bdb_trans.hpp

ncbi源码

/*
 * ===========================================================================
 * PRODUCTION $Log: bdb_trans.hpp,v $
 * PRODUCTION Revision 1000.0  2004/04/12 17:14:32  gouriano
 * PRODUCTION PRODUCTION: IMPORTED [CATCHUP_003] Dev-tree R1.2
 * PRODUCTION
 * ===========================================================================
 */

#ifndef BDB_TRANS__HPP
#define BDB_TRANS__HPP
/* $Id: bdb_trans.hpp,v 1000.0 2004/04/12 17:14:32 gouriano Exp $
 * ===========================================================================
 *
 *                            PUBLIC DOMAIN NOTICE
 *               National Center for Biotechnology Information
 *
 *  This software/database is a "United States Government Work" under the
 *  terms of the United States Copyright Act.  It was written as part of
 *  the author's official duties as a United States Government employee and
 *  thus cannot be copyrighted.  This software/database is freely available
 *  to the public for use. The National Library of Medicine and the U.S.
 *  Government have not placed any restriction on its use or reproduction.
 *
 *  Although all reasonable efforts have been taken to ensure the accuracy
 *  and reliability of the software and data, the NLM and the U.S.
 *  Government do not and cannot warrant the performance or results that
 *  may be obtained by using this software or data. The NLM and the U.S.
 *  Government disclaim all warranties, express or implied, including
 *  warranties of performance, merchantability or fitness for any particular
 *  purpose.
 *
 *  Please cite the author in any work or product based on this material.
 *
 * ===========================================================================
 *
 * Author:  Anatoliy Kuznetsov
 *   
 * File Description: Transaction support
 *
 */

/// @file bdb_trans.hpp
/// Wrapper around Berkeley DB transaction structure

#include <bdb/bdb_env.hpp>

#include <vector>

BEGIN_NCBI_SCOPE

/** @addtogroup BDB
 *
 * @{
 */

class   CBDB_RawFile;

/// BDB transaction object.
///

class NCBI_BDB_EXPORT CBDB_Transaction
{
public:
    CBDB_Transaction(CBDB_Env& env);

    ~CBDB_Transaction();
        
    /// Commit transaction
    void Commit();
    
    /// Abort transaction
    void Abort();
    
    /// Rollback transaction (same as Abort)
    void Rollback() { Abort(); }

    /// Get low level Berkeley DB transaction handle.
    ///
    /// Function uses lazy initialization paradigm, and actual
    /// transaction is created "on demand". First call to GetTxn()
    /// creates the handle which lives until commit or rollback point.
    ///
    /// @return Transaction handle
    ///
    DB_TXN*  GetTxn();


protected:

    /// Add file to the list of connected files
    void AddFile(CBDB_RawFile* dbfile);
    
    /// Remove file from the list of connected files.
    /// Has no effect if file has not been added before by AddFile
    void RemoveFile(CBDB_RawFile* dbfile);
    
    /// Return TRUE if transaction handle has been requested by some
    /// client (File)
    bool IsInProgress() const { return m_Txn != 0; }

private:
    /// Abort transaction with error checking or without
    void x_Abort(bool ignore_errors);

private:
    CBDB_Transaction(const CBDB_Transaction& trans);
    CBDB_Transaction& operator=(const CBDB_Transaction& trans);
protected:
    CBDB_Env&               m_Env;        ///< Associated environment
    DB_TXN*                 m_Txn;        ///< Transaction handle
    vector<CBDB_RawFile*>   m_TransFiles; ///< Files connected to transaction
    
private:
    friend class CBDB_RawFile;
};

/* @} */

END_NCBI_SCOPE

/*
 * ===========================================================================
 * $Log: bdb_trans.hpp,v $
 * Revision 1000.0  2004/04/12 17:14:32  gouriano
 * PRODUCTION: IMPORTED [CATCHUP_003] Dev-tree R1.2
 *
 * Revision 1.2  2003/12/29 17:07:13  kuznets
 * GetTxn() - relaxed function visibility restriction to public
 *
 * Revision 1.1  2003/12/10 19:10:53  kuznets
 * Initial revision
 *
 *
 * ===========================================================================
 */


#endif  /* BDB_ENV__HPP */