jdbm.recman
Class TransactionManager

java.lang.Object
  jdbm.recman.TransactionManager

public final class TransactionManager
extends java.lang.Object

This class manages the transaction log that belongs to every RecordFile. The transaction log is either clean, or in progress. In the latter case, the transaction manager takes care of a roll forward.

Implementation note: this is a proof-of-concept implementation which hasn't been optimized for speed. For instance, all sorts of streams are created for every transaction.

Nested Class Summary

static class

TransactionManager.BlockIoComparator INNER CLASS.

Method Summary

void	setMaximumTransactionsInLog(int maxTxns) Set the maximum number of transactions to record in the log (and keep in memory) before the log is synchronized with the main database file.
void	synchronizeLog() Synchronize log file data with the main database file.

Methods inherited from class java.lang.Object

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

Method Detail

synchronizeLog

public void synchronizeLog()
                    throws java.io.IOException

Synchronize log file data with the main database file.

After this call, the main database file is guaranteed to be consistent and guaranteed to be the only file needed for backup purposes.

Throws:

java.io.IOException

setMaximumTransactionsInLog

public void setMaximumTransactionsInLog(int maxTxns)
                                 throws java.io.IOException

Set the maximum number of transactions to record in the log (and keep in memory) before the log is synchronized with the main database file.

This method must be called while there are no pending transactions in the log.

Throws:

java.io.IOException