jdbm.recman

Class SnapshotRecordManager

java.lang.Object

jdbm.recman.SnapshotRecordManager

All Implemented Interfaces:

ActionRecordManager, RecordManager

public class SnapshotRecordManager
extends java.lang.Object
implements ActionRecordManager

TODO SnapshotRecordManager.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	SnapshotRecordManager.RecordIO

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.ThreadLocal<ActionContext>	actionContextVar Per thread action context
(package private) java.util.concurrent.locks.Lock	bigLock Lock used to serialize write actions and some management operatins
(package private) SnapshotRecordManager.RecordIO	recordIO Passed to cache as IO callback
protected RecordManager	recordManager Wrapped RecordManager
(package private) LRUCache<java.lang.Long,java.lang.Object>	versionedCache Versioned cache
(package private) ActionVersioning	versioning Used for keeping track of actions versions

Fields inherited from interface jdbm.RecordManager

NAME_DIRECTORY_ROOT

Constructor Summary

Constructors

Constructor and Description
SnapshotRecordManager(RecordManager recordManager, int size) Construct a SanshotRecordManager wrapping another RecordManager

Method Summary

Modifier and Type	Method and Description
void	abortAction(ActionContext actionContext) Aborts the given action.
ActionContext	beginAction(boolean readOnly, java.lang.String whoStarted) Initializes the context for the action.
private void	checkIfClosed() Check if RecordManager has been closed.
void	close() Closes the record manager.
void	commit() Commit (make persistent) all changes since beginning of transaction.
void	delete(long recid) Deletes a record.
void	endAction(ActionContext actionContext) Ends the action associated with the context.
java.lang.Object	fetch(long recid) Fetches a record using standard Java serialization.
java.lang.Object	fetch(long recid, Serializer serializer) Fetches a record using a custom serializer.
long	getNamedObject(java.lang.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(java.lang.Object obj) Inserts a new record using a custom serializer.
long	insert(java.lang.Object obj, Serializer serializer) Inserts a new record using a custom serializer.
void	rollback() Rollback (cancel) all changes since beginning of transaction.
void	setCurrentActionContext(ActionContext context) Set the context as the current action context for the given thread
void	setNamedObject(java.lang.String name, long recid) Set the record id of a named object.
void	setRoot(int id, long rowid) Sets the indicated root rowid.
java.lang.String	toString()
void	unsetCurrentActionContext(ActionContext context) Unsets the context as the current action context.
void	update(long recid, java.lang.Object obj) Updates a record using standard Java serialization.
void	update(long recid, java.lang.Object obj, Serializer serializer) Updates a record using a custom serializer.

Methods inherited from class java.lang.Object

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

Field Detail

recordManager

protected RecordManager recordManager

Wrapped RecordManager

actionContextVar

private static final java.lang.ThreadLocal<ActionContext> actionContextVar

Per thread action context

versioning

ActionVersioning versioning

Used for keeping track of actions versions

versionedCache

LRUCache<java.lang.Long,java.lang.Object> versionedCache

Versioned cache

recordIO

SnapshotRecordManager.RecordIO recordIO

Passed to cache as IO callback

bigLock

java.util.concurrent.locks.Lock bigLock

Lock used to serialize write actions and some management operatins

Constructor Detail

SnapshotRecordManager

public SnapshotRecordManager(RecordManager recordManager,
                             int size)

Construct a SanshotRecordManager wrapping another RecordManager

Parameters:

recordManager - Wrapped RecordManager

Method Detail

beginAction

public ActionContext beginAction(boolean readOnly,
                                 java.lang.String whoStarted)

Initializes the context for the action. Implicity sets the context as the current action.

Specified by:

beginAction in interface ActionRecordManager

Parameters:

readOnly - true if action does not do any modification

whoStarted - caller can use this for debugging

Returns:

The created action context

setCurrentActionContext

public void setCurrentActionContext(ActionContext context)

Set the context as the current action context for the given thread

Specified by:

setCurrentActionContext in interface ActionRecordManager

Parameters:

context - identifies the context

unsetCurrentActionContext

public void unsetCurrentActionContext(ActionContext context)

Unsets the context as the current action context. Given context should be current action context for the calling thread.

Specified by:

unsetCurrentActionContext in interface ActionRecordManager

Parameters:

context - identifies the context.

endAction

public void endAction(ActionContext actionContext)

Ends the action associated with the context. ReadWrite actions' changes are made visible to readers.

Specified by:

endAction in interface ActionRecordManager

Parameters:

actionContext - identifies the action to end

abortAction

public void abortAction(ActionContext actionContext)

Aborts the given action. For write actions, actions's changes should not be made visible to readers.

Specified by:

abortAction in interface ActionRecordManager

Parameters:

actionContext - identifies the action to abort

getRecordManager

public RecordManager getRecordManager()

Get the underlying Record Manager.

Returns:

underlying RecordManager

insert

public long insert(java.lang.Object obj)
            throws java.io.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:

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

insert

public long insert(java.lang.Object obj,
                   Serializer serializer)
            throws java.io.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:

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

delete

public void delete(long recid)
            throws java.io.IOException

Deletes a record.

Specified by:

delete in interface RecordManager

Parameters:

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

Throws:

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

update

public void update(long recid,
                   java.lang.Object obj)
            throws java.io.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:

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

update

public void update(long recid,
                   java.lang.Object obj,
                   Serializer serializer)
            throws java.io.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:

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

fetch

public java.lang.Object fetch(long recid)
                       throws java.io.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:

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

fetch

public java.lang.Object fetch(long recid,
                              Serializer serializer)
                       throws java.io.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:

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

close

public void close()
           throws java.io.IOException

Closes the record manager.

Specified by:

close in interface RecordManager

Throws:

java.io.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 java.io.IOException

Returns the indicated root rowid.

Specified by:

getRoot in interface RecordManager

Throws:

java.io.IOException

See Also:

getRootCount()

setRoot

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

Sets the indicated root rowid.

Specified by:

setRoot in interface RecordManager

Throws:

java.io.IOException

See Also:

getRootCount()

commit

public void commit()
            throws java.io.IOException

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

Specified by:

commit in interface RecordManager

Throws:

java.io.IOException

rollback

public void rollback()
              throws java.io.IOException

Rollback (cancel) all changes since beginning of transaction.

Specified by:

rollback in interface RecordManager

Throws:

java.io.IOException

getNamedObject

public long getNamedObject(java.lang.String name)
                    throws java.io.IOException

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

Specified by:

getNamedObject in interface RecordManager

Throws:

java.io.IOException

setNamedObject

public void setNamedObject(java.lang.String name,
                           long recid)
                    throws java.io.IOException

Set the record id of a named object.

Specified by:

setNamedObject in interface RecordManager

Throws:

java.io.IOException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

checkIfClosed

private void checkIfClosed()
                    throws java.lang.IllegalStateException

Check if RecordManager has been closed. If so, throw an IllegalStateException

Throws:

java.lang.IllegalStateException