summaryrefslogtreecommitdiffstats
path: root/src/H5FDsec2.c
blob: b383b923004b70c1c14c2944043add9317011ad4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
/*
 * Copyright © 1999 NCSA
 *                  All rights reserved.
 *
 * Programmer:  Robb Matzke <matzke@llnl.gov>
 *              Thursday, July 29, 1999
 *
 * Purpose:	The POSIX unbuffered file driver using only the HDF5 public
 *		API and with a few optimizations: the lseek() call is made
 *		only when the current file position is unknown or needs to be
 *		changed based on previous I/O through this driver (don't mix
 *		I/O from this driver with I/O from other parts of the
 *		application to the same file).
 */
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <hdf5.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>


#undef MAX
#define MAX(X,Y)	((X)>(Y)?(X):(Y))

/* The driver identification number, initialized at runtime */
static hid_t H5FD_SEC2_g = 0;

/* File operations */
#define OP_UNKNOWN	0
#define OP_READ		1
#define OP_WRITE	2

/*
 * 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_sec2_t {
    H5FD_t	pub;			/*public stuff, must be first	*/
    int		fd;			/*the unix file			*/
    haddr_t	eoa;			/*end of allocated region	*/
    haddr_t	eof;			/*end of file; current file size*/
    haddr_t	pos;			/*current file I/O position	*/
    int		op;			/*last operation		*/
#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_sec2_t;

/*
 * This driver supports systems that have the lseek64() function by defining
 * some macros here so we don't have to have conditional compilations later
 * throughout the code.
 *
 * file_offset_t:	The datatype for file offsets, the second argument of
 *			the lseek() or lseek64() call.
 *
 * file_seek:		The function which adjusts the current file position,
 *			either lseek() or lseek64().
 */
#ifdef HAVE_LSEEK64
#   define file_offset_t	off64_t
#   define file_seek		lseek64
#else
#   define file_offset_t	off_t
#   define file_seek		lseek
#endif

/*
 * 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(file_offset_t)-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(file_offset_t)<sizeof(size_t) ||      \
                                 HADDR_UNDEF==(A)+(Z) ||		      \
				 (file_offset_t)((A)+(Z))<(file_offset_t)(A))

/* Prototypes */
static H5FD_t *H5FD_sec2_open(const char *name, unsigned flags, hid_t fapl_id,
			      haddr_t maxaddr);
static herr_t H5FD_sec2_close(H5FD_t *_file);
static int H5FD_sec2_cmp(const H5FD_t *_f1, const H5FD_t *_f2);
static haddr_t H5FD_sec2_get_eoa(H5FD_t *_file);
static herr_t H5FD_sec2_set_eoa(H5FD_t *_file, haddr_t addr);
static haddr_t H5FD_sec2_get_eof(H5FD_t *_file);
static herr_t H5FD_sec2_read(H5FD_t *_file, hid_t fapl_id, haddr_t addr,
			     hsize_t size, void *buf);
static herr_t H5FD_sec2_write(H5FD_t *_file, hid_t fapl_id, haddr_t addr,
			      hsize_t size, const void *buf);
static herr_t H5FD_sec2_flush(H5FD_t *_file);

static const H5FD_class_t H5FD_sec2_g = {
    "sec2",					/*name			*/
    MAXADDR,					/*maxaddr		*/
    0, 						/*fapl_size		*/
    NULL,					/*fapl_copy		*/
    NULL, 					/*fapl_free		*/
    0,						/*dxpl_size		*/
    NULL,					/*dxpl_copy		*/
    NULL,					/*dxpl_free		*/
    H5FD_sec2_open,				/*open			*/
    H5FD_sec2_close,				/*close			*/
    H5FD_sec2_cmp,				/*cmp			*/
    NULL,					/*alloc			*/
    NULL,					/*free			*/
    H5FD_sec2_get_eoa,				/*get_eoa		*/
    H5FD_sec2_set_eoa, 				/*set_eoa		*/
    H5FD_sec2_get_eof,				/*get_eof		*/
    H5FD_sec2_read,				/*read			*/
    H5FD_sec2_write,				/*write			*/
    H5FD_sec2_flush,				/*flush			*/
    H5FD_FLMAP_SINGLE,				/*fl_map		*/
};


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_init
 *
 * Purpose:	Initialize this driver by registering the driver with the
 *		library.
 *
 * Return:	Success:	The driver ID for the sec2 driver.
 *
 *		Failure:	Negative.
 *
 * Programmer:	Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5FD_sec2_init(void)
{
    if (!H5FD_SEC2_g) {
	H5FD_SEC2_g = H5FDregister(&H5FD_sec2_g);
    }
    return H5FD_SEC2_g;
}


/*-------------------------------------------------------------------------
 * Function:	H5Pset_fapl_sec2
 *
 * Purpose:	Modify the file access property list to use the H5FD_SEC2
 *		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:
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5Pset_fapl_sec2(hid_t fapl_id)
{
    /*NO TRACE*/
    if (H5P_FILE_ACCESS!=H5Pget_class(fapl_id)) return -1;
    return H5Pset_driver(fapl_id, H5FD_SEC2, NULL);
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_open
 *
 * Purpose:	Create and/or opens a Unix file 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:
 *
 *-------------------------------------------------------------------------
 */
static H5FD_t *
H5FD_sec2_open(const char *name, unsigned flags, hid_t fapl_id/*unused*/,
	       haddr_t maxaddr)
{
    unsigned	o_flags;
    int		fd;
    struct stat	sb;
    H5FD_sec2_t	*file=NULL;
    
    /* Check arguments */
    if (!name || !*name) return NULL;
    if (0==maxaddr || HADDR_UNDEF==maxaddr) return NULL;
    if (ADDR_OVERFLOW(maxaddr)) return NULL;

    /* Build the open flags */
    o_flags = (H5F_ACC_RDWR & flags) ? O_RDWR : O_RDONLY;
    if (H5F_ACC_TRUNC & flags) o_flags |= O_TRUNC;
    if (H5F_ACC_CREAT & flags) o_flags |= O_CREAT;
    if (H5F_ACC_EXCL & flags) o_flags |= O_EXCL;

    /* Open the file */
    if ((fd=open(name, o_flags, 0666))<0) return NULL;
    if (fstat(fd, &sb)<0) {
	close(fd);
	return NULL;
    }

    /* Create the new file struct */
    file = calloc(1, sizeof(H5FD_sec2_t));
    file->fd = fd;
    file->eof = sb.st_size;
    file->pos = HADDR_UNDEF;
    file->op = OP_UNKNOWN;
    file->device = sb.st_dev;
    file->inode = sb.st_ino;

    return (H5FD_t*)file;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_close
 *
 * Purpose:	Closes a Unix file.
 *
 * Return:	Success:	0
 *
 *		Failure:	-1, file not closed.
 *
 * Programmer:	Robb Matzke
 *              Thursday, July 29, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_sec2_close(H5FD_t *_file)
{
    H5FD_sec2_t	*file = (H5FD_sec2_t*)_file;

    if (H5FD_sec2_flush(_file)<0) return -1;
    if (close(file->fd)<0) return -1;
    free(file);
    return 0;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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:
 *
 *-------------------------------------------------------------------------
 */
static int
H5FD_sec2_cmp(const H5FD_t *_f1, const H5FD_t *_f2)
{
    const H5FD_sec2_t	*f1 = (const H5FD_sec2_t*)_f1;
    const H5FD_sec2_t	*f2 = (const H5FD_sec2_t*)_f2;

    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;

    return 0;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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_sec2_get_eoa(H5FD_t *_file)
{
    H5FD_sec2_t	*file = (H5FD_sec2_t*)_file;
    return file->eoa;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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_sec2_set_eoa(H5FD_t *_file, haddr_t addr)
{
    H5FD_sec2_t	*file = (H5FD_sec2_t*)_file;
    file->eoa = addr;
    return 0;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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:
 *
 *-------------------------------------------------------------------------
 */
static haddr_t
H5FD_sec2_get_eof(H5FD_t *_file)
{
    H5FD_sec2_t	*file = (H5FD_sec2_t*)_file;
    return MAX(file->eof, file->eoa);
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_sec2_read(H5FD_t *_file, hid_t dxpl_id/*unused*/, haddr_t addr,
	       hsize_t size, void *buf/*out*/)
{
    H5FD_sec2_t		*file = (H5FD_sec2_t*)_file;
    ssize_t		nbytes;
    
    assert(file && file->pub.cls);
    assert(buf);

    /* Check for overflow conditions */
    if (HADDR_UNDEF==addr) return -1;
    if (REGION_OVERFLOW(addr, size)) return -1;
    if (addr+size>file->eoa) return -1;

    /* Seek to the correct location */
    if ((addr!=file->pos || OP_READ!=file->op) &&
	file_seek(file->fd, (file_offset_t)addr, SEEK_SET)<0) {
	file->pos = HADDR_UNDEF;
	file->op = OP_UNKNOWN;
	return -1;
    }

    /*
     * Read data, being careful of interrupted system calls, partial results,
     * and the end of the file.
     */
    while (size>0) {
	do nbytes = read(file->fd, buf, size);
	while (-1==nbytes && EINTR==errno);
	if (-1==nbytes) {
	    /* error */
	    file->pos = HADDR_UNDEF;
	    file->op = OP_UNKNOWN;
	    return -1;
	}
	if (0==nbytes) {
	    /* end of file but not end of format address space */
	    memset(buf, 0, size);
	    size = 0;
	}
	assert(nbytes>=0);
	assert((hsize_t)nbytes<=size);
	size -= (hsize_t)nbytes;
	addr += (haddr_t)nbytes;
	buf = (char*)buf + nbytes;
    }
    
    /* Update current position */
    file->pos = addr;
    file->op = OP_READ;
    return 0;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_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:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_sec2_write(H5FD_t *_file, hid_t dxpl_id/*unused*/, haddr_t addr,
		hsize_t size, const void *buf)
{
    H5FD_sec2_t		*file = (H5FD_sec2_t*)_file;
    ssize_t		nbytes;
    
    assert(file && file->pub.cls);
    assert(buf);

    /* Check for overflow conditions */
    if (HADDR_UNDEF==addr) return -1;
    if (REGION_OVERFLOW(addr, size)) return -1;
    if (addr+size>file->eoa) return -1;
    
    /* Seek to the correct location */
    if ((addr!=file->pos || OP_WRITE!=file->op) &&
	file_seek(file->fd, (file_offset_t)addr, SEEK_SET)<0) {
	file->pos = HADDR_UNDEF;
	file->op = OP_UNKNOWN;
	return -1;
    }

    /*
     * Write the data, being careful of interrupted system calls and partial
     * results
     */
    while (size>0) {
	do nbytes = write(file->fd, buf, size);
	while (-1==nbytes && EINTR==errno);
	if (-1==nbytes) {
	    /* error */
	    file->pos = HADDR_UNDEF;
	    file->op = OP_UNKNOWN;
	    return -1;
	}
	assert(nbytes>0);
	assert((hsize_t)nbytes<=size);
	size -= (hsize_t)nbytes;
	addr += (haddr_t)nbytes;
	buf = (const char*)buf + nbytes;
    }
    
    /* Update current position and eof */
    file->pos = addr;
    file->op = OP_WRITE;
    if (file->pos>file->eof) file->eof = file->pos;

    return 0;
}


/*-------------------------------------------------------------------------
 * Function:	H5FD_sec2_flush
 *
 * Purpose:	Makes sure that the true file size is the same (or larger)
 *		than the end-of-address.
 *
 * Return:	Success:	Non-negative
 *
 *		Failure:	Negative
 *
 * Programmer:	Robb Matzke
 *              Wednesday, August  4, 1999
 *
 * Modifications:
 *
 *-------------------------------------------------------------------------
 */
static herr_t
H5FD_sec2_flush(H5FD_t *_file)
{
    H5FD_sec2_t	*file = (H5FD_sec2_t*)_file;

    if (file->eoa>file->eof) {
	if (-1==file_seek(file->fd, file->eoa-1, SEEK_SET)) return -1;
	if (write(file->fd, "", 1)!=1) return -1;
	file->eof = file->eoa;
	file->pos = file->eoa;
	file->op = OP_WRITE;
    }

    return 0;
}