    throws IOException

Rename a structure within a given index.

Returns:

Returns true iff a structure was successfully renamed.

Throws:

IOException

configure

public static void configure(Index index,
             Object o)

Configures an object with the index, if the object implements IndexConfigurable

close

public static void close(Object o)
                  throws IOException

Check to see if an object is closeable, and if so, close it. Propagate any exception thrown.

Parameters:

o - object to check for being closeable.

Throws:

IOException - if exception thrown while closing.