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

    final int noOfAdditionalRecords = tc.getNoOfAdditionalRecords();
    System.out.println("Deleting " + noOfAdditionalRecords + " additional records in " + dbs.size() + " databases");
    long start = System.currentTimeMillis();
    for (Database<String, String> db : dbs)
    {
      Transaction txn = null;
      try
      {
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn = Transaction.startTransaction(false);
        }
        for (int i = noOfBaseRecords; i < noOfBaseRecords + noOfAdditionalRecords; i++)
        {
          db.delete(s_vrs_keys[i]);
        }
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn.commit();
          txn = null;
        }
      }
      finally
      {
        if (txn != null)
        {
          txn.rollback();
        }
      }
    }
    long time = System.currentTimeMillis() - start;
    double res = (float) time / (noOfAdditionalRecords * dbs.size());

View Full Code Here

    final int vrsValuesLen = s_vrs_values.length;
    int dbNo = 0;
    int i = 0;
    for (Database<String, String> db : dbs)
    {
      Transaction txn = null;
      try
      {
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn = Transaction.startTransaction(false);
        }
        for (i = 0; i < noOfRecords; i++)
        {
          db.update(s_vrs_keys[i], s_vrs_values[vrsValuesLen - i - 1]);
        }
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn.commit();
          txn = null;
        }
      }
      catch (RuntimeException e)
      {
        System.err.println("DB #" + dbNo);
        System.err.println("Entry " + i);
        throw e;
      }
      finally
      {
        if (txn != null)
        {
          txn.rollback();
        }
      }
      dbNo++;
    }
    long time = System.currentTimeMillis() - start;

View Full Code Here

    final int noOfRecords = tc.getNoOfBaseRecords();
    System.out.println("Deleting 1/3rd of " + noOfRecords + " (all) records in " + dbs.size() + " databases");
    long start = System.currentTimeMillis();
    for (Database<String, String> db : dbs)
    {
      Transaction txn = null;
      try
      {
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn = Transaction.startTransaction(false);
        }
        for (int i = 0; i < noOfRecords / 3; i++)
        {
          db.delete(s_vrs_keys[3 * i]);
        }
        if (db instanceof TransactionalDatabase<?, ?>)
        {
          txn.commit();
          txn = null;
        }
      }
      finally
      {
        if (txn != null)
        {
          txn.rollback();
        }
      }
    }
    long time = System.currentTimeMillis() - start;
    double res = (float) time / ((noOfRecords / 3) * dbs.size());

View Full Code Here

  public void testUpdateCommit()
  {
    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.update(1, 100L);
        db.update(2, 200L);
        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

  public void testUpdateRollback()
  {
    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.update(1, 100L);
        db.update(2, 200L);
        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

  public void testClearCommit()
  {
    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.clear();
        txn.commit();


        txn = Transaction.startTransaction(true);
        assertEquals(0, db.size());
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

  public void testClearRollback()
  {
    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.clear();
        db.insert(1, 100L);
        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

  public void testCompactCommit()
  {
    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.delete(1);
        db.insert(3, 30L);
        txn.commit();


        txn = Transaction.startTransaction(false);
        db.compact();
        txn.commit();


        txn = Transaction.startTransaction(true);
        assertEquals(2, db.size());
        assertEquals(30L, db.get(3).longValue());
        assertEquals(20L, db.get(2).longValue());
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

  public void testCompactRollback()
  {
    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.delete(1);
        db.insert(3, 30L);
        txn.commit();


        txn = Transaction.startTransaction(false);
        db.compact();
        txn.rollback();


        txn = Transaction.startTransaction(true);
        assertEquals(2, db.size());
        assertEquals(30L, db.get(3).longValue());
        assertEquals(20L, db.get(2).longValue());
      }
      finally
      {
        txn.rollback();
      }
    }
    finally
    {
      tearDownDatabase(db);

View Full Code Here

  public void testDeleteCommit()
  {
    Database<Integer, Long> db = createDatabaseWoTxn();
    try
    {
      Transaction txn = Transaction.startTransaction(false);
      try
      {
        db.insert(1, 10L);
        db.insert(2, 20L);
        db.insert(3, 30L);
        txn.commit();


        txn = Transaction.startTransaction(false);
        db.delete(2);
        txn.commit();


        txn = Transaction.startTransaction(true);
        assertEquals(2, db.size());
        assertEquals(30L, db.get(3).longValue());
        assertEquals(10L, db.get(1).longValue());
        assertNull(db.get(2));
      }
      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.