org.basex.data
Class Data

java.lang.Object
  org.basex.data.Data

Direct Known Subclasses:

DiskData, MemData

public abstract class Data
extends java.lang.Object

This class provides access to the database. The storage representation depends on the underlying implementation. Note that the methods of this class are optimized for performance. They won't check if you ask for wrong data. If you request a text node, e.g., get sure your pre value actually points to a text node. The same applies to the update operations; if you write an attribute to an element node, your database will get messed up.

Author:

Workgroup DBIS, University of Konstanz 2005-07, ISC License, Christian Gruen

Field Summary

static byte	ATTR Node kind: Attribute.
Names	atts Attribute name index.
static byte	COMM Node kind: Comment.
int	contentID Index Reference for content tag.
boolean	deepfs File system indicator.
int	dirID Index Reference for directory tag.
static byte	DOC Node kind: Document.
static byte	ELEM Node kind: Element.
int	fileID Index Reference for file tag.
MetaData	meta Meta data.
int	nameID Index Reference for name tag.
static byte	PI Node kind: Processing instruction.
int	size Table size.
int	sizeID Index Reference for size attribute.
int	suffixID Index Reference for suffix attribute.
Names	tags Tag index.
static byte	TEXT Node kind: Text.
int	timeID Index Reference for time attribute.

Constructor Summary

Data()

Method Summary

byte[]	atom(int pre) Returns an atomized content for any node kind.
double	atomNum(int pre) Returns a atomized numeric content for any node kind.
byte[]	attName(int pre) Returns an attribute name.
int	attNameID(byte[] tok) Returns an id for the specified attribute name.
abstract int	attNameID(int pre) Returns an attribute name id (reference to the attribute name index).
abstract double	attNum(int pre) Returns an attribute value as double value.
abstract int	attSize(int pre, int kind) Returns a number of attributes.
abstract byte[]	attValue(int pre) Returns an attribute value.
byte[]	attValue(int att, int pre) Finds the specified attribute and returns its value.
abstract void	close() Closes the current database.
abstract void	closeIndex(Index.TYPE index) Closes the specified index.
abstract void	delete(int pre) Deletes a node and its descendants.
abstract void	flush() Flushes the table data.
abstract int[][]	ftIDs(byte[] fulltext, FTOption ftOption) Returns the indexed id references for the specified fulltext token.
abstract int	id(int pre) Returns a unique node id.
int[]	ids(Index.TYPE type, byte[] token) Returns the indexed id references for the specified token.
abstract void	info(PrintOutput out) Returns info on the index structures.
void	initNames() Dissolves the references to often used tag names and attributes.
abstract void	insert(int pre, int par, byte[] val, byte kind) Inserts a tag name, text node, comment or processing instruction.
abstract void	insert(int pre, int par, byte[] name, byte[] val) Inserts an attribute.
abstract void	insert(int pre, int par, Data d) Insert a data instance at the specified pre value.
abstract int	kind(int pre) Returns a node kind.
boolean	noLeaf(int id) Returns if the specified tag is no leaf element.
abstract int	nrFTIDs(byte[] token) Returns the number of indexed id references for the specified token.
int	nrIDs(Index.TYPE type, byte[] token) Returns the number of indexed id references for the specified token.
int	nrTags(int id) Returns the number of occurrences of the specified tag.
abstract void	openIndex(Index.TYPE type, Index ind) Opens the specified index.
abstract int	parent(int pre, int kind) Returns a pre value of the parent node.
abstract int	pre(int id) Returns a pre value.
abstract int	size(int pre, int kind) Returns a size value (number of descendant table entries).
byte[]	tag(int pre) Returns a tag name.
int	tagID(byte[] tok) Returns an id for the specified tag.
abstract int	tagID(int pre) Returns a tag id (reference to the tag index).
abstract byte[]	text(int pre) Returns a text.
abstract int	textLen(int pre) Returns a text length.
abstract double	textNum(int pre) Returns a text as double value.
abstract void	update(int pre, byte[] val) Updates a tag name, text node, comment or processing instruction.
abstract void	update(int pre, byte[] name, byte[] val) Updates an attribute name and value.

Methods inherited from class java.lang.Object

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

Field Detail

ATTR

public static final byte ATTR

Node kind: Attribute.

See Also:

Constant Field Values

atts

public Names atts

Attribute name index.

COMM

public static final byte COMM

Node kind: Comment.

See Also:

Constant Field Values

contentID

public int contentID

Index Reference for content tag.

deepfs

public boolean deepfs

File system indicator.

dirID

public int dirID

Index Reference for directory tag.

DOC

public static final byte DOC

Node kind: Document.

See Also:

Constant Field Values

ELEM

public static final byte ELEM

Node kind: Element.

See Also:

Constant Field Values

fileID

public int fileID

Index Reference for file tag.

meta

public MetaData meta

Meta data.

nameID

public int nameID

Index Reference for name tag.

PI

public static final byte PI

Node kind: Processing instruction.

See Also:

Constant Field Values

size

public int size

Table size.

sizeID

public int sizeID

Index Reference for size attribute.

suffixID

public int suffixID

Index Reference for suffix attribute.

tags

public Names tags

Tag index.

TEXT

public static final byte TEXT

Node kind: Text.

See Also:

Constant Field Values

timeID

public int timeID

Index Reference for time attribute.

Constructor Detail

Data

public Data()

Method Detail

atom

public final byte[] atom(int pre)

Returns an atomized content for any node kind. The atomized value can be an attribute value or XML content.

Parameters:

pre - pre value

Returns:

atomized value

atomNum

public final double atomNum(int pre)

Returns a atomized numeric content for any node kind. The atomized value can be an attribute value or XML content.

Parameters:

pre - pre value

Returns:

atomized value

attName

public final byte[] attName(int pre)

Returns an attribute name.

Parameters:

pre - pre value

Returns:

name reference

attNameID

public final int attNameID(byte[] tok)

Returns an id for the specified attribute name.

Parameters:

tok - token to be found

Returns:

name reference

attNameID

public abstract int attNameID(int pre)

Returns an attribute name id (reference to the attribute name index).

Parameters:

pre - pre value

Returns:

token reference

attNum

public abstract double attNum(int pre)

Returns an attribute value as double value.

Parameters:

pre - pre value

Returns:

numeric value

attSize

public abstract int attSize(int pre,
                            int kind)

Returns a number of attributes.

Parameters:

pre - pre value

kind - node kind

Returns:

number of attributes

attValue

public abstract byte[] attValue(int pre)

Returns an attribute value.

Parameters:

pre - pre value

Returns:

atomized value

attValue

public final byte[] attValue(int att,
                             int pre)

Finds the specified attribute and returns its value.

Parameters:

att - attribute to be found

pre - pre value

Returns:

attribute value

close

public abstract void close()
                    throws java.io.IOException

Closes the current database.

Throws:

java.io.IOException - in case the database could not be closed

closeIndex

public abstract void closeIndex(Index.TYPE index)
                         throws java.io.IOException

Closes the specified index.

Parameters:

index - index to be closed

Throws:

java.io.IOException - in case the index could not be closed

delete

public abstract void delete(int pre)

Deletes a node and its descendants.

Parameters:

pre - pre value of the node to delete

flush

public abstract void flush()

Flushes the table data.

ftIDs

public abstract int[][] ftIDs(byte[] fulltext,
                              FTOption ftOption)

Returns the indexed id references for the specified fulltext token.

Parameters:

fulltext - token to be looked up

ftOption - fulltext options

Returns:

id array

id

public abstract int id(int pre)

Returns a unique node id.

Parameters:

pre - pre value

Returns:

node id

ids

public final int[] ids(Index.TYPE type,
                       byte[] token)

Returns the indexed id references for the specified token.

Parameters:

type - index to be looked up

token - token to be found

Returns:

id array

info

public abstract void info(PrintOutput out)
                   throws java.io.IOException

Returns info on the index structures.

Parameters:

out - output stream

Throws:

java.io.IOException - I/O exception

initNames

public final void initNames()

Dissolves the references to often used tag names and attributes.

insert

public abstract void insert(int pre,
                            int par,
                            byte[] val,
                            byte kind)

Inserts a tag name, text node, comment or processing instruction.

Parameters:

pre - pre value

par - parent of node

val - value to be inserted

kind - node kind

insert

public abstract void insert(int pre,
                            int par,
                            byte[] name,
                            byte[] val)

Inserts an attribute.

Parameters:

pre - pre value

par - parent of node

name - attribute name

val - attribute value

insert

public abstract void insert(int pre,
                            int par,
                            Data d)

Insert a data instance at the specified pre value. Note that the specified data instance must differ from this instance.

Parameters:

pre - pre value

par - parent of node

d - data instance to copy from

kind

public abstract int kind(int pre)

Returns a node kind.

Parameters:

pre - pre value

Returns:

node kind

noLeaf

public final boolean noLeaf(int id)

Returns if the specified tag is no leaf element.

Parameters:

id - id of the tag name

Returns:

result of check

nrFTIDs

public abstract int nrFTIDs(byte[] token)

Returns the number of indexed id references for the specified token.

Parameters:

token - token to be looked up

Returns:

id array

nrIDs

public final int nrIDs(Index.TYPE type,
                       byte[] token)

Returns the number of indexed id references for the specified token.

Parameters:

type - index type.

token - text to be found

Returns:

id array

nrTags

public final int nrTags(int id)

Returns the number of occurrences of the specified tag.

Parameters:

id - id of the tag name

Returns:

number of occurrences

openIndex

public abstract void openIndex(Index.TYPE type,
                               Index ind)
                        throws java.io.IOException

Opens the specified index.

Parameters:

type - index to be opened

ind - index instance

Throws:

java.io.IOException - in case the index could not be opened

parent

public abstract int parent(int pre,
                           int kind)

Returns a pre value of the parent node.

Parameters:

pre - pre value

kind - node kind

Returns:

pre value of the parent node

pre

public abstract int pre(int id)

Returns a pre value.

Parameters:

id - unique node id

Returns:

pre value or -1 if id was not found

size

public abstract int size(int pre,
                         int kind)

Returns a size value (number of descendant table entries).

Parameters:

pre - pre value

kind - node kind

Returns:

size value

tag

public final byte[] tag(int pre)

Returns a tag name.

Parameters:

pre - pre value

Returns:

name reference

tagID

public final int tagID(byte[] tok)

Returns an id for the specified tag.

Parameters:

tok - token to be found

Returns:

name reference

tagID

public abstract int tagID(int pre)

Returns a tag id (reference to the tag index).

Parameters:

pre - pre value

Returns:

token reference

text

public abstract byte[] text(int pre)

Returns a text.

Parameters:

pre - pre value

Returns:

atomized value

textLen

public abstract int textLen(int pre)

Returns a text length.

Parameters:

pre - pre value

Returns:

atomized value

textNum

public abstract double textNum(int pre)

Returns a text as double value.

Parameters:

pre - pre value

Returns:

numeric value

update

public abstract void update(int pre,
                            byte[] val)

Updates a tag name, text node, comment or processing instruction.

Parameters:

pre - pre of the text node to change

val - value to be updated

update

public abstract void update(int pre,
                            byte[] name,
                            byte[] val)

Updates an attribute name and value.

Parameters:

pre - pre of node to insert after

name - attribute name

val - attribute value