org.apache.xindice.core.filer
Class HashFiler

java.lang.Object
  org.apache.xindice.core.filer.Paged
      org.apache.xindice.core.filer.HashFiler

All Implemented Interfaces:

Configurable, DBObject, Filer, Named

public class HashFiler

extends Paged

implements Filer

HashFiler is a Filer implementation based on the Paged class. By extending Paged, HashFiler inherits the ability to maintain Record metadata such as creation and modification time. It also provides quite a bit more flexibility in its ability to retreive blocks of data and allocate Record space.
HashFile has folowing configuration attributes:

• pagesize: Size of the page used by the paged file. Default page size is 4096 bytes. This parameter can be set only before paged file is created. Once it is created, this parameter can not be changed.
• pagecount: This parameter has a special meaning for HashFiler. This determines the size of the hash table main storage, which is equal to the number of pages filer will be created with. The default is 1024. Please note that if made too small, it will affect efficiency of the hash table.
• maxkeysize: Maximum allowed size of the key. Default maximum key size is 256 bytes.
• max-descriptors: Defines maximum amount of simultaneously opened file descriptors this paged file can have. Several descriptors are needed to provide multithreaded access to the underlying file. Too large number will limit amount of collections you can open. Default value is 16 (DEFAULT_DESCRIPTORS_MAX).

Version:

$Revision: 571938 $, $Date: 2007-09-02 06:14:13 -0400 (Sun, 02 Sep 2007) $

Nested Class Summary

protected class

HashFiler.HashPageHeader HashPageHeader

Nested classes inherited from class org.apache.xindice.core.filer.Paged

Paged.FileHeader, Paged.Page, Paged.PageHeader, Paged.PageKey

Field Summary

protected static byte

RECORD Record page status

Fields inherited from class org.apache.xindice.core.filer.Paged

CONFIG_DESCRIPTORS_MAX, CONFIG_KEYSIZE_MAX, CONFIG_PAGECOUNT, CONFIG_PAGESIZE, DELETED, NO_PAGE, OVERFLOW, UNUSED

Constructor Summary

HashFiler()

Method Summary

Paged.FileHeader	createFileHeader() createFileHeader must be implemented by a Paged implementation in order to create an appropriate subclass instance of a FileHeader.
Paged.PageHeader	createPageHeader() createPageHeader must be implemented by a Paged implementation in order to create an appropriate subclass instance of a PageHeader.
boolean	deleteRecord(Key key) deleteRecord removes a Record from the Filer based on the specified Key.
String	getName() getName retrieves the contextually important name of the object
long	getRecordCount() getRecordCount returns the number of Records in the Filer.
RecordSet	getRecordSet() getRecordSet returns a RecordSet object for the current Filer.
Record	readRecord(Key key) readRecord returns a Record from the Filer based on the specified Key.
Record	readRecord(Key key, boolean metaOnly) readRecord returns a Record from the Filer based on the specified Key containing filer meta information and value.
void	setConfig(Configuration config) setConfig sets the configuration information for the Configurable object instance.
void	setLocation(File root, String location) setLocation tells the Filer where to store its data.
protected void	unlinkPages(Paged.Page page) Mark pages in primary store as 'DELETED', and let Paged handle all overflow pages.
Record	writeRecord(Key key, Value value) writeRecord writes a Value to the Filer based on the specified Key.

Methods inherited from class org.apache.xindice.core.filer.Paged

checkOpened, close, closeDescriptor, create, deleteArrayInt, deleteArrayLong, deleteArrayShort, deleteArrayValue, drop, exists, flush, getConfig, getDescriptor, getFile, getFileHeader, getFreePage, getPage, insertArrayInt, insertArrayLong, insertArrayShort, insertArrayValue, isOpened, open, putDescriptor, readValue, readValue, setFile, unlinkPages, writeValue, writeValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.xindice.core.filer.Filer

flush

Methods inherited from interface org.apache.xindice.core.DBObject

close, create, drop, exists, isOpened, open

Methods inherited from interface org.apache.xindice.util.Configurable

getConfig

Field Detail

RECORD

protected static final byte RECORD

Record page status

See Also:

Constant Field Values

Constructor Detail

HashFiler

public HashFiler()

Method Detail

setLocation

public void setLocation(File root,
                        String location)

Description copied from interface: Filer

setLocation tells the Filer where to store its data.

Specified by:

setLocation in interface Filer

Parameters:

root - The root under which to store data

location - The name to use for storing data

getName

public String getName()

Description copied from interface: Named

getName retrieves the contextually important name of the object

Specified by:

getName in interface Named

Returns:

The object's name

setConfig

public void setConfig(Configuration config)

Description copied from interface: Configurable

setConfig sets the configuration information for the Configurable object instance.

Specified by:

setConfig in interface Configurable

Overrides:

setConfig in class Paged

readRecord

public Record readRecord(Key key)
                  throws DBException

Description copied from interface: Filer

readRecord returns a Record from the Filer based on the specified Key.

Specified by:

readRecord in interface Filer

Parameters:

key - The Record's Key

Returns:

The returned Record

Throws:

DBException

readRecord

public Record readRecord(Key key,
                         boolean metaOnly)
                  throws DBException

Description copied from interface: Filer

readRecord returns a Record from the Filer based on the specified Key containing filer meta information and value.

Specified by:

readRecord in interface Filer

Parameters:

key - The Record's Key

metaOnly - if true, resulting record contains only meta information

Returns:

The returned Record

Throws:

DBException

writeRecord

public Record writeRecord(Key key,
                          Value value)
                   throws DBException

Description copied from interface: Filer

writeRecord writes a Value to the Filer based on the specified Key.

Specified by:

writeRecord in interface Filer

Parameters:

key - The Record's Key

value - The Record's Value

Returns:

Written Record

Throws:

DBException

unlinkPages

protected void unlinkPages(Paged.Page page)
                    throws IOException

Mark pages in primary store as 'DELETED', and let Paged handle all overflow pages.

Overrides:

unlinkPages in class Paged

Parameters:

page - The starting Page to unlink

Throws:

IOException - if an Exception occurs

deleteRecord

public boolean deleteRecord(Key key)
                     throws DBException

Description copied from interface: Filer

deleteRecord removes a Record from the Filer based on the specified Key.

Specified by:

deleteRecord in interface Filer

Parameters:

key - The Record's Key

Returns:

Whether or not the Record was deleted

Throws:

DBException

getRecordCount

public long getRecordCount()
                    throws DBException

Description copied from interface: Filer

getRecordCount returns the number of Records in the Filer.

Specified by:

getRecordCount in interface Filer

Returns:

The Record count

Throws:

DBException

getRecordSet

public RecordSet getRecordSet()
                       throws DBException

Description copied from interface: Filer

getRecordSet returns a RecordSet object for the current Filer.

Specified by:

getRecordSet in interface Filer

Returns:

The Filer Enumerator

Throws:

DBException

createFileHeader

public Paged.FileHeader createFileHeader()

Description copied from class: Paged

createFileHeader must be implemented by a Paged implementation in order to create an appropriate subclass instance of a FileHeader.

Specified by:

createFileHeader in class Paged

Returns:

a new FileHeader

createPageHeader

public Paged.PageHeader createPageHeader()

Description copied from class: Paged

createPageHeader must be implemented by a Paged implementation in order to create an appropriate subclass instance of a PageHeader.

Specified by:

createPageHeader in class Paged

Returns:

a new PageHeader