/*
 * Copyright (c) 2009, PostgreSQL Global Development Group
 * See the LICENSE file in the project root for more information.
 */

package org.postgresql.xa;

import org.postgresql.PGConnection;
import org.postgresql.core.BaseConnection;
import org.postgresql.core.TransactionState;
import org.postgresql.ds.PGPooledConnection;
import org.postgresql.util.GT;
import org.postgresql.util.PSQLException;
import org.postgresql.util.PSQLState;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.LinkedList;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.sql.XAConnection;
import javax.transaction.xa.XAException;
import javax.transaction.xa.XAResource;
import javax.transaction.xa.Xid;

The PostgreSQL implementation of XAResource.
This implementation doesn't support transaction interleaving (see JTA specification, section
3.4.4) and suspend/resume.
Two-phase commit requires PostgreSQL server version 8.1 or higher.
Author:
Heikki Linnakangas (heikki.linnakangas@iki.fi)/**
 * <p>The PostgreSQL implementation of {@link XAResource}.</p>
 *
 * <p>This implementation doesn't support transaction interleaving (see JTA specification, section
 * 3.4.4) and suspend/resume.</p>
 *
 * <p>Two-phase commit requires PostgreSQL server version 8.1 or higher.</p>
 *
 * @author Heikki Linnakangas (heikki.linnakangas@iki.fi)
 */
public class PGXAConnection extends PGPooledConnection implements XAConnection, XAResource {

  private static final Logger LOGGER = Logger.getLogger(PGXAConnection.class.getName());

  
Underlying physical database connection. It's used for issuing PREPARE TRANSACTION/ COMMIT
PREPARED/ROLLBACK PREPARED commands.
/**
   * Underlying physical database connection. It's used for issuing PREPARE TRANSACTION/ COMMIT
   * PREPARED/ROLLBACK PREPARED commands.
   */
  private final BaseConnection conn;

  private Xid currentXid;

  private State state;
  private Xid preparedXid;
  private boolean committedOrRolledBack;

  /*
   * When an XA transaction is started, we put the underlying connection into non-autocommit mode.
   * The old setting is saved in localAutoCommitMode, so that we can restore it when the XA
   * transaction ends and the connection returns into local transaction mode.
   */
  private boolean localAutoCommitMode = true;

  private void debug(String s) {
    if (LOGGER.isLoggable(Level.FINEST)) {
      LOGGER.log(Level.FINEST, "XAResource {0}: {1}", new Object[]{Integer.toHexString(this.hashCode()), s});
    }
  }

  public PGXAConnection(BaseConnection conn) throws SQLException {
    super(conn, true, true);
    this.conn = conn;
    this.state = State.IDLE;
  }

  
XAConnection interface.
/**
   * XAConnection interface.
   */
  @Override
  public Connection getConnection() throws SQLException {
    Connection conn = super.getConnection();

    // When we're outside an XA transaction, autocommit
    // is supposed to be true, per usual JDBC convention.
    // When an XA transaction is in progress, it should be
    // false.
    if (state == State.IDLE) {
      conn.setAutoCommit(true);
    }

    /*
     * Wrap the connection in a proxy to forbid application from fiddling with transaction state
     * directly during an XA transaction
     */
    ConnectionHandler handler = new ConnectionHandler(conn);
    return (Connection) Proxy.newProxyInstance(getClass().getClassLoader(),
        new Class[]{Connection.class, PGConnection.class}, handler);
  }

  @Override
  public XAResource getXAResource() {
    return this;
  }

  /*
   * A java.sql.Connection proxy class to forbid calls to transaction control methods while the
   * connection is used for an XA transaction.
   */
  private class ConnectionHandler implements InvocationHandler {
    private final Connection con;

    ConnectionHandler(Connection con) {
      this.con = con;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
      if (state != State.IDLE) {
        String methodName = method.getName();
        if (methodName.equals("commit")
            || methodName.equals("rollback")
            || methodName.equals("setSavePoint")
            || (methodName.equals("setAutoCommit") && (Boolean) args[0])) {
          throw new PSQLException(
              GT.tr(
                  "Transaction control methods setAutoCommit(true), commit, rollback and setSavePoint not allowed while an XA transaction is active."),
              PSQLState.OBJECT_NOT_IN_STATE);
        }
      }
      try {
        /*
         * If the argument to equals-method is also a wrapper, present the original unwrapped
         * connection to the underlying equals method.
         */
        if (method.getName().equals("equals") && args.length == 1) {
          Object arg = args[0];
          if (arg != null && Proxy.isProxyClass(arg.getClass())) {
            InvocationHandler h = Proxy.getInvocationHandler(arg);
            if (h instanceof ConnectionHandler) {
              // unwrap argument
              args = new Object[]{((ConnectionHandler) h).con};
            }
          }
        }

        return method.invoke(con, args);
      } catch (InvocationTargetException ex) {
        throw ex.getTargetException();
      }
    }
  }

  
Preconditions:

    
Flags must be one of TMNOFLAGS, TMRESUME or TMJOIN
    
xid != null
    
Connection must not be associated with a transaction
    
The TM hasn't seen the xid before

Implementation deficiency preconditions:

    
TMRESUME not supported.
    
If flags is TMJOIN, we must be in ended state, and xid must be the current transaction
    
Unless flags is TMJOIN, previous transaction using the connection must be committed or prepared or rolled
    back

Postconditions:

    
Connection is associated with the transaction

/**
   * <p>Preconditions:</p>
   * <ol>
   *     <li>Flags must be one of TMNOFLAGS, TMRESUME or TMJOIN</li>
   *     <li>xid != null</li>
   *     <li>Connection must not be associated with a transaction</li>
   *     <li>The TM hasn't seen the xid before</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>TMRESUME not supported.</li>
   *     <li>If flags is TMJOIN, we must be in ended state, and xid must be the current transaction</li>
   *     <li>Unless flags is TMJOIN, previous transaction using the connection must be committed or prepared or rolled
   *     back</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Connection is associated with the transaction</li>
   * </ol>
   */
  @Override
  public void start(Xid xid, int flags) throws XAException {
    if (LOGGER.isLoggable(Level.FINEST)) {
      debug("starting transaction xid = " + xid);
    }

    // Check preconditions
    if (flags != XAResource.TMNOFLAGS && flags != XAResource.TMRESUME
        && flags != XAResource.TMJOIN) {
      throw new PGXAException(GT.tr("Invalid flags {0}", flags), XAException.XAER_INVAL);
    }

    if (xid == null) {
      throw new PGXAException(GT.tr("xid must not be null"), XAException.XAER_INVAL);
    }

    if (state == State.ACTIVE) {
      throw new PGXAException(GT.tr("Connection is busy with another transaction"),
          XAException.XAER_PROTO);
    }

    // We can't check precondition 4 easily, so we don't. Duplicate xid will be catched in prepare
    // phase.

    // Check implementation deficiency preconditions
    if (flags == TMRESUME) {
      throw new PGXAException(GT.tr("suspend/resume not implemented"), XAException.XAER_RMERR);
    }

    // It's ok to join an ended transaction. WebLogic does that.
    if (flags == TMJOIN) {
      if (state != State.ENDED) {
        throw new PGXAException(
            GT.tr(
                "Invalid protocol state requested. Attempted transaction interleaving is not supported. xid={0}, currentXid={1}, state={2}, flags={3}",
                xid, currentXid, state, flags), XAException.XAER_RMERR);
      }

      if (!xid.equals(currentXid)) {
        throw new PGXAException(
            GT.tr(
                "Invalid protocol state requested. Attempted transaction interleaving is not supported. xid={0}, currentXid={1}, state={2}, flags={3}",
                xid, currentXid, state, flags), XAException.XAER_RMERR);
      }
    } else if (state == State.ENDED) {
      throw new PGXAException(GT.tr("Invalid protocol state requested. Attempted transaction interleaving is not supported. xid={0}, currentXid={1}, state={2}, flags={3}", xid, currentXid, state, flags),
          XAException.XAER_RMERR);
    }

    // Only need save localAutoCommitMode for NOFLAGS, TMRESUME and TMJOIN already saved old
    // localAutoCommitMode.
    if (flags == TMNOFLAGS) {
      try {
        localAutoCommitMode = conn.getAutoCommit();
        conn.setAutoCommit(false);
      } catch (SQLException ex) {
        throw new PGXAException(GT.tr("Error disabling autocommit"), ex, XAException.XAER_RMERR);
      }
    }

    // Preconditions are met, Associate connection with the transaction
    state = State.ACTIVE;
    currentXid = xid;
    preparedXid = null;
    committedOrRolledBack = false;
  }

  
Preconditions:

    
Flags is one of TMSUCCESS, TMFAIL, TMSUSPEND
    
xid != null
    
Connection is associated with transaction xid

Implementation deficiency preconditions:

    
Flags is not TMSUSPEND

Postconditions:

    
Connection is disassociated from the transaction.

/**
   * <p>Preconditions:</p>
   * <ol>
   *     <li>Flags is one of TMSUCCESS, TMFAIL, TMSUSPEND</li>
   *     <li>xid != null</li>
   *     <li>Connection is associated with transaction xid</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>Flags is not TMSUSPEND</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Connection is disassociated from the transaction.</li>
   * </ol>
   */
  @Override
  public void end(Xid xid, int flags) throws XAException {
    if (LOGGER.isLoggable(Level.FINEST)) {
      debug("ending transaction xid = " + xid);
    }

    // Check preconditions

    if (flags != XAResource.TMSUSPEND && flags != XAResource.TMFAIL
        && flags != XAResource.TMSUCCESS) {
      throw new PGXAException(GT.tr("Invalid flags {0}", flags), XAException.XAER_INVAL);
    }

    if (xid == null) {
      throw new PGXAException(GT.tr("xid must not be null"), XAException.XAER_INVAL);
    }

    if (state != State.ACTIVE || !currentXid.equals(xid)) {
      throw new PGXAException(GT.tr("tried to call end without corresponding start call. state={0}, start xid={1}, currentXid={2}, preparedXid={3}", state, xid, currentXid, preparedXid),
          XAException.XAER_PROTO);
    }

    // Check implementation deficiency preconditions
    if (flags == XAResource.TMSUSPEND) {
      throw new PGXAException(GT.tr("suspend/resume not implemented"), XAException.XAER_RMERR);
    }

    // We ignore TMFAIL. It's just a hint to the RM. We could roll back immediately
    // if TMFAIL was given.

    // All clear. We don't have any real work to do.
    state = State.ENDED;
  }

  
Prepares transaction. Preconditions:

    
xid != null
    
xid is in ended state

Implementation deficiency preconditions:

    
xid was associated with this connection

Postconditions:

    
Transaction is prepared

/**
   * <p>Prepares transaction. Preconditions:</p>
   * <ol>
   *     <li>xid != null</li>
   *     <li>xid is in ended state</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>xid was associated with this connection</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Transaction is prepared</li>
   * </ol>
   */
  @Override
  public int prepare(Xid xid) throws XAException {
    if (LOGGER.isLoggable(Level.FINEST)) {
      debug("preparing transaction xid = " + xid);
    }

    // Check preconditions
    if (currentXid == null && preparedXid != null) {
      if (LOGGER.isLoggable(Level.FINEST)) {
        debug("Prepare xid " + xid + " but current connection is not attached to a transaction"
            + " while it was prepared in past with prepared xid " + preparedXid);
      }
      throw new PGXAException(GT.tr(
          "Preparing already prepared transaction, the prepared xid {0}, prepare xid={1}", preparedXid, xid), XAException.XAER_PROTO);
    } else if (currentXid == null) {
      throw new PGXAException(GT.tr(
          "Current connection does not have an associated xid. prepare xid={0}", xid), XAException.XAER_NOTA);
    }
    if (!currentXid.equals(xid)) {
      if (LOGGER.isLoggable(Level.FINEST)) {
        debug("Error to prepare xid " + xid + ", the current connection already bound with xid " + currentXid);
      }
      throw new PGXAException(GT.tr(
          "Not implemented: Prepare must be issued using the same connection that started the transaction. currentXid={0}, prepare xid={1}", currentXid, xid),
          XAException.XAER_RMERR);
    }
    if (state != State.ENDED) {
      throw new PGXAException(GT.tr("Prepare called before end. prepare xid={0}, state={1}", xid), XAException.XAER_INVAL);
    }

    state = State.IDLE;
    preparedXid = currentXid;
    currentXid = null;

    try {
      String s = RecoveredXid.xidToString(xid);

      Statement stmt = conn.createStatement();
      try {
        stmt.executeUpdate("PREPARE TRANSACTION '" + s + "'");
      } finally {
        stmt.close();
      }
      conn.setAutoCommit(localAutoCommitMode);

      return XA_OK;
    } catch (SQLException ex) {
      throw new PGXAException(GT.tr("Error preparing transaction. prepare xid={0}", xid), ex, mapSQLStateToXAErrorCode(ex));
    }
  }

  
Recovers transaction. Preconditions:

    
flag must be one of TMSTARTRSCAN, TMENDRSCAN, TMNOFLAGS or TMSTARTTRSCAN | TMENDRSCAN
    
If flag isn't TMSTARTRSCAN or TMSTARTRSCAN | TMENDRSCAN, a recovery scan must be in progress

Postconditions:

    
list of prepared xids is returned

/**
   * <p>Recovers transaction. Preconditions:</p>
   * <ol>
   *     <li>flag must be one of TMSTARTRSCAN, TMENDRSCAN, TMNOFLAGS or TMSTARTTRSCAN | TMENDRSCAN</li>
   *     <li>If flag isn't TMSTARTRSCAN or TMSTARTRSCAN | TMENDRSCAN, a recovery scan must be in progress</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>list of prepared xids is returned</li>
   * </ol>
   */
  @Override
  public Xid[] recover(int flag) throws XAException {
    // Check preconditions
    if (flag != TMSTARTRSCAN && flag != TMENDRSCAN && flag != TMNOFLAGS
        && flag != (TMSTARTRSCAN | TMENDRSCAN)) {
      throw new PGXAException(GT.tr("Invalid flags {0}", flag), XAException.XAER_INVAL);
    }

    // We don't check for precondition 2, because we would have to add some additional state in
    // this object to keep track of recovery scans.

    // All clear. We return all the xids in the first TMSTARTRSCAN call, and always return
    // an empty array otherwise.
    if ((flag & TMSTARTRSCAN) == 0) {
      return new Xid[0];
    } else {
      try {
        Statement stmt = conn.createStatement();
        try {
          // If this connection is simultaneously used for a transaction,
          // this query gets executed inside that transaction. It's OK,
          // except if the transaction is in abort-only state and the
          // backed refuses to process new queries. Hopefully not a problem
          // in practise.
          ResultSet rs = stmt.executeQuery(
              "SELECT gid FROM pg_prepared_xacts where database = current_database()");
          LinkedList<Xid> l = new LinkedList<Xid>();
          while (rs.next()) {
            Xid recoveredXid = RecoveredXid.stringToXid(rs.getString(1));
            if (recoveredXid != null) {
              l.add(recoveredXid);
            }
          }
          rs.close();

          return l.toArray(new Xid[0]);
        } finally {
          stmt.close();
        }
      } catch (SQLException ex) {
        throw new PGXAException(GT.tr("Error during recover"), ex, XAException.XAER_RMERR);
      }
    }
  }

  
Preconditions:

    
xid is known to the RM or it's in prepared state

Implementation deficiency preconditions:

    
xid must be associated with this connection if it's not in prepared state.

Postconditions:

    
Transaction is rolled back and disassociated from connection

/**
   * <p>Preconditions:</p>
   * <ol>
   *     <li>xid is known to the RM or it's in prepared state</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>xid must be associated with this connection if it's not in prepared state.</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Transaction is rolled back and disassociated from connection</li>
   * </ol>
   */
  @Override
  public void rollback(Xid xid) throws XAException {
    if (LOGGER.isLoggable(Level.FINEST)) {
      debug("rolling back xid = " + xid);
    }

    // We don't explicitly check precondition 1.

    try {
      if (currentXid != null && currentXid.equals(xid)) {
        state = State.IDLE;
        currentXid = null;
        conn.rollback();
        conn.setAutoCommit(localAutoCommitMode);
      } else {
        String s = RecoveredXid.xidToString(xid);

        conn.setAutoCommit(true);
        Statement stmt = conn.createStatement();
        try {
          stmt.executeUpdate("ROLLBACK PREPARED '" + s + "'");
        } finally {
          stmt.close();
        }
      }
      committedOrRolledBack = true;
    } catch (SQLException ex) {
      int errorCode = XAException.XAER_RMERR;
      if (PSQLState.UNDEFINED_OBJECT.getState().equals(ex.getSQLState())) {
        if (committedOrRolledBack || !xid.equals(preparedXid)) {
          if (LOGGER.isLoggable(Level.FINEST)) {
            debug("rolling back xid " + xid + " while the connection prepared xid is " + preparedXid
                + (committedOrRolledBack ? ", but the connection was already committed/rolled-back" : ""));
          }
          errorCode = XAException.XAER_NOTA;
        }
      }
      if (PSQLState.isConnectionError(ex.getSQLState())) {
        if (LOGGER.isLoggable(Level.FINEST)) {
          debug("rollback connection failure (sql error code " + ex.getSQLState() + "), reconnection could be expected");
        }
        errorCode = XAException.XAER_RMFAIL;
      }
      throw new PGXAException(GT.tr("Error rolling back prepared transaction. rollback xid={0}, preparedXid={1}, currentXid={2}", xid, preparedXid), ex, errorCode);
    }
  }

  @Override
  public void commit(Xid xid, boolean onePhase) throws XAException {
    if (LOGGER.isLoggable(Level.FINEST)) {
      debug("committing xid = " + xid + (onePhase ? " (one phase) " : " (two phase)"));
    }

    if (xid == null) {
      throw new PGXAException(GT.tr("xid must not be null"), XAException.XAER_INVAL);
    }

    if (onePhase) {
      commitOnePhase(xid);
    } else {
      commitPrepared(xid);
    }
  }

  
Preconditions:

    
xid must in ended state.

Implementation deficiency preconditions:

    
this connection must have been used to run the transaction

Postconditions:

    
Transaction is committed

/**
   * <p>Preconditions:</p>
   * <ol>
   *     <li>xid must in ended state.</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>this connection must have been used to run the transaction</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Transaction is committed</li>
   * </ol>
   */
  private void commitOnePhase(Xid xid) throws XAException {
    try {
      // Check preconditions
      if (xid.equals(preparedXid)) { // TODO: check if the condition should be negated
        throw new PGXAException(GT.tr("One-phase commit called for xid {0} but connection was prepared with xid {1}",
            xid, preparedXid), XAException.XAER_PROTO);
      }
      if (currentXid == null && !committedOrRolledBack) {
        // In fact, we don't know if xid is bogus, or if it just wasn't associated with this connection.
        // Assume it's our fault.
        // TODO: pick proper error message. Current one does not clarify what went wrong
        throw new PGXAException(GT.tr(
            "Not implemented: one-phase commit must be issued using the same connection that was used to start it", xid),
            XAException.XAER_RMERR);
      }
      if (!xid.equals(currentXid) || committedOrRolledBack) {
        throw new PGXAException(GT.tr("One-phase commit with unknown xid. commit xid={0}, currentXid={1}",
            xid, currentXid), XAException.XAER_NOTA);
      }
      if (state != State.ENDED) {
        throw new PGXAException(GT.tr("commit called before end. commit xid={0}, state={1}", xid, state), XAException.XAER_PROTO);
      }

      // Preconditions are met. Commit
      state = State.IDLE;
      currentXid = null;
      committedOrRolledBack = true;

      conn.commit();
      conn.setAutoCommit(localAutoCommitMode);
    } catch (SQLException ex) {
      throw new PGXAException(GT.tr("Error during one-phase commit. commit xid={0}", xid), ex, mapSQLStateToXAErrorCode(ex));
    }
  }

  
Commits prepared transaction. Preconditions:

    
xid must be in prepared state in the server

Implementation deficiency preconditions:

    
Connection must be in idle state

Postconditions:

    
Transaction is committed

/**
   * <p>Commits prepared transaction. Preconditions:</p>
   * <ol>
   *     <li>xid must be in prepared state in the server</li>
   * </ol>
   *
   * <p>Implementation deficiency preconditions:</p>
   * <ol>
   *     <li>Connection must be in idle state</li>
   * </ol>
   *
   * <p>Postconditions:</p>
   * <ol>
   *     <li>Transaction is committed</li>
   * </ol>
   */
  private void commitPrepared(Xid xid) throws XAException {
    try {
      // Check preconditions. The connection mustn't be used for another
      // other XA or local transaction, or the COMMIT PREPARED command
      // would mess it up.
      if (state != State.IDLE
          || conn.getTransactionState() != TransactionState.IDLE) {
        throw new PGXAException(
            GT.tr("Not implemented: 2nd phase commit must be issued using an idle connection. commit xid={0}, currentXid={1}, state={2}, transactionState={3}", xid, currentXid, state, conn.getTransactionState()),
            XAException.XAER_RMERR);
      }

      String s = RecoveredXid.xidToString(xid);

      localAutoCommitMode = conn.getAutoCommit();
      conn.setAutoCommit(true);
      Statement stmt = conn.createStatement();
      try {
        stmt.executeUpdate("COMMIT PREPARED '" + s + "'");
      } finally {
        stmt.close();
        conn.setAutoCommit(localAutoCommitMode);
      }
      committedOrRolledBack = true;
    } catch (SQLException ex) {
      int errorCode = XAException.XAER_RMERR;
      if (PSQLState.UNDEFINED_OBJECT.getState().equals(ex.getSQLState())) {
        if (committedOrRolledBack || !xid.equals(preparedXid)) {
          if (LOGGER.isLoggable(Level.FINEST)) {
            debug("committing xid " + xid + " while the connection prepared xid is " + preparedXid
                + (committedOrRolledBack ? ", but the connection was already committed/rolled-back" : ""));
          }
          errorCode = XAException.XAER_NOTA;
        }
      }
      if (PSQLState.isConnectionError(ex.getSQLState())) {
        if (LOGGER.isLoggable(Level.FINEST)) {
          debug("commit connection failure (sql error code " + ex.getSQLState() + "), reconnection could be expected");
        }
        errorCode = XAException.XAER_RMFAIL;
      }
      throw new PGXAException(GT.tr("Error committing prepared transaction. commit xid={0}, preparedXid={1}, currentXid={2}", xid, preparedXid, currentXid), ex, errorCode);
    }
  }

  @Override
  public boolean isSameRM(XAResource xares) throws XAException {
    // This trivial implementation makes sure that the
    // application server doesn't try to use another connection
    // for prepare, commit and rollback commands.
    return xares == this;
  }

  
Does nothing, since we don't do heuristics.
/**
   * Does nothing, since we don't do heuristics.
   */
  @Override
  public void forget(Xid xid) throws XAException {
    throw new PGXAException(GT.tr("Heuristic commit/rollback not supported. forget xid={0}", xid),
        XAException.XAER_NOTA);
  }

  
We don't do transaction timeouts. Just returns 0.
/**
   * We don't do transaction timeouts. Just returns 0.
   */
  @Override
  public int getTransactionTimeout() {
    return 0;
  }

  
We don't do transaction timeouts. Returns false.
/**
   * We don't do transaction timeouts. Returns false.
   */
  @Override
  public boolean setTransactionTimeout(int seconds) {
    return false;
  }

  private int mapSQLStateToXAErrorCode(SQLException sqlException) {
    if (isPostgreSQLIntegrityConstraintViolation(sqlException)) {
      return XAException.XA_RBINTEGRITY;
    }

    return XAException.XAER_RMFAIL;
  }

  private boolean isPostgreSQLIntegrityConstraintViolation(SQLException sqlException) {
    return sqlException instanceof PSQLException
        && sqlException.getSQLState().length() == 5
        && sqlException.getSQLState().startsWith("23"); // Class 23 - Integrity Constraint Violation
  }

  private enum State {
    
PGXAConnection not associated with a XA-transaction. You can still call PGXAConnection.getConnection() and use the connection outside XA. currentXid is null. autoCommit is true on a connection by getConnection, per normal JDBC rules, though the caller can change it to false and manage transactions itself using Connection.commit and rollback. /**
     * {@code PGXAConnection} not associated with a XA-transaction. You can still call {@link #getConnection()} and
     * use the connection outside XA. {@code currentXid} is {@code null}. autoCommit is {@code true} on a connection
     * by getConnection, per normal JDBC rules, though the caller can change it to {@code false} and manage
     * transactions itself using Connection.commit and rollback.
     */
    IDLE,
    
PGXAConnection.start(Xid, int) has been called, and we're associated with an XA transaction. currentXid is valid. autoCommit is false on a connection returned by getConnection, and should not be messed with by the caller or the XA transaction will be broken. /**
     * {@link #start(Xid, int)} has been called, and we're associated with an XA transaction. {@code currentXid}
     * is valid. autoCommit is false on a connection returned by getConnection, and should not be messed with by
     * the caller or the XA transaction will be broken.
     */
    ACTIVE,
    
PGXAConnection.end(Xid, int) has been called, but the transaction has not yet been prepared. currentXid is still valid. You shouldn't use the connection for anything else than issuing a XAResource.commit(Xid, boolean) or rollback. /**
     * {@link #end(Xid, int)} has been called, but the transaction has not yet been prepared. {@code currentXid}
     * is still valid. You shouldn't use the connection for anything else than issuing a {@link XAResource#commit(Xid, boolean)} or
     * rollback.
     */
    ENDED
  }

}