/*

* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Implementation of IPC key generation (POSIX Standard).

*

*/

// INCLUDE FILES

#include <sys/ipc.h>

#include <sys/stat.h>

#include <liblogger.h>

#include <unistd.h>

#include <e32const.h>

// -----------------------------------------------------------------------------

// Funcation name: ftok

// Description: Convert a pathname and project identifier to an IPC key.

// Returns: None zero number: On success

//          -1              : On error.

// In case of error, errno value set to

//          EACCESS:      Access denied.

//          ENOENT:       Path name does not exist or path name is a empty string.

//          ENAMETOOLONG: Path name too long.

//          ELOOP:        Too many symbolic links were encountered in resolving path.

//          ENOTDIR:      Component of the path prefix is not a directory.

// -----------------------------------------------------------------------------

//

extern "C" {

TInt GeneratePathKey(const char* aPath)

    {

    if(aPath == NULL)

        {

        return -1;

        }

    TInt key = 0;

    TInt index = 0;

    while(*aPath != '\0')

        {

        index++;

        if(index > 16)

            {

            index = 0;

            }

        key += ((*aPath << index) + *aPath);

        aPath++;

        }

    return key;

    }

EXPORT_C key_t ftok(const char *pathname, int proj_id)

    {

    // 1. check the path status.

    // 2. if path doesn't exists then return error -1 and set the errno with appropriate value.

    // 3. else generate the IPC key.

	struct stat st;

    // 1.

	if (stat(pathname, &st) < 0)

	    {

	    // 2.

		return (key_t)-1;

	    }

    // 3. File exists.

    // Is it a special file.

    char splFileName[KMaxFileName+1];

    if (readlink(pathname, splFileName, KMaxFileName) > 0)

        {

    	return (key_t) (proj_id << 24 | GeneratePathKey(splFileName));

        }

	else

	    {

    	return (key_t) (proj_id << 24 | GeneratePathKey(pathname));

        }

    }

} // extern "C" {

//  End of File