org.janusgraph.diskstorage.keycolumnvalue

Interface StoreManager

All Known Subinterfaces:

KeyColumnValueStoreManager, KeyValueStoreManager, OrderedKeyValueStoreManager

All Known Implementing Classes:

AbstractStoreManager, DistributedStoreManager, ExpectedValueCheckingStoreManager, KCVSManagerProxy, LocalStoreManager, MetricInstrumentedStoreManager, OrderedKeyValueStoreManagerAdapter, TTLKCVSManager

public interface StoreManager

Generic interface to a backend storage engine.

Author:

Matthias Broecheler (me@matthiasb.com)

Method Summary

Modifier and Type	Method and Description
StoreTransaction	beginTransaction(BaseTransactionConfig config) Returns a transaction handle for a new transaction according to the given configuration.
void	clearStorage() Deletes and clears all database in this storage manager.
void	close() Closes the Storage Manager and all databases that have been opened.
boolean	exists() Check whether database exists in this storage manager.
StoreFeatures	getFeatures() Returns the features supported by this storage manager
default Object	getHadoopManager() Returns org.janusgraph.hadoop.HadoopStoreManager
List<KeyRange>	getLocalKeyPartition() Returns KeyRanges locally hosted on this machine.
String	getName() Return an identifier for the StoreManager.

Method Detail

beginTransaction

StoreTransaction beginTransaction(BaseTransactionConfig config)
                           throws BackendException

Returns a transaction handle for a new transaction according to the given configuration.

Returns:

New Transaction Handle

Throws:

BackendException

close

void close()
    throws BackendException

Closes the Storage Manager and all databases that have been opened.

Throws:

BackendException

clearStorage

void clearStorage()
           throws BackendException

Deletes and clears all database in this storage manager.

ATTENTION: Invoking this method will delete ALL your data!!

Throws:

BackendException

exists

boolean exists()
        throws BackendException

Check whether database exists in this storage manager.

Returns:

Flag indicating whether database exists

Throws:

BackendException

getFeatures

StoreFeatures getFeatures()

Returns the features supported by this storage manager

Returns:

The supported features of this storage manager

See Also:

StoreFeatures

getName

String getName()

Return an identifier for the StoreManager. Two managers with the same name would open databases that read and write the same underlying data; two store managers with different names should be, for data read/write purposes, completely isolated from each other.

Examples:

• Cassandra keyspace
• HBase tablename
• InMemoryStore heap address (i.e. default toString()).

Returns:

Name for this StoreManager

getLocalKeyPartition

List<KeyRange> getLocalKeyPartition()
                             throws BackendException

Returns KeyRanges locally hosted on this machine. The start of each KeyRange is inclusive. The end is exclusive. The start and end must each be at least 4 bytes in length.

Returns:

A list of local key ranges

Throws:

UnsupportedOperationException - if the underlying store does not support this operation. Check StoreFeatures.hasLocalKeyPartition() first.

BackendException

getHadoopManager

default Object getHadoopManager()
                         throws BackendException

Returns org.janusgraph.hadoop.HadoopStoreManager

Returns:

A HadoopStoreManager if supported.

Throws:

BackendException