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
|
/*-------------------------------------------------------------------------
*
* be-fsstubs.c
* support for filesystem operations on large objects
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.32 1999/05/10 00:45:09 momjian Exp $
*
* NOTES
* This should be moved to a more appropriate place. It is here
* for lack of a better place.
*
* Builtin functions for open/close/read/write operations on large objects.
*
* These functions operate in the current portal variable context, which
* means the large object descriptors hang around between transactions and
* are not deallocated until explicitly closed, or until the portal is
* closed.
*-------------------------------------------------------------------------
*/
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <postgres.h>
#include <lib/dllist.h>
#include <libpq/libpq.h>
#include <libpq/libpq-fs.h>
#include <nodes/nodes.h>
#include <utils/memutils.h>
#include <lib/fstack.h>
#include <utils/mcxt.h>
#include <storage/fd.h> /* for O_ */
#include <storage/large_object.h>
#include <libpq/be-fsstubs.h>
/* [PA] is Pascal André <andre@via.ecp.fr> */
/*#define FSDB 1*/
#define MAX_LOBJ_FDS 256
#define BUFSIZE 1024
#define FNAME_BUFSIZE 8192
static LargeObjectDesc *cookies[MAX_LOBJ_FDS];
static GlobalMemory fscxt = NULL;
static int newLOfd(LargeObjectDesc *lobjCookie);
static void deleteLOfd(int fd);
/*****************************************************************************
* File Interfaces for Large Objects
*****************************************************************************/
int
lo_open(Oid lobjId, int mode)
{
LargeObjectDesc *lobjDesc;
int fd;
MemoryContext currentContext;
#if FSDB
elog(NOTICE, "LOopen(%u,%d)", lobjId, mode);
#endif
if (fscxt == NULL)
fscxt = CreateGlobalMemory("Filesystem");
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
lobjDesc = inv_open(lobjId, mode);
if (lobjDesc == NULL)
{ /* lookup failed */
MemoryContextSwitchTo(currentContext);
#if FSDB
elog(NOTICE, "cannot open large object %u", lobjId);
#endif
return -1;
}
fd = newLOfd(lobjDesc);
/* switch context back to orig. */
MemoryContextSwitchTo(currentContext);
return fd;
}
int
lo_close(int fd)
{
MemoryContext currentContext;
if (fd < 0 || fd >= MAX_LOBJ_FDS)
{
elog(ERROR, "lo_close: large obj descriptor (%d) out of range", fd);
return -2;
}
if (cookies[fd] == NULL)
{
elog(ERROR, "lo_close: invalid large obj descriptor (%d)", fd);
return -3;
}
#if FSDB
elog(NOTICE, "LOclose(%d)", fd);
#endif
Assert(fscxt != NULL);
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
inv_close(cookies[fd]);
MemoryContextSwitchTo(currentContext);
deleteLOfd(fd);
return 0;
}
/*
* We assume the large object supports byte oriented reads and seeks so
* that our work is easier.
*/
int
lo_read(int fd, char *buf, int len)
{
MemoryContext currentContext;
int status;
if (fd < 0 || fd >= MAX_LOBJ_FDS)
{
elog(ERROR, "lo_read: large obj descriptor (%d) out of range", fd);
return -2;
}
if (cookies[fd] == NULL)
{
elog(ERROR, "lo_read: invalid large obj descriptor (%d)", fd);
return -3;
}
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
status = inv_read(cookies[fd], buf, len);
MemoryContextSwitchTo(currentContext);
return(status);
}
int
lo_write(int fd, char *buf, int len)
{
MemoryContext currentContext;
int status;
if (fd < 0 || fd >= MAX_LOBJ_FDS)
{
elog(ERROR, "lo_write: large obj descriptor (%d) out of range", fd);
return -2;
}
if (cookies[fd] == NULL)
{
elog(ERROR, "lo_write: invalid large obj descriptor (%d)", fd);
return -3;
}
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
status = inv_write(cookies[fd], buf, len);
MemoryContextSwitchTo(currentContext);
return(status);
}
int
lo_lseek(int fd, int offset, int whence)
{
MemoryContext currentContext;
int ret;
if (fd < 0 || fd >= MAX_LOBJ_FDS)
{
elog(ERROR, "lo_lseek: large obj descriptor (%d) out of range", fd);
return -2;
}
if (cookies[fd] == NULL)
{
elog(ERROR, "lo_lseek: invalid large obj descriptor (%d)", fd);
return -3;
}
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
ret = inv_seek(cookies[fd], offset, whence);
MemoryContextSwitchTo(currentContext);
return ret;
}
Oid
lo_creat(int mode)
{
LargeObjectDesc *lobjDesc;
MemoryContext currentContext;
Oid lobjId;
if (fscxt == NULL)
fscxt = CreateGlobalMemory("Filesystem");
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
lobjDesc = inv_create(mode);
if (lobjDesc == NULL)
{
MemoryContextSwitchTo(currentContext);
return InvalidOid;
}
lobjId = RelationGetRelid(lobjDesc->heap_r);
inv_close(lobjDesc);
/* switch context back to original memory context */
MemoryContextSwitchTo(currentContext);
return lobjId;
}
int
lo_tell(int fd)
{
if (fd < 0 || fd >= MAX_LOBJ_FDS)
{
elog(ERROR, "lo_tell: large object descriptor (%d) out of range", fd);
return -2;
}
if (cookies[fd] == NULL)
{
elog(ERROR, "lo_tell: invalid large object descriptor (%d)", fd);
return -3;
}
return inv_tell(cookies[fd]);
}
int
lo_unlink(Oid lobjId)
{
return inv_destroy(lobjId);
}
/*****************************************************************************
* Read/Write using varlena
*****************************************************************************/
struct varlena *
loread(int fd, int len)
{
struct varlena *retval;
int totalread = 0;
retval = (struct varlena *) palloc(VARHDRSZ + len);
totalread = lo_read(fd, VARDATA(retval), len);
VARSIZE(retval) = totalread + VARHDRSZ;
return retval;
}
int
lowrite(int fd, struct varlena * wbuf)
{
int totalwritten;
int bytestowrite;
bytestowrite = VARSIZE(wbuf) - VARHDRSZ;
totalwritten = lo_write(fd, VARDATA(wbuf), bytestowrite);
return totalwritten;
}
/*****************************************************************************
* Import/Export of Large Object
*****************************************************************************/
/*
* lo_import -
* imports a file as an (inversion) large object.
*/
Oid
lo_import(text *filename)
{
File fd;
int nbytes,
tmp;
char buf[BUFSIZE];
char fnamebuf[FNAME_BUFSIZE];
LargeObjectDesc *lobj;
Oid lobjOid;
/*
* open the file to be read in
*/
StrNCpy(fnamebuf, VARDATA(filename), VARSIZE(filename) - VARHDRSZ + 1);
#ifndef __CYGWIN32__
fd = PathNameOpenFile(fnamebuf, O_RDONLY, 0666);
#else
fd = PathNameOpenFile(fnamebuf, O_RDONLY | O_BINARY, 0666);
#endif
if (fd < 0)
{ /* error */
elog(ERROR, "be_lo_import: can't open unix file \"%s\"\n",
fnamebuf);
}
/*
* create an inversion "object"
*/
lobj = inv_create(INV_READ | INV_WRITE);
if (lobj == NULL)
{
elog(ERROR, "lo_import: can't create inv object for \"%s\"",
fnamebuf);
}
/*
* the oid for the large object is just the oid of the relation
* XInv??? which contains the data.
*/
lobjOid = RelationGetRelid(lobj->heap_r);
/*
* read in from the Unix file and write to the inversion file
*/
while ((nbytes = FileRead(fd, buf, BUFSIZE)) > 0)
{
tmp = inv_write(lobj, buf, nbytes);
if (tmp < nbytes)
{
elog(ERROR, "lo_import: error while reading \"%s\"",
fnamebuf);
}
}
FileClose(fd);
inv_close(lobj);
return lobjOid;
}
/*
* lo_export -
* exports an (inversion) large object.
*/
int4
lo_export(Oid lobjId, text *filename)
{
File fd;
int nbytes,
tmp;
char buf[BUFSIZE];
char fnamebuf[FNAME_BUFSIZE];
LargeObjectDesc *lobj;
mode_t oumask;
/*
* open the inversion "object"
*/
lobj = inv_open(lobjId, INV_READ);
if (lobj == NULL)
{
elog(ERROR, "lo_export: can't open inv object %u", lobjId);
}
/*
* open the file to be written to
*/
StrNCpy(fnamebuf, VARDATA(filename), VARSIZE(filename) - VARHDRSZ + 1);
oumask = umask((mode_t) 0);
#ifndef __CYGWIN32__
fd = PathNameOpenFile(fnamebuf, O_CREAT | O_WRONLY | O_TRUNC, 0666);
#else
fd = PathNameOpenFile(fnamebuf, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0666);
#endif
umask(oumask);
if (fd < 0)
{ /* error */
elog(ERROR, "lo_export: can't open unix file \"%s\"",
fnamebuf);
}
/*
* read in from the Unix file and write to the inversion file
*/
while ((nbytes = inv_read(lobj, buf, BUFSIZE)) > 0)
{
tmp = FileWrite(fd, buf, nbytes);
if (tmp < nbytes)
{
elog(ERROR, "lo_export: error while writing \"%s\"",
fnamebuf);
}
}
inv_close(lobj);
FileClose(fd);
return 1;
}
/*
* lo_commit -
* prepares large objects for transaction commit [PA, 7/17/98]
*/
void
_lo_commit(void)
{
int i;
MemoryContext currentContext;
if (fscxt == NULL)
return;
currentContext = MemoryContextSwitchTo((MemoryContext) fscxt);
for (i = 0; i < MAX_LOBJ_FDS; i++)
{
if (cookies[i] != NULL)
inv_cleanindex(cookies[i]);
}
MemoryContextSwitchTo(currentContext);
}
/*****************************************************************************
* Support routines for this file
*****************************************************************************/
static int
newLOfd(LargeObjectDesc *lobjCookie)
{
int i;
for (i = 0; i < MAX_LOBJ_FDS; i++)
{
if (cookies[i] == NULL)
{
cookies[i] = lobjCookie;
return i;
}
}
return -1;
}
static void
deleteLOfd(int fd)
{
cookies[fd] = NULL;
}
|