org.basex.data

Class DiskData

java.lang.Object

org.basex.data.Data

org.basex.data.DiskData

public final class DiskData
extends Data

This class stores and organizes the database table and the index structures for textual content in a compressed disk structure. The table mapping is documented in Data.

Author:

BaseX Team 2005-12, BSD License, Christian Gruen, Tim Petrowsky

Field Summary

Fields inherited from class org.basex.data.Data

atnindex, ATTR, atvindex, COMM, DOC, ELEM, ftxindex, meta, nspaces, paths, PI, pins, resources, tagindex, TEXT, txtindex

Constructor Summary

Constructors

Constructor and Description
DiskData(MetaData md, Names nm, Names at, PathSummary ps, Namespaces n) Internal database constructor, called from DiskBuilder.build().
DiskData(java.lang.String db, Context ctx) Default constructor, called from Open.open(java.lang.String, org.basex.core.Context).

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the database.
void	closeIndex(IndexToken.IndexType type) Closes the specified index.
protected void	delete(int pre, boolean text) Deletes the specified text entry.
void	finishUpdate() Finishes an update operation: removes the update file and the exclusive lock.
protected long	index(int pre, int id, byte[] value, int kind) Indexes a text and returns the reference.
protected void	indexBegin() Notify the index structures that an update operation is started.
protected void	indexDelete(int pre, int size) Delete a node and its descendants from the corresponding indexes.
protected void	indexEnd() Notify the index structures that an update operation is finished.
void	init() Initializes the database.
void	setIndex(IndexToken.IndexType type, Index index) Assigns the specified index.
boolean	startUpdate() Starts an update operation: writes a file to disk to indicate that an update is going on, and exclusively locks the table.
byte[]	text(int pre, boolean text) Returns a text (text, comment, pi) or attribute value.
double	textDbl(int pre, boolean text) Returns a text (text, comment, pi) or attribute value as double value.
long	textItr(int pre, boolean text) Returns a text (text, comment, pi) or attribute value as integer value.
int	textLen(int pre, boolean text) Returns the byte length of a text (text, comment, pi).
IOFile	updateFile() Returns a file that indicates ongoing updates.
protected void	updateText(int pre, byte[] value, int kind) Updates the specified text or attribute value.

Methods inherited from class org.basex.data.Data

atom, attr, attSize, attValue, count, delete, doc, elem, id, info, inMemory, insert, insert, insertAttr, isEmpty, iter, kind, name, name, ns, nsFlag, nsFlag, parent, pre, pre, replace, single, size, size, text, toString, update, update, uri

Methods inherited from class java.lang.Object

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

Constructor Detail

DiskData

public DiskData(java.lang.String db,
        Context ctx)
         throws java.io.IOException

Default constructor, called from Open.open(java.lang.String, org.basex.core.Context).

Parameters:

db - name of database

ctx - database context

Throws:

java.io.IOException - I/O Exception

DiskData

public DiskData(MetaData md,
        Names nm,
        Names at,
        PathSummary ps,
        Namespaces n)
         throws java.io.IOException

Internal database constructor, called from DiskBuilder.build().

Parameters:

md - meta data

nm - tags

at - attributes

ps - path summary

n - namespaces

Throws:

java.io.IOException - I/O Exception

Method Detail

init

public void init()
          throws java.io.IOException

Initializes the database.

Throws:

java.io.IOException - I/O exception

close

public void close()

Description copied from class: Data

Closes the database.

Specified by:

close in class Data

closeIndex

public void closeIndex(IndexToken.IndexType type)

Description copied from class: Data

Closes the specified index.

Specified by:

closeIndex in class Data

Parameters:

type - index to be closed

setIndex

public void setIndex(IndexToken.IndexType type,
            Index index)

Description copied from class: Data

Assigns the specified index.

Specified by:

setIndex in class Data

Parameters:

type - index to be opened

index - index instance

startUpdate

public boolean startUpdate()

Description copied from class: Data

Starts an update operation: writes a file to disk to indicate that an update is going on, and exclusively locks the table.

Specified by:

startUpdate in class Data

Returns:

success flag

finishUpdate

public void finishUpdate()

Description copied from class: Data

Finishes an update operation: removes the update file and the exclusive lock.

Specified by:

finishUpdate in class Data

updateFile

public IOFile updateFile()

Returns a file that indicates ongoing updates.

Returns:

updating file

text

public byte[] text(int pre,
          boolean text)

Description copied from class: Data

Returns a text (text, comment, pi) or attribute value.

Specified by:

text in class Data

Parameters:

pre - pre value

text - text/attribute flag

Returns:

atomized value

textItr

public long textItr(int pre,
           boolean text)

Description copied from class: Data

Returns a text (text, comment, pi) or attribute value as integer value.

Specified by:

textItr in class Data

Parameters:

pre - pre value

text - text/attribute flag

Returns:

numeric value

textDbl

public double textDbl(int pre,
             boolean text)

Description copied from class: Data

Returns a text (text, comment, pi) or attribute value as double value.

Specified by:

textDbl in class Data

Parameters:

pre - pre value

text - text/attribute flag

Returns:

numeric value

textLen

public int textLen(int pre,
          boolean text)

Description copied from class: Data

Returns the byte length of a text (text, comment, pi).

Specified by:

textLen in class Data

Parameters:

pre - pre value

text - text/attribute flag

Returns:

length

delete

protected void delete(int pre,
          boolean text)

Description copied from class: Data

Deletes the specified text entry.

Specified by:

delete in class Data

Parameters:

pre - pre value

text - text (text, comment or pi) or attribute flag

updateText

protected void updateText(int pre,
              byte[] value,
              int kind)

Description copied from class: Data

Updates the specified text or attribute value.

Specified by:

updateText in class Data

Parameters:

pre - pre value

value - content

kind - node kind

indexBegin

protected void indexBegin()

Description copied from class: Data

Notify the index structures that an update operation is started.

indexEnd

protected void indexEnd()

Description copied from class: Data

Notify the index structures that an update operation is finished.

index

protected long index(int pre,
         int id,
         byte[] value,
         int kind)

Description copied from class: Data

Indexes a text and returns the reference.

Specified by:

index in class Data

Parameters:

pre - pre value

id - id value

value - text to be indexed

kind - node kind

Returns:

reference

indexDelete

protected void indexDelete(int pre,
               int size)

Description copied from class: Data

Delete a node and its descendants from the corresponding indexes.

Specified by:

indexDelete in class Data

Parameters:

pre - pre value of the node to delete

size - number of descendants