- reword and provide an example for non-proportionally scaling an
[imager.git] / iolayer.c
CommitLineData
7ac6a2e9 1#include "imio.h"
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2#include "iolayer.h"
3#include "log.h"
4#include <stdlib.h>
5#include <stdio.h>
6#ifdef _MSC_VER
7#include <io.h>
8#endif
35891892 9#include <string.h>
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10
11#define IOL_DEB(x)
12
13
14char *io_type_names[] = { "FDSEEK", "FDNOSEEK", "BUFFER", "CBSEEK", "CBNOSEEK", "BUFCHAIN" };
15
16
17/*
18=head1 NAME
19
20iolayer.c - encapsulates different source of data into a single framework.
21
22=head1 SYNOPSIS
23
24 io_glue *ig = io_new_fd( fileno(stdin) );
25 method = io_reqmeth( IOL_NOSEEK | IOL_MMAP ); // not implemented yet
26 io_glue_commit_types(ig); // always assume IOL_SEEK for now
27 switch (method) {
28 case IOL_NOSEEK:
29 code that uses ig->readcb()
30 to read data goes here.
31 break;
32 case IOL_MMAP:
33 code that uses ig->readcb()
34 to read data goes here.
35 break;
36 }
37
38 io_glue_DESTROY(ig);
39 // and much more
40
41=head1 DESCRIPTION
42
43iolayer.c implements the basic functions to create and destroy io_glue
44objects for Imager. The typical usage pattern for data sources is:
45
46 1. Create the source (io_new_fd)
47 2. Define how you want to get data from it (io_reqmeth)
48 3. read from it using the interface requested (ig->readdb, ig->mmapcb)
49 4. Close the source, which
50 shouldn't really close the underlying source. (io_glue DESTROY)
51
52=head1 FUNCTION REFERENCE
53
54Some of these functions are internal.
55
b8c2033e 56=over
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57
58=cut
59*/
60
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61static ssize_t fd_read(io_glue *ig, void *buf, size_t count);
62static ssize_t fd_write(io_glue *ig, const void *buf, size_t count);
63static off_t fd_seek(io_glue *ig, off_t offset, int whence);
64static void fd_close(io_glue *ig);
65static ssize_t fd_size(io_glue *ig);
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66
67/*
68 * Callbacks for sources that cannot seek
69 */
70
71/* fakeseek_read: read method for when emulating a seekable source
72static
73ssize_t
74fakeseek_read(io_glue *ig, void *buf, size_t count) {
75 io_ex_fseek *exdata = ig->exdata;
76 return 0;
77}
78*/
79
80
81
82/*
83 * Callbacks for sources that can seek
84 */
85
86/*
87=item realseek_read(ig, buf, count)
88
89Does the reading from a source that can be seeked on
90
91 ig - io_glue object
92 buf - buffer to return data in
93 count - number of bytes to read into buffer max
94
95=cut
96*/
97
98static
99ssize_t
100realseek_read(io_glue *ig, void *buf, size_t count) {
101 io_ex_rseek *ier = ig->exdata;
10461f9a 102 void *p = ig->source.cb.p;
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103 ssize_t rc = 0;
104 size_t bc = 0;
105 char *cbuf = buf;
106
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107 IOL_DEB( printf("realseek_read: fd = %d, ier->cpos = %ld, buf = %p, "
108 "count = %d\n", fd, (long) ier->cpos, buf, count) );
109 /* Is this a good idea? Would it be better to handle differently?
110 skip handling? */
111 while( count!=bc && (rc = ig->source.cb.readcb(p,cbuf+bc,count-bc))>0 ) {
112 bc+=rc;
113 }
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114
115 ier->cpos += bc;
116 IOL_DEB( printf("realseek_read: rc = %d, bc = %d\n", rc, bc) );
117 return bc;
118}
119
120
121/*
122=item realseek_write(ig, buf, count)
123
124Does the writing to a 'source' that can be seeked on
125
126 ig - io_glue object
127 buf - buffer that contains data
128 count - number of bytes to write
129
130=cut
131*/
132
133static
134ssize_t
135realseek_write(io_glue *ig, const void *buf, size_t count) {
136 io_ex_rseek *ier = ig->exdata;
10461f9a 137 void *p = ig->source.cb.p;
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138 ssize_t rc = 0;
139 size_t bc = 0;
140 char *cbuf = (char*)buf;
141
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142 IOL_DEB( printf("realseek_write: ig = %p, ier->cpos = %ld, buf = %p, "
143 "count = %d\n", ig, (long) ier->cpos, buf, count) );
02d1d628 144
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145 /* Is this a good idea? Would it be better to handle differently?
146 skip handling? */
147 while( count!=bc && (rc = ig->source.cb.writecb(p,cbuf+bc,count-bc))>0 ) {
148 bc+=rc;
149 }
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150
151 ier->cpos += bc;
152 IOL_DEB( printf("realseek_write: rc = %d, bc = %d\n", rc, bc) );
153 return bc;
154}
155
156
157/*
158=item realseek_close(ig)
159
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160Closes a source that can be seeked on. Not sure if this should be an
161actual close or not. Does nothing for now. Should be fixed.
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162
163 ig - data source
164
10461f9a 165=cut */
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166
167static
168void
169realseek_close(io_glue *ig) {
170 mm_log((1, "realseek_close(ig %p)\n", ig));
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171 if (ig->source.cb.closecb)
172 ig->source.cb.closecb(ig->source.cb.p);
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173}
174
175
176/* realseek_seek(ig, offset, whence)
177
178Implements seeking for a source that is seekable, the purpose of having this is to be able to
179have an offset into a file that is different from what the underlying library thinks.
180
181 ig - data source
182 offset - offset into stream
183 whence - whence argument a la lseek
184
185=cut
186*/
187
188static
189off_t
190realseek_seek(io_glue *ig, off_t offset, int whence) {
191 /* io_ex_rseek *ier = ig->exdata; Needed later */
10461f9a 192 void *p = ig->source.cb.p;
02d1d628 193 int rc;
930c67c8 194 IOL_DEB( printf("realseek_seek(ig %p, offset %ld, whence %d)\n", ig, (long) offset, whence) );
10461f9a 195 rc = ig->source.cb.seekcb(p, offset, whence);
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196
197 IOL_DEB( printf("realseek_seek: rc %ld\n", (long) rc) );
198 return rc;
199 /* FIXME: How about implementing this offset handling stuff? */
200}
201
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202/*
203 * Callbacks for sources that are a fixed size buffer
204 */
205
206/*
207=item buffer_read(ig, buf, count)
208
209Does the reading from a buffer source
210
211 ig - io_glue object
212 buf - buffer to return data in
213 count - number of bytes to read into buffer max
214
215=cut
216*/
217
218static
219ssize_t
220buffer_read(io_glue *ig, void *buf, size_t count) {
221 io_ex_buffer *ieb = ig->exdata;
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222
223 IOL_DEB( printf("buffer_read: fd = %d, ier->cpos = %ld, buf = %p, count = %d\n", fd, (long) ier->cpos, buf, count) );
224
225 if ( ieb->cpos+count > ig->source.buffer.len ) {
226 mm_log((1,"buffer_read: short read: cpos=%d, len=%d, count=%d\n", ieb->cpos, ig->source.buffer.len));
227 count = ig->source.buffer.len - ieb->cpos;
228 }
229
230 memcpy(buf, ig->source.buffer.data+ieb->cpos, count);
231 ieb->cpos += count;
232 IOL_DEB( printf("buffer_read: rc = %d, count = %d\n", rc, count) );
233 return count;
234}
235
236
237/*
238=item buffer_write(ig, buf, count)
239
240Does nothing, returns -1
241
242 ig - io_glue object
243 buf - buffer that contains data
244 count - number of bytes to write
245
246=cut
247*/
248
249static
250ssize_t
251buffer_write(io_glue *ig, const void *buf, size_t count) {
252 mm_log((1, "buffer_write called, this method should never be called.\n"));
253 return -1;
254}
255
256
257/*
258=item buffer_close(ig)
259
260Closes a source that can be seeked on. Not sure if this should be an actual close
261or not. Does nothing for now. Should be fixed.
262
263 ig - data source
264
265=cut
266*/
267
268static
269void
270buffer_close(io_glue *ig) {
271 mm_log((1, "buffer_close(ig %p)\n", ig));
272 /* FIXME: Do stuff here */
273}
274
275
276/* buffer_seek(ig, offset, whence)
277
278Implements seeking for a buffer source.
279
280 ig - data source
281 offset - offset into stream
282 whence - whence argument a la lseek
283
284=cut
285*/
286
287static
288off_t
289buffer_seek(io_glue *ig, off_t offset, int whence) {
290 io_ex_buffer *ieb = ig->exdata;
291 off_t reqpos = offset
292 + (whence == SEEK_CUR)*ieb->cpos
293 + (whence == SEEK_END)*ig->source.buffer.len;
294
295 if (reqpos > ig->source.buffer.len) {
296 mm_log((1, "seeking out of readable range\n"));
297 return (off_t)-1;
298 }
299
300 ieb->cpos = reqpos;
301 IOL_DEB( printf("buffer_seek(ig %p, offset %ld, whence %d)\n", ig, (long) offset, whence) );
302
303 return reqpos;
304 /* FIXME: How about implementing this offset handling stuff? */
305}
306
307
308
309
310
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311/*
312 * Callbacks for sources that are a chain of variable sized buffers
313 */
314
315
316
317/* Helper functions for buffer chains */
318
319static
320io_blink*
faa9b3e7 321io_blink_new(void) {
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322 io_blink *ib;
323
324 mm_log((1, "io_blink_new()\n"));
325
326 ib = mymalloc(sizeof(io_blink));
327
328 ib->next = NULL;
329 ib->prev = NULL;
330 ib->len = BBSIZ;
331
332 memset(&ib->buf, 0, ib->len);
333 return ib;
334}
335
336
337
338/*
339=item io_bchain_advance(ieb)
340
341Advances the buffer chain to the next link - extending if
342necessary. Also adjusts the cpos and tfill counters as needed.
343
344 ieb - buffer chain object
345
346=cut
347*/
348
349static
350void
351io_bchain_advance(io_ex_bchain *ieb) {
352 if (ieb->cp->next == NULL) {
353 ieb->tail = io_blink_new();
354 ieb->tail->prev = ieb->cp;
355 ieb->cp->next = ieb->tail;
356
357 ieb->tfill = 0; /* Only set this if we added a new slice */
358 }
359 ieb->cp = ieb->cp->next;
360 ieb->cpos = 0;
361}
362
363
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364
365/*
366=item io_bchain_destroy()
367
368frees all resources used by a buffer chain.
369
370=cut
371*/
372
373void
374io_destroy_bufchain(io_ex_bchain *ieb) {
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375 io_blink *cp;
376 mm_log((1, "io_destroy_bufchain(ieb %p)\n", ieb));
377 cp = ieb->head;
378
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379 while(cp) {
380 io_blink *t = cp->next;
4dfa5522 381 myfree(cp);
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382 cp = t;
383 }
384}
385
386
387
388
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389/*
390
391static
392void
393bufchain_dump(io_ex_bchain *ieb) {
394 mm_log((1, " buf_chain_dump(ieb %p)\n"));
395 mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
396 mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
397 mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
398 mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
399 mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
400 mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
401 mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
402 mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
403}
404*/
405
406/*
407 * TRUE if lengths are NOT equal
408 */
409
410/*
411static
412void
413chainlencert( io_glue *ig ) {
414 int clen;
415 int cfl = 0;
416 size_t csize = 0;
417 size_t cpos = 0;
418 io_ex_bchain *ieb = ig->exdata;
419 io_blink *cp = ieb->head;
420
421
422 if (ieb->gpos > ieb->length) mm_log((1, "BBAR : ieb->gpos = %d, ieb->length = %d\n", ieb->gpos, ieb->length));
423
424 while(cp) {
425 clen = (cp == ieb->tail) ? ieb->tfill : cp->len;
426 if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
427 if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
428
429 if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
430 if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
431
432 if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
433 if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
434
435 if (cp == ieb->cp) {
436 cfl = 1;
437 cpos += ieb->cpos;
438 }
439
440 if (!cfl) cpos += clen;
441
442 csize += clen;
443 cp = cp->next;
444 }
445 if (( csize != ieb->length )) mm_log((1, "BAR : csize = %d, ieb->length = %d\n", csize, ieb->length));
446 if (( cpos != ieb->gpos )) mm_log((1, "BAR : cpos = %d, ieb->gpos = %d\n", cpos, ieb->gpos ));
447}
448
449
450static
451void
452chaincert( io_glue *ig) {
453 size_t csize = 0;
454 io_ex_bchain *ieb = ig->exdata;
455 io_blink *cp = ieb->head;
456
457 mm_log((1, "Chain verification.\n"));
458
459 mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
460 mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
461 mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
462 mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
463 mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
464 mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
465 mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
466 mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
467
468 while(cp) {
469 int clen = cp == ieb->tail ? ieb->tfill : cp->len;
470 mm_log((1, "link: %p <- %p -> %p\n", cp->prev, cp, cp->next));
471 if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
472 if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
473
474 if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
475 if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
476
477 if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
478 if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
479
480 csize += clen;
481 cp = cp->next;
482 }
483
484 mm_log((1, "csize = %d %s ieb->length = %d\n", csize, csize == ieb->length ? "==" : "!=", ieb->length));
485}
486*/
487
488
489
490
491
492
493
494
495
496
497
498/*
499=item bufchain_read(ig, buf, count)
500
501Does the reading from a source that can be seeked on
502
503 ig - io_glue object
504 buf - buffer to return data in
505 count - number of bytes to read into buffer max
506
507=cut
508*/
509
510static
511ssize_t
512bufchain_read(io_glue *ig, void *buf, size_t count) {
513 io_ex_bchain *ieb = ig->exdata;
514 size_t scount = count;
515 char *cbuf = buf;
516 size_t sk;
517
518 mm_log((1, "bufchain_read(ig %p, buf %p, count %ld)\n", ig, buf, count));
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519
520 while( scount ) {
521 int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
522 if (clen == ieb->cpos) {
523 if (ieb->cp == ieb->tail) break; /* EOF */
524 ieb->cp = ieb->cp->next;
525 ieb->cpos = 0;
526 clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
527 }
528
529 sk = clen - ieb->cpos;
530 sk = sk > scount ? scount : sk;
531
532 memcpy(&cbuf[count-scount], &ieb->cp->buf[ieb->cpos], sk);
533 scount -= sk;
534 ieb->cpos += sk;
535 ieb->gpos += sk;
536 }
537
538 mm_log((1, "bufchain_read: returning %d\n", count-scount));
539 return count-scount;
540}
541
542
543
544
545
546/*
547=item bufchain_write(ig, buf, count)
548
549Does the writing to a 'source' that can be seeked on
550
551 ig - io_glue object
552 buf - buffer that contains data
553 count - number of bytes to write
554
555=cut
556*/
557
558static
559ssize_t
560bufchain_write(io_glue *ig, const void *buf, size_t count) {
561 char *cbuf = (char *)buf;
562 io_ex_bchain *ieb = ig->exdata;
563 size_t ocount = count;
564 size_t sk;
565
930c67c8 566 mm_log((1, "bufchain_write: ig = %p, buf = %p, count = %d\n", ig, buf, count));
02d1d628 567
930c67c8 568 IOL_DEB( printf("bufchain_write: ig = %p, ieb->cpos = %ld, buf = %p, count = %d\n", ig, (long) ieb->cpos, buf, count) );
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569
570 while(count) {
571 mm_log((2, "bufchain_write: - looping - count = %d\n", count));
572 if (ieb->cp->len == ieb->cpos) {
573 mm_log((1, "bufchain_write: cp->len == ieb->cpos = %d - advancing chain\n", (long) ieb->cpos));
574 io_bchain_advance(ieb);
575 }
576
577 sk = ieb->cp->len - ieb->cpos;
578 sk = sk > count ? count : sk;
579 memcpy(&ieb->cp->buf[ieb->cpos], &cbuf[ocount-count], sk);
580
581 if (ieb->cp == ieb->tail) {
582 int extend = ieb->cpos + sk - ieb->tfill;
583 mm_log((2, "bufchain_write: extending tail by %d\n", extend));
584 if (extend > 0) {
585 ieb->length += extend;
586 ieb->tfill += extend;
587 }
588 }
589
590 ieb->cpos += sk;
591 ieb->gpos += sk;
592 count -= sk;
593 }
594 return ocount;
595}
596
597/*
598=item bufchain_close(ig)
599
600Closes a source that can be seeked on. Not sure if this should be an actual close
601or not. Does nothing for now. Should be fixed.
602
603 ig - data source
604
605=cut
606*/
607
608static
609void
610bufchain_close(io_glue *ig) {
611 mm_log((1, "bufchain_close(ig %p)\n",ig));
930c67c8 612 IOL_DEB( printf("bufchain_close(ig %p)\n", ig) );
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613 /* FIXME: Commit a seek point here */
614
615}
616
617
618/* bufchain_seek(ig, offset, whence)
619
620Implements seeking for a source that is seekable, the purpose of having this is to be able to
621have an offset into a file that is different from what the underlying library thinks.
622
623 ig - data source
624 offset - offset into stream
625 whence - whence argument a la lseek
626
627=cut
628*/
629
630static
631off_t
632bufchain_seek(io_glue *ig, off_t offset, int whence) {
633 io_ex_bchain *ieb = ig->exdata;
634 io_blink *ib = NULL;
635 int wrlen;
636
637 off_t cof = 0;
638 off_t scount = offset;
639 off_t sk;
640
641 mm_log((1, "bufchain_seek(ig %p, offset %ld, whence %d)\n", ig, offset, whence));
642
643 switch (whence) {
644 case SEEK_SET: /* SEEK_SET = 0, From the top */
645 ieb->cp = ieb->head;
646 ieb->cpos = 0;
647 ieb->gpos = 0;
648
649 while( scount ) {
650 int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
651 if (clen == ieb->cpos) {
652 if (ieb->cp == ieb->tail) break; /* EOF */
653 ieb->cp = ieb->cp->next;
654 ieb->cpos = 0;
655 clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
656 }
657
658 sk = clen - ieb->cpos;
659 sk = sk > scount ? scount : sk;
660
661 scount -= sk;
662 ieb->cpos += sk;
663 ieb->gpos += sk;
664 }
665
666 wrlen = scount;
667
668 if (wrlen > 0) {
669 /*
670 * extending file - get ieb into consistent state and then
671 * call write which will get it to the correct position
672 */
673 char TB[BBSIZ];
674 memset(TB, 0, BBSIZ);
675 ieb->gpos = ieb->length;
676 ieb->cpos = ieb->tfill;
677
678 while(wrlen > 0) {
b33c08f8 679 ssize_t rc, wl = i_min(wrlen, BBSIZ);
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680 mm_log((1, "bufchain_seek: wrlen = %d, wl = %d\n", wrlen, wl));
681 rc = bufchain_write( ig, TB, wl );
682 if (rc != wl) m_fatal(0, "bufchain_seek: Unable to extend file\n");
683 wrlen -= rc;
684 }
685 }
686
687 break;
688
689 case SEEK_CUR:
690 m_fatal(123, "SEEK_CUR IS NOT IMPLEMENTED\n");
691
692 /*
693 case SEEK_CUR:
694 ib = ieb->cp;
695 if (cof < 0) {
696 cof += ib->cpos;
697 cpos = 0;
698 while(cof < 0 && ib->prev) {
699 ib = ib->prev;
700 cof += ib->len;
701 }
702 */
703
704 case SEEK_END: /* SEEK_END = 2 */
705 if (cof>0) m_fatal(0, "bufchain_seek: SEEK_END + %d : Extending files via seek not supported!\n", cof);
706
707 ieb->cp = ieb->tail;
708 ieb->cpos = ieb->tfill;
709
710 if (cof<0) {
711 cof += ieb->cpos;
712 ieb->cpos = 0;
713
714 while(cof<0 && ib->prev) {
715 ib = ib->prev;
716 cof += ib->len;
717 }
718
719 if (cof<0) m_fatal(0, "bufchain_seek: Tried to seek before start of file\n");
720 ieb->gpos = ieb->length+offset;
721 ieb->cpos = cof;
722 }
723 break;
724 default:
725 m_fatal(0, "bufchain_seek: Unhandled seek request: whence = %d\n", whence );
726 }
727
728 mm_log((2, "bufchain_seek: returning ieb->gpos = %d\n", ieb->gpos));
729 return ieb->gpos;
730}
731
732
733
734
735
736
737/*
738 * Methods for setting up data source
739 */
740
741/*
742=item io_obj_setp_buffer(io, p, len)
743
744Sets an io_object for reading from a buffer source
745
746 io - io object that describes a source
747 p - pointer to buffer
748 len - length of buffer
749
750=cut
751*/
752
753void
4dfa5522
AMH
754io_obj_setp_buffer(io_obj *io, char *p, size_t len, closebufp closecb, void *closedata) {
755 io->buffer.type = BUFFER;
756 io->buffer.data = p;
757 io->buffer.len = len;
758 io->buffer.closecb = closecb;
759 io->buffer.closedata = closedata;
02d1d628
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760}
761
762
763/*
4dfa5522 764=item io_obj_setp_buchain(io)
02d1d628
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765
766Sets an io_object for reading/writing from a buffer source
767
768 io - io object that describes a source
769 p - pointer to buffer
770 len - length of buffer
771
772=cut
773*/
774
775void
776io_obj_setp_bufchain(io_obj *io) {
777 io->type = BUFCHAIN;
778}
779
780
781/*
10461f9a 782=item io_obj_setp_cb2(io, p, readcb, writecb, seekcb, closecb, destroycb)
02d1d628
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783
784Sets an io_object for reading from a source that uses callbacks
785
786 io - io object that describes a source
10461f9a
TC
787 p - pointer to data for callbacks
788 readcb - read callback to read from source
789 writecb - write callback to write to source
790 seekcb - seek callback to seek on source
791 closecb - flush any pending data
792 destroycb - release any extra resources
02d1d628
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793
794=cut
795*/
796
797void
10461f9a
TC
798io_obj_setp_cb2(io_obj *io, void *p, readl readcb, writel writecb, seekl seekcb, closel closecb, destroyl destroycb) {
799 io->cb.type = CBSEEK;
800 io->cb.p = p;
801 io->cb.readcb = readcb;
802 io->cb.writecb = writecb;
803 io->cb.seekcb = seekcb;
804 io->cb.closecb = closecb;
805 io->cb.destroycb = destroycb;
806}
807
808void
809io_obj_setp_cb(io_obj *io, void *p, readl readcb, writel writecb,
810 seekl seekcb) {
811 io_obj_setp_cb2(io, p, readcb, writecb, seekcb, NULL, NULL);
02d1d628
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812}
813
814/*
815=item io_glue_commit_types(ig)
816
817Creates buffers and initializes structures to read with the chosen interface.
818
819 ig - io_glue object
820
821=cut
822*/
823
824void
825io_glue_commit_types(io_glue *ig) {
826 io_type inn = ig->source.type;
527c0c3e 827
930c67c8 828 mm_log((1, "io_glue_commit_types(ig %p)\n", ig));
02d1d628 829 mm_log((1, "io_glue_commit_types: source type %d (%s)\n", inn, io_type_names[inn]));
527c0c3e
AMH
830
831 if (ig->flags & 0x01) {
832 mm_log((1, "io_glue_commit_types: type already set up\n"));
833 return;
834 }
835
02d1d628
AMH
836 switch (inn) {
837 case BUFCHAIN:
838 {
839 io_ex_bchain *ieb = mymalloc(sizeof(io_ex_bchain));
840
841 ieb->offset = 0;
842 ieb->length = 0;
843 ieb->cpos = 0;
844 ieb->gpos = 0;
845 ieb->tfill = 0;
c3cc977e 846
02d1d628
AMH
847 ieb->head = io_blink_new();
848 ieb->cp = ieb->head;
849 ieb->tail = ieb->head;
850
851 ig->exdata = ieb;
852 ig->readcb = bufchain_read;
853 ig->writecb = bufchain_write;
854 ig->seekcb = bufchain_seek;
855 ig->closecb = bufchain_close;
856 }
857 break;
858 case CBSEEK:
02d1d628
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859 {
860 io_ex_rseek *ier = mymalloc(sizeof(io_ex_rseek));
861
862 ier->offset = 0;
863 ier->cpos = 0;
864
865 ig->exdata = ier;
866 ig->readcb = realseek_read;
867 ig->writecb = realseek_write;
868 ig->seekcb = realseek_seek;
869 ig->closecb = realseek_close;
870 }
4dfa5522
AMH
871 break;
872 case BUFFER:
873 {
874 io_ex_buffer *ieb = mymalloc(sizeof(io_ex_buffer));
875 ieb->offset = 0;
876 ieb->cpos = 0;
877
878 ig->exdata = ieb;
879 ig->readcb = buffer_read;
880 ig->writecb = buffer_write;
881 ig->seekcb = buffer_seek;
882 ig->closecb = buffer_close;
883 }
884 break;
10461f9a
TC
885 case FDSEEK:
886 {
887 ig->exdata = NULL;
888 ig->readcb = fd_read;
889 ig->writecb = fd_write;
890 ig->seekcb = fd_seek;
891 ig->closecb = fd_close;
892 break;
893 }
02d1d628 894 }
527c0c3e 895 ig->flags |= 0x01; /* indicate source has been setup already */
02d1d628
AMH
896}
897
898/*
899=item io_glue_gettypes(ig, reqmeth)
900
901Returns a set of compatible interfaces to read data with.
902
903 ig - io_glue object
904 reqmeth - request mask
905
906The request mask is a bit mask (of something that hasn't been implemented yet)
907of interfaces that it would like to read data from the source which the ig
908describes.
909
910=cut
911*/
912
913void
914io_glue_gettypes(io_glue *ig, int reqmeth) {
915
916 ig = NULL;
917 reqmeth = 0;
918
919 /* FIXME: Implement this function! */
920 /* if (ig->source.type =
921 if (reqmeth & IO_BUFF) */
922
923}
924
925
926/*
927=item io_new_bufchain()
928
929returns a new io_glue object that has the 'empty' source and but can
930be written to and read from later (like a pseudo file).
931
932=cut
933*/
934
935io_glue *
936io_new_bufchain() {
4dfa5522
AMH
937 io_glue *ig;
938 mm_log((1, "io_new_bufchain()\n"));
939 ig = mymalloc(sizeof(io_glue));
527c0c3e 940 memset(ig, 0, sizeof(*ig));
02d1d628
AMH
941 io_obj_setp_bufchain(&ig->source);
942 return ig;
943}
944
945
c3cc977e
AMH
946
947
948
4dfa5522
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949/*
950=item io_new_buffer(data, len)
951
952Returns a new io_glue object that has the source defined as reading
953from specified buffer. Note that the buffer is not copied.
954
955 data - buffer to read from
956 len - length of buffer
c3cc977e 957
4dfa5522
AMH
958=cut
959*/
960
961io_glue *
962io_new_buffer(char *data, size_t len, closebufp closecb, void *closedata) {
963 io_glue *ig;
964 mm_log((1, "io_new_buffer(data %p, len %d, closecb %p, closedata %p)\n", data, len, closecb, closedata));
965 ig = mymalloc(sizeof(io_glue));
966 memset(ig, 0, sizeof(*ig));
967 io_obj_setp_buffer(&ig->source, data, len, closecb, closedata);
527c0c3e 968 ig->flags = 0;
4dfa5522
AMH
969 return ig;
970}
c3cc977e
AMH
971
972
02d1d628
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973/*
974=item io_new_fd(fd)
975
976returns a new io_glue object that has the source defined as reading
977from specified filedescriptor. Note that the the interface to recieving
978data from the io_glue callbacks hasn't been done yet.
979
980 fd - file descriptor to read/write from
981
982=cut
983*/
984
985io_glue *
986io_new_fd(int fd) {
4dfa5522
AMH
987 io_glue *ig;
988 mm_log((1, "io_new_fd(fd %d)\n", fd));
989 ig = mymalloc(sizeof(io_glue));
261f91c5 990 memset(ig, 0, sizeof(*ig));
10461f9a
TC
991 ig->source.type = FDSEEK;
992 ig->source.fdseek.fd = fd;
527c0c3e 993 ig->flags = 0;
10461f9a 994#if 0
02d1d628
AMH
995#ifdef _MSC_VER
996 io_obj_setp_cb(&ig->source, (void*)fd, _read, _write, _lseek);
997#else
998 io_obj_setp_cb(&ig->source, (void*)fd, read, write, lseek);
10461f9a 999#endif
02d1d628 1000#endif
4dfa5522 1001 mm_log((1, "(%p) <- io_new_fd\n", ig));
02d1d628
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1002 return ig;
1003}
1004
10461f9a
TC
1005io_glue *io_new_cb(void *p, readl readcb, writel writecb, seekl seekcb,
1006 closel closecb, destroyl destroycb) {
1007 io_glue *ig;
02d1d628 1008
10461f9a
TC
1009 mm_log((1, "io_new_cb(p %p, readcb %p, writecb %p, seekcb %p, closecb %p, "
1010 "destroycb %p)\n", p, readcb, writecb, seekcb, closecb, destroycb));
1011 ig = mymalloc(sizeof(io_glue));
527c0c3e 1012 memset(ig, 0, sizeof(*ig));
10461f9a
TC
1013 io_obj_setp_cb2(&ig->source, p, readcb, writecb, seekcb, closecb, destroycb);
1014 mm_log((1, "(%p) <- io_new_cb\n", ig));
1015
1016 return ig;
1017}
02d1d628
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1018
1019/*
1020=item io_slurp(ig)
1021
1022Takes the source that the io_glue is bound to and allocates space
1023for a return buffer and returns the entire content in a single buffer.
1024Note: This only works for io_glue objects that contain a bufchain. It
1025is usefull for saving to scalars and such.
1026
1027 ig - io_glue object
1028 c - pointer to a pointer to where data should be copied to
1029
1030=cut
1031*/
1032
1033size_t
1034io_slurp(io_glue *ig, unsigned char **c) {
1035 ssize_t rc;
1036 off_t orgoff;
1037 io_ex_bchain *ieb;
1038 unsigned char *cc;
1039 io_type inn = ig->source.type;
1040
1041 if ( inn != BUFCHAIN ) {
1042 m_fatal(0, "io_slurp: called on a source that is not from a bufchain\n");
1043 }
1044
1045 ieb = ig->exdata;
1046 cc = *c = mymalloc( ieb->length );
1047
1048 orgoff = ieb->gpos;
1049
1050 bufchain_seek(ig, 0, SEEK_SET);
1051
1052 rc = bufchain_read(ig, cc, ieb->length);
1053
1054 if (rc != ieb->length)
1055 m_fatal(1, "io_slurp: bufchain_read returned an incomplete read: rc = %d, request was %d\n", rc, ieb->length);
1056
1057 return rc;
1058}
1059
10461f9a
TC
1060/*
1061=item fd_read(ig, buf, count)
1062
1063=cut
1064*/
1065static ssize_t fd_read(io_glue *ig, void *buf, size_t count) {
1066#ifdef _MSC_VER
1067 return _read(ig->source.fdseek.fd, buf, count);
1068#else
1069 return read(ig->source.fdseek.fd, buf, count);
1070#endif
1071}
1072
1073static ssize_t fd_write(io_glue *ig, const void *buf, size_t count) {
1074#ifdef _MSC_VER
1075 return _write(ig->source.fdseek.fd, buf, count);
1076#else
1077 return write(ig->source.fdseek.fd, buf, count);
1078#endif
1079}
1080
1081static off_t fd_seek(io_glue *ig, off_t offset, int whence) {
1082#ifdef _MSC_VER
1083 return _lseek(ig->source.fdseek.fd, offset, whence);
1084#else
1085 return lseek(ig->source.fdseek.fd, offset, whence);
1086#endif
1087}
1088
1089static void fd_close(io_glue *ig) {
1090 /* no, we don't close it */
1091}
1092
1093static ssize_t fd_size(io_glue *ig) {
1094 mm_log((1, "fd_size(ig %p) unimplemented\n", ig));
1095
1096 return -1;
1097}
02d1d628
AMH
1098
1099/*
1100=item io_glue_DESTROY(ig)
1101
1102A destructor method for io_glue objects. Should clean up all related buffers.
1103Might leave us with a dangling pointer issue on some buffers.
1104
1105 ig - io_glue object to destroy.
1106
1107=cut
1108*/
1109
1110void
1111io_glue_DESTROY(io_glue *ig) {
c3cc977e
AMH
1112 io_type inn = ig->source.type;
1113 mm_log((1, "io_glue_DESTROY(ig %p)\n", ig));
1114
1115 switch (inn) {
1116 case BUFCHAIN:
1117 {
1118 io_ex_bchain *ieb = ig->exdata;
1119 io_destroy_bufchain(ieb);
4dfa5522 1120 myfree(ieb);
c3cc977e
AMH
1121 }
1122 break;
1123 case CBSEEK:
c3cc977e
AMH
1124 {
1125 io_ex_rseek *ier = ig->exdata;
10461f9a
TC
1126 if (ig->source.cb.destroycb)
1127 ig->source.cb.destroycb(ig->source.cb.p);
c3cc977e
AMH
1128 myfree(ier);
1129 }
4dfa5522
AMH
1130 break;
1131 case BUFFER:
1132 {
1133 io_ex_buffer *ieb = ig->exdata;
1134 if (ig->source.buffer.closecb) {
1135 mm_log((1,"calling close callback %p for io_buffer\n", ig->source.buffer.closecb));
1136 ig->source.buffer.closecb(ig->source.buffer.closedata);
1137 }
1138 myfree(ieb);
1139 }
1140 break;
10461f9a
TC
1141 default:
1142 break;
c3cc977e
AMH
1143 }
1144 myfree(ig);
02d1d628 1145}
b8c2033e
AMH
1146
1147
1148/*
1149=back
1150
1151=head1 AUTHOR
1152
1153Arnar M. Hrafnkelsson <addi@umich.edu>
1154
1155=head1 SEE ALSO
1156
1157Imager(3)
1158
1159=cut
1160*/