net.java.sip.communicator.service.fileaccess
Interface FailSafeTransaction

All Known Implementing Classes:

FailSafeTransactionImpl

public interface FailSafeTransaction

A failsafe transaction interface. By failsafe we mean here that the file concerned always stays in a coherent state.

Author:

Benoit Pradelle

Method Summary

void	beginTransaction() Begins a new transaction.
void	commit() Closes the transaction and commit the changes.
void	restoreFile() Ensure that the file accessed is in a coherent state.
void	rollback() Closes the transation and cancel the changes.

Method Detail

restoreFile

void restoreFile()
                 throws IllegalStateException,
                        IOException

Ensure that the file accessed is in a coherent state. This function is useful to do a failsafe read without starting a transaction.

Throws:

IllegalStateException - if the file doesn't exists anymore

IOException - if an IOException occurs during the file restoration

beginTransaction

void beginTransaction()
                      throws IllegalStateException,
                             IOException

Begins a new transaction. If a transaction is already active, commits the changes and begin a new transaction. A transaction can be closed by a commit or rollback operation. When the transaction begins, the file is restored to a coherent state if needed.

Throws:

IllegalStateException - if the file doesn't exists anymore

IOException - if an IOException occurs during the transaction creation

commit

void commit()
            throws IllegalStateException,
                   IOException

Closes the transaction and commit the changes. Everything written in the file during the transaction is saved.

Throws:

IllegalStateException - if the file doesn't exists anymore

IOException - if an IOException occurs during the operation

rollback

void rollback()
              throws IllegalStateException,
                     IOException

Closes the transation and cancel the changes. Everything written in the file during the transaction is NOT saved.

Throws:

IllegalStateException - if the file doesn't exists anymore

IOException - if an IOException occurs during the operation