Knopflerfish OSGi 5.2.0

org.osgi.service.dmt.spi
Interface TransactionalDataSession

All Superinterfaces:
ReadableDataSession, ReadWriteDataSession

public interface TransactionalDataSession
extends ReadWriteDataSession

Provides atomic read-write access to the part of the tree handled by the plugin that created this session.

Author:
$Id: 14e5b379945c794fbb29c0c369e1f652795cf46a $

Method Summary
 void commit()
          Commits a series of DMT operations issued in the current atomic session since the last transaction boundary.
 void rollback()
          Rolls back a series of DMT operations issued in the current atomic session since the last transaction boundary.
 
Methods inherited from interface org.osgi.service.dmt.spi.ReadWriteDataSession
copy, createInteriorNode, createLeafNode, deleteNode, renameNode, setNodeTitle, setNodeType, setNodeValue
 
Methods inherited from interface org.osgi.service.dmt.spi.ReadableDataSession
close, getChildNodeNames, getMetaNode, getNodeSize, getNodeTimestamp, getNodeTitle, getNodeType, getNodeValue, getNodeVersion, isLeafNode, isNodeUri, nodeChanged
 

Method Detail

commit

void commit()
            throws DmtException
Commits a series of DMT operations issued in the current atomic session since the last transaction boundary. Transaction boundaries are the creation of this object that starts the session, and all subsequent commit() and rollback() calls.

This method can fail even if all operations were successful. This can happen due to some multi-node semantic constraints defined by a specific implementation. For example, node A can be required to always have children A/B, A/C and A/D. If this condition is broken when commit() is executed, the method will fail, and throw a METADATA_MISMATCH exception.

In many cases the tree is not the only way to manage a given part of the system. It may happen that while modifying some nodes in an atomic session, the underlying settings are modified parallelly outside the scope of the DMT. If this is detected during commit, an exception with the code CONCURRENT_ACCESS is thrown.

Throws:
DmtException - with the following possible error codes
  • METADATA_MISMATCH if the operation failed because of meta-data restrictions
  • CONCURRENT_ACCESS if it is detected that some modification has been made outside the scope of the DMT to the nodes affected in the session's operations
  • DATA_STORE_FAILURE if an error occurred while accessing the data store
  • COMMAND_FAILED if some unspecified error is encountered while attempting to complete the command
java.lang.SecurityException - if the caller does not have the necessary permissions to execute the underlying management operation

rollback

void rollback()
              throws DmtException
Rolls back a series of DMT operations issued in the current atomic session since the last transaction boundary. Transaction boundaries are the creation of this object that starts the session, and all subsequent commit() and rollback() calls.

Throws:
DmtException - with the error code ROLLBACK_FAILED in case the rollback did not succeed
java.lang.SecurityException - if the caller does not have the necessary permissions to execute the underlying management operation

Knopflerfish OSGi 5.2.0