/*
* Copyright (C) 1997 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.
*/
#include <H5private.h>
#include <H5private.h>
#include <H5Eprivate.h>
#include <H5Fprivate.h>
#include <H5MMprivate.h>
#include <sys/types.h>
#include <sys/stat.h>
#define PABLO_MASK H5F_stdio
static hbool_t interface_initialize_g = FALSE;
#define INTERFACE_INIT NULL
static H5F_low_t *H5F_stdio_open(const char *name, uintn flags,
H5F_search_t *key);
static herr_t H5F_stdio_close(H5F_low_t *lf);
static herr_t H5F_stdio_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
uint8 *buf);
static herr_t H5F_stdio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
const uint8 *buf);
static herr_t H5F_stdio_flush(H5F_low_t *lf);
const H5F_low_class_t H5F_LOW_STDIO[1] =
{
{
NULL, /* use default access(2) func */
H5F_stdio_open, /* open method */
H5F_stdio_close, /* close method */
H5F_stdio_read, /* read method */
H5F_stdio_write, /* write method */
H5F_stdio_flush, /* flush method */
NULL, /* extend method */
}};
/*-------------------------------------------------------------------------
* Function: H5F_stdio_open
*
* Purpose: Opens a file with name NAME. The FLAGS are a bit field with
* the possible values defined in H5F_low_open().
*
* Bugs: H5F_ACC_EXCL has a race condition.
*
* 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: Low-level file pointer
*
* Failure: NULL
*
* Programmer: Robb Matzke
* Wednesday, October 22, 1997
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static H5F_low_t *
H5F_stdio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
{
H5F_low_t *lf = NULL;
FILE *f = NULL;
struct stat sb;
FUNC_ENTER(H5F_stdio_open, NULL);
if (access(name, F_OK) < 0) {
if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_WRITE)) {
f = fopen(name, "wb+");
} else {
HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
"file doesn't exist and CREAT wasn't specified");
}
} else if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_EXCL)) {
HRETURN_ERROR(H5E_IO, H5E_FILEEXISTS, NULL,
"file exists but CREAT and EXCL were specified");
} else if (flags & H5F_ACC_WRITE) {
if (flags & H5F_ACC_TRUNC)
f = fopen(name, "wb+");
else
f = fopen(name, "rb+");
} else {
f = fopen(name, "rb");
}
if (!f)
HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "fopen failed");
/* Build the return value */
lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
lf->u.stdio.f = f;
lf->u.stdio.op = H5F_OP_SEEK;
lf->u.stdio.cur = 0;
H5F_addr_reset(&(lf->eof));
if (fseek(lf->u.stdio.f, 0, SEEK_END) < 0) {
lf->u.stdio.op = H5F_OP_UNKNOWN;
} else {
H5F_addr_inc(&(lf->eof), ftell(lf->u.stdio.f));
}
/* The unique key */
if (key) {
fstat(fileno(f), &sb);
key->dev = sb.st_dev;
key->ino = sb.st_ino;
}
FUNC_LEAVE(lf);
}
/*-------------------------------------------------------------------------
* Function: H5F_stdio_close
*
* Purpose: Closes a file.
*
* Errors:
* IO CLOSEERROR Fclose failed.
*
* Return: Success: SUCCEED
*
* Failure: FAIL
*
* Programmer: Robb Matzke
* Wednesday, October 22, 1997
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static herr_t
H5F_stdio_close(H5F_low_t *lf)
{
FUNC_ENTER(H5F_stdio_close, FAIL);
if (fclose(lf->u.stdio.f) < 0) {
HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "fclose failed");
}
lf->u.stdio.f = NULL;
FUNC_LEAVE(SUCCEED);
}
/*-------------------------------------------------------------------------
* 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: Success: SUCCEED
*
* Failure: FAIL
*
* Programmer: Robb Matzke
* Wednesday, October 22, 1997
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static herr_t
H5F_stdio_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
{
size_t n;
off_t offset;
FUNC_ENTER(H5F_stdio_read, FAIL);
/* Check for overflow */
offset = addr->offset; /*FIX_ME*/
assert("address overflowed" && offset == addr->offset);
assert("overflow" && offset + size >= offset);
/* Check easy cases */
if (0 == size)
HRETURN(SUCCEED);
if (offset >= lf->eof.offset) {
HDmemset(buf, 0, size);
HRETURN(SUCCEED);
}
/*
* Seek to the correct file position.
*/
if (!H5F_OPT_SEEK ||
lf->u.stdio.op != H5F_OP_READ ||
lf->u.stdio.cur != offset) {
if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
}
lf->u.stdio.cur = offset;
}
/*
* Read zeros past the logical end of file (physical is handled below)
*/
if ((size_t) offset + size > lf->eof.offset) {
size_t nbytes = (size_t) offset + size - lf->eof.offset;
HDmemset(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, lf->u.stdio.f);
if (n <= 0 && ferror(lf->u.stdio.f)) {
lf->u.stdio.op = H5F_OP_UNKNOWN;
HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "fread failed");
} else if (n < size) {
HDmemset(buf + n, 0, size - n);
}
/*
* Update the file position data.
*/
lf->u.stdio.op = H5F_OP_READ;
lf->u.stdio.cur = offset + n; /*FIX_ME*/
FUNC_LEAVE(SUCCEED);
}
/*-------------------------------------------------------------------------
* 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: Success: SUCCEED
*
* Failure: FAIL
*
* Programmer: Robb Matzke
* Wednesday, October 22, 1997
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static herr_t
H5F_stdio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
const uint8 *buf)
{
off_t offset;
FUNC_ENTER(H5F_stdio_write, FAIL);
/* Check for overflow */
offset = addr->offset; /*FIX_ME*/
assert("address overflowed" && offset == addr->offset);
assert("overflow" && offset + size >= offset);
/*
* Seek to the correct file position.
*/
if (!H5F_OPT_SEEK ||
lf->u.stdio.op != H5F_OP_WRITE ||
lf->u.stdio.cur != offset) {
if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
}
lf->u.stdio.cur = offset;
}
/*
* 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, lf->u.stdio.f)) {
lf->u.stdio.op = H5F_OP_UNKNOWN;
HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fwrite failed");
}
/*
* Update seek optimizing data.
*/
lf->u.stdio.op = H5F_OP_WRITE;
lf->u.stdio.cur = offset + size; /*FIX_ME*/
FUNC_LEAVE(SUCCEED);
}
/*-------------------------------------------------------------------------
* Function: H5F_stdio_flush
*
* Purpose: Makes sure that all data is on disk.
*
* Errors:
* IO WRITEERROR Fflush failed.
*
* Return: Success: SUCCEED
*
* Failure: FAIL
*
* Programmer: Robb Matzke
* Wednesday, October 22, 1997
*
* Modifications:
*
*-------------------------------------------------------------------------
*/
static herr_t
H5F_stdio_flush(H5F_low_t *lf)
{
FUNC_ENTER(H5F_stdio_flush, FAIL);
/*
* What happens to the file position? Is it guaranteed to be the same
* after the fflush() as it was before?
*/
lf->u.stdio.op = H5F_OP_UNKNOWN;
/*
* Flush
*/
if (fflush(lf->u.stdio.f) < 0) {
HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fflush failed");
}
FUNC_LEAVE(SUCCEED);
}