jdbm.recman

Class CacheRecordManager

java.lang.Object

jdbm.recman.CacheRecordManager

All Implemented Interfaces:

RecordManager

public class CacheRecordManager
extends Object
implements RecordManager

A RecordManager wrapping and caching another RecordManager.

Author:

Alex Boisvert, Cees de Groot

Field Summary

Fields

Modifier and Type	Field and Description
protected CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry>	cache Cache for underlying RecordManager
protected RecordManager	recordManager Wrapped RecordManager

Fields inherited from interface jdbm.RecordManager

NAME_DIRECTORY_ROOT

Constructor Summary

Constructors

Constructor and Description
CacheRecordManager(RecordManager recordManager, CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry> cache) Construct a CacheRecordManager wrapping another RecordManager and using a given cache policy.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the record manager.
void	commit() Commit (make persistent) all changes since beginning of transaction.
void	delete(long recid) Deletes a record.
Object	fetch(long recid) Fetches a record using standard Java serialization.
Object	fetch(long recid, Serializer serializer) Fetches a record using a custom serializer.
CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry>	getCachePolicy() Get the underlying cache policy
long	getNamedObject(String name) Obtain the record id of a named object.
RecordManager	getRecordManager() Get the underlying Record Manager.
long	getRoot(int id) Returns the indicated root rowid.
int	getRootCount() Returns the number of slots available for "root" rowids.
long	insert(Object obj) Inserts a new record using a custom serializer.
long	insert(Object obj, Serializer serializer) Inserts a new record using a custom serializer.
void	rollback() Rollback (cancel) all changes since beginning of transaction.
void	setNamedObject(String name, long recid) Set the record id of a named object.
void	setRoot(int id, long rowid) Sets the indicated root rowid.
void	update(long recid, Object obj) Updates a record using standard Java serialization.
void	update(long recid, Object obj, Serializer serializer) Updates a record using a custom serializer.
protected void	updateCacheEntries() Update all dirty cache objects to the underlying RecordManager.

Methods inherited from class java.lang.Object

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

Field Detail

recordManager

protected RecordManager recordManager

Wrapped RecordManager

cache

protected CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry> cache

Cache for underlying RecordManager

Constructor Detail

CacheRecordManager

public CacheRecordManager(RecordManager recordManager,
                          CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry> cache)

Construct a CacheRecordManager wrapping another RecordManager and using a given cache policy.

Parameters:

recordManager - Wrapped RecordManager

cache - Cache policy

Method Detail

getRecordManager

public RecordManager getRecordManager()

Get the underlying Record Manager.

Returns:

underlying RecordManager or null if CacheRecordManager has been closed.

getCachePolicy

public CachePolicy<Long,jdbm.recman.CacheRecordManager.CacheEntry> getCachePolicy()

Get the underlying cache policy

Returns:

underlying CachePolicy or null if CacheRecordManager has been closed.

insert

public long insert(Object obj)
            throws IOException

Inserts a new record using a custom serializer.

Specified by:

insert in interface RecordManager

Parameters:

obj - the object for the new record.

Returns:

the rowid for the new record.

Throws:

IOException - when one of the underlying I/O operations fails.

insert

public long insert(Object obj,
                   Serializer serializer)
            throws IOException

Inserts a new record using a custom serializer.

Specified by:

insert in interface RecordManager

Parameters:

obj - the object for the new record.

serializer - a custom serializer

Returns:

the rowid for the new record.

Throws:

IOException - when one of the underlying I/O operations fails.

delete

public void delete(long recid)
            throws IOException

Deletes a record.

Specified by:

delete in interface RecordManager

Parameters:

recid - the rowid for the record that should be deleted.

Throws:

IOException - when one of the underlying I/O operations fails.

update

public void update(long recid,
                   Object obj)
            throws IOException

Updates a record using standard Java serialization.

Specified by:

update in interface RecordManager

Parameters:

recid - the recid for the record that is to be updated.

obj - the new object for the record.

Throws:

IOException - when one of the underlying I/O operations fails.

update

public void update(long recid,
                   Object obj,
                   Serializer serializer)
            throws IOException

Updates a record using a custom serializer.

Specified by:

update in interface RecordManager

Parameters:

recid - the recid for the record that is to be updated.

obj - the new object for the record.

serializer - a custom serializer

Throws:

IOException - when one of the underlying I/O operations fails.

fetch

public Object fetch(long recid)
             throws IOException

Fetches a record using standard Java serialization.

Specified by:

fetch in interface RecordManager

Parameters:

recid - the recid for the record that must be fetched.

Returns:

the object contained in the record.

Throws:

IOException - when one of the underlying I/O operations fails.

fetch

public Object fetch(long recid,
                    Serializer serializer)
             throws IOException

Fetches a record using a custom serializer.

Specified by:

fetch in interface RecordManager

Parameters:

recid - the recid for the record that must be fetched.

serializer - a custom serializer

Returns:

the object contained in the record.

Throws:

IOException - when one of the underlying I/O operations fails.

close

public void close()
           throws IOException

Closes the record manager.

Specified by:

close in interface RecordManager

Throws:

IOException - when one of the underlying I/O operations fails.

getRootCount

public int getRootCount()

Returns the number of slots available for "root" rowids. These slots can be used to store special rowids, like rowids that point to other rowids. Root rowids are useful for bootstrapping access to a set of data.

Specified by:

getRootCount in interface RecordManager

getRoot

public long getRoot(int id)
             throws IOException

Returns the indicated root rowid.

Specified by:

getRoot in interface RecordManager

Throws:

IOException

See Also:

getRootCount()

setRoot

public void setRoot(int id,
                    long rowid)
             throws IOException

Sets the indicated root rowid.

Specified by:

setRoot in interface RecordManager

Throws:

IOException

See Also:

getRootCount()

commit

public void commit()
            throws IOException

Commit (make persistent) all changes since beginning of transaction.

Specified by:

commit in interface RecordManager

Throws:

IOException

rollback

public void rollback()
              throws IOException

Rollback (cancel) all changes since beginning of transaction.

Specified by:

rollback in interface RecordManager

Throws:

IOException

getNamedObject

public long getNamedObject(String name)
                    throws IOException

Obtain the record id of a named object. Returns 0 if named object doesn't exist.

Specified by:

getNamedObject in interface RecordManager

Throws:

IOException

setNamedObject

public void setNamedObject(String name,
                           long recid)
                    throws IOException

Set the record id of a named object.

Specified by:

setNamedObject in interface RecordManager

Throws:

IOException

updateCacheEntries

protected void updateCacheEntries()
                           throws IOException

Update all dirty cache objects to the underlying RecordManager.

Throws:

IOException