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 current database.
void	closeIndex(IndexToken.IndexType type) Closes the specified index.
protected void	delete(int pre, boolean text) Deletes the specified text entry.
void	flush() Flushes the database.
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.
boolean	pinned() Checks if this database is also opened (pinned) by other instances.
static boolean	pinned(IOFile dbpath, java.lang.String uuid) Checks if a database is pinned by processes that have a UUID different to the specified one.
void	setIndex(IndexToken.IndexType type, Index index) Assigns the specified index.
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).
boolean	update(boolean updating) Marks a database as updating.
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, 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

flush

public void flush()

Description copied from class: Data

Flushes the database.

Specified by:

flush in class Data

close

public void close()
           throws java.io.IOException

Description copied from class: Data

Closes the current database.

Specified by:

close in class Data

Throws:

java.io.IOException - I/O exception

closeIndex

public void closeIndex(IndexToken.IndexType type)
                throws java.io.IOException

Description copied from class: Data

Closes the specified index.

Specified by:

closeIndex in class Data

Parameters:

type - index to be closed

Throws:

java.io.IOException - I/O exception

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

update

public boolean update(boolean updating)

Description copied from class: Data

Marks a database as updating.

Specified by:

update in class Data

Parameters:

updating - updating flag (start/stop updating process)

Returns:

success flag

updateFile

public IOFile updateFile()

Returns a file that indicates ongoing updates.

Returns:

updating file

pinned

public boolean pinned()

Description copied from class: Data

Checks if this database is also opened (pinned) by other instances.

Specified by:

pinned in class Data

Returns:

result of check

pinned

public static boolean pinned(IOFile dbpath,
             java.lang.String uuid)

Checks if a database is pinned by processes that have a UUID different to the specified one.

Parameters:

dbpath - database path

uuid - unique id

Returns:

result of check

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