forked from parrot/parrot
-
Notifications
You must be signed in to change notification settings - Fork 0
/
buffer.c
782 lines (606 loc) · 22 KB
/
buffer.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
/*
Copyright (C) 2001-2009, Parrot Foundation.
$Id$
=head1 NAME
src/io/buffer.c - I/O buffering
=head1 DESCRIPTION
This file implements a collection of utility functions for I/O buffering.
=head2 Functions
=over 4
=cut
*/
#include "parrot/parrot.h"
#include "io_private.h"
/* HEADERIZER HFILE: include/parrot/io.h */
/* HEADERIZER BEGIN: static */
/* Don't modify between HEADERIZER BEGIN / HEADERIZER END. Your changes will be lost. */
static INTVAL io_is_end_of_line(ARGIN(const char *c))
__attribute__nonnull__(1);
#define ASSERT_ARGS_io_is_end_of_line __attribute__unused__ int _ASSERT_ARGS_CHECK = \
PARROT_ASSERT_ARG(c)
/* Don't modify between HEADERIZER BEGIN / HEADERIZER END. Your changes will be lost. */
/* HEADERIZER END: static */
/*
=item C<INTVAL Parrot_io_init_buffer(PARROT_INTERP)>
Initialize buffering on STDOUT and STDIN.
=cut
*/
INTVAL
Parrot_io_init_buffer(PARROT_INTERP)
{
ASSERT_ARGS(Parrot_io_init_buffer)
if (Parrot_io_STDOUT(interp))
Parrot_io_setlinebuf(interp, Parrot_io_STDOUT(interp));
if (Parrot_io_STDIN(interp))
Parrot_io_setbuf(interp, Parrot_io_STDIN(interp), PIO_UNBOUND);
return 0;
}
/*
=item C<void Parrot_io_setbuf(PARROT_INTERP, PMC *filehandle, size_t bufsize)>
Set the buffering mode for the filehandle.
=cut
*/
void
Parrot_io_setbuf(PARROT_INTERP, ARGMOD(PMC *filehandle), size_t bufsize)
{
ASSERT_ARGS(Parrot_io_setbuf)
INTVAL filehandle_flags = Parrot_io_get_flags(interp, filehandle);
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
unsigned char *buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
unsigned char *buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
size_t buffer_size;
/* If there is already a buffer, make sure we flush before modifying it. */
if (buffer_start)
Parrot_io_flush_buffer(interp, filehandle);
/* Choose an appropriate buffer size for caller */
switch (bufsize) {
case 0:
Parrot_io_set_buffer_size(interp, filehandle, 0);
break;
case PIO_UNBOUND:
Parrot_io_set_buffer_size(interp, filehandle,
PIO_GETBLKSIZE(Parrot_io_get_os_handle(interp, filehandle)));
break;
default:
Parrot_io_set_buffer_size(interp, filehandle,
(bufsize >= PIO_GRAIN ? bufsize : PIO_GRAIN));
break;
}
buffer_size = Parrot_io_get_buffer_size(interp, filehandle);
if (buffer_start && (buffer_flags & PIO_BF_MALLOC)) {
mem_sys_free(buffer_start);
Parrot_io_set_buffer_start(interp, filehandle, NULL);
Parrot_io_set_buffer_next(interp, filehandle, NULL);
buffer_start = buffer_next = NULL;
}
if (buffer_size > 0) {
buffer_start = buffer_next = (unsigned char *)mem_sys_allocate(buffer_size);
Parrot_io_set_buffer_start(interp, filehandle, buffer_start);
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
buffer_flags |= PIO_BF_MALLOC;
}
else
buffer_flags &= ~PIO_BF_MALLOC;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
if (buffer_size != 0) {
filehandle_flags &= ~PIO_F_LINEBUF;
filehandle_flags |= PIO_F_BLKBUF;
}
else
filehandle_flags &= ~(PIO_F_BLKBUF | PIO_F_LINEBUF);
Parrot_io_set_flags(interp, filehandle, filehandle_flags);
}
/*
=item C<INTVAL Parrot_io_setlinebuf(PARROT_INTERP, PMC *filehandle)>
Set the file handle to line buffering mode.
=cut
*/
INTVAL
Parrot_io_setlinebuf(PARROT_INTERP, ARGMOD(PMC *filehandle))
{
ASSERT_ARGS(Parrot_io_setlinebuf)
INTVAL filehandle_flags = Parrot_io_get_flags(interp, filehandle);
/* already linebuffering */
if (filehandle_flags & PIO_F_LINEBUF)
return 0;
/* Reuse setbuf call */
Parrot_io_setbuf(interp, filehandle, PIO_LINEBUFSIZE);
/* Then switch to linebuf */
filehandle_flags &= ~PIO_F_BLKBUF;
filehandle_flags |= PIO_F_LINEBUF;
Parrot_io_set_flags(interp, filehandle, filehandle_flags);
/* Parrot_io_set_record_separator(interp, filehandle, '\n'); */
return 0;
}
/*
=item C<INTVAL Parrot_io_flush_buffer(PARROT_INTERP, PMC *filehandle)>
Flush the I/O buffer for a given filehandle object.
=cut
*/
INTVAL
Parrot_io_flush_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle))
{
ASSERT_ARGS(Parrot_io_flush_buffer)
long wrote;
size_t to_write;
STRING fake;
unsigned char *buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
unsigned char *buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
/*
* Either buffering is null, disabled, or empty.
*/
if (!buffer_start
|| (Parrot_io_get_flags(interp, filehandle) & (PIO_F_BLKBUF | PIO_F_LINEBUF)) == 0
|| (buffer_flags & (PIO_BF_WRITEBUF | PIO_BF_READBUF)) == 0)
return 0;
/*
* Write flush
*/
if (buffer_flags & PIO_BF_WRITEBUF) {
to_write = buffer_next - buffer_start;
/* Flush to next layer */
fake.strstart = (char *)buffer_start;
fake.bufused = to_write;
wrote = PIO_WRITE(interp, filehandle, &fake);
if (wrote == (long)to_write) {
Parrot_io_set_buffer_next(interp, filehandle, buffer_start);
/* Release buffer */
Parrot_io_set_buffer_flags(interp, filehandle, (buffer_flags & ~PIO_BF_WRITEBUF));
return 0;
}
else {
Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_PIO_ERROR,
"Attempt to flush invalid write buffer");
}
}
/*
* Read flush
*/
else if (buffer_flags & PIO_BF_READBUF) {
Parrot_io_set_buffer_next(interp, filehandle, buffer_start);
/* Release buffer */
Parrot_io_set_buffer_flags(interp, filehandle, (buffer_flags & ~PIO_BF_READBUF));
}
return -1;
}
/*
=item C<size_t Parrot_io_fill_readbuf(PARROT_INTERP, PMC *filehandle)>
The buffer layer's C<Fill> function.
=cut
*/
size_t
Parrot_io_fill_readbuf(PARROT_INTERP, ARGMOD(PMC *filehandle))
{
ASSERT_ARGS(Parrot_io_fill_readbuf)
size_t got;
STRING fake;
STRING *s = &fake;
PIOOFF_T pos = Parrot_io_get_file_position(interp, filehandle);
fake.strstart = (char *)Parrot_io_get_buffer_start(interp, filehandle);
fake.bufused = Parrot_io_get_buffer_size(interp, filehandle);
got = PIO_READ(interp, filehandle, &s);
/* buffer-filling does not change fileposition */
Parrot_io_set_file_position(interp, filehandle, pos);
/* nothing to get */
if (got == 0)
return 0;
Parrot_io_set_buffer_end(interp, filehandle,
(got + Parrot_io_get_buffer_start(interp, filehandle)));
Parrot_io_set_buffer_next(interp, filehandle,
Parrot_io_get_buffer_start(interp, filehandle));
Parrot_io_set_buffer_flags(interp, filehandle,
(Parrot_io_get_buffer_flags(interp, filehandle) | PIO_BF_READBUF));
return got;
}
/*
=item C<size_t Parrot_io_read_buffer(PARROT_INTERP, PMC *filehandle, STRING
**buf)>
The buffer layer's C<Read> function.
=cut
*/
size_t
Parrot_io_read_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle),
ARGIN(STRING **buf))
{
ASSERT_ARGS(Parrot_io_read_buffer)
unsigned char *out_buf, *buffer_start, *buffer_next, *buffer_end;
STRING *s;
size_t len;
size_t current = 0;
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
/* write buffer flush */
if (buffer_flags & PIO_BF_WRITEBUF) {
Parrot_io_flush_buffer(interp, filehandle);
buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
}
buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
buffer_end = Parrot_io_get_buffer_end(interp, filehandle);
/* line buffered read */
if (Parrot_io_get_flags(interp, filehandle) & PIO_F_LINEBUF)
return Parrot_io_readline_buffer(interp, filehandle, buf);
if (*buf == NULL) {
*buf = Parrot_gc_new_string_header(interp, 0);
(*buf)->bufused = len = 2048;
}
s = *buf;
len = s->bufused;
if (!s->strstart)
Parrot_gc_allocate_string_storage(interp, s, len);
out_buf = (unsigned char *)s->strstart;
/* read Data from buffer */
if (buffer_flags & PIO_BF_READBUF) {
const size_t avail = buffer_end - buffer_next;
current = avail < len ? avail : len;
memcpy(out_buf, buffer_next, current);
buffer_next += current;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
Parrot_io_set_file_position(interp, filehandle, (current +
Parrot_io_get_file_position(interp, filehandle)));
/* buffer completed */
if (current == avail) {
buffer_flags &= ~PIO_BF_READBUF;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
/* Reset next and end */
Parrot_io_set_buffer_end(interp, filehandle, NULL);
Parrot_io_set_buffer_next(interp, filehandle, buffer_start);
}
/* requested length satisfied */
if (len == current) {
s->strlen = s->bufused = len;
return current;
}
else {
/* more data needed */
out_buf += current;
len -= current;
}
}
/* (re)fill the readbuffer */
if (!(buffer_flags & PIO_BF_READBUF)) {
size_t got;
if (len >= Parrot_io_get_buffer_size(interp, filehandle)) {
STRING fake;
STRING *sf = &fake;
fake.strstart = (char *)out_buf;
fake.bufused = len;
got = PIO_READ(interp, filehandle, &sf);
s->strlen = s->bufused = current + got;
Parrot_io_set_file_position(interp, filehandle,
(got + Parrot_io_get_file_position(interp, filehandle)));
return current + got;
}
got = Parrot_io_fill_readbuf(interp, filehandle);
len = (len < got)
? len
: (got > 0) ? got : 0;
}
/* read from the read_buffer */
buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
buffer_end = Parrot_io_get_buffer_end(interp, filehandle);
memcpy(out_buf, buffer_next, len);
s->strlen = s->bufused = current + len;
buffer_next += len;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
Parrot_io_set_file_position(interp, filehandle,
(len + Parrot_io_get_file_position(interp, filehandle)));
/* is the buffer is completely empty ? */
if (buffer_next == buffer_end) {
Parrot_io_set_buffer_flags(interp, filehandle,
(buffer_flags & ~PIO_BF_READBUF));
/* Reset next and end */
Parrot_io_set_buffer_end(interp, filehandle, NULL);
Parrot_io_set_buffer_next(interp, filehandle, buffer_start);
}
return current + len;
}
/*
=item C<size_t Parrot_io_peek_buffer(PARROT_INTERP, PMC *filehandle, STRING
**buf)>
Retrieve the next character in the buffer without modifying the stream.
=cut
*/
size_t
Parrot_io_peek_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle),
ARGOUT(STRING **buf))
{
ASSERT_ARGS(Parrot_io_peek_buffer)
unsigned char *buffer_next;
STRING * const s = Parrot_io_make_string(interp, buf, 1);
UINTVAL len = 1;
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
/* write buffer flush */
if (buffer_flags & PIO_BF_WRITEBUF) {
Parrot_io_flush_buffer(interp, filehandle);
buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
}
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
/* (re)fill the buffer */
if (! (buffer_flags & PIO_BF_READBUF)) {
size_t got;
/* promote to buffered if unbuffered */
if (Parrot_io_get_buffer_size(interp, filehandle) == 0) {
Parrot_io_setbuf(interp, filehandle, 1);
return Parrot_io_peek_buffer(interp, filehandle, buf);
}
/* Parrot_io_fill_readbuf() can return -1, but len should be positive */
got = Parrot_io_fill_readbuf(interp, filehandle);
/* avoid signedness problems between size_t got and UINTVAL len */
if (len > got) {
if (got > 0)
len = (UINTVAL)got;
else
len = 0;
}
}
/* if we got any data, then copy out the next byte */
memmove(s->strstart, buffer_next, len);
s->bufused = s->strlen = len;
return len;
}
/*
=item C<size_t Parrot_io_readline_buffer(PARROT_INTERP, PMC *filehandle, STRING
**buf)>
This is called from C<Parrot_io_read_buffer()> to do line buffered reading if
that is what is required.
=cut
*/
size_t
Parrot_io_readline_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle), ARGOUT(STRING **buf))
{
ASSERT_ARGS(Parrot_io_readline_buffer)
size_t l;
unsigned char *out_buf;
unsigned char *buf_start;
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
unsigned char *buffer_next;
unsigned char *buffer_end;
size_t len;
STRING *s;
if (*buf == NULL) {
*buf = Parrot_gc_new_string_header(interp, 0);
}
s = *buf;
s->strlen = 0;
/* fill empty buffer */
if (!(buffer_flags & PIO_BF_READBUF)) {
if (Parrot_io_fill_readbuf(interp, filehandle) == 0)
return 0;
}
/* Retrieve filled buffer */
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
buffer_end = Parrot_io_get_buffer_end(interp, filehandle);
buf_start = buffer_next;
for (l = 0; buffer_next < buffer_end;) {
l++;
if (io_is_end_of_line((char *)buffer_next)) {
Parrot_io_set_buffer_next(interp, filehandle, ++buffer_next);
break;
}
Parrot_io_set_buffer_next(interp, filehandle, ++buffer_next);
/* if there is a buffer, readline is called by the read opcode
* - return just that part
*/
if (s->bufused && l == s->bufused)
break;
/* buffer completed; copy out and refill */
if (buffer_next == buffer_end) {
len = buffer_end - buf_start;
if (s->bufused < l) {
if (s->strstart) {
Parrot_gc_reallocate_string_storage(interp, s, l);
}
else {
Parrot_gc_allocate_string_storage(interp, s, l);
}
}
out_buf = (unsigned char*)s->strstart + s->strlen;
memcpy(out_buf, buf_start, len);
s->strlen = s->bufused = l;
if (Parrot_io_fill_readbuf(interp, filehandle) == 0)
return l;
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
buffer_end = Parrot_io_get_buffer_end(interp, filehandle);
buf_start = Parrot_io_get_buffer_start(interp, filehandle);
}
}
if (s->bufused < l) {
if (s->strstart) {
Parrot_gc_reallocate_string_storage(interp, s, l);
}
else {
Parrot_gc_allocate_string_storage(interp, s, l);
}
}
out_buf = (unsigned char*)s->strstart + s->strlen;
len = buffer_next - buf_start;
memcpy(out_buf, buf_start, len);
s->strlen = s->bufused = l;
/* check if buffer is finished */
if (buffer_next == buffer_end) {
Parrot_io_set_buffer_flags(interp, filehandle,
(Parrot_io_get_buffer_flags(interp, filehandle) & ~PIO_BF_READBUF));
Parrot_io_set_buffer_next(interp, filehandle,
Parrot_io_get_buffer_start(interp, filehandle));
Parrot_io_set_buffer_end(interp, filehandle, NULL);
}
return l;
}
/*
=item C<size_t Parrot_io_write_buffer(PARROT_INTERP, PMC *filehandle, STRING
*s)>
The buffer layer's C<Write> function.
=cut
*/
size_t
Parrot_io_write_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle), ARGIN(STRING *s))
{
ASSERT_ARGS(Parrot_io_write_buffer)
void * const buffer = s->strstart;
unsigned char * const buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
unsigned char * buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
const size_t buffer_size = Parrot_io_get_buffer_size(interp, filehandle);
INTVAL buffer_flags = Parrot_io_get_buffer_flags(interp, filehandle);
const size_t len = s->bufused;
int need_flush;
size_t avail;
if (len <= 0)
return 0;
if (buffer_flags & PIO_BF_WRITEBUF)
avail = buffer_size - (buffer_next - buffer_start);
else if (buffer_flags & PIO_BF_READBUF) {
buffer_flags &= ~PIO_BF_READBUF;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
buffer_next = buffer_start;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
avail = buffer_size;
}
else
avail = buffer_size;
/* If we are line buffered, check for newlines.
* If any, we should flush */
need_flush = 0;
if (Parrot_io_get_flags(interp, filehandle) & PIO_F_LINEBUF) {
/* scan from end, it's likely that EOL is at end of string */
const char *p = (char*)buffer + len - 1;
size_t i;
for (i = 0; i < len; ++i, --p) {
if (io_is_end_of_line(p)) {
need_flush = 1;
break;
}
}
}
/*
* Large writes (multiples of blocksize) should write
* through generally for best performance, else you are
* just doing extra memcpys.
* FIXME: This is badly optimized, will fixup later.
*/
if (need_flush || len >= buffer_size) {
long wrote;
/* Write through, skip buffer. */
Parrot_io_flush_buffer(interp, filehandle);
wrote = PIO_WRITE(interp, filehandle, s);
if (wrote == (long)len) {
Parrot_io_set_file_position(interp, filehandle, (wrote +
Parrot_io_get_file_position(interp, filehandle)));
return wrote;
}
/* Write error */
else
return (size_t)-1;
}
else if (avail > len) {
buffer_flags |= PIO_BF_WRITEBUF;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
memmove(buffer_next, buffer, len);
buffer_next += len;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
Parrot_io_set_file_position(interp, filehandle, (len +
Parrot_io_get_file_position(interp, filehandle)));
return len;
}
else {
const unsigned int diff = (int)(len - avail);
buffer_flags |= PIO_BF_WRITEBUF;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
/* Fill remainder, flush, then try to buffer more */
memmove(buffer_next, buffer, avail);
buffer_next += avail;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
Parrot_io_set_file_position(interp, filehandle, (avail +
Parrot_io_get_file_position(interp, filehandle)));
Parrot_io_flush_buffer(interp, filehandle);
buffer_flags |= PIO_BF_WRITEBUF;
Parrot_io_set_buffer_flags(interp, filehandle, buffer_flags);
buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
memmove(buffer_start, ((const char *)buffer + avail), diff);
buffer_next += diff;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
Parrot_io_set_file_position(interp, filehandle, (diff +
Parrot_io_get_file_position(interp, filehandle)));
return len;
}
}
/*
=item C<PIOOFF_T Parrot_io_seek_buffer(PARROT_INTERP, PMC *filehandle, PIOOFF_T
offset, INTVAL whence)>
The buffer layer's C<Seek> function.
=cut
*/
PIOOFF_T
Parrot_io_seek_buffer(PARROT_INTERP, ARGMOD(PMC *filehandle),
PIOOFF_T offset, INTVAL whence)
{
ASSERT_ARGS(Parrot_io_seek_buffer)
PIOOFF_T newpos;
PIOOFF_T file_pos = Parrot_io_get_file_position(interp, filehandle);
unsigned char *buffer_start = Parrot_io_get_buffer_start(interp, filehandle);
unsigned char *buffer_next = Parrot_io_get_buffer_next(interp, filehandle);
unsigned char *buffer_end = Parrot_io_get_buffer_end(interp, filehandle);
switch (whence) {
case SEEK_SET:
newpos = offset;
break;
case SEEK_CUR:
newpos = file_pos + offset;
break;
case SEEK_END:
newpos = PIO_SEEK(interp, filehandle, offset,
whence);
if (newpos == -1)
return -1;
break;
default:
/* XXX: somehow report the illegal whence value */
return -1;
}
if ((newpos < file_pos - (buffer_next - buffer_start))
|| (newpos >= file_pos + (buffer_end - buffer_next))) {
Parrot_io_flush_buffer(interp, filehandle);
newpos = PIO_SEEK(interp, filehandle, newpos, SEEK_SET);
}
else {
buffer_next += newpos - file_pos;
Parrot_io_set_buffer_next(interp, filehandle, buffer_next);
}
Parrot_io_set_file_position(interp, filehandle, newpos);
return newpos;
}
/*
=item C<static INTVAL io_is_end_of_line(const char *c)>
Determine if the current character is the end of the line.
Note that this is not a portable solution, but it is what the old architecture
was doing, once you boil away the useless macros. This will need to change to
support the Strings PDD, but is left as-is for now, for a smooth transition to
the new architecture.
=cut
*/
static INTVAL
io_is_end_of_line(ARGIN(const char *c))
{
ASSERT_ARGS(io_is_end_of_line)
if ((*(c)) == '\n')
return 1;
return 0;
}
/*
=back
=head1 SEE ALSO
F<src/io/api.c>,
F<src/io/unix.c>,
F<src/io/win32.c>,
F<src/io/portable.c>,
F<src/io.c>,
F<src/io/io_private.h>.
=cut
*/
/*
* Local variables:
* c-file-style: "parrot"
* End:
* vim: expandtab shiftwidth=4:
*/