AOO410/main/cosv/inc/cosv/openclose.hxx

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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
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 *************************************************************/



#ifndef CSV_OPENCLOSE_HXX
#define CSV_OPENCLOSE_HXX


namespace csv
{

// Open modes for storages:
enum E_RWMode
{
	rwDefault	= 0x0000,		//	Keep old settings. If there are none, set default.
	rwRead		= 0x0001,		//  Reads only
	rwWrite		= 0x0002,       //  Writes only
	rwReadWrite	= 0x0003        //  Reads and writes.
};

enum E_OpenMode
{
	omCreateIfNecessary 	= 0x0000,   // Creates a new file only, if file does not exist.
	omCreateNot 			= 0x0010,   // Open fails, if file does not exist.
	omCreate	 			= 0x0020 	// Existing file will be deleted.
};
enum E_ShareMode
{
	shmShareNot		= 0x0000,		// Allow others nothing
	shmShareRead	= 0x0004,		// Allow others to read
	shmShareAll		= 0x000C      	// Allow others to read and write
};

/** Constants for filemode combinations
    These combinations are the only ones, guaranteed to be supported.
*/
const UINT32	CFM_RW 		= rwReadWrite;
const UINT32	CFM_CREATE 	=
    static_cast< UINT32 >(rwReadWrite) | static_cast< UINT32 >(omCreate);
const UINT32	CFM_READ 	=
    static_cast< UINT32 >(rwRead) | static_cast< UINT32 >(omCreateNot) |
    static_cast< UINT32 >(shmShareRead);



class OpenClose
{
  public:
    virtual ~OpenClose() {}

    bool   	            open(
							UINT32			in_nOpenModeInfo = 0 ); /// Combination of values of E_RWMode and E_ShareMode und E_OpenMode. 0 := Keep existing mode.
    void   	            close();

    bool                is_open() const;

  private:
    virtual bool   	    do_open(
							UINT32			in_nOpenModeInfo ) = 0;
    virtual void   	    do_close() = 0;
    virtual bool        inq_is_open() const = 0;
};



class OpenCloseGuard
{
  public:
						OpenCloseGuard(
							OpenClose &			i_rOpenClose,
							UINT32				i_nOpenModeInfo = 0 );
						~OpenCloseGuard();
						operator bool() const;

  private:
    // Forbidden:
						OpenCloseGuard(OpenCloseGuard&);
    OpenCloseGuard &    operator=(OpenCloseGuard&);

    // DATA
	OpenClose &			rOpenClose;
};


// IMPLEMENTATION

inline bool
OpenClose::open( UINT32 i_nOpenModeInfo )
    { return do_open(i_nOpenModeInfo); }
inline void
OpenClose::close()
    { do_close(); }
inline bool
OpenClose::is_open() const
    { return inq_is_open(); }

inline
OpenCloseGuard::OpenCloseGuard( OpenClose &	i_rOpenClose,
							    UINT32		i_nOpenModeInfo )
    :	rOpenClose(i_rOpenClose)
    { rOpenClose.open(i_nOpenModeInfo); }
inline
OpenCloseGuard::~OpenCloseGuard()
    { if (rOpenClose.is_open()) rOpenClose.close(); }
inline
OpenCloseGuard::operator bool() const
    { return rOpenClose.is_open(); }




}   // namespace csv






#endif