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package org.hsqldb.jdbc;

import java.sql.SQLException;
import java.sql.Savepoint;

/* $Id: JDBCSavepoint.java 5969 2019-04-27 14:59:54Z fredt $ */

// Revision 1.10  2006/07/12 12:38:22  boucherb
// - full synch up to Mustang b90

The representation of a savepoint, which is a point within
the current transaction that can be referenced from the
Connection.rollback method. When a transaction
is rolled back to a savepoint all changes made after that
savepoint are undone.

Savepoints can be either named or unnamed. Unnamed savepoints
are identified by an ID generated by the underlying data source.


HSQLDB-Specific Information:
 

SQL 2003 standard does not support unnamed savepoints. However, this
feature is supported from version 2.0.

If the connection is autoCommit, setting savepoints has no effect as any
such savepoint is cleared upon the execution of the first transactional
statement. 



Author:
Campbell Burnet (campbell-burnet@users dot sourceforge.net)
Since:
JDK 1.4, HSQLDB 1.7.2/**
 * The representation of a savepoint, which is a point within
 * the current transaction that can be referenced from the
 * <code>Connection.rollback</code> method. When a transaction
 * is rolled back to a savepoint all changes made after that
 * savepoint are undone.
 * <p>
 * Savepoints can be either named or unnamed. Unnamed savepoints
 * are identified by an ID generated by the underlying data source.
 *
 * <!-- start Release-specific documentation -->
 * <div class="ReleaseSpecificDocumentation">
 * <h3>HSQLDB-Specific Information:</h3> <p>
 *
 * SQL 2003 standard does not support unnamed savepoints. However, this
 * feature is supported from version 2.0.<p>
 *
 * If the connection is autoCommit, setting savepoints has no effect as any
 * such savepoint is cleared upon the execution of the first transactional
 * statement. <p>
 *
 * </div>
 * <!-- end release-specific documentation -->
 *
 *
 * @author Campbell Burnet (campbell-burnet@users dot sourceforge.net)
 * @since JDK 1.4, HSQLDB 1.7.2
 */
public class JDBCSavepoint implements Savepoint {

    int            id;
    String         name;
    JDBCConnection connection;

    JDBCSavepoint(String name, JDBCConnection conn) throws SQLException {

        if (name == null) {
            throw JDBCUtil.nullArgument("name");
        }

        if (conn == null) {
            throw JDBCUtil.nullArgument("conn");
        }

        this.name       = name;
        this.id         = -1;
        this.connection = conn;
    }

    JDBCSavepoint(JDBCConnection conn) throws SQLException {

        if (conn == null) {
            throw JDBCUtil.nullArgument("conn");
        }

        this.id         = conn.getSavepointID();
        this.name       = "SYSTEM_SAVEPOINT_" + id;
        this.connection = conn;
    }

    
Retrieves the generated ID for the savepoint that this
Savepoint object represents.
Throws:
SQLException – if this is a named savepoint
Returns:
the numeric ID of this savepoint
Since:
1.4/**
     * Retrieves the generated ID for the savepoint that this
     * <code>Savepoint</code> object represents.
     * @return the numeric ID of this savepoint
     * @exception SQLException if this is a named savepoint
     * @since 1.4
     */
    public int getSavepointId() throws SQLException {

        if (id != -1) {
            return id;
        }

        throw JDBCUtil.notSupported();
    }

    
Retrieves the name of the savepoint that this Savepoint
object represents.
Throws:
SQLException – if this is an un-named savepoint
Returns:
the name of this savepoint
Since:
1.4/**
     * Retrieves the name of the savepoint that this <code>Savepoint</code>
     * object represents.
     *
     * @return the name of this savepoint
     * @exception SQLException if this is an un-named savepoint
     * @since 1.4
     */
    public String getSavepointName() throws SQLException {

        if (id == -1) {
            return name;
        }

        throw JDBCUtil.notSupported();
    }

    public String toString() {
        return super.toString() + "[name=" + name + "]";
    }
}