[svn-r1785] Added stdio VFL driver, which uses the new public H5E calls.

1 files changed, 706 insertions, 0 deletions

diff --git a/src/H5FDstdio.c b/src/H5FDstdio.c
new file mode 100644
index 0000000..ac8cdc2
--- /dev/null
+++ b/src/H5FDstdio.c
@@ -0,0 +1,706 @@
+/*
+ * Copyright © 1999 NCSA
+ *		      All rights reserved.
+ *
+ * Programmer: Robb Matzke <matzke@llnl.gov>
+ *	       Wednesday, October 22, 1997
+ *
+ * Purpose:    This is the Posix stdio.h I/O subclass of H5Flow.
+ *
+ * Notes:  Ported to the new H5FD architecture on 10/18/99 - QAK
+ *
+ */
+#include "hdf5.h"
+#include <assert.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef WIN32
+#include <windows.h>
+#endif
+
+#ifdef MAX
+#undef MAX
+#endif /* MAX */
+#define MAX(X,Y)	((X)>(Y)?(X):(Y))
+
+/* The driver identification number, initialized at runtime */
+static hid_t H5FD_STDIO_g = 0;
+
+/* File operations */
+typedef enum {
+    H5FD_STDIO_OP_UNKNOWN=0,
+    H5FD_STDIO_OP_READ=1,
+    H5FD_STDIO_OP_WRITE=2,
+    H5FD_STDIO_OP_SEEK=3
+} H5FD_stdio_file_op;
+
+/*
+ * 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 Unix file). The `pos'
+ * value is used to eliminate file position updates when they would be a
+ * no-op. Unfortunately we've found systems that use separate file position
+ * indicators for reading and writing so the lseek can only be eliminated if
+ * the current operation is the same as the previous operation.  When opening
+ * a file the `eof' will be set to the current file size, `eoa' will be set
+ * to zero, `pos' will be set to H5F_ADDR_UNDEF (as it is when an error
+ * occurs), and `op' will be set to H5F_OP_UNKNOWN.
+ */
+typedef struct H5FD_stdio_t {
+    H5FD_t	pub;			/*public stuff, must be first	*/
+    FILE *	fp;			    /*the file handle */
+    haddr_t	eoa;			/*end of allocated region	*/
+    haddr_t	eof;			/*end of file; current file size*/
+    haddr_t	pos;			/*current file I/O position	*/
+    H5FD_stdio_file_op op;	/*last operation		*/
+    unsigned write_access;  /* Flag to indicate the file was opened with write access */
+#ifndef WIN32
+    /*
+     * On most systems the combination of device and i-node number uniquely
+     * identify a file.
+     */
+    dev_t	device;			/*file device number		*/
+    ino_t	inode;			/*file i-node number		*/
+#else
+    /*
+     * On WIN32 the low-order word of a unique identifier associated with the
+     * file and the volume serial number uniquely identify a file. This number
+     * (which, both? -rpm) may change when the system is restarted or when the
+     * file is opened. After a process opens a file, the identifier is
+     * constant until the file is closed. An application can use this
+     * identifier and the volume serial number to determine whether two
+     * handles refer to the same file.
+     */
+    int fileindexlo;
+    int fileindexhi;
+#endif
+} H5FD_stdio_t;
+
+/*
+ * 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 by the second
+ *			argument of the file seek function.
+ */
+#define MAXADDR (((haddr_t)1<<(8*sizeof(long)-1))-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) || \
+    sizeof(long)<sizeof(size_t) || HADDR_UNDEF==(A)+(Z) || (long)((A)+(Z))<(long)(A))
+
+/* Prototypes */
+static H5FD_t *H5FD_stdio_open(const char *name, unsigned flags,
+                 hid_t fapl_id, haddr_t maxaddr);
+static herr_t H5FD_stdio_close(H5FD_t *lf);
+static int H5FD_stdio_cmp(const H5FD_t *_f1, const H5FD_t *_f2);
+static haddr_t H5FD_stdio_get_eoa(H5FD_t *_file);
+static herr_t H5FD_stdio_set_eoa(H5FD_t *_file, haddr_t addr);
+static haddr_t H5FD_stdio_get_eof(H5FD_t *_file);
+static herr_t H5FD_stdio_read(H5FD_t *lf, hid_t fapl_id, haddr_t addr,
+                hsize_t size, void *buf);
+static herr_t H5FD_stdio_write(H5FD_t *lf, hid_t fapl_id, haddr_t addr,
+                hsize_t size, const void *buf);
+static herr_t H5FD_stdio_flush(H5FD_t *_file);
+
+static const H5FD_class_t H5FD_stdio_g = {
+    "stdio",				/*name			*/
+    MAXADDR,				/*maxaddr		*/
+    NULL,					/*sb_size		*/
+    NULL,					/*sb_encode		*/
+    NULL,					/*sb_decode		*/
+    0, 						/*fapl_size		*/
+    NULL,					/*fapl_get		*/
+    NULL,					/*fapl_copy		*/
+    NULL, 					/*fapl_free		*/
+    0,						/*dxpl_size		*/
+    NULL,					/*dxpl_copy		*/
+    NULL,					/*dxpl_free		*/
+    H5FD_stdio_open,		/*open			*/
+    H5FD_stdio_close,		/*close			*/
+    H5FD_stdio_cmp,			/*cmp			*/
+    NULL,					/*alloc			*/
+    NULL,					/*free			*/
+    H5FD_stdio_get_eoa,		/*get_eoa		*/
+    H5FD_stdio_set_eoa, 	/*set_eoa		*/
+    H5FD_stdio_get_eof,		/*get_eof		*/
+    H5FD_stdio_read,		/*read			*/
+    H5FD_stdio_write,		/*write			*/
+    H5FD_stdio_flush,		/*flush			*/
+    H5FD_FLMAP_SINGLE,		/*fl_map		*/
+};
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_init
+ *
+ * Purpose:	Initialize this driver by registering the driver with the
+ *		library.
+ *
+ * Return:	Success:	The driver ID for the stdio driver.
+ *
+ *		Failure:	Negative.
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, July 29, 1999
+ *
+ * Modifications:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5FD_stdio_init(void)
+{
+    if (H5I_VFL!=H5Iget_type(H5FD_STDIO_g))
+        H5FD_STDIO_g = H5FDregister(&H5FD_stdio_g);
+    return(H5FD_STDIO_g);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pset_fapl_stdio
+ *
+ * Purpose:	Modify the file access property list to use the H5FD_STDIO
+ *		driver defined in this source file.  There are no driver
+ *		specific properties.
+ *		
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Thursday, February 19, 1998
+ *
+ * Modifications:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_fapl_stdio(hid_t fapl_id)
+{
+    if (H5P_FILE_ACCESS!=H5Pget_class(fapl_id))
+        return -1;
+
+    return(H5Pset_driver(fapl_id, H5FD_STDIO, NULL));
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_open
+ *
+ * Purpose:	Create and/or opens a Standard C file as an HDF5 file.
+ *
+ * Bugs:	H5F_ACC_EXCL has a race condition. (? -QAK)
+ *
+ * Errors:
+ *		IO	  CANTOPENFILE	File doesn't exist and CREAT wasn't
+ *					specified. 
+ *		IO	  CANTOPENFILE	Fopen failed. 
+ *		IO	  FILEEXISTS	File exists but CREAT and EXCL were
+ *					specified. 
+ *
+ * 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
+ *		Wednesday, October 22, 1997
+ *
+ * Modifications:
+ *      Ported to VFL/H5FD layer - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5FD_t *
+H5FD_stdio_open( const char *name, unsigned flags, hid_t fapl_id,
+    haddr_t maxaddr)
+{
+    FILE		   *f = NULL;
+    unsigned    write_access=0;     /* File opened with write access? */
+    H5FD_stdio_t	*file=NULL;
+    static const char *func="H5FD_stdio_open";  /* Function Name for error reporting */
+#ifdef WIN32
+	HFILE filehandle;
+	struct _BY_HANDLE_FILE_INFORMATION fileinfo;
+	int results;   
+#else /* WIN32 */
+    struct stat		    sb;
+#endif  /* WIN32 */
+
+    /* Shut compiler up */
+    fapl_id=fapl_id;
+
+    /* Check arguments */
+    if (!name || !*name) return NULL;
+    if (0==maxaddr || HADDR_UNDEF==maxaddr) return NULL;
+    if (ADDR_OVERFLOW(maxaddr)) return NULL;
+
+    if (access(name, F_OK) < 0) {
+        if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_RDWR)) {
+            f = fopen(name, "wb+");
+            write_access=1;     /* Note the write access */
+        } else {
+            H5Epush_ret(func, H5E_IO, H5E_CANTOPENFILE,
+                  "file doesn't exist and CREAT wasn't specified", NULL);
+        }
+    } else if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_EXCL)) {
+        H5Epush_ret(func, H5E_IO, H5E_FILEEXISTS,
+		      "file exists but CREAT and EXCL were specified", NULL);
+
+    } else if (flags & H5F_ACC_RDWR) {
+        if (flags & H5F_ACC_TRUNC)
+            f = fopen(name, "wb+");
+        else
+            f = fopen(name, "rb+");
+        write_access=1;     /* Note the write access */
+    } else {
+        f = fopen(name, "rb");
+    }
+    if (!f)
+        H5Epush_ret(func, H5E_IO, H5E_CANTOPENFILE, "fopen failed", NULL);
+
+    /* Build the return value */
+    if (NULL==(file = calloc(1,sizeof(H5FD_stdio_t)))) {
+        H5Epush_ret(func, H5E_RESOURCE, H5E_NOSPACE,
+                   "memory allocation failed", NULL);
+      }
+    file->fp = f;
+    file->op = H5FD_STDIO_OP_SEEK;
+    file->pos = HADDR_UNDEF;
+    file->write_access=write_access;    /* Note the write_access for later */
+    if (fseek(file->fp, 0, SEEK_END) < 0) {
+        file->op = H5FD_STDIO_OP_UNKNOWN;
+    } else {
+        long x = ftell (file->fp);
+        assert (x>=0);
+        file->eof = x;
+    }
+
+    /* The unique key */
+#ifdef WIN32
+#error "Needs correct fileindexhi & fileindexlo, code below is from sec2 driver"
+    filehandle = _get_osfhandle(fd);
+    results = GetFileInformationByHandle(filehandle, &fileinfo);
+    file->fileindexhi = fileinfo.nFileIndexHigh;
+    file->fileindexlo = fileinfo.nFileIndexLow;
+#else
+    fstat(fileno(file->fp), &sb);
+    file->device = sb.st_dev;
+    file->inode = sb.st_ino;
+#endif
+    return((H5FD_t*)file);
+}   /* end H5FD_stdio_open() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_stdio_close
+ *
+ * Purpose:	Closes a file.
+ *
+ * Errors:
+ *		IO	  CLOSEERROR	Fclose failed. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
+ *
+ * Modifications:
+ *      Ported to VFL/H5FD layer - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_stdio_close(H5FD_t *_file)
+{
+    H5FD_stdio_t	*file = (H5FD_stdio_t*)_file;
+    static const char *func="H5FD_stdio_close";  /* Function Name for error reporting */
+
+    if (H5FD_stdio_flush(_file)<0) 
+        H5Epush_ret(func, H5E_IO, H5E_WRITEERROR, "flush failed", -1);
+    if (fclose(file->fp) < 0)
+        H5Epush_ret(func, H5E_IO, H5E_CLOSEERROR, "fclose failed", -1);
+
+    free(file);
+
+    return(0);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_cmp
+ *
+ * Purpose:	Compares two files belonging to this driver using an
+ *		arbitrary (but consistent) ordering.
+ *
+ * Return:	Success:	A value like strcmp()
+ *
+ *		Failure:	never fails (arguments were checked by the
+ *				caller).
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, July 29, 1999
+ *
+ * Modifications:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5FD_stdio_cmp(const H5FD_t *_f1, const H5FD_t *_f2)
+{
+    const H5FD_stdio_t	*f1 = (const H5FD_stdio_t*)_f1;
+    const H5FD_stdio_t	*f2 = (const H5FD_stdio_t*)_f2;
+
+#ifdef WIN32
+    if (f1->fileindexhi < f2->fileindexhi) return -1;
+    if (f1->fileindexhi > f2->fileindexhi) return 1;
+
+    if (f1->fileindexlo < f2->fileindexlo) return -1;
+    if (f1->fileindexlo > f2->fileindexlo) return 1;
+
+#else
+    if (f1->device < f2->device) return -1;
+    if (f1->device > f2->device) return 1;
+
+    if (f1->inode < f2->inode) return -1;
+    if (f1->inode > f2->inode) return 1;
+#endif
+    return 0;
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_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:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static haddr_t
+H5FD_stdio_get_eoa(H5FD_t *_file)
+{
+    H5FD_stdio_t	*file = (H5FD_stdio_t*)_file;
+
+    return(file->eoa);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_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:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_stdio_set_eoa(H5FD_t *_file, haddr_t addr)
+{
+    H5FD_stdio_t	*file = (H5FD_stdio_t*)_file;
+
+    file->eoa = addr;
+
+    return(0);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_stdio_get_eof
+ *
+ * Purpose:	Returns the end-of-file marker, which is the greater of
+ *		either the Unix end-of-file or the HDF5 end-of-address
+ *		markers.
+ *
+ * Return:	Success:	End of file address, the first address past
+ *				the end of the "file", either the Unix file
+ *				or the HDF5 file.
+ *
+ *		Failure:	HADDR_UNDEF
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, July 29, 1999
+ *
+ * Modifications:
+ *      Stolen from the sec2 driver - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static haddr_t
+H5FD_stdio_get_eof(H5FD_t *_file)
+{
+    H5FD_stdio_t	*file = (H5FD_stdio_t*)_file;
+
+    return(MAX(file->eof, file->eoa));
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_stdio_read
+ *
+ * Purpose:	Reads SIZE bytes beginning at address ADDR in file LF and
+ *		places them in buffer BUF.  Reading past the logical or
+ *		physical end of file returns zeros instead of failing.
+ *
+ * Errors:
+ *		IO	  READERROR	Fread failed. 
+ *		IO	  SEEKERROR	Fseek failed. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
+ *
+ * Modifications:
+ *		June 2, 1998	Albert Cheng
+ *		Added xfer_mode argument
+ *
+ *      Ported to VFL/H5FD layer - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_stdio_read(H5FD_t *_file, hid_t dxpl_id, haddr_t addr, hsize_t size,
+    void *buf/*out*/)
+{
+    size_t		n;
+    H5FD_stdio_t		*file = (H5FD_stdio_t*)_file;
+    static const char *func="H5FD_stdio_read";  /* Function Name for error reporting */
+
+    /* Shut compiler up */
+    dxpl_id=dxpl_id;
+
+    /* Check for overflow */
+    if (HADDR_UNDEF==addr) 
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+    if (REGION_OVERFLOW(addr, size))
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+    if (addr+size>file->eoa)
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+
+    /* Check easy cases */
+    if (0 == size)
+        return(0);
+    if ((uint64_t)addr >= file->eof) {
+        memset(buf, 0, size);
+        return(0);
+    }
+
+    /*
+     * Seek to the correct file position.
+     */
+    if (!(file->op == H5FD_STDIO_OP_READ || file->op==H5FD_STDIO_OP_SEEK) ||
+            file->pos != addr) {
+        if (fseek(file->fp, addr, SEEK_SET) < 0) {
+            file->op = H5FD_STDIO_OP_UNKNOWN;
+            file->pos = HADDR_UNDEF;
+            H5Epush_ret(func, H5E_IO, H5E_SEEKERROR, "fseek failed", -1);
+        }
+        file->pos = addr;
+    }
+
+    /*
+     * Read zeros past the logical end of file (physical is handled below)
+     */
+    if ((size_t) addr + size > file->eof) {
+        size_t nbytes = (size_t) addr + size - file->eof;
+        memset((unsigned char *)buf + size - nbytes, 0, nbytes);
+        size -= nbytes;
+    }
+    
+    /*
+     * Read the data.  Since we're reading single-byte values, a partial read
+     * will advance the file position by N.  If N is negative or an error
+     * occurs then the file position is undefined.
+     */
+    n = fread(buf, 1, size, file->fp);
+    if (n <= 0 && ferror(file->fp)) {
+        file->op = H5FD_STDIO_OP_UNKNOWN;
+        file->pos = HADDR_UNDEF;
+        H5Epush_ret(func, H5E_IO, H5E_READERROR, "fread failed", -1);
+    } else if (n < size) {
+        memset((unsigned char *)buf + n, 0, size - n);
+    }
+    
+    /*
+     * Update the file position data.
+     */
+    file->op = H5FD_STDIO_OP_READ;
+    file->pos = addr+n; /*checked for overflow above*/
+    return(0);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_stdio_write
+ *
+ * Purpose:	Writes SIZE bytes from the beginning of BUF into file LF at
+ *		file address ADDR.
+ *
+ * Errors:
+ *		IO	  SEEKERROR	Fseek failed. 
+ *		IO	  WRITEERROR	Fwrite failed. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
+ *
+ * Modifications:
+ *		June 2, 1998	Albert Cheng
+ *		Added xfer_mode argument
+ *
+ *      Ported to VFL/H5FD layer - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_stdio_write(H5FD_t *_file, hid_t dxpl_id, haddr_t addr,
+		hsize_t size, const void *buf)
+{
+    H5FD_stdio_t		*file = (H5FD_stdio_t*)_file;
+    static const char *func="H5FD_stdio_write";  /* Function Name for error reporting */
+
+    /* Shut compiler up */
+    dxpl_id=dxpl_id;
+
+    /* Check for overflow conditions */
+    if (HADDR_UNDEF==addr)
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+    if (REGION_OVERFLOW(addr, size))
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+    if (addr+size>file->eoa)
+        H5Epush_ret (func, H5E_IO, H5E_OVERFLOW, "file address overflowed", -1);
+    
+    /*
+     * Seek to the correct file position.
+     */
+    if (!(file->op == H5FD_STDIO_OP_WRITE || file->op==H5FD_STDIO_OP_SEEK) ||
+                file->pos != addr) {
+        if (fseek(file->fp, addr, SEEK_SET) < 0) {
+            file->op = H5FD_STDIO_OP_UNKNOWN;
+            file->pos = HADDR_UNDEF;
+            H5Epush_ret(func, H5E_IO, H5E_SEEKERROR, "fseek failed", -1);
+        }
+        file->pos = addr;
+    }
+    
+    /*
+     * Write the buffer.  On successful return, the file position will be
+     * advanced by the number of bytes read.  Otherwise nobody knows where it
+     * is.
+     */
+    if (size != fwrite(buf, 1, size, file->fp)) {
+        file->op = H5FD_STDIO_OP_UNKNOWN;
+        file->pos = HADDR_UNDEF;
+        H5Epush_ret(func, H5E_IO, H5E_WRITEERROR, "fwrite failed", -1);
+    }
+    
+    /*
+     * Update seek optimizing data.
+     */
+    file->op = H5FD_STDIO_OP_WRITE;
+    file->pos = addr + size;
+
+    /* Update EOF if necessary */
+    if (file->pos>file->eof)
+        file->eof = file->pos;
+
+    return(0);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_stdio_flush
+ *
+ * Purpose:	Makes sure that all data is on disk.
+ *
+ * Errors:
+ *		IO	  SEEKERROR     fseek failed. 
+ *		IO	  WRITEERROR    fflush or fwrite failed. 
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
+ *
+ * Modifications:
+ *      Ported to VFL/H5FD layer - QAK, 10/18/99
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_stdio_flush(H5FD_t *_file)
+{
+    H5FD_stdio_t	*file = (H5FD_stdio_t*)_file;
+    static const char *func="H5FD_stdio_flush";  /* Function Name for error reporting */
+
+    /* Only try to flush the file if we have write access */
+    if(file->write_access) {
+         /* Makes sure that the true file size is the same (or larger) than the end-of-address. */
+        if (file->eoa>file->eof) {
+            if (fseek(file->fp, file->eoa-1, SEEK_SET)<0)
+                H5Epush_ret(func, H5E_IO, H5E_SEEKERROR, "fseek failed", -1);
+            if (fwrite("", 1, 1, file->fp)!=1)
+                H5Epush_ret(func, H5E_IO, H5E_SEEKERROR, "EOF fwrite failed", -1);
+            file->eof = file->eoa;
+            file->pos = file->eoa;
+            /* fall through to set the IO operation */
+        }
+
+        /*
+         * What happens to the file position?  Is it guaranteed to be the same
+         * after the fflush() as it was before?
+         */
+        file->op = H5FD_STDIO_OP_UNKNOWN;
+
+        /*
+         * Flush
+         */
+        if (fflush(file->fp) < 0)
+            H5Epush_ret(func, H5E_IO, H5E_WRITEERROR, "fflush failed", -1);
+      } /* end if */
+    else {
+        /* Double-check for problems */
+        if (file->eoa>file->eof)
+            H5Epush_ret(func, H5E_IO, H5E_TRUNCATED, "eoa>eof!", -1);
+      } /* end else */
+
+    return(0);
+}