org.ov4j.hessianImpl
Class Container<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

java.lang.Object
  org.ov4j.hessianImpl.Container<T,C>

All Implemented Interfaces:

IContainer<T,C>

public class Container<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>
extends java.lang.Object
implements IContainer<T,C>

Author:

smolloy

Field Summary

protected java.util.ArrayList<C>	cachedIds IDs kept in cache.
protected boolean	closed Flag to indicate if DB is closed.
protected boolean	closing Flag for closing.
protected long	counter Next filename to assign.
protected java.lang.String	dbName Name of the DB.
protected static java.lang.String	DELETED_FOLDER Folder name where to store deleted ids.
protected java.util.TreeMap<C,java.lang.String>	deletedMap Current live deleted ID to filename Map.
protected java.util.TreeMap<C,java.lang.String>	deletedMapWrk Current work deleted ID to filename Map.
protected static java.lang.Comparable<?>[]	EMPTY_COMPARABLE_ARRAY Empty Comparable array.
protected static DirFileFilter	FOLDER_FILTER FileFilter accepting folder files.
protected java.lang.Thread	hookThread Shutdown hook to make sure memory is saved to file when VM shuts down.
protected java.util.TreeMap<C,java.lang.String>	idMap Current live ID to filename Map.
protected java.util.TreeMap<C,java.lang.String>	idMapWrk Current work ID to filename Map.
protected static java.lang.String	ITEM_FOLDER Folder name where to store items.
protected static java.lang.String	LIVE_FOLDER Folder name where to store live data.
protected java.io.File	liveDeleted Live deleted ids folder.
protected java.io.File	liveItems Live items folder.
protected static long	MAX_CACHE_TIME Maximum amount of time an item will stay cached before being uncached automatically.
protected static int	MAX_ITEM_CACHED Maximum number of items to cache.
protected static int	MAX_LOADTHREAD Maximum number of items to cache.
protected static int	MAX_RETRY Maximum number of save retries when encountering ConcurrentModificationException.
protected int	pendingSaves Number of pending save or delete operations.
protected java.util.ArrayList<java.lang.Runnable>	pendingTasks List of pending tasks to execute.
protected java.util.TreeMap<C,Item<T,C>>	recentMap Recently loaded cache.
protected java.util.TreeMap<java.lang.String,C>	revIdMap Current live filename to ID map.
protected java.util.TreeMap<java.lang.String,C>	revIdMapWrk Current work filename to ID map.
protected boolean	runningPendingTasks Flag for performing pending tasks.
protected java.lang.Object	saveLock Lock used to avoid concurrent saving
protected static java.lang.String	VERSION_FOLDER Folder name where to store versions.
protected static java.lang.String	WORK_FOLDER Folder name where to store work data not yet committed.
protected java.io.File	workDeleted Work deleted ids folder.
protected java.io.File	workItems Work items folder.

Constructor Summary

Container(java.lang.String dbName, long delay, long saveInterval)
Constructor.

Method Summary

protected void	backup() Backup the data and ID map databases.
void	batchDelete(Item<T,C>[] items, boolean keepTrack) Delete an array of items all at once, items which are not found will simply be ignored.
void	batchMerge(C[] ids) Merge an array of items all at once, items which are not found will simply be ignored.
void	batchSave(Item<T,C>[] items, boolean abortOnDuplicate) Save array of items all at once.
protected void	cacheItem(C id, Item<T,C> it) Add an item to the cache.
void	clear() Clear all data in the container.
void	close() Close the container.
void	close(boolean removeHook)
void	commit() Commit all changes.
void	delete(Item<T,C> it, boolean keepTrack) Delete the item.
C[]	deletedIds() Retrieve list of IDs that have been deleted.
C[]	deletedIdsSince(long timestamp) Retrieve a list of IDs that have been deleted since the given timestamp.
void	duplicate(IContainer<T,C> cont) Converts the given IContainer into an hessian implementation.
protected C	filenameToId(java.lang.String filename) Generate ID from filename.
protected java.lang.String	idToFilename(C id) Generate filename for given ID.
boolean	inUse(C id) Determine if the given id is in use.
boolean	isClosed() Determine if the container has already been closed.
C[]	listModifiedSince(long timestamp) List all items modified since the given timestamp.
Item<T,C>[]	load(C[] ids, boolean allVersions) Load multiple items at once, using the specified ids.
Item<T,C>	load(C id, boolean allVersions) Load an item using its id.
Item<T,C>[]	modifiedSince(long timestamp, boolean allVersions) Load all items modified since the given timestamp.
protected void	populateDeletedMap() Populate the deleted ID map from files.
protected void	populateIdMap() Populate the ID map from files.
void	release(java.lang.Object obj) Release the object so it can be garbage collected immediately.
void	rollback() Rollback and discard all changes since last commit.
void	save(Item<T,C> it) Save the item.
java.lang.String	toString() Returns a string representation of this Container.
protected void	uncacheItem(C id) Remove an item from cache.
void	waitForPendingSaves() Wait for all saves and deletes pending tasks to finish.
void	waitForPendingTasks() Wait for all tasks pending tasks to finish.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_COMPARABLE_ARRAY

protected static final java.lang.Comparable<?>[] EMPTY_COMPARABLE_ARRAY

Empty Comparable array.

ITEM_FOLDER

protected static final java.lang.String ITEM_FOLDER

Folder name where to store items.

See Also:

Constant Field Values

VERSION_FOLDER

protected static final java.lang.String VERSION_FOLDER

Folder name where to store versions.

See Also:

Constant Field Values

DELETED_FOLDER

protected static final java.lang.String DELETED_FOLDER

Folder name where to store deleted ids.

See Also:

Constant Field Values

LIVE_FOLDER

protected static final java.lang.String LIVE_FOLDER

Folder name where to store live data.

See Also:

Constant Field Values

WORK_FOLDER

protected static final java.lang.String WORK_FOLDER

Folder name where to store work data not yet committed.

See Also:

Constant Field Values

FOLDER_FILTER

protected static final DirFileFilter FOLDER_FILTER

FileFilter accepting folder files.

MAX_ITEM_CACHED

protected static final int MAX_ITEM_CACHED

Maximum number of items to cache.

MAX_LOADTHREAD

protected static final int MAX_LOADTHREAD

Maximum number of items to cache.

MAX_RETRY

protected static final int MAX_RETRY

Maximum number of save retries when encountering ConcurrentModificationException.

MAX_CACHE_TIME

protected static final long MAX_CACHE_TIME

Maximum amount of time an item will stay cached before being uncached automatically.

dbName

protected java.lang.String dbName

Name of the DB.

closed

protected boolean closed

Flag to indicate if DB is closed.

liveItems

protected java.io.File liveItems

Live items folder.

liveDeleted

protected java.io.File liveDeleted

Live deleted ids folder.

workItems

protected java.io.File workItems

Work items folder.

workDeleted

protected java.io.File workDeleted

Work deleted ids folder.

idMap

protected java.util.TreeMap<C extends java.lang.Comparable<? super C>,java.lang.String> idMap

Current live ID to filename Map.

revIdMap

protected java.util.TreeMap<java.lang.String,C extends java.lang.Comparable<? super C>> revIdMap

Current live filename to ID map.

deletedMap

protected java.util.TreeMap<C extends java.lang.Comparable<? super C>,java.lang.String> deletedMap

Current live deleted ID to filename Map.

idMapWrk

protected java.util.TreeMap<C extends java.lang.Comparable<? super C>,java.lang.String> idMapWrk

Current work ID to filename Map.

revIdMapWrk

protected java.util.TreeMap<java.lang.String,C extends java.lang.Comparable<? super C>> revIdMapWrk

Current work filename to ID map.

deletedMapWrk

protected java.util.TreeMap<C extends java.lang.Comparable<? super C>,java.lang.String> deletedMapWrk

Current work deleted ID to filename Map.

recentMap

protected java.util.TreeMap<C extends java.lang.Comparable<? super C>,Item<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>> recentMap

Recently loaded cache.

cachedIds

protected java.util.ArrayList<C extends java.lang.Comparable<? super C>> cachedIds

IDs kept in cache.

counter

protected long counter

Next filename to assign.

saveLock

protected final java.lang.Object saveLock

Lock used to avoid concurrent saving

pendingTasks

protected java.util.ArrayList<java.lang.Runnable> pendingTasks

List of pending tasks to execute.

closing

protected boolean closing

Flag for closing.

runningPendingTasks

protected boolean runningPendingTasks

Flag for performing pending tasks.

pendingSaves

protected int pendingSaves

Number of pending save or delete operations.

hookThread

protected transient java.lang.Thread hookThread

Shutdown hook to make sure memory is saved to file when VM shuts down.

Constructor Detail

Container

public Container(java.lang.String dbName,
                 long delay,
                 long saveInterval)
          throws java.io.IOException

Constructor.

Parameters:

dbName - Name of the database.

delay - Delay before the first save.

saveInterval - Interval (in ms) between periodic replication to backup database.

Throws:

java.io.IOException

Method Detail

backup

protected void backup()

Backup the data and ID map databases.

batchDelete

public void batchDelete(Item<T,C>[] items,
                        boolean keepTrack)
                 throws java.io.IOException

Description copied from interface: IContainer

Delete an array of items all at once, items which are not found will simply be ignored.

Specified by:

batchDelete in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

items - Items to be deleted.

keepTrack - Whether or not the ID should be kept in history.

Throws:

java.io.IOException

See Also:

org.ov4j.IContainer#batchDelete(org.ov4j.data.Item[], boolean)

batchMerge

public void batchMerge(C[] ids)
                throws java.io.IOException

Description copied from interface: IContainer

Merge an array of items all at once, items which are not found will simply be ignored.

Specified by:

batchMerge in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

ids - IDs to be merged.

Throws:

java.io.IOException

See Also:

IContainer.batchMerge(java.lang.Comparable[])

batchSave

public void batchSave(Item<T,C>[] items,
                      boolean abortOnDuplicate)
               throws java.io.IOException

Description copied from interface: IContainer

Save array of items all at once. If abortOnDuplicate is set to true, data will not be saved if 1 or more item ids are in use.

Specified by:

batchSave in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

items - Array of items to be saved.

abortOnDuplicate - Whether or not saving should abort when an item has an ID already in use.

Throws:

java.io.IOException

See Also:

org.ov4j.IContainer#batchSave(org.ov4j.data.Item[], boolean)

cacheItem

protected void cacheItem(C id,
                         Item<T,C> it)

Add an item to the cache.

Parameters:

id - ID of the item.

it - Item to cache.

clear

public void clear()

Description copied from interface: IContainer

Clear all data in the container.

Specified by:

clear in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

See Also:

IContainer.clear()

close

public void close()
           throws java.io.IOException

Description copied from interface: IContainer

Close the container.

Specified by:

close in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Throws:

java.io.IOException

See Also:

IContainer.close()

close

public void close(boolean removeHook)
           throws java.io.IOException

Throws:

java.io.IOException

See Also:

IContainer.close()

commit

public void commit()

Description copied from interface: IContainer

Commit all changes.

Specified by:

commit in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

See Also:

IContainer.commit()

delete

public void delete(Item<T,C> it,
                   boolean keepTrack)
            throws java.io.IOException

Description copied from interface: IContainer

Delete the item.

Specified by:

delete in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

it - Item to be deleted.

keepTrack - Whether or not the ID should be kept in history.

Throws:

java.io.IOException

See Also:

IContainer.delete(org.ov4j.data.Item, boolean)

deletedIds

public C[] deletedIds()

Description copied from interface: IContainer

Retrieve list of IDs that have been deleted.

Specified by:

deletedIds in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Returns:

All IDs deleted.

See Also:

IContainer.deletedIds()

deletedIdsSince

public C[] deletedIdsSince(long timestamp)
                                                            throws java.io.IOException

Description copied from interface: IContainer

Retrieve a list of IDs that have been deleted since the given timestamp.

Specified by:

deletedIdsSince in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

timestamp - Timestamp to use.

Returns:

All IDS deleted since the given timestamp.

Throws:

java.io.IOException

See Also:

IContainer.deletedIdsSince(long)

duplicate

public void duplicate(IContainer<T,C> cont)
               throws java.io.IOException

Converts the given IContainer into an hessian implementation.

Specified by:

duplicate in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

cont - IContainer to convert.

Throws:

java.io.IOException

filenameToId

protected C filenameToId(java.lang.String filename)
                                                          throws java.io.IOException

Generate ID from filename.

Parameters:

filename - Filename from which to generate ID.

Returns:

ID generated

Throws:

java.io.IOException

idToFilename

protected java.lang.String idToFilename(C id)
                                 throws java.io.IOException

Generate filename for given ID.

Parameters:

id - ID for which to generate a filename.

Returns:

Filename generated.

Throws:

java.io.IOException

inUse

public boolean inUse(C id)

Description copied from interface: IContainer

Determine if the given id is in use.

Specified by:

inUse in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

id - ID to check.

Returns:

True if the ID is already used in the system.

See Also:

IContainer.inUse(java.lang.Comparable)

isClosed

public boolean isClosed()

Description copied from interface: IContainer

Determine if the container has already been closed.

Specified by:

isClosed in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Returns:

True if the container has been closed.

See Also:

IContainer.isClosed()

listModifiedSince

public C[] listModifiedSince(long timestamp)
                                                              throws java.io.IOException

Description copied from interface: IContainer

List all items modified since the given timestamp.

Specified by:

listModifiedSince in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

timestamp - Timestamp to use.

Returns:

An array of IDs for items modified since specified timestamp.

Throws:

java.io.IOException

See Also:

IContainer.listModifiedSince(long)

load

public Item<T,C> load(C id,
                      boolean allVersions)
                                                                                                                                          throws java.io.IOException

Description copied from interface: IContainer

Load an item using its id.

Specified by:

load in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

id - ID to look for.

allVersions - Whether or not all versions should be loaded.

Returns:

The item with specified ID.

Throws:

java.io.IOException

See Also:

IContainer.load(java.lang.Comparable, boolean)

load

public Item<T,C>[] load(C[] ids,
                        boolean allVersions)
                                                                                                                                            throws java.io.IOException

Description copied from interface: IContainer

Load multiple items at once, using the specified ids.

Specified by:

load in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

ids - Array of IDs to look for.

allVersions - Whether or not all versions should be loaded.

Returns:

An array of items with specified IDs, not necessarily in the same order.

Throws:

java.io.IOException

See Also:

IContainer.load(java.lang.Comparable[], boolean)

modifiedSince

public Item<T,C>[] modifiedSince(long timestamp,
                                 boolean allVersions)
                                                                                                                                                     throws java.io.IOException

Description copied from interface: IContainer

Load all items modified since the given timestamp.

Specified by:

modifiedSince in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

timestamp - Timestamp to use.

allVersions - Whether or not all versions should be loaded.

Returns:

An array of items modified since specified timestamp.

Throws:

java.io.IOException

See Also:

IContainer.modifiedSince(long, boolean)

populateDeletedMap

protected void populateDeletedMap()
                           throws java.io.IOException

Populate the deleted ID map from files.

Throws:

java.io.IOException

populateIdMap

protected void populateIdMap()
                      throws java.io.IOException

Populate the ID map from files.

Throws:

java.io.IOException

release

public void release(java.lang.Object obj)

Description copied from interface: IContainer

Release the object so it can be garbage collected immediately.

Specified by:

release in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

obj - Object to release.

See Also:

IContainer.release(java.lang.Object)

rollback

public void rollback()

Description copied from interface: IContainer

Rollback and discard all changes since last commit.

Specified by:

rollback in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

See Also:

IContainer.rollback()

save

public void save(Item<T,C> it)
          throws java.io.IOException

Description copied from interface: IContainer

Save the item.

Specified by:

save in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

Parameters:

it - Item to be saved.

Throws:

java.io.IOException

See Also:

IContainer.save(org.ov4j.data.Item)

toString

public java.lang.String toString()

Returns a string representation of this Container.

Overrides:

toString in class java.lang.Object

Returns:

String representation of the Container.

uncacheItem

protected void uncacheItem(C id)

Remove an item from cache.

Parameters:

id - ID of the item.

waitForPendingSaves

public void waitForPendingSaves()

Description copied from interface: IContainer

Wait for all saves and deletes pending tasks to finish.

Specified by:

waitForPendingSaves in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

See Also:

IContainer.waitForPendingSaves()

waitForPendingTasks

public void waitForPendingTasks()

Description copied from interface: IContainer

Wait for all tasks pending tasks to finish.

Specified by:

waitForPendingTasks in interface IContainer<T extends java.lang.Comparable<? super T> & java.lang.Cloneable & java.io.Serializable,C extends java.lang.Comparable<? super C>>

See Also:

IContainer.waitForPendingTasks()