/
iolayer.c
846 lines (608 loc) · 19 KB
/
iolayer.c
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
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
#include "io.h"
#include "iolayer.h"
#include "log.h"
#include <stdlib.h>
#include <stdio.h>
#ifdef _MSC_VER
#include <io.h>
#endif
#define IOL_DEB(x)
char *io_type_names[] = { "FDSEEK", "FDNOSEEK", "BUFFER", "CBSEEK", "CBNOSEEK", "BUFCHAIN" };
/*
=head1 NAME
iolayer.c - encapsulates different source of data into a single framework.
=head1 SYNOPSIS
io_glue *ig = io_new_fd( fileno(stdin) );
method = io_reqmeth( IOL_NOSEEK | IOL_MMAP ); // not implemented yet
io_glue_commit_types(ig); // always assume IOL_SEEK for now
switch (method) {
case IOL_NOSEEK:
code that uses ig->readcb()
to read data goes here.
break;
case IOL_MMAP:
code that uses ig->readcb()
to read data goes here.
break;
}
io_glue_DESTROY(ig);
// and much more
=head1 DESCRIPTION
iolayer.c implements the basic functions to create and destroy io_glue
objects for Imager. The typical usage pattern for data sources is:
1. Create the source (io_new_fd)
2. Define how you want to get data from it (io_reqmeth)
3. read from it using the interface requested (ig->readdb, ig->mmapcb)
4. Close the source, which
shouldn't really close the underlying source. (io_glue DESTROY)
=head1 FUNCTION REFERENCE
Some of these functions are internal.
=over 4
=cut
*/
/*
* Callbacks for sources that cannot seek
*/
/* fakeseek_read: read method for when emulating a seekable source
static
ssize_t
fakeseek_read(io_glue *ig, void *buf, size_t count) {
io_ex_fseek *exdata = ig->exdata;
return 0;
}
*/
/*
* Callbacks for sources that can seek
*/
/*
=item realseek_read(ig, buf, count)
Does the reading from a source that can be seeked on
ig - io_glue object
buf - buffer to return data in
count - number of bytes to read into buffer max
=cut
*/
static
ssize_t
realseek_read(io_glue *ig, void *buf, size_t count) {
io_ex_rseek *ier = ig->exdata;
int fd = (int)ig->source.cb.p;
ssize_t rc = 0;
size_t bc = 0;
char *cbuf = buf;
IOL_DEB( printf("realseek_read: fd = %d, ier->cpos = %ld, buf = 0x%p, count = %d\n", fd, (long) ier->cpos, buf, count) );
/* Is this a good idea? Would it be better to handle differently? skip handling? */
while( count!=bc && (rc = ig->source.cb.readcb(fd,cbuf+bc,count-bc))>0 ) bc+=rc;
ier->cpos += bc;
IOL_DEB( printf("realseek_read: rc = %d, bc = %d\n", rc, bc) );
return bc;
}
/*
=item realseek_write(ig, buf, count)
Does the writing to a 'source' that can be seeked on
ig - io_glue object
buf - buffer that contains data
count - number of bytes to write
=cut
*/
static
ssize_t
realseek_write(io_glue *ig, const void *buf, size_t count) {
io_ex_rseek *ier = ig->exdata;
int fd = (int)ig->source.cb.p;
ssize_t rc = 0;
size_t bc = 0;
char *cbuf = (char*)buf;
IOL_DEB( printf("realseek_write: fd = %d, ier->cpos = %ld, buf = 0x%p, count = %d\n", fd, (long) ier->cpos, buf, count) );
/* Is this a good idea? Would it be better to handle differently? skip handling? */
while( count!=bc && (rc = ig->source.cb.writecb(fd,cbuf+bc,count-bc))>0 ) bc+=rc;
ier->cpos += bc;
IOL_DEB( printf("realseek_write: rc = %d, bc = %d\n", rc, bc) );
return bc;
}
/*
=item realseek_close(ig)
Closes a source that can be seeked on. Not sure if this should be an actual close
or not. Does nothing for now. Should be fixed.
ig - data source
=cut
*/
static
void
realseek_close(io_glue *ig) {
mm_log((1, "realseek_close(ig %p)\n", ig));
/* FIXME: Do stuff here */
}
/* realseek_seek(ig, offset, whence)
Implements seeking for a source that is seekable, the purpose of having this is to be able to
have an offset into a file that is different from what the underlying library thinks.
ig - data source
offset - offset into stream
whence - whence argument a la lseek
=cut
*/
static
off_t
realseek_seek(io_glue *ig, off_t offset, int whence) {
/* io_ex_rseek *ier = ig->exdata; Needed later */
int fd = (int)ig->source.cb.p;
int rc;
IOL_DEB( printf("realseek_seek(ig 0x%p, offset %ld, whence %d)\n", ig, (long) offset, whence) );
rc = lseek(fd, offset, whence);
IOL_DEB( printf("realseek_seek: rc %ld\n", (long) rc) );
return rc;
/* FIXME: How about implementing this offset handling stuff? */
}
/*
* Callbacks for sources that are a chain of variable sized buffers
*/
/* Helper functions for buffer chains */
static
io_blink*
io_blink_new() {
io_blink *ib;
mm_log((1, "io_blink_new()\n"));
ib = mymalloc(sizeof(io_blink));
ib->next = NULL;
ib->prev = NULL;
ib->len = BBSIZ;
memset(&ib->buf, 0, ib->len);
return ib;
}
/*
=item io_bchain_advance(ieb)
Advances the buffer chain to the next link - extending if
necessary. Also adjusts the cpos and tfill counters as needed.
ieb - buffer chain object
=cut
*/
static
void
io_bchain_advance(io_ex_bchain *ieb) {
if (ieb->cp->next == NULL) {
ieb->tail = io_blink_new();
ieb->tail->prev = ieb->cp;
ieb->cp->next = ieb->tail;
ieb->tfill = 0; /* Only set this if we added a new slice */
}
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
}
/*
static
void
bufchain_dump(io_ex_bchain *ieb) {
mm_log((1, " buf_chain_dump(ieb %p)\n"));
mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
}
*/
/*
* TRUE if lengths are NOT equal
*/
/*
static
void
chainlencert( io_glue *ig ) {
int clen;
int cfl = 0;
size_t csize = 0;
size_t cpos = 0;
io_ex_bchain *ieb = ig->exdata;
io_blink *cp = ieb->head;
if (ieb->gpos > ieb->length) mm_log((1, "BBAR : ieb->gpos = %d, ieb->length = %d\n", ieb->gpos, ieb->length));
while(cp) {
clen = (cp == ieb->tail) ? ieb->tfill : cp->len;
if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
if (cp == ieb->cp) {
cfl = 1;
cpos += ieb->cpos;
}
if (!cfl) cpos += clen;
csize += clen;
cp = cp->next;
}
if (( csize != ieb->length )) mm_log((1, "BAR : csize = %d, ieb->length = %d\n", csize, ieb->length));
if (( cpos != ieb->gpos )) mm_log((1, "BAR : cpos = %d, ieb->gpos = %d\n", cpos, ieb->gpos ));
}
static
void
chaincert( io_glue *ig) {
size_t csize = 0;
io_ex_bchain *ieb = ig->exdata;
io_blink *cp = ieb->head;
mm_log((1, "Chain verification.\n"));
mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
while(cp) {
int clen = cp == ieb->tail ? ieb->tfill : cp->len;
mm_log((1, "link: %p <- %p -> %p\n", cp->prev, cp, cp->next));
if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
csize += clen;
cp = cp->next;
}
mm_log((1, "csize = %d %s ieb->length = %d\n", csize, csize == ieb->length ? "==" : "!=", ieb->length));
}
*/
/*
=item bufchain_read(ig, buf, count)
Does the reading from a source that can be seeked on
ig - io_glue object
buf - buffer to return data in
count - number of bytes to read into buffer max
=cut
*/
static
ssize_t
bufchain_read(io_glue *ig, void *buf, size_t count) {
io_ex_bchain *ieb = ig->exdata;
size_t scount = count;
char *cbuf = buf;
size_t sk;
mm_log((1, "bufchain_read(ig %p, buf %p, count %ld)\n", ig, buf, count));
IOL_DEB( printf("bufchain_read: fd = %d, ier->cpos = %ld, buf = 0x%p, count = %d\n", fd, (long) ier->cpos, buf, count) );
while( scount ) {
int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
if (clen == ieb->cpos) {
if (ieb->cp == ieb->tail) break; /* EOF */
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
}
sk = clen - ieb->cpos;
sk = sk > scount ? scount : sk;
memcpy(&cbuf[count-scount], &ieb->cp->buf[ieb->cpos], sk);
scount -= sk;
ieb->cpos += sk;
ieb->gpos += sk;
}
mm_log((1, "bufchain_read: returning %d\n", count-scount));
return count-scount;
}
/*
=item bufchain_write(ig, buf, count)
Does the writing to a 'source' that can be seeked on
ig - io_glue object
buf - buffer that contains data
count - number of bytes to write
=cut
*/
static
ssize_t
bufchain_write(io_glue *ig, const void *buf, size_t count) {
char *cbuf = (char *)buf;
io_ex_bchain *ieb = ig->exdata;
size_t ocount = count;
size_t sk;
mm_log((1, "bufchain_write: ig = %p, buf = 0x%p, count = %d\n", ig, buf, count));
IOL_DEB( printf("bufchain_write: ig = %p, ieb->cpos = %ld, buf = 0x%p, count = %d\n", ig, (long) ieb->cpos, buf, count) );
while(count) {
mm_log((2, "bufchain_write: - looping - count = %d\n", count));
if (ieb->cp->len == ieb->cpos) {
mm_log((1, "bufchain_write: cp->len == ieb->cpos = %d - advancing chain\n", (long) ieb->cpos));
io_bchain_advance(ieb);
}
sk = ieb->cp->len - ieb->cpos;
sk = sk > count ? count : sk;
memcpy(&ieb->cp->buf[ieb->cpos], &cbuf[ocount-count], sk);
if (ieb->cp == ieb->tail) {
int extend = ieb->cpos + sk - ieb->tfill;
mm_log((2, "bufchain_write: extending tail by %d\n", extend));
if (extend > 0) {
ieb->length += extend;
ieb->tfill += extend;
}
}
ieb->cpos += sk;
ieb->gpos += sk;
count -= sk;
}
return ocount;
}
/*
=item bufchain_close(ig)
Closes a source that can be seeked on. Not sure if this should be an actual close
or not. Does nothing for now. Should be fixed.
ig - data source
=cut
*/
static
void
bufchain_close(io_glue *ig) {
mm_log((1, "bufchain_close(ig %p)\n",ig));
IOL_DEB( printf("bufchain_close(ig 0x%p)\n", ig) );
/* FIXME: Commit a seek point here */
}
/* bufchain_seek(ig, offset, whence)
Implements seeking for a source that is seekable, the purpose of having this is to be able to
have an offset into a file that is different from what the underlying library thinks.
ig - data source
offset - offset into stream
whence - whence argument a la lseek
=cut
*/
static
off_t
bufchain_seek(io_glue *ig, off_t offset, int whence) {
io_ex_bchain *ieb = ig->exdata;
io_blink *ib = NULL;
int wrlen;
off_t cof = 0;
off_t scount = offset;
off_t sk;
mm_log((1, "bufchain_seek(ig %p, offset %ld, whence %d)\n", ig, offset, whence));
switch (whence) {
case SEEK_SET: /* SEEK_SET = 0, From the top */
ieb->cp = ieb->head;
ieb->cpos = 0;
ieb->gpos = 0;
while( scount ) {
int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
if (clen == ieb->cpos) {
if (ieb->cp == ieb->tail) break; /* EOF */
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
}
sk = clen - ieb->cpos;
sk = sk > scount ? scount : sk;
scount -= sk;
ieb->cpos += sk;
ieb->gpos += sk;
}
wrlen = scount;
if (wrlen > 0) {
/*
* extending file - get ieb into consistent state and then
* call write which will get it to the correct position
*/
char TB[BBSIZ];
memset(TB, 0, BBSIZ);
ieb->gpos = ieb->length;
ieb->cpos = ieb->tfill;
while(wrlen > 0) {
ssize_t rc, wl = min(wrlen, BBSIZ);
mm_log((1, "bufchain_seek: wrlen = %d, wl = %d\n", wrlen, wl));
rc = bufchain_write( ig, TB, wl );
if (rc != wl) m_fatal(0, "bufchain_seek: Unable to extend file\n");
wrlen -= rc;
}
}
break;
case SEEK_CUR:
m_fatal(123, "SEEK_CUR IS NOT IMPLEMENTED\n");
/*
case SEEK_CUR:
ib = ieb->cp;
if (cof < 0) {
cof += ib->cpos;
cpos = 0;
while(cof < 0 && ib->prev) {
ib = ib->prev;
cof += ib->len;
}
*/
case SEEK_END: /* SEEK_END = 2 */
if (cof>0) m_fatal(0, "bufchain_seek: SEEK_END + %d : Extending files via seek not supported!\n", cof);
ieb->cp = ieb->tail;
ieb->cpos = ieb->tfill;
if (cof<0) {
cof += ieb->cpos;
ieb->cpos = 0;
while(cof<0 && ib->prev) {
ib = ib->prev;
cof += ib->len;
}
if (cof<0) m_fatal(0, "bufchain_seek: Tried to seek before start of file\n");
ieb->gpos = ieb->length+offset;
ieb->cpos = cof;
}
break;
default:
m_fatal(0, "bufchain_seek: Unhandled seek request: whence = %d\n", whence );
}
mm_log((2, "bufchain_seek: returning ieb->gpos = %d\n", ieb->gpos));
return ieb->gpos;
}
/*
* Methods for setting up data source
*/
/*
=item io_obj_setp_buffer(io, p, len)
Sets an io_object for reading from a buffer source
io - io object that describes a source
p - pointer to buffer
len - length of buffer
=cut
*/
void
io_obj_setp_buffer(io_obj *io, void *p, size_t len) {
io->buffer.type = BUFFER;
io->buffer.c = (char*) p;
io->buffer.len = len;
}
/*
=item io_obj_setp_cbuf(io, p)
Sets an io_object for reading/writing from a buffer source
io - io object that describes a source
p - pointer to buffer
len - length of buffer
=cut
*/
void
io_obj_setp_bufchain(io_obj *io) {
io->type = BUFCHAIN;
}
/*
=item io_obj_setp_cb(io, p, readcb, writecb, seekcb)
Sets an io_object for reading from a source that uses callbacks
io - io object that describes a source
p - pointer to data for callbacks
readcb - read callback to read from source
writecb - write callback to write to source
seekcb - seek callback to seek on source
=cut
*/
void
io_obj_setp_cb(io_obj *io, void *p, readl readcb, writel writecb, seekl seekcb) {
io->cb.type = CBSEEK;
io->cb.p = p;
io->cb.readcb = readcb;
io->cb.writecb = writecb;
io->cb.seekcb = seekcb;
}
/*
=item io_glue_commit_types(ig)
Creates buffers and initializes structures to read with the chosen interface.
ig - io_glue object
=cut
*/
void
io_glue_commit_types(io_glue *ig) {
io_type inn = ig->source.type;
mm_log((1, "io_glue_commit_types(ig 0x%p)\n", ig));
mm_log((1, "io_glue_commit_types: source type %d (%s)\n", inn, io_type_names[inn]));
switch (inn) {
case BUFCHAIN:
{
io_ex_bchain *ieb = mymalloc(sizeof(io_ex_bchain));
ieb->offset = 0;
ieb->length = 0;
ieb->cpos = 0;
ieb->gpos = 0;
ieb->tfill = 0;
ieb->head = io_blink_new();
ieb->cp = ieb->head;
ieb->tail = ieb->head;
ig->exdata = ieb;
ig->readcb = bufchain_read;
ig->writecb = bufchain_write;
ig->seekcb = bufchain_seek;
ig->closecb = bufchain_close;
}
break;
case CBSEEK:
default:
{
io_ex_rseek *ier = mymalloc(sizeof(io_ex_rseek));
ier->offset = 0;
ier->cpos = 0;
ig->exdata = ier;
ig->readcb = realseek_read;
ig->writecb = realseek_write;
ig->seekcb = realseek_seek;
ig->closecb = realseek_close;
}
}
}
/*
=item io_glue_gettypes(ig, reqmeth)
Returns a set of compatible interfaces to read data with.
ig - io_glue object
reqmeth - request mask
The request mask is a bit mask (of something that hasn't been implemented yet)
of interfaces that it would like to read data from the source which the ig
describes.
=cut
*/
void
io_glue_gettypes(io_glue *ig, int reqmeth) {
ig = NULL;
reqmeth = 0;
/* FIXME: Implement this function! */
/* if (ig->source.type =
if (reqmeth & IO_BUFF) */
}
/*
=item io_new_bufchain()
returns a new io_glue object that has the 'empty' source and but can
be written to and read from later (like a pseudo file).
=cut
*/
io_glue *
io_new_bufchain() {
io_glue *ig = mymalloc(sizeof(io_glue));
io_obj_setp_bufchain(&ig->source);
return ig;
}
/*
=item io_new_fd(fd)
returns a new io_glue object that has the source defined as reading
from specified filedescriptor. Note that the the interface to recieving
data from the io_glue callbacks hasn't been done yet.
fd - file descriptor to read/write from
=cut
*/
io_glue *
io_new_fd(int fd) {
io_glue *ig = mymalloc(sizeof(io_glue));
#ifdef _MSC_VER
io_obj_setp_cb(&ig->source, (void*)fd, _read, _write, _lseek);
#else
io_obj_setp_cb(&ig->source, (void*)fd, read, write, lseek);
#endif
return ig;
}
/*
=item io_slurp(ig)
Takes the source that the io_glue is bound to and allocates space
for a return buffer and returns the entire content in a single buffer.
Note: This only works for io_glue objects that contain a bufchain. It
is usefull for saving to scalars and such.
ig - io_glue object
c - pointer to a pointer to where data should be copied to
=cut
*/
size_t
io_slurp(io_glue *ig, unsigned char **c) {
ssize_t rc;
off_t orgoff;
io_ex_bchain *ieb;
unsigned char *cc;
io_type inn = ig->source.type;
if ( inn != BUFCHAIN ) {
m_fatal(0, "io_slurp: called on a source that is not from a bufchain\n");
}
ieb = ig->exdata;
cc = *c = mymalloc( ieb->length );
orgoff = ieb->gpos;
bufchain_seek(ig, 0, SEEK_SET);
rc = bufchain_read(ig, cc, ieb->length);
if (rc != ieb->length)
m_fatal(1, "io_slurp: bufchain_read returned an incomplete read: rc = %d, request was %d\n", rc, ieb->length);
return rc;
}
/*
=item io_glue_DESTROY(ig)
A destructor method for io_glue objects. Should clean up all related buffers.
Might leave us with a dangling pointer issue on some buffers.
ig - io_glue object to destroy.
=cut
*/
void
io_glue_DESTROY(io_glue *ig) {
free(ig);
/* FIXME: Handle extradata and such */
}