org.exist.dom
Class SymbolTable

java.lang.Object
  org.exist.dom.SymbolTable

public class SymbolTable
extends Object

Maintains a global symbol table shared by a database instance. The symbol table maps namespace URIs and node names to unique, numeric ids. Internally, the db does not store node QNames in clear text. Instead, it uses the numeric ids maintained here. The global SymbolTable singleton can be retrieved from BrokerPool.getSymbols(). It is saved into the database file "symbols.dbx".

Author:

wolf

Field Summary

static short	FILE_FORMAT_VERSION_ID
static String	FILE_NAME
static int	LENGTH_LOCAL_NAME
static int	LENGTH_NS_URI

Constructor Summary

SymbolTable(BrokerPool pool, Configuration config)

Method Summary

void	backupSymbolsTo(OutputStream os)
String[]	defaultPrefixList() Returns a list of default prefixes registered.
void	flush()
String	getDefaultNamespace(String prefix) Returns a namespace URI for the given prefix if there's a default mapping.
File	getFile()
static String	getFileName()
String	getMimeType(int id)
int	getMimeTypeId(String mimeType)
String	getName(short id) Returns the local name registered for the id or null if the name is not known.
String	getNamespace(short id) Returns the namespace URI registered for the id or null if the namespace URI is not known.
short	getNSSymbol(String ns) Returns a unique id for the specified namespace URI.
QName	getQName(short type, String namespaceURI, String localName, String prefix) Retrieve a shared QName instance from the temporary pool.
short	getSymbol(Attr attr) Return a unique id for the local node name of the specified attribute.
short	getSymbol(Element element) Return a unique id for the local node name of the specified element.
short	getSymbol(String name) Returns a unique id for the specified local name.
boolean	hasChanged() Returns true if the symbol table needs to be saved to persistent storage.
void	loadSymbols() Read the global symbol table.
void	read(VariableByteInput istream) Read the symbol table.
void	saveSymbols() Save the global symbol table.
void	write(VariableByteOutputStream ostream) Write the symbol table to persistent storage.

Methods inherited from class java.lang.Object

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

Field Detail

FILE_NAME

public static final String FILE_NAME

See Also:

Constant Field Values

FILE_FORMAT_VERSION_ID

public static final short FILE_FORMAT_VERSION_ID

See Also:

Constant Field Values

LENGTH_LOCAL_NAME

public static int LENGTH_LOCAL_NAME

LENGTH_NS_URI

public static int LENGTH_NS_URI

Constructor Detail

SymbolTable

public SymbolTable(BrokerPool pool,
                   Configuration config)
            throws EXistException

Throws:

EXistException

Method Detail

getFileName

public static String getFileName()

getQName

public QName getQName(short type,
                      String namespaceURI,
                      String localName,
                      String prefix)

Retrieve a shared QName instance from the temporary pool. TODO: make the namePool thread-local to avoid synchronization.

Parameters:

namespaceURI -

localName -

prefix -

getSymbol

public short getSymbol(Element element)

Return a unique id for the local node name of the specified element.

Parameters:

element -

getSymbol

public short getSymbol(Attr attr)

Return a unique id for the local node name of the specified attribute.

Parameters:

attr -

getSymbol

public short getSymbol(String name)

Returns a unique id for the specified local name. If the name is the local name of an attribute, it should start with a '@' character.

Parameters:

name -

getNSSymbol

public short getNSSymbol(String ns)

Returns a unique id for the specified namespace URI.

Parameters:

ns -

getNamespace

public String getNamespace(short id)

Returns the namespace URI registered for the id or null if the namespace URI is not known. Returns the empty string if the namespace is empty.

Parameters:

id -

hasChanged

public boolean hasChanged()

Returns true if the symbol table needs to be saved to persistent storage.

getName

public String getName(short id)

Returns the local name registered for the id or null if the name is not known.

Parameters:

id -

getDefaultNamespace

public String getDefaultNamespace(String prefix)

Returns a namespace URI for the given prefix if there's a default mapping.

Parameters:

prefix -

defaultPrefixList

public String[] defaultPrefixList()

Returns a list of default prefixes registered.

getMimeTypeId

public int getMimeTypeId(String mimeType)

getMimeType

public String getMimeType(int id)

write

public void write(VariableByteOutputStream ostream)
           throws IOException

Write the symbol table to persistent storage.

Parameters:

ostream -

Throws:

IOException

read

public void read(VariableByteInput istream)
          throws IOException

Read the symbol table.

Parameters:

istream -

Throws:

IOException

getFile

public File getFile()

saveSymbols

public void saveSymbols()
                 throws EXistException

Save the global symbol table. The global symbol table stores QNames and namespace/prefix mappings.

Throws:

EXistException

loadSymbols

public void loadSymbols()
                 throws EXistException

Read the global symbol table. The global symbol table stores QNames and namespace/prefix mappings.

Throws:

EXistException

backupSymbolsTo

public void backupSymbolsTo(OutputStream os)
                     throws IOException

Throws:

IOException

flush

public void flush()
           throws EXistException

Throws:

EXistException