org.apache.jackrabbit.core.data
Class MultiDataStore

java.lang.Object
  org.apache.jackrabbit.core.data.MultiDataStore

All Implemented Interfaces:

DataStore

public class MultiDataStore
extends Object
implements DataStore

A MultiDataStore can handle two independent DataStores.

Attention: You will lost the global single instance mechanism !

It can be used if you have two storage systems. One for fast access and a other one like a archive DataStore on a slower storage system. All Files will be added to the primary DataStore. On read operations first the primary dataStore will be used and if no Record is found the archive DataStore will be used. The GarabageCollector will only remove files from the archive DataStore.

The internal MoveDataTask will be started automatically and could be configured with the following properties.

The Configuration:

 <DataStore class="org.apache.jackrabbit.core.data.MultiDataStore">
     <param name="maxAge" value="60"/>
     <param name="moveDataTaskSleep" value="604800"/>
     <param name="moveDataTaskFirstRunHourOfDay" value="1"/>
     <param name="sleepBetweenRecords" value="100"/>
     <param name="delayedDelete" value="false"/>
     <param name="delayedDeleteSleep" value="86400"/>
     <param name="primary" value="org.apache.jackrabbit.core.data.db.DbDataStore">
        <param .../>
     </param>
     <param name="archive" value="org.apache.jackrabbit.core.data.FileDataStore">
        <param .../>
     </param>
 </DataStore>
 

• maxAge: defines how many days the content will reside in the primary data store. DataRecords that have been added before this time span will be moved to the archive data store. (default = 60)
• moveDataTaskSleep: specifies the sleep time of the moveDataTaskThread in seconds. (default = 60 * 60 * 24 * 7, which equals 7 days)
• moveDataTaskNextRunHourOfDay: specifies the hour at which the moveDataTaskThread initiates its first run (default = 1 which means 01:00 at night)
• sleepBetweenRecords: specifies the delay in milliseconds between scanning data records (default = 100)
• delayedDelete: its possible to delay the delete operation on the primary data store. The DataIdentifiers will be written to a temporary file. The file will be processed after a defined sleep (see delayedDeleteSleep) It's useful if you like to create a snapshot of the primary data store backend in the meantime before the data will be deleted. (default = false)
• delayedDeleteSleep: specifies the sleep time of the delayedDeleteTaskThread in seconds. (default = 60 * 60 * 24, which equals 1 day). This means the delayed delete from the primary data store will be processed after one day.

Nested Class Summary

class	MultiDataStore.DeleteDelayedIdentifiersTask Class to clean up the delayed DataRecords from the primary data store.
class	MultiDataStore.MoveDataTask Class for maintaining the MultiDataStore.

Constructor Summary

MultiDataStore()

Method Summary

DataRecord	addRecord(InputStream stream) Creates a new data record in the primary data store.
void	clearInUse() Clear the in-use list.
void	close() Close the data store
int	deleteAllOlderThan(long min) Delete objects that have a modified date older than the specified date from the archive data store.
Iterator<DataIdentifier>	getAllIdentifiers() Get all identifiers from the archive data store.
long	getDelayedDeleteSleep()
int	getMaxAge()
int	getMinRecordLength() Get the minimum size of an object that should be stored in the primary data store.
int	getMoveDataTaskFirstRunHourOfDay()
int	getMoveDataTaskSleep()
DataRecord	getRecord(DataIdentifier identifier) Returns the identified data record from the primary data store.
DataRecord	getRecordFromReference(String reference) Returns the record that matches the given binary reference.
DataRecord	getRecordIfStored(DataIdentifier identifier) Check if a record for the given identifier exists in the primary data store.
long	getSleepBetweenRecords()
void	init(String homeDir) Initialized the data store
boolean	isDelayedDelete()
void	setArchiveDataStore(DataStore dataStore) Setter for the archive dataStore
void	setDelayedDelete(boolean delayedDelete)
void	setDelayedDeleteSleep(long delayedDeleteSleep)
void	setMaxAge(int maxAge)
void	setMoveDataTaskFirstRunHourOfDay(int hourOfDay)
void	setMoveDataTaskSleep(int sleep)
void	setPrimaryDataStore(DataStore dataStore) Setter for the primary dataStore
void	setSleepBetweenRecords(long millis)
void	updateModifiedDateOnAccess(long before) From now on, update the modified date of an object even when accessing it in the archive data store.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiDataStore

public MultiDataStore()

Method Detail

setPrimaryDataStore

public void setPrimaryDataStore(DataStore dataStore)

Setter for the primary dataStore

Parameters:

dataStore -

setArchiveDataStore

public void setArchiveDataStore(DataStore dataStore)

Setter for the archive dataStore

Parameters:

dataStore -

getRecordIfStored

public DataRecord getRecordIfStored(DataIdentifier identifier)
                             throws DataStoreException

Check if a record for the given identifier exists in the primary data store. If not found there it will be returned from the archive data store. If no record exists, this method returns null.

Specified by:

getRecordIfStored in interface DataStore

Parameters:

identifier - data identifier

Returns:

the record if found, and null if not

Throws:

DataStoreException - if the data store could not be accessed

getRecord

public DataRecord getRecord(DataIdentifier identifier)
                     throws DataStoreException

Returns the identified data record from the primary data store. If not found there it will be returned from the archive data store. The given identifier should be the identifier of a previously saved data record. Since records are never removed, there should never be cases where the identified record is not found. Abnormal cases like that are treated as errors and handled by throwing an exception.

Specified by:

getRecord in interface DataStore

Parameters:

identifier - data identifier

Returns:

identified data record

Throws:

DataStoreException - if the data store could not be accessed, or if the given identifier is invalid

addRecord

public DataRecord addRecord(InputStream stream)
                     throws DataStoreException

Creates a new data record in the primary data store. The given binary stream is consumed and a binary record containing the consumed stream is created and returned. If the same stream already exists in another record, then that record is returned instead of creating a new one.

The given stream is consumed and not closed by this method. It is the responsibility of the caller to close the stream. A typical call pattern would be:

     InputStream stream = ...;
     try {
         record = store.addRecord(stream);
     } finally {
         stream.close();
     }
 

Specified by:

addRecord in interface DataStore

Parameters:

stream - binary stream

Returns:

data record that contains the given stream

Throws:

DataStoreException - if the data store could not be accessed

updateModifiedDateOnAccess

public void updateModifiedDateOnAccess(long before)

From now on, update the modified date of an object even when accessing it in the archive data store. Usually, the modified date is only updated when creating a new object, or when a new link is added to an existing object. When this setting is enabled, even getLength() will update the modified date.

Specified by:

updateModifiedDateOnAccess in interface DataStore

Parameters:

before - - update the modified date to the current time if it is older than this value

deleteAllOlderThan

public int deleteAllOlderThan(long min)
                       throws DataStoreException

Delete objects that have a modified date older than the specified date from the archive data store.

Specified by:

deleteAllOlderThan in interface DataStore

Parameters:

min - the minimum time

Returns:

the number of data records deleted

Throws:

DataStoreException

getAllIdentifiers

public Iterator<DataIdentifier> getAllIdentifiers()
                                           throws DataStoreException

Get all identifiers from the archive data store.

Specified by:

getAllIdentifiers in interface DataStore

Returns:

an iterator over all DataIdentifier objects

Throws:

DataStoreException - if the list could not be read

getRecordFromReference

public DataRecord getRecordFromReference(String reference)
                                  throws DataStoreException

Description copied from interface: DataStore

Returns the record that matches the given binary reference. Returns null if the reference is invalid, for example if it points to a record that does not exist.

Specified by:

getRecordFromReference in interface DataStore

Parameters:

reference - binary reference

Returns:

matching record, or null

Throws:

DataStoreException - if the data store could not be accessed

init

public void init(String homeDir)
          throws RepositoryException

Initialized the data store

Specified by:

init in interface DataStore

Parameters:

homeDir - the home directory of the repository

Throws:

RepositoryException

getMinRecordLength

public int getMinRecordLength()

Get the minimum size of an object that should be stored in the primary data store.

Specified by:

getMinRecordLength in interface DataStore

Returns:

the minimum size in bytes

close

public void close()
           throws DataStoreException

Close the data store

Specified by:

close in interface DataStore

Throws:

DataStoreException - if a problem occurred

clearInUse

public void clearInUse()

Clear the in-use list. This is only used for testing to make the the garbage collection think that objects are no longer in use.

Specified by:

clearInUse in interface DataStore

getMaxAge

public int getMaxAge()

setMaxAge

public void setMaxAge(int maxAge)

getMoveDataTaskSleep

public int getMoveDataTaskSleep()

getMoveDataTaskFirstRunHourOfDay

public int getMoveDataTaskFirstRunHourOfDay()

setMoveDataTaskSleep

public void setMoveDataTaskSleep(int sleep)

setMoveDataTaskFirstRunHourOfDay

public void setMoveDataTaskFirstRunHourOfDay(int hourOfDay)

setSleepBetweenRecords

public void setSleepBetweenRecords(long millis)

getSleepBetweenRecords

public long getSleepBetweenRecords()

isDelayedDelete

public boolean isDelayedDelete()

setDelayedDelete

public void setDelayedDelete(boolean delayedDelete)

getDelayedDeleteSleep

public long getDelayedDeleteSleep()

setDelayedDeleteSleep

public void setDelayedDeleteSleep(long delayedDeleteSleep)