/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the files COPYING and Copyright.html.  COPYING can be found at the root   *
 * of the source code distribution tree; Copyright.html can be found at the  *
 * root level of an installed copy of the electronic HDF5 document set and   *
 * is linked from the top-level documents page.  It can also be found at     *
 * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
 * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * Programmer:  Robb Matzke <matzke@llnl.gov>
 *              Tuesday, August 10, 1999
 *
 * Purpose:  A driver which stores the HDF5 data in main memory  using
 *    only the HDF5 public API. This driver is useful for fast
 *    access to small, temporary hdf5 files.
 */

/* Interface initialization */
#define H5_INTERFACE_INIT_FUNC  H5FD_core_init_interface


#include "H5private.h"    /* Generic Functions      */
#include "H5Eprivate.h"    /* Error handling        */
#include "H5Fprivate.h"    /* File access        */
#include "H5FDprivate.h"  /* File drivers        */
#include "H5FDcore.h"           /* Core file driver      */
#include "H5Iprivate.h"    /* IDs            */
#include "H5MMprivate.h"  /* Memory management      */
#include "H5Pprivate.h"    /* Property lists      */

/* The driver identification number, initialized at runtime */
static hid_t H5FD_CORE_g = 0;

/*
 * The description of a file belonging to this driver. The `eoa' and `eof'
 * determine the amount of hdf5 address space in use and the high-water mark
 * of the file (the current size of the underlying memory).
 */
typedef struct H5FD_core_t {
    H5FD_t  pub;      /*public stuff, must be first  */
    char  *name;      /*for equivalence testing  */
    unsigned char *mem;      /*the underlying memory    */
    haddr_t  eoa;      /*end of allocated region  */
    haddr_t  eof;      /*current allocated size  */
    size_t  increment;    /*multiples for mem allocation  */
    int    fd;      /*backing store file descriptor  */
    hbool_t  dirty;      /*changes not saved?    */
} H5FD_core_t;

/* Driver-specific file access properties */
typedef struct H5FD_core_fapl_t {
    size_t  increment;    /*how much to grow memory  */
    hbool_t  backing_store;    /*write to file name on flush  */
} H5FD_core_fapl_t;

/* Allocate memory in multiples of this size by default */
#define H5FD_CORE_INCREMENT    8192

/*
 * These macros check for overflow of various quantities.  These macros
 * assume that file_offset_t is signed and haddr_t and size_t are unsigned.
 *
 * ADDR_OVERFLOW:  Checks whether a file address of type `haddr_t'
 *      is too large to be represented by the second argument
 *      of the file seek function.
 *
 * SIZE_OVERFLOW:  Checks whether a buffer size of type `hsize_t' is too
 *      large to be represented by the `size_t' type.
 *
 * REGION_OVERFLOW:  Checks whether an address and size pair describe data
 *      which can be addressed entirely in memory.
 */
#define MAXADDR     ((haddr_t)((~(size_t)0)-1))
#define ADDR_OVERFLOW(A)  (HADDR_UNDEF==(A) || (A) > (haddr_t)MAXADDR)
#define SIZE_OVERFLOW(Z)  ((Z) > (hsize_t)MAXADDR)
#define REGION_OVERFLOW(A,Z)  (ADDR_OVERFLOW(A) || SIZE_OVERFLOW(Z) ||      \
                                 HADDR_UNDEF==(A)+(Z) ||          \
         (size_t)((A)+(Z))<(size_t)(A))

/* Prototypes */
static void *H5FD_core_fapl_get(H5FD_t *_file);
static H5FD_t *H5FD_core_open(const char *name, unsigned flags, hid_t fapl_id,
            haddr_t maxaddr);
static herr_t H5FD_core_close(H5FD_t *_file);
static int H5FD_core_cmp(const H5FD_t *_f1, const H5FD_t *_f2);
static haddr_t H5FD_core_get_eoa(H5FD_t *_file);
static herr_t H5FD_core_set_eoa(H5FD_t *_file, haddr_t addr);
static haddr_t H5FD_core_get_eof(H5FD_t *_file);
static herr_t  H5FD_core_get_handle(H5FD_t *_file, hid_t fapl, void** file_handle);
static herr_t H5FD_core_read(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, haddr_t addr,
           size_t size, void *buf);
static herr_t H5FD_core_write(H5FD_t *_file, H5FD_mem_t type, hid_t fapl_id, haddr_t addr,
            size_t size, const void *buf);
static herr_t H5FD_core_flush(H5FD_t *_file, hid_t dxpl_id, unsigned closing);

static const H5FD_class_t H5FD_core_g = {
    "core",          /*name      */
    MAXADDR,          /*maxaddr    */
    H5F_CLOSE_WEAK,        /*fc_degree    */
    NULL,          /*sb_size    */
    NULL,          /*sb_encode    */
    NULL,          /*sb_decode    */
    sizeof(H5FD_core_fapl_t),      /*fapl_size    */
    H5FD_core_fapl_get,        /*fapl_get    */
    NULL,          /*fapl_copy    */
    NULL,           /*fapl_free    */
    0,            /*dxpl_size    */
    NULL,          /*dxpl_copy    */
    NULL,          /*dxpl_free    */
    H5FD_core_open,        /*open      */
    H5FD_core_close,        /*close      */
    H5FD_core_cmp,        /*cmp      */
    NULL,                /*query      */
    NULL,          /*alloc      */
    NULL,          /*free      */
    H5FD_core_get_eoa,        /*get_eoa    */
    H5FD_core_set_eoa,         /*set_eoa    */
    H5FD_core_get_eof,        /*get_eof    */
    H5FD_core_get_handle,                       /*get_handle            */
    H5FD_core_read,        /*read      */
    H5FD_core_write,        /*write      */
    H5FD_core_flush,        /*flush      */
    NULL,                                       /*lock                  */
    NULL,                                       /*unlock                */
    H5FD_FLMAP_SINGLE         /*fl_map    */
};


/*--------------------------------------------------------------------------
NAME
   H5FD_core_init_interface -- Initialize interface-specific information
USAGE
    herr_t H5FD_core_init_interface()

RETURNS
    Non-negative on success/Negative on failure
DESCRIPTION
    Initializes any interface-specific data or routines.  (Just calls
    H5FD_core_init currently).

--------------------------------------------------------------------------*/
static herr_t
H5FD_core_init_interface(void)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5FD_core_init_interface)

    FUNC_LEAVE_NOAPI(H5FD_core_init())
} /* H5FD_core_init_interface() */


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_init
 *
 * Purpose:  Initialize this driver by registering the driver with the
 *    library.
 *
 * Return:  Success:  The driver ID for the core driver.
 *
 *    Failure:  Negative.
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5FD_core_init(void)
{
    hid_t ret_value=H5FD_CORE_g;   /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_init, FAIL)

    if (H5I_VFL!=H5Iget_type(H5FD_CORE_g))
        H5FD_CORE_g = H5FD_register(&H5FD_core_g,sizeof(H5FD_class_t));

    /* Set return value */
    ret_value=H5FD_CORE_g;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*---------------------------------------------------------------------------
 * Function:  H5FD_core_term
 *
 * Purpose:  Shut down the VFD
 *
 * Return:  <none>
 *
 * Programmer:  Quincey Koziol
 *              Friday, Jan 30, 2004
 *
 * Modification:
 *
 *---------------------------------------------------------------------------
 */
void
H5FD_core_term(void)
{
    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5FD_core_term)

    /* Reset VFL ID */
    H5FD_CORE_g=0;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5FD_core_term() */


/*-------------------------------------------------------------------------
 * Function:  H5Pset_fapl_core
 *
 * Purpose:  Modify the file access property list to use the H5FD_CORE
 *    driver defined in this source file.  The INCREMENT specifies
 *    how much to grow the memory each time we need more.
 *
 * Return:  Non-negative on success/Negative on failure
 *
 * Programmer:  Robb Matzke
 *    Thursday, February 19, 1998
 *
 * Modifications:
 *     Robb Matzke, 1999-10-19
 *    Added the BACKING_STORE argument. If set then the entire file
 *    contents are flushed to a file with the same name as this
 *    core file.
 *
 *    Raymond Lu, 2001-10-25
 *    Changed the file access list to the new generic list.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Pset_fapl_core(hid_t fapl_id, size_t increment, hbool_t backing_store)
{
    H5FD_core_fapl_t  fa;
    H5P_genplist_t *plist;      /* Property list pointer */
    herr_t ret_value;

    FUNC_ENTER_API(H5Pset_fapl_core, FAIL)
    H5TRACE3("e","izb",fapl_id,increment,backing_store);

    /* Check argument */
    if(NULL == (plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)))
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list")

    fa.increment = increment;
    fa.backing_store = backing_store;

    ret_value= H5P_set_driver(plist, H5FD_CORE, &fa);

done:
    FUNC_LEAVE_API(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5Pget_fapl_core
 *
 * Purpose:  Queries properties set by the H5Pset_fapl_core() function.
 *
 * Return:  Success:  Non-negative
 *
 *    Failure:  Negative
 *
 * Programmer:  Robb Matzke
 *              Tuesday, August 10, 1999
 *
 * Modifications:
 *    Robb Matzke, 1999-10-19
 *    Added the BACKING_STORE argument.
 *
 *    Raymond Lu
 *    2001-10-25
 *    Changed file access list to the new generic property list.
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Pget_fapl_core(hid_t fapl_id, size_t *increment/*out*/,
     hbool_t *backing_store/*out*/)
{
    H5FD_core_fapl_t  *fa;
    H5P_genplist_t *plist;      /* Property list pointer */
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_API(H5Pget_fapl_core, FAIL)
    H5TRACE3("e","ixx",fapl_id,increment,backing_store);

    if(NULL == (plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)))
        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list")
    if (H5FD_CORE!=H5P_get_driver(plist))
        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "incorrect VFL driver")
    if (NULL==(fa=H5P_get_driver_info(plist)))
        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "bad VFL driver info")

    if (increment)
        *increment = fa->increment;
    if (backing_store)
        *backing_store = fa->backing_store;

done:
    FUNC_LEAVE_API(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_fapl_get
 *
 * Purpose:  Returns a copy of the file access properties.
 *
 * Return:  Success:  Ptr to new file access properties.
 *
 *    Failure:  NULL
 *
 * Programmer:  Robb Matzke
 *              Friday, August 13, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static void *
H5FD_core_fapl_get(H5FD_t *_file)
{
    H5FD_core_t    *file = (H5FD_core_t*)_file;
    H5FD_core_fapl_t  *fa = NULL;
    void      *ret_value;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_fapl_get, NULL)

    if (NULL==(fa=H5MM_calloc(sizeof(H5FD_core_fapl_t))))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")

    fa->increment = file->increment;
    fa->backing_store = (file->fd>=0);

    /* Set return value */
    ret_value=fa;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_open
 *
 * Purpose:  Create memory as an HDF5 file.
 *
 * Return:  Success:  A pointer to a new file data structure. The
 *        public fields will be initialized by the
 *        caller, which is always H5FD_open().
 *
 *    Failure:  NULL
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *    Robb Matzke, 1999-10-19
 *    The backing store file is created and opened if specified.
 *-------------------------------------------------------------------------
 */
static H5FD_t *
H5FD_core_open(const char *name, unsigned UNUSED flags, hid_t fapl_id,
         haddr_t maxaddr)
{
    H5FD_core_t    *file=NULL;
    H5FD_core_fapl_t  *fa=NULL;
    H5P_genplist_t *plist;      /* Property list pointer */
    int      fd=-1;
    H5FD_t    *ret_value;

    FUNC_ENTER_NOAPI(H5FD_core_open, NULL)

    /* Check arguments */
    if (!(H5F_ACC_CREAT & flags))
        HGOTO_ERROR(H5E_ARGS, H5E_UNSUPPORTED, NULL, "must create core files, not open them")
    if (0==maxaddr || HADDR_UNDEF==maxaddr)
        HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, NULL, "bogus maxaddr")
    if (ADDR_OVERFLOW(maxaddr))
        HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, NULL, "maxaddr overflow")
    if (H5P_DEFAULT!=fapl_id) {
        if(NULL == (plist = H5I_object(fapl_id)))
            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file access property list")
        fa = H5P_get_driver_info(plist);
    } /* end if */

    /* Open backing store */
    if (fa && fa->backing_store && name &&
            (fd=HDopen(name, (O_CREAT|O_TRUNC|O_RDWR), 0666))<0)
        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open backing store")

    /* Create the new file struct */
    if (NULL==(file=H5MM_calloc(sizeof(H5FD_core_t))))
        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate file struct")
    file->fd = fd;
    if (name && *name)
        file->name = HDstrdup(name);

    /*
     * The increment comes from either the file access property list or the
     * default value. But if the file access property list was zero then use
     * the default value instead.
     */
    file->increment = (fa && fa->increment>0) ?  fa->increment : H5FD_CORE_INCREMENT;

    /* Set return value */
    ret_value=(H5FD_t *)file;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_close
 *
 * Purpose:  Closes the file.
 *
 * Return:  Success:  0
 *
 *    Failure:  -1
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *     Robb Matzke, 1999-10-19
 *    The contents of memory are written to the backing store if
 *    one is open.
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_core_close(H5FD_t *_file)
{
    H5FD_core_t  *file = (H5FD_core_t*)_file;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_close, FAIL)

    /* Release resources */
    if (file->fd>=0)
        HDclose(file->fd);
    if (file->name)
        H5MM_xfree(file->name);
    if (file->mem)
        H5MM_xfree(file->mem);
    HDmemset(file, 0, sizeof(H5FD_core_t));
    H5MM_xfree(file);

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_cmp
 *
 * Purpose:  Compares two files belonging to this driver by name. If one
 *    file doesn't have a name then it is less than the other file.
 *    If neither file has a name then the comparison is by file
 *    address.
 *
 * Return:  Success:  A value like strcmp()
 *
 *    Failure:  never fails (arguments were checked by the
 *        caller).
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static int
H5FD_core_cmp(const H5FD_t *_f1, const H5FD_t *_f2)
{
    const H5FD_core_t  *f1 = (const H5FD_core_t*)_f1;
    const H5FD_core_t  *f2 = (const H5FD_core_t*)_f2;
    int      ret_value;

    FUNC_ENTER_NOAPI(H5FD_core_cmp, FAIL)

    if (NULL==f1->name && NULL==f2->name) {
        if (f1<f2)
            HGOTO_DONE(-1)
        if (f1>f2)
            HGOTO_DONE(1)
        HGOTO_DONE(0)
    }

    if (NULL==f1->name)
        HGOTO_DONE(-1)
    if (NULL==f2->name)
        HGOTO_DONE(1)

    ret_value = HDstrcmp(f1->name, f2->name);

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_get_eoa
 *
 * Purpose:  Gets the end-of-address marker for the file. The EOA marker
 *    is the first address past the last byte allocated in the
 *    format address space.
 *
 * Return:  Success:  The end-of-address marker.
 *
 *    Failure:  HADDR_UNDEF
 *
 * Programmer:  Robb Matzke
 *              Monday, August  2, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static haddr_t
H5FD_core_get_eoa(H5FD_t *_file)
{
    haddr_t ret_value;   /* Return value */

    H5FD_core_t  *file = (H5FD_core_t*)_file;

    FUNC_ENTER_NOAPI(H5FD_core_get_eoa, HADDR_UNDEF)

    /* Set return value */
    ret_value=file->eoa;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_set_eoa
 *
 * Purpose:  Set the end-of-address marker for the file. This function is
 *    called shortly after an existing HDF5 file is opened in order
 *    to tell the driver where the end of the HDF5 data is located.
 *
 * Return:  Success:  0
 *
 *    Failure:  -1
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_core_set_eoa(H5FD_t *_file, haddr_t addr)
{
    H5FD_core_t  *file = (H5FD_core_t*)_file;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_set_eoa, FAIL)

    if (ADDR_OVERFLOW(addr))
        HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "address overflow")

    file->eoa = addr;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_get_eof
 *
 * Purpose:  Returns the end-of-file marker, which is the greater of
 *    either the size of the underlying memory or the HDF5
 *    end-of-address markers.
 *
 * Return:  Success:  End of file address, the first address past
 *        the end of the "file", either the memory
 *        or the HDF5 file.
 *
 *    Failure:  HADDR_UNDEF
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static haddr_t
H5FD_core_get_eof(H5FD_t *_file)
{
    haddr_t ret_value;   /* Return value */

    H5FD_core_t  *file = (H5FD_core_t*)_file;

    FUNC_ENTER_NOAPI(H5FD_core_get_eof, HADDR_UNDEF)

    /* Set return value */
    ret_value=MAX(file->eof, file->eoa);

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:       H5FD_core_get_handle
 *
 * Purpose:        Returns the file handle of CORE file driver.
 *
 * Returns:        Non-negative if succeed or negative if fails.
 *
 * Programmer:     Raymond Lu
 *                 Sept. 16, 2002
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
/* ARGSUSED */
static herr_t
H5FD_core_get_handle(H5FD_t *_file, hid_t UNUSED fapl, void** file_handle)
{
    H5FD_core_t         *file = (H5FD_core_t *)_file;
    herr_t              ret_value = SUCCEED;

    FUNC_ENTER_NOAPI(H5FD_core_get_handle, FAIL)

    if(!file_handle)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "file handle not valid")

    *file_handle = &(file->mem);

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_read
 *
 * Purpose:  Reads SIZE bytes of data from FILE beginning at address ADDR
 *    into buffer BUF according to data transfer properties in
 *    DXPL_ID.
 *
 * Return:  Success:  Zero. Result is stored in caller-supplied
 *        buffer BUF.
 *
 *    Failure:  -1, Contents of buffer BUF are undefined.
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
/* ARGSUSED */
static herr_t
H5FD_core_read(H5FD_t *_file, H5FD_mem_t UNUSED type, hid_t UNUSED dxpl_id, haddr_t addr,
         size_t size, void *buf/*out*/)
{
    H5FD_core_t  *file = (H5FD_core_t*)_file;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_read, FAIL)

    assert(file && file->pub.cls);
    assert(buf);

    /* Check for overflow conditions */
    if (HADDR_UNDEF == addr)
        HGOTO_ERROR(H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed")
    if (REGION_OVERFLOW(addr, size))
        HGOTO_ERROR(H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed")
    if (addr + size > file->eoa)
        HGOTO_ERROR(H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed")

    /* Read the part which is before the EOF marker */
    if (addr < file->eof) {
        size_t nbytes;
#ifndef NDEBUG
        hsize_t temp_nbytes;

        temp_nbytes = file->eof-addr;
        H5_CHECK_OVERFLOW(temp_nbytes,hsize_t,size_t);
        nbytes = MIN(size,(size_t)temp_nbytes);
#else /* NDEBUG */
        nbytes = MIN(size,(size_t)(file->eof-addr));
#endif /* NDEBUG */

        HDmemcpy(buf, file->mem + addr, nbytes);
        size -= nbytes;
        addr += nbytes;
        buf = (char *)buf + nbytes;
    }

    /* Read zeros for the part which is after the EOF markers */
    if (size > 0)
        HDmemset(buf, 0, size);

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_write
 *
 * Purpose:  Writes SIZE bytes of data to FILE beginning at address ADDR
 *    from buffer BUF according to data transfer properties in
 *    DXPL_ID.
 *
 * Return:  Success:  Zero
 *
 *    Failure:  -1
 *
 * Programmer:  Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
/* ARGSUSED */
static herr_t
H5FD_core_write(H5FD_t *_file, H5FD_mem_t UNUSED type, hid_t UNUSED dxpl_id, haddr_t addr,
    size_t size, const void *buf)
{
    H5FD_core_t    *file = (H5FD_core_t*)_file;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_write, FAIL)

    assert(file && file->pub.cls);
    assert(buf);

    /* Check for overflow conditions */
    if (REGION_OVERFLOW(addr, size))
        HGOTO_ERROR(H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed")
    if (addr+size>file->eoa)
        HGOTO_ERROR(H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed")

    /*
     * Allocate more memory if necessary, careful of overflow. Also, if the
     * allocation fails then the file should remain in a usable state.  Be
     * careful of non-Posix realloc() that doesn't understand what to do when
     * the first argument is null.
     */
    if (addr+size>file->eof) {
        unsigned char *x;
        size_t new_eof;

        H5_ASSIGN_OVERFLOW(new_eof,file->increment*((addr+size)/file->increment),hsize_t,size_t);

        if ((addr+size) % file->increment)
            new_eof += file->increment;
        if (NULL==file->mem)
            x = H5MM_malloc(new_eof);
        else
            x = H5MM_realloc(file->mem, new_eof);
        if (!x)
            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate memory block")
        file->mem = x;
        file->eof = new_eof;
    }

    /* Write from BUF to memory */
    HDmemcpy(file->mem+addr, buf, size);
    file->dirty = TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value)
}


/*-------------------------------------------------------------------------
 * Function:  H5FD_core_flush
 *
 * Purpose:  Flushes the file to backing store if there is any and if the
 *    dirty flag is set.
 *
 * Return:  Success:  0
 *
 *    Failure:  -1
 *
 * Programmer:  Robb Matzke
 *              Friday, October 15, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
/* ARGSUSED */
static herr_t
H5FD_core_flush(H5FD_t *_file, hid_t UNUSED dxpl_id, unsigned UNUSED closing)
{
    H5FD_core_t  *file = (H5FD_core_t*)_file;
    herr_t      ret_value=SUCCEED;       /* Return value */

    FUNC_ENTER_NOAPI(H5FD_core_flush, FAIL)

    /* Write to backing store */
    if (file->dirty && file->fd>=0) {
        haddr_t size = file->eof;
        unsigned char *ptr = file->mem;

        if (0!=HDlseek(file->fd, (off_t)0, SEEK_SET))
            HGOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "error seeking in backing store")

        while (size) {
            ssize_t n;

            H5_CHECK_OVERFLOW(size,hsize_t,size_t);
            n = HDwrite(file->fd, ptr, (size_t)size);
            if (n<0 && EINTR==errno)
                continue;
            if (n<0)
                HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "error writing backing store")
            ptr += (size_t)n;
            size -= (size_t)n;
        }
        file->dirty = FALSE;
    }

done:
    FUNC_LEAVE_NOAPI(ret_value)
}
