/*

 * File: ftk_mmap_sylixos.c

 * Author:  Han.hui <sylixos@gmail.com>

 * Brief:   sylixos mmap implemention.

 *

 * Copyright (c) 2009 - 2010  Li XianJing <xianjimli@hotmail.com>

 *

 * Licensed under the Academic Free License version 2.1

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */



/*

 * History:

 * ================================================================

 * 2011-05-15 Han.hui <sylixos@gmail.com> created

 *

 */



#include "ftk_log.h"

#include "ftk_mmap.h"

#include "ftk_allocator.h"

#include <sys/mman.h>



struct _FtkMmap

{

    int fd;

    void* data;

    size_t length;

};



int      ftk_mmap_exist(const char* filename)

{

    struct stat st = {0};

    return_val_if_fail(filename != NULL, 0);



    return stat(filename, &st) == 0;

}



FtkMmap* ftk_mmap_create(const char* filename, size_t offset, size_t size)

{

    FtkMmap* thiz = NULL;

    struct stat st = {0};

    return_val_if_fail(filename != NULL, NULL);

    if(stat(filename, &st) != 0)

    {

        return NULL;

    }

    return_val_if_fail(offset < st.st_size, NULL);



    size = (offset + size) <= st.st_size ? size : st.st_size - offset;



    thiz = FTK_ZALLOC(sizeof(FtkMmap));

    return_val_if_fail(thiz != NULL, NULL);



    thiz->fd = open(filename, O_RDONLY);

    if(thiz->fd > 0)

    {

        thiz->length = size;

        thiz->data = mmap(NULL, size, PROT_READ, MAP_PRIVATE, thiz->fd, offset);

    }



    if(thiz->data == NULL || thiz->data == MAP_FAILED)

    {

        close(thiz->fd);

        FTK_ZFREE(thiz, sizeof(*thiz));

        ftk_logd("%s mmap %s failed.\n", __func__, filename);

    }



    return thiz;

}



void*    ftk_mmap_data(FtkMmap* thiz)

{

    return_val_if_fail(thiz != NULL, NULL);



    return thiz->data;

}



size_t   ftk_mmap_length(FtkMmap* thiz)

{

    return_val_if_fail(thiz != NULL, 0);



    return thiz->length;

}



void     ftk_mmap_destroy(FtkMmap* thiz)

{

    if(thiz != NULL)

    {

        close(thiz->fd);

        munmap(thiz->data, thiz->length);



        FTK_ZFREE(thiz, sizeof(*thiz));

    }



    return;

}