/*-------------------------------------------------------------------------
*
* Copyright (c) 2009-2011, PostgreSQL Global Development Group
*
*
*-------------------------------------------------------------------------
*/
package org.postgresql.copy;

import java.sql.SQLException;

/**
 * Exchange bulk data between client and PostgreSQL database tables.
 * See CopyIn and CopyOut for full interfaces for corresponding copy directions.
 */
public interface CopyOperation {

    /**
     * @return number of fields in each row for this operation
     */
    int getFieldCount();

    /**
     * @return overall format of each row: 0 = textual, 1 = binary
     */
    int getFormat();

    /**
     * @param field number of field (0..fieldCount()-1)
     * @return format of requested field: 0 = textual, 1 = binary
     */
    int getFieldFormat(int field);
    
    /**
     * @return is connection reserved for this Copy operation?
     */
    boolean isActive();
    
    /**
     * Cancels this copy operation, discarding any exchanged data.
     * @throws SQLException if cancelling fails
     */
    void cancelCopy() throws SQLException;

    /**
     * After succesful end of copy, returns the number
     * of database records handled in that operation.
     * Only implemented in PostgreSQL server version 8.2 and up.
     * Otherwise, returns -1.
     * @return number of handled rows or -1
     */
    public long getHandledRowCount();
}
