Examples of org.helidb.txn.Transaction

org.helidb.txn.Transaction
ikipedia.org/wiki/ACID">this Wikipedia article. At the end of the logical operation, it is either {@link #commit()}:ed, i.e. persisted to the database storage, or {@link #rollback()}:ed, i.e. discarded.
A transaction always involves just one execution thread. Several different threads may have their own transactions, and the transactions' ACID:ity properties guarantee that they will never see data in an intermediate state. This is accomplished by the thread locking implemented in the involved databases.
HeliDB has both read/write and read only transactions. It is up to the {@link org.helidb.Database} implementation used if they are treateddifferently. For instance, a {@code Database} could allow several concurrentread only transactions, but only one simultaneous transaction if that transaction is read/write.
A new transaction is started by any of the static {@link #startTransaction(boolean)} or {@link #getOrStartTransaction(boolean)}methods. If the thread already is involved in a transaction and wants to get that transaction's {@code Transaction} object, it can call any of the staticgetter methods.
Implementation note:
A database joins a {@code Transaction} via its{@link TransactionCollaborator}. It uses one collaborator object per transaction it is involved in. The collaborator keeps track of the state for the database associated with just that transaction. @author Karl Gustafsson @since 1.0 @see TransactionCollaborator @see TransactionalDatabase

  public void testRollback()
  {
    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.fasterInsert(Integer.valueOf(1), Long.valueOf(2));
        db.fasterInsert(Integer.valueOf(123), Long.valueOf(234));
        assertEquals(Long.valueOf(2), db.get(Integer.valueOf(1)));
        assertEquals(Long.valueOf(234), db.get(Integer.valueOf(123)));
      }
      finally
      {
        txn.rollback();
      }


      txn = Transaction.startTransaction(true);
      try
      {
        assertNull(db.get(Integer.valueOf(1)));
        assertNull(db.get(Integer.valueOf(123)));
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

      catch (NoTransactionException e)
      {
        // ok
      }


      Transaction txn = Transaction.startTransaction(true);
      try
      {
        assertEquals(Long.valueOf(2), db.get(Integer.valueOf(1)));
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

    try
    {
      populateDb(db);


      assertNull(Transaction.getCurrentTransactionOrNull());
      Transaction txn = Transaction.startTransaction(true);
      try
      {
        try
        {
          db.fasterInsert(Integer.valueOf(3), Long.valueOf(333));
          fail();
        }
        catch (ReadOnlyTransactionException e)
        {
          // ok
        }


        assertNull(db.get(Integer.valueOf(3)));
      }
      finally
      {
        txn.commit();
      }


      txn = Transaction.startTransaction(true);
      try
      {
        assertNull(db.get(Integer.valueOf(3)));
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      populateDb(db);
      boolean committed = false;
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.fasterInsert(Integer.valueOf(3), Long.valueOf(333L));
        tearDownDatabase(db);
        destroyed = true;
        committed = true;
        try
        {
          txn.commit();
        }
        catch (IllegalStateException e)
        {
          // ok
        }
      }
      finally
      {
        if (!committed)
        {
          txn.rollback();
        }
      }
    }
    finally
    {

View Full Code Here

    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      populateDb(db);
      boolean committed = false;
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.fasterInsert(Integer.valueOf(3), Long.valueOf(333L));
        tearDownDatabase(db);
        destroyed = true;
        committed = true;
        try
        {
          txn.rollback();
        }
        catch (IllegalStateException e)
        {
          // ok
        }
      }
      finally
      {
        if (!committed)
        {
          txn.rollback();
        }
      }
    }
    finally
    {

View Full Code Here

  public void testInsertCommit()
  {
    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.insert(1, 10L);
        db.insert(2, 20L);
        txn.commit();


        txn = Transaction.startTransaction(true);
        assertEquals(2, db.size());
        assertEquals(20L, db.get(2).longValue());
        assertEquals(10L, db.get(1).longValue());
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

  public void testInsertRollback()
  {
    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.insert(1, 10L);
        db.insert(2, 20L);
        txn.commit();


        txn = Transaction.startTransaction(false);
        db.insert(3, 30L);
        db.insert(4, 40L);
        txn.rollback();


        txn = Transaction.startTransaction(true);
        assertEquals(2, db.size());
        assertEquals(20L, db.get(2).longValue());
        assertEquals(10L, db.get(1).longValue());
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

0 1 2 3 4 5 6 7

TOP

Related Classes of org.helidb.txn.Transaction

org.helidb.doc.ProgrammersGuideExamplesTest

org.helidb.impl.txn.AbstractTransactionalDatabase

org.helidb.impl.txn.log.AbstractLoggingTxnDbOnConstantRecordSizeBackendTest

org.helidb.impl.txn.log.AbstractLoggingTxnDbTest

org.helidb.resources.perf.PerformanceTestRunner

org.helidb.txn.AbstractTransactionalDatabaseOnConstantRecordSizeBackendTest

org.helidb.txn.AbstractTransactionalDatabaseOnVariableRecordSizeBackendTest

org.helidb.txn.TransactionTest

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.