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Merge branch 'mh/fast-import-notes-fix-new'
[git.git] / convert.c
blob4e17e45ed265b3f4861d1b7a1e86edaa4df3b1ac
1 #include "cache.h"
2 #include "attr.h"
3 #include "run-command.h"
4 #include "quote.h"
5 #include "sigchain.h"
6 #include "pkt-line.h"
7
8 /*
9 * convert.c - convert a file when checking it out and checking it in.
10 *
11 * This should use the pathname to decide on whether it wants to do some
12 * more interesting conversions (automatic gzip/unzip, general format
13 * conversions etc etc), but by default it just does automatic CRLF<->LF
14 * translation when the "text" attribute or "auto_crlf" option is set.
15 */
16
17 /* Stat bits: When BIN is set, the txt bits are unset */
18 #define CONVERT_STAT_BITS_TXT_LF 0x1
19 #define CONVERT_STAT_BITS_TXT_CRLF 0x2
20 #define CONVERT_STAT_BITS_BIN 0x4
21
22 enum crlf_action {
23 CRLF_UNDEFINED,
24 CRLF_BINARY,
25 CRLF_TEXT,
26 CRLF_TEXT_INPUT,
27 CRLF_TEXT_CRLF,
28 CRLF_AUTO,
29 CRLF_AUTO_INPUT,
30 CRLF_AUTO_CRLF
31 };
32
33 struct text_stat {
34 /* NUL, CR, LF and CRLF counts */
35 unsigned nul, lonecr, lonelf, crlf;
36
37 /* These are just approximations! */
38 unsigned printable, nonprintable;
39 };
40
41 static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
42 {
43 unsigned long i;
44
45 memset(stats, 0, sizeof(*stats));
46
47 for (i = 0; i < size; i++) {
48 unsigned char c = buf[i];
49 if (c == '\r') {
50 if (i+1 < size && buf[i+1] == '\n') {
51 stats->crlf++;
52 i++;
53 } else
54 stats->lonecr++;
55 continue;
56 }
57 if (c == '\n') {
58 stats->lonelf++;
59 continue;
60 }
61 if (c == 127)
62 /* DEL */
63 stats->nonprintable++;
64 else if (c < 32) {
65 switch (c) {
66 /* BS, HT, ESC and FF */
67 case '\b': case '\t': case '\033': case '\014':
68 stats->printable++;
69 break;
70 case 0:
71 stats->nul++;
72 /* fall through */
73 default:
74 stats->nonprintable++;
75 }
76 }
77 else
78 stats->printable++;
79 }
80
81 /* If file ends with EOF then don't count this EOF as non-printable. */
82 if (size >= 1 && buf[size-1] == '\032')
83 stats->nonprintable--;
84 }
85
86 /*
87 * The same heuristics as diff.c::mmfile_is_binary()
88 * We treat files with bare CR as binary
89 */
90 static int convert_is_binary(unsigned long size, const struct text_stat *stats)
91 {
92 if (stats->lonecr)
93 return 1;
94 if (stats->nul)
95 return 1;
96 if ((stats->printable >> 7) < stats->nonprintable)
97 return 1;
98 return 0;
99 }
100
101 static unsigned int gather_convert_stats(const char *data, unsigned long size)
102 {
103 struct text_stat stats;
104 int ret = 0;
105 if (!data || !size)
106 return 0;
107 gather_stats(data, size, &stats);
108 if (convert_is_binary(size, &stats))
109 ret |= CONVERT_STAT_BITS_BIN;
110 if (stats.crlf)
111 ret |= CONVERT_STAT_BITS_TXT_CRLF;
112 if (stats.lonelf)
113 ret |= CONVERT_STAT_BITS_TXT_LF;
114
115 return ret;
116 }
117
118 static const char *gather_convert_stats_ascii(const char *data, unsigned long size)
119 {
120 unsigned int convert_stats = gather_convert_stats(data, size);
121
122 if (convert_stats & CONVERT_STAT_BITS_BIN)
123 return "-text";
124 switch (convert_stats) {
125 case CONVERT_STAT_BITS_TXT_LF:
126 return "lf";
127 case CONVERT_STAT_BITS_TXT_CRLF:
128 return "crlf";
129 case CONVERT_STAT_BITS_TXT_LF | CONVERT_STAT_BITS_TXT_CRLF:
130 return "mixed";
131 default:
132 return "none";
133 }
134 }
135
136 const char *get_cached_convert_stats_ascii(const char *path)
137 {
138 const char *ret;
139 unsigned long sz;
140 void *data = read_blob_data_from_cache(path, &sz);
141 ret = gather_convert_stats_ascii(data, sz);
142 free(data);
143 return ret;
144 }
145
146 const char *get_wt_convert_stats_ascii(const char *path)
147 {
148 const char *ret = "";
149 struct strbuf sb = STRBUF_INIT;
150 if (strbuf_read_file(&sb, path, 0) >= 0)
151 ret = gather_convert_stats_ascii(sb.buf, sb.len);
152 strbuf_release(&sb);
153 return ret;
154 }
155
156 static int text_eol_is_crlf(void)
157 {
158 if (auto_crlf == AUTO_CRLF_TRUE)
159 return 1;
160 else if (auto_crlf == AUTO_CRLF_INPUT)
161 return 0;
162 if (core_eol == EOL_CRLF)
163 return 1;
164 if (core_eol == EOL_UNSET && EOL_NATIVE == EOL_CRLF)
165 return 1;
166 return 0;
167 }
168
169 static enum eol output_eol(enum crlf_action crlf_action)
170 {
171 switch (crlf_action) {
172 case CRLF_BINARY:
173 return EOL_UNSET;
174 case CRLF_TEXT_CRLF:
175 return EOL_CRLF;
176 case CRLF_TEXT_INPUT:
177 return EOL_LF;
178 case CRLF_UNDEFINED:
179 case CRLF_AUTO_CRLF:
180 return EOL_CRLF;
181 case CRLF_AUTO_INPUT:
182 return EOL_LF;
183 case CRLF_TEXT:
184 case CRLF_AUTO:
185 /* fall through */
186 return text_eol_is_crlf() ? EOL_CRLF : EOL_LF;
187 }
188 warning("Illegal crlf_action %d\n", (int)crlf_action);
189 return core_eol;
190 }
191
192 static void check_safe_crlf(const char *path, enum crlf_action crlf_action,
193 struct text_stat *old_stats, struct text_stat *new_stats,
194 enum safe_crlf checksafe)
195 {
196 if (old_stats->crlf && !new_stats->crlf ) {
197 /*
198 * CRLFs would not be restored by checkout
199 */
200 if (checksafe == SAFE_CRLF_WARN)
201 warning(_("CRLF will be replaced by LF in %s.\n"
202 "The file will have its original line"
203 " endings in your working directory."), path);
204 else /* i.e. SAFE_CRLF_FAIL */
205 die(_("CRLF would be replaced by LF in %s."), path);
206 } else if (old_stats->lonelf && !new_stats->lonelf ) {
207 /*
208 * CRLFs would be added by checkout
209 */
210 if (checksafe == SAFE_CRLF_WARN)
211 warning(_("LF will be replaced by CRLF in %s.\n"
212 "The file will have its original line"
213 " endings in your working directory."), path);
214 else /* i.e. SAFE_CRLF_FAIL */
215 die(_("LF would be replaced by CRLF in %s"), path);
216 }
217 }
218
219 static int has_cr_in_index(const char *path)
220 {
221 unsigned long sz;
222 void *data;
223 int has_cr;
224
225 data = read_blob_data_from_cache(path, &sz);
226 if (!data)
227 return 0;
228 has_cr = memchr(data, '\r', sz) != NULL;
229 free(data);
230 return has_cr;
231 }
232
233 static int will_convert_lf_to_crlf(size_t len, struct text_stat *stats,
234 enum crlf_action crlf_action)
235 {
236 if (output_eol(crlf_action) != EOL_CRLF)
237 return 0;
238 /* No "naked" LF? Nothing to convert, regardless. */
239 if (!stats->lonelf)
240 return 0;
241
242 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
243 /* If we have any CR or CRLF line endings, we do not touch it */
244 /* This is the new safer autocrlf-handling */
245 if (stats->lonecr || stats->crlf)
246 return 0;
247
248 if (convert_is_binary(len, stats))
249 return 0;
250 }
251 return 1;
252
253 }
254
255 static int crlf_to_git(const char *path, const char *src, size_t len,
256 struct strbuf *buf,
257 enum crlf_action crlf_action, enum safe_crlf checksafe)
258 {
259 struct text_stat stats;
260 char *dst;
261 int convert_crlf_into_lf;
262
263 if (crlf_action == CRLF_BINARY ||
264 (src && !len))
265 return 0;
266
267 /*
268 * If we are doing a dry-run and have no source buffer, there is
269 * nothing to analyze; we must assume we would convert.
270 */
271 if (!buf && !src)
272 return 1;
273
274 gather_stats(src, len, &stats);
275 /* Optimization: No CRLF? Nothing to convert, regardless. */
276 convert_crlf_into_lf = !!stats.crlf;
277
278 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
279 if (convert_is_binary(len, &stats))
280 return 0;
281 /*
282 * If the file in the index has any CR in it, do not
283 * convert. This is the new safer autocrlf handling,
284 * unless we want to renormalize in a merge or
285 * cherry-pick.
286 */
287 if ((checksafe != SAFE_CRLF_RENORMALIZE) && has_cr_in_index(path))
288 convert_crlf_into_lf = 0;
289 }
290 if ((checksafe == SAFE_CRLF_WARN ||
291 (checksafe == SAFE_CRLF_FAIL)) && len) {
292 struct text_stat new_stats;
293 memcpy(&new_stats, &stats, sizeof(new_stats));
294 /* simulate "git add" */
295 if (convert_crlf_into_lf) {
296 new_stats.lonelf += new_stats.crlf;
297 new_stats.crlf = 0;
298 }
299 /* simulate "git checkout" */
300 if (will_convert_lf_to_crlf(len, &new_stats, crlf_action)) {
301 new_stats.crlf += new_stats.lonelf;
302 new_stats.lonelf = 0;
303 }
304 check_safe_crlf(path, crlf_action, &stats, &new_stats, checksafe);
305 }
306 if (!convert_crlf_into_lf)
307 return 0;
308
309 /*
310 * At this point all of our source analysis is done, and we are sure we
311 * would convert. If we are in dry-run mode, we can give an answer.
312 */
313 if (!buf)
314 return 1;
315
316 /* only grow if not in place */
317 if (strbuf_avail(buf) + buf->len < len)
318 strbuf_grow(buf, len - buf->len);
319 dst = buf->buf;
320 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
321 /*
322 * If we guessed, we already know we rejected a file with
323 * lone CR, and we can strip a CR without looking at what
324 * follow it.
325 */
326 do {
327 unsigned char c = *src++;
328 if (c != '\r')
329 *dst++ = c;
330 } while (--len);
331 } else {
332 do {
333 unsigned char c = *src++;
334 if (! (c == '\r' && (1 < len && *src == '\n')))
335 *dst++ = c;
336 } while (--len);
337 }
338 strbuf_setlen(buf, dst - buf->buf);
339 return 1;
340 }
341
342 static int crlf_to_worktree(const char *path, const char *src, size_t len,
343 struct strbuf *buf, enum crlf_action crlf_action)
344 {
345 char *to_free = NULL;
346 struct text_stat stats;
347
348 if (!len || output_eol(crlf_action) != EOL_CRLF)
349 return 0;
350
351 gather_stats(src, len, &stats);
352 if (!will_convert_lf_to_crlf(len, &stats, crlf_action))
353 return 0;
354
355 /* are we "faking" in place editing ? */
356 if (src == buf->buf)
357 to_free = strbuf_detach(buf, NULL);
358
359 strbuf_grow(buf, len + stats.lonelf);
360 for (;;) {
361 const char *nl = memchr(src, '\n', len);
362 if (!nl)
363 break;
364 if (nl > src && nl[-1] == '\r') {
365 strbuf_add(buf, src, nl + 1 - src);
366 } else {
367 strbuf_add(buf, src, nl - src);
368 strbuf_addstr(buf, "\r\n");
369 }
370 len -= nl + 1 - src;
371 src = nl + 1;
372 }
373 strbuf_add(buf, src, len);
374
375 free(to_free);
376 return 1;
377 }
378
379 struct filter_params {
380 const char *src;
381 unsigned long size;
382 int fd;
383 const char *cmd;
384 const char *path;
385 };
386
387 static int filter_buffer_or_fd(int in, int out, void *data)
388 {
389 /*
390 * Spawn cmd and feed the buffer contents through its stdin.
391 */
392 struct child_process child_process = CHILD_PROCESS_INIT;
393 struct filter_params *params = (struct filter_params *)data;
394 int write_err, status;
395 const char *argv[] = { NULL, NULL };
396
397 /* apply % substitution to cmd */
398 struct strbuf cmd = STRBUF_INIT;
399 struct strbuf path = STRBUF_INIT;
400 struct strbuf_expand_dict_entry dict[] = {
401 { "f", NULL, },
402 { NULL, NULL, },
403 };
404
405 /* quote the path to preserve spaces, etc. */
406 sq_quote_buf(&path, params->path);
407 dict[0].value = path.buf;
408
409 /* expand all %f with the quoted path */
410 strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
411 strbuf_release(&path);
412
413 argv[0] = cmd.buf;
414
415 child_process.argv = argv;
416 child_process.use_shell = 1;
417 child_process.in = -1;
418 child_process.out = out;
419
420 if (start_command(&child_process))
421 return error("cannot fork to run external filter '%s'", params->cmd);
422
423 sigchain_push(SIGPIPE, SIG_IGN);
424
425 if (params->src) {
426 write_err = (write_in_full(child_process.in,
427 params->src, params->size) < 0);
428 if (errno == EPIPE)
429 write_err = 0;
430 } else {
431 write_err = copy_fd(params->fd, child_process.in);
432 if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
433 write_err = 0;
434 }
435
436 if (close(child_process.in))
437 write_err = 1;
438 if (write_err)
439 error("cannot feed the input to external filter '%s'", params->cmd);
440
441 sigchain_pop(SIGPIPE);
442
443 status = finish_command(&child_process);
444 if (status)
445 error("external filter '%s' failed %d", params->cmd, status);
446
447 strbuf_release(&cmd);
448 return (write_err || status);
449 }
450
451 static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd,
452 struct strbuf *dst, const char *cmd)
453 {
454 /*
455 * Create a pipeline to have the command filter the buffer's
456 * contents.
457 *
458 * (child --> cmd) --> us
459 */
460 int err = 0;
461 struct strbuf nbuf = STRBUF_INIT;
462 struct async async;
463 struct filter_params params;
464
465 memset(&async, 0, sizeof(async));
466 async.proc = filter_buffer_or_fd;
467 async.data = &params;
468 async.out = -1;
469 params.src = src;
470 params.size = len;
471 params.fd = fd;
472 params.cmd = cmd;
473 params.path = path;
474
475 fflush(NULL);
476 if (start_async(&async))
477 return 0; /* error was already reported */
478
479 if (strbuf_read(&nbuf, async.out, len) < 0) {
480 err = error("read from external filter '%s' failed", cmd);
481 }
482 if (close(async.out)) {
483 err = error("read from external filter '%s' failed", cmd);
484 }
485 if (finish_async(&async)) {
486 err = error("external filter '%s' failed", cmd);
487 }
488
489 if (!err) {
490 strbuf_swap(dst, &nbuf);
491 }
492 strbuf_release(&nbuf);
493 return !err;
494 }
495
496 #define CAP_CLEAN (1u<<0)
497 #define CAP_SMUDGE (1u<<1)
498
499 struct cmd2process {
500 struct hashmap_entry ent; /* must be the first member! */
501 unsigned int supported_capabilities;
502 const char *cmd;
503 struct child_process process;
504 };
505
506 static int cmd_process_map_initialized;
507 static struct hashmap cmd_process_map;
508
509 static int cmd2process_cmp(const struct cmd2process *e1,
510 const struct cmd2process *e2,
511 const void *unused)
512 {
513 return strcmp(e1->cmd, e2->cmd);
514 }
515
516 static struct cmd2process *find_multi_file_filter_entry(struct hashmap *hashmap, const char *cmd)
517 {
518 struct cmd2process key;
519 hashmap_entry_init(&key, strhash(cmd));
520 key.cmd = cmd;
521 return hashmap_get(hashmap, &key, NULL);
522 }
523
524 static int packet_write_list(int fd, const char *line, ...)
525 {
526 va_list args;
527 int err;
528 va_start(args, line);
529 for (;;) {
530 if (!line)
531 break;
532 if (strlen(line) > LARGE_PACKET_DATA_MAX)
533 return -1;
534 err = packet_write_fmt_gently(fd, "%s\n", line);
535 if (err)
536 return err;
537 line = va_arg(args, const char*);
538 }
539 va_end(args);
540 return packet_flush_gently(fd);
541 }
542
543 static void read_multi_file_filter_status(int fd, struct strbuf *status)
544 {
545 struct strbuf **pair;
546 char *line;
547 for (;;) {
548 line = packet_read_line(fd, NULL);
549 if (!line)
550 break;
551 pair = strbuf_split_str(line, '=', 2);
552 if (pair[0] && pair[0]->len && pair[1]) {
553 /* the last "status=<foo>" line wins */
554 if (!strcmp(pair[0]->buf, "status=")) {
555 strbuf_reset(status);
556 strbuf_addbuf(status, pair[1]);
557 }
558 }
559 strbuf_list_free(pair);
560 }
561 }
562
563 static void kill_multi_file_filter(struct hashmap *hashmap, struct cmd2process *entry)
564 {
565 if (!entry)
566 return;
567
568 entry->process.clean_on_exit = 0;
569 kill(entry->process.pid, SIGTERM);
570 finish_command(&entry->process);
571
572 hashmap_remove(hashmap, entry, NULL);
573 free(entry);
574 }
575
576 static void stop_multi_file_filter(struct child_process *process)
577 {
578 sigchain_push(SIGPIPE, SIG_IGN);
579 /* Closing the pipe signals the filter to initiate a shutdown. */
580 close(process->in);
581 close(process->out);
582 sigchain_pop(SIGPIPE);
583 /* Finish command will wait until the shutdown is complete. */
584 finish_command(process);
585 }
586
587 static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, const char *cmd)
588 {
589 int err;
590 struct cmd2process *entry;
591 struct child_process *process;
592 const char *argv[] = { cmd, NULL };
593 struct string_list cap_list = STRING_LIST_INIT_NODUP;
594 char *cap_buf;
595 const char *cap_name;
596
597 entry = xmalloc(sizeof(*entry));
598 entry->cmd = cmd;
599 entry->supported_capabilities = 0;
600 process = &entry->process;
601
602 child_process_init(process);
603 process->argv = argv;
604 process->use_shell = 1;
605 process->in = -1;
606 process->out = -1;
607 process->clean_on_exit = 1;
608 process->clean_on_exit_handler = stop_multi_file_filter;
609
610 if (start_command(process)) {
611 error("cannot fork to run external filter '%s'", cmd);
612 return NULL;
613 }
614
615 hashmap_entry_init(entry, strhash(cmd));
616
617 sigchain_push(SIGPIPE, SIG_IGN);
618
619 err = packet_write_list(process->in, "git-filter-client", "version=2", NULL);
620 if (err)
621 goto done;
622
623 err = strcmp(packet_read_line(process->out, NULL), "git-filter-server");
624 if (err) {
625 error("external filter '%s' does not support filter protocol version 2", cmd);
626 goto done;
627 }
628 err = strcmp(packet_read_line(process->out, NULL), "version=2");
629 if (err)
630 goto done;
631 err = packet_read_line(process->out, NULL) != NULL;
632 if (err)
633 goto done;
634
635 err = packet_write_list(process->in, "capability=clean", "capability=smudge", NULL);
636
637 for (;;) {
638 cap_buf = packet_read_line(process->out, NULL);
639 if (!cap_buf)
640 break;
641 string_list_split_in_place(&cap_list, cap_buf, '=', 1);
642
643 if (cap_list.nr != 2 || strcmp(cap_list.items[0].string, "capability"))
644 continue;
645
646 cap_name = cap_list.items[1].string;
647 if (!strcmp(cap_name, "clean")) {
648 entry->supported_capabilities |= CAP_CLEAN;
649 } else if (!strcmp(cap_name, "smudge")) {
650 entry->supported_capabilities |= CAP_SMUDGE;
651 } else {
652 warning(
653 "external filter '%s' requested unsupported filter capability '%s'",
654 cmd, cap_name
655 );
656 }
657
658 string_list_clear(&cap_list, 0);
659 }
660
661 done:
662 sigchain_pop(SIGPIPE);
663
664 if (err || errno == EPIPE) {
665 error("initialization for external filter '%s' failed", cmd);
666 kill_multi_file_filter(hashmap, entry);
667 return NULL;
668 }
669
670 hashmap_add(hashmap, entry);
671 return entry;
672 }
673
674 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
675 int fd, struct strbuf *dst, const char *cmd,
676 const unsigned int wanted_capability)
677 {
678 int err;
679 struct cmd2process *entry;
680 struct child_process *process;
681 struct strbuf nbuf = STRBUF_INIT;
682 struct strbuf filter_status = STRBUF_INIT;
683 const char *filter_type;
684
685 if (!cmd_process_map_initialized) {
686 cmd_process_map_initialized = 1;
687 hashmap_init(&cmd_process_map, (hashmap_cmp_fn) cmd2process_cmp, 0);
688 entry = NULL;
689 } else {
690 entry = find_multi_file_filter_entry(&cmd_process_map, cmd);
691 }
692
693 fflush(NULL);
694
695 if (!entry) {
696 entry = start_multi_file_filter(&cmd_process_map, cmd);
697 if (!entry)
698 return 0;
699 }
700 process = &entry->process;
701
702 if (!(wanted_capability & entry->supported_capabilities))
703 return 0;
704
705 if (CAP_CLEAN & wanted_capability)
706 filter_type = "clean";
707 else if (CAP_SMUDGE & wanted_capability)
708 filter_type = "smudge";
709 else
710 die("unexpected filter type");
711
712 sigchain_push(SIGPIPE, SIG_IGN);
713
714 assert(strlen(filter_type) < LARGE_PACKET_DATA_MAX - strlen("command=\n"));
715 err = packet_write_fmt_gently(process->in, "command=%s\n", filter_type);
716 if (err)
717 goto done;
718
719 err = strlen(path) > LARGE_PACKET_DATA_MAX - strlen("pathname=\n");
720 if (err) {
721 error("path name too long for external filter");
722 goto done;
723 }
724
725 err = packet_write_fmt_gently(process->in, "pathname=%s\n", path);
726 if (err)
727 goto done;
728
729 err = packet_flush_gently(process->in);
730 if (err)
731 goto done;
732
733 if (fd >= 0)
734 err = write_packetized_from_fd(fd, process->in);
735 else
736 err = write_packetized_from_buf(src, len, process->in);
737 if (err)
738 goto done;
739
740 read_multi_file_filter_status(process->out, &filter_status);
741 err = strcmp(filter_status.buf, "success");
742 if (err)
743 goto done;
744
745 err = read_packetized_to_strbuf(process->out, &nbuf) < 0;
746 if (err)
747 goto done;
748
749 read_multi_file_filter_status(process->out, &filter_status);
750 err = strcmp(filter_status.buf, "success");
751
752 done:
753 sigchain_pop(SIGPIPE);
754
755 if (err || errno == EPIPE) {
756 if (!strcmp(filter_status.buf, "error")) {
757 /* The filter signaled a problem with the file. */
758 } else if (!strcmp(filter_status.buf, "abort")) {
759 /*
760 * The filter signaled a permanent problem. Don't try to filter
761 * files with the same command for the lifetime of the current
762 * Git process.
763 */
764 entry->supported_capabilities &= ~wanted_capability;
765 } else {
766 /*
767 * Something went wrong with the protocol filter.
768 * Force shutdown and restart if another blob requires filtering.
769 */
770 error("external filter '%s' failed", cmd);
771 kill_multi_file_filter(&cmd_process_map, entry);
772 }
773 } else {
774 strbuf_swap(dst, &nbuf);
775 }
776 strbuf_release(&nbuf);
777 return !err;
778 }
779
780 static struct convert_driver {
781 const char *name;
782 struct convert_driver *next;
783 const char *smudge;
784 const char *clean;
785 const char *process;
786 int required;
787 } *user_convert, **user_convert_tail;
788
789 static int apply_filter(const char *path, const char *src, size_t len,
790 int fd, struct strbuf *dst, struct convert_driver *drv,
791 const unsigned int wanted_capability)
792 {
793 const char *cmd = NULL;
794
795 if (!drv)
796 return 0;
797
798 if (!dst)
799 return 1;
800
801 if ((CAP_CLEAN & wanted_capability) && !drv->process && drv->clean)
802 cmd = drv->clean;
803 else if ((CAP_SMUDGE & wanted_capability) && !drv->process && drv->smudge)
804 cmd = drv->smudge;
805
806 if (cmd && *cmd)
807 return apply_single_file_filter(path, src, len, fd, dst, cmd);
808 else if (drv->process && *drv->process)
809 return apply_multi_file_filter(path, src, len, fd, dst, drv->process, wanted_capability);
810
811 return 0;
812 }
813
814 static int read_convert_config(const char *var, const char *value, void *cb)
815 {
816 const char *key, *name;
817 int namelen;
818 struct convert_driver *drv;
819
820 /*
821 * External conversion drivers are configured using
822 * "filter.<name>.variable".
823 */
824 if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
825 return 0;
826 for (drv = user_convert; drv; drv = drv->next)
827 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
828 break;
829 if (!drv) {
830 drv = xcalloc(1, sizeof(struct convert_driver));
831 drv->name = xmemdupz(name, namelen);
832 *user_convert_tail = drv;
833 user_convert_tail = &(drv->next);
834 }
835
836 /*
837 * filter.<name>.smudge and filter.<name>.clean specifies
838 * the command line:
839 *
840 * command-line
841 *
842 * The command-line will not be interpolated in any way.
843 */
844
845 if (!strcmp("smudge", key))
846 return git_config_string(&drv->smudge, var, value);
847
848 if (!strcmp("clean", key))
849 return git_config_string(&drv->clean, var, value);
850
851 if (!strcmp("process", key))
852 return git_config_string(&drv->process, var, value);
853
854 if (!strcmp("required", key)) {
855 drv->required = git_config_bool(var, value);
856 return 0;
857 }
858
859 return 0;
860 }
861
862 static int count_ident(const char *cp, unsigned long size)
863 {
864 /*
865 * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
866 */
867 int cnt = 0;
868 char ch;
869
870 while (size) {
871 ch = *cp++;
872 size--;
873 if (ch != '$')
874 continue;
875 if (size < 3)
876 break;
877 if (memcmp("Id", cp, 2))
878 continue;
879 ch = cp[2];
880 cp += 3;
881 size -= 3;
882 if (ch == '$')
883 cnt++; /* $Id$ */
884 if (ch != ':')
885 continue;
886
887 /*
888 * "$Id: ... "; scan up to the closing dollar sign and discard.
889 */
890 while (size) {
891 ch = *cp++;
892 size--;
893 if (ch == '$') {
894 cnt++;
895 break;
896 }
897 if (ch == '\n')
898 break;
899 }
900 }
901 return cnt;
902 }
903
904 static int ident_to_git(const char *path, const char *src, size_t len,
905 struct strbuf *buf, int ident)
906 {
907 char *dst, *dollar;
908
909 if (!ident || (src && !count_ident(src, len)))
910 return 0;
911
912 if (!buf)
913 return 1;
914
915 /* only grow if not in place */
916 if (strbuf_avail(buf) + buf->len < len)
917 strbuf_grow(buf, len - buf->len);
918 dst = buf->buf;
919 for (;;) {
920 dollar = memchr(src, '$', len);
921 if (!dollar)
922 break;
923 memmove(dst, src, dollar + 1 - src);
924 dst += dollar + 1 - src;
925 len -= dollar + 1 - src;
926 src = dollar + 1;
927
928 if (len > 3 && !memcmp(src, "Id:", 3)) {
929 dollar = memchr(src + 3, '$', len - 3);
930 if (!dollar)
931 break;
932 if (memchr(src + 3, '\n', dollar - src - 3)) {
933 /* Line break before the next dollar. */
934 continue;
935 }
936
937 memcpy(dst, "Id$", 3);
938 dst += 3;
939 len -= dollar + 1 - src;
940 src = dollar + 1;
941 }
942 }
943 memmove(dst, src, len);
944 strbuf_setlen(buf, dst + len - buf->buf);
945 return 1;
946 }
947
948 static int ident_to_worktree(const char *path, const char *src, size_t len,
949 struct strbuf *buf, int ident)
950 {
951 unsigned char sha1[20];
952 char *to_free = NULL, *dollar, *spc;
953 int cnt;
954
955 if (!ident)
956 return 0;
957
958 cnt = count_ident(src, len);
959 if (!cnt)
960 return 0;
961
962 /* are we "faking" in place editing ? */
963 if (src == buf->buf)
964 to_free = strbuf_detach(buf, NULL);
965 hash_sha1_file(src, len, "blob", sha1);
966
967 strbuf_grow(buf, len + cnt * 43);
968 for (;;) {
969 /* step 1: run to the next '$' */
970 dollar = memchr(src, '$', len);
971 if (!dollar)
972 break;
973 strbuf_add(buf, src, dollar + 1 - src);
974 len -= dollar + 1 - src;
975 src = dollar + 1;
976
977 /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
978 if (len < 3 || memcmp("Id", src, 2))
979 continue;
980
981 /* step 3: skip over Id$ or Id:xxxxx$ */
982 if (src[2] == '$') {
983 src += 3;
984 len -= 3;
985 } else if (src[2] == ':') {
986 /*
987 * It's possible that an expanded Id has crept its way into the
988 * repository, we cope with that by stripping the expansion out.
989 * This is probably not a good idea, since it will cause changes
990 * on checkout, which won't go away by stash, but let's keep it
991 * for git-style ids.
992 */
993 dollar = memchr(src + 3, '$', len - 3);
994 if (!dollar) {
995 /* incomplete keyword, no more '$', so just quit the loop */
996 break;
997 }
998
999 if (memchr(src + 3, '\n', dollar - src - 3)) {
1000 /* Line break before the next dollar. */
1001 continue;
1002 }
1003
1004 spc = memchr(src + 4, ' ', dollar - src - 4);
1005 if (spc && spc < dollar-1) {
1006 /* There are spaces in unexpected places.
1007 * This is probably an id from some other
1008 * versioning system. Keep it for now.
1009 */
1010 continue;
1011 }
1012
1013 len -= dollar + 1 - src;
1014 src = dollar + 1;
1015 } else {
1016 /* it wasn't a "Id$" or "Id:xxxx$" */
1017 continue;
1018 }
1019
1020 /* step 4: substitute */
1021 strbuf_addstr(buf, "Id: ");
1022 strbuf_add(buf, sha1_to_hex(sha1), 40);
1023 strbuf_addstr(buf, " $");
1024 }
1025 strbuf_add(buf, src, len);
1026
1027 free(to_free);
1028 return 1;
1029 }
1030
1031 static enum crlf_action git_path_check_crlf(struct git_attr_check *check)
1032 {
1033 const char *value = check->value;
1034
1035 if (ATTR_TRUE(value))
1036 return CRLF_TEXT;
1037 else if (ATTR_FALSE(value))
1038 return CRLF_BINARY;
1039 else if (ATTR_UNSET(value))
1040 ;
1041 else if (!strcmp(value, "input"))
1042 return CRLF_TEXT_INPUT;
1043 else if (!strcmp(value, "auto"))
1044 return CRLF_AUTO;
1045 return CRLF_UNDEFINED;
1046 }
1047
1048 static enum eol git_path_check_eol(struct git_attr_check *check)
1049 {
1050 const char *value = check->value;
1051
1052 if (ATTR_UNSET(value))
1053 ;
1054 else if (!strcmp(value, "lf"))
1055 return EOL_LF;
1056 else if (!strcmp(value, "crlf"))
1057 return EOL_CRLF;
1058 return EOL_UNSET;
1059 }
1060
1061 static struct convert_driver *git_path_check_convert(struct git_attr_check *check)
1062 {
1063 const char *value = check->value;
1064 struct convert_driver *drv;
1065
1066 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1067 return NULL;
1068 for (drv = user_convert; drv; drv = drv->next)
1069 if (!strcmp(value, drv->name))
1070 return drv;
1071 return NULL;
1072 }
1073
1074 static int git_path_check_ident(struct git_attr_check *check)
1075 {
1076 const char *value = check->value;
1077
1078 return !!ATTR_TRUE(value);
1079 }
1080
1081 struct conv_attrs {
1082 struct convert_driver *drv;
1083 enum crlf_action attr_action; /* What attr says */
1084 enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
1085 int ident;
1086 };
1087
1088 static const char *conv_attr_name[] = {
1089 "crlf", "ident", "filter", "eol", "text",
1090 };
1091 #define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
1092
1093 static void convert_attrs(struct conv_attrs *ca, const char *path)
1094 {
1095 int i;
1096 static struct git_attr_check ccheck[NUM_CONV_ATTRS];
1097
1098 if (!ccheck[0].attr) {
1099 for (i = 0; i < NUM_CONV_ATTRS; i++)
1100 ccheck[i].attr = git_attr(conv_attr_name[i]);
1101 user_convert_tail = &user_convert;
1102 git_config(read_convert_config, NULL);
1103 }
1104
1105 if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
1106 ca->crlf_action = git_path_check_crlf(ccheck + 4);
1107 if (ca->crlf_action == CRLF_UNDEFINED)
1108 ca->crlf_action = git_path_check_crlf(ccheck + 0);
1109 ca->attr_action = ca->crlf_action;
1110 ca->ident = git_path_check_ident(ccheck + 1);
1111 ca->drv = git_path_check_convert(ccheck + 2);
1112 if (ca->crlf_action != CRLF_BINARY) {
1113 enum eol eol_attr = git_path_check_eol(ccheck + 3);
1114 if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF)
1115 ca->crlf_action = CRLF_AUTO_INPUT;
1116 else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF)
1117 ca->crlf_action = CRLF_AUTO_CRLF;
1118 else if (eol_attr == EOL_LF)
1119 ca->crlf_action = CRLF_TEXT_INPUT;
1120 else if (eol_attr == EOL_CRLF)
1121 ca->crlf_action = CRLF_TEXT_CRLF;
1122 }
1123 ca->attr_action = ca->crlf_action;
1124 } else {
1125 ca->drv = NULL;
1126 ca->crlf_action = CRLF_UNDEFINED;
1127 ca->ident = 0;
1128 }
1129 if (ca->crlf_action == CRLF_TEXT)
1130 ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
1131 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
1132 ca->crlf_action = CRLF_BINARY;
1133 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE)
1134 ca->crlf_action = CRLF_AUTO_CRLF;
1135 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT)
1136 ca->crlf_action = CRLF_AUTO_INPUT;
1137 }
1138
1139 int would_convert_to_git_filter_fd(const char *path)
1140 {
1141 struct conv_attrs ca;
1142
1143 convert_attrs(&ca, path);
1144 if (!ca.drv)
1145 return 0;
1146
1147 /*
1148 * Apply a filter to an fd only if the filter is required to succeed.
1149 * We must die if the filter fails, because the original data before
1150 * filtering is not available.
1151 */
1152 if (!ca.drv->required)
1153 return 0;
1154
1155 return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN);
1156 }
1157
1158 const char *get_convert_attr_ascii(const char *path)
1159 {
1160 struct conv_attrs ca;
1161
1162 convert_attrs(&ca, path);
1163 switch (ca.attr_action) {
1164 case CRLF_UNDEFINED:
1165 return "";
1166 case CRLF_BINARY:
1167 return "-text";
1168 case CRLF_TEXT:
1169 return "text";
1170 case CRLF_TEXT_INPUT:
1171 return "text eol=lf";
1172 case CRLF_TEXT_CRLF:
1173 return "text eol=crlf";
1174 case CRLF_AUTO:
1175 return "text=auto";
1176 case CRLF_AUTO_CRLF:
1177 return "text=auto eol=crlf";
1178 case CRLF_AUTO_INPUT:
1179 return "text=auto eol=lf";
1180 }
1181 return "";
1182 }
1183
1184 int convert_to_git(const char *path, const char *src, size_t len,
1185 struct strbuf *dst, enum safe_crlf checksafe)
1186 {
1187 int ret = 0;
1188 struct conv_attrs ca;
1189
1190 convert_attrs(&ca, path);
1191
1192 ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN);
1193 if (!ret && ca.drv && ca.drv->required)
1194 die("%s: clean filter '%s' failed", path, ca.drv->name);
1195
1196 if (ret && dst) {
1197 src = dst->buf;
1198 len = dst->len;
1199 }
1200 ret |= crlf_to_git(path, src, len, dst, ca.crlf_action, checksafe);
1201 if (ret && dst) {
1202 src = dst->buf;
1203 len = dst->len;
1204 }
1205 return ret | ident_to_git(path, src, len, dst, ca.ident);
1206 }
1207
1208 void convert_to_git_filter_fd(const char *path, int fd, struct strbuf *dst,
1209 enum safe_crlf checksafe)
1210 {
1211 struct conv_attrs ca;
1212 convert_attrs(&ca, path);
1213
1214 assert(ca.drv);
1215 assert(ca.drv->clean || ca.drv->process);
1216
1217 if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN))
1218 die("%s: clean filter '%s' failed", path, ca.drv->name);
1219
1220 crlf_to_git(path, dst->buf, dst->len, dst, ca.crlf_action, checksafe);
1221 ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
1222 }
1223
1224 static int convert_to_working_tree_internal(const char *path, const char *src,
1225 size_t len, struct strbuf *dst,
1226 int normalizing)
1227 {
1228 int ret = 0, ret_filter = 0;
1229 struct conv_attrs ca;
1230
1231 convert_attrs(&ca, path);
1232
1233 ret |= ident_to_worktree(path, src, len, dst, ca.ident);
1234 if (ret) {
1235 src = dst->buf;
1236 len = dst->len;
1237 }
1238 /*
1239 * CRLF conversion can be skipped if normalizing, unless there
1240 * is a smudge or process filter (even if the process filter doesn't
1241 * support smudge). The filters might expect CRLFs.
1242 */
1243 if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
1244 ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
1245 if (ret) {
1246 src = dst->buf;
1247 len = dst->len;
1248 }
1249 }
1250
1251 ret_filter = apply_filter(path, src, len, -1, dst, ca.drv, CAP_SMUDGE);
1252 if (!ret_filter && ca.drv && ca.drv->required)
1253 die("%s: smudge filter %s failed", path, ca.drv->name);
1254
1255 return ret | ret_filter;
1256 }
1257
1258 int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
1259 {
1260 return convert_to_working_tree_internal(path, src, len, dst, 0);
1261 }
1262
1263 int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst)
1264 {
1265 int ret = convert_to_working_tree_internal(path, src, len, dst, 1);
1266 if (ret) {
1267 src = dst->buf;
1268 len = dst->len;
1269 }
1270 return ret | convert_to_git(path, src, len, dst, SAFE_CRLF_RENORMALIZE);
1271 }
1272
1273 /*****************************************************************
1274 *
1275 * Streaming conversion support
1276 *
1277 *****************************************************************/
1278
1279 typedef int (*filter_fn)(struct stream_filter *,
1280 const char *input, size_t *isize_p,
1281 char *output, size_t *osize_p);
1282 typedef void (*free_fn)(struct stream_filter *);
1283
1284 struct stream_filter_vtbl {
1285 filter_fn filter;
1286 free_fn free;
1287 };
1288
1289 struct stream_filter {
1290 struct stream_filter_vtbl *vtbl;
1291 };
1292
1293 static int null_filter_fn(struct stream_filter *filter,
1294 const char *input, size_t *isize_p,
1295 char *output, size_t *osize_p)
1296 {
1297 size_t count;
1298
1299 if (!input)
1300 return 0; /* we do not keep any states */
1301 count = *isize_p;
1302 if (*osize_p < count)
1303 count = *osize_p;
1304 if (count) {
1305 memmove(output, input, count);
1306 *isize_p -= count;
1307 *osize_p -= count;
1308 }
1309 return 0;
1310 }
1311
1312 static void null_free_fn(struct stream_filter *filter)
1313 {
1314 ; /* nothing -- null instances are shared */
1315 }
1316
1317 static struct stream_filter_vtbl null_vtbl = {
1318 null_filter_fn,
1319 null_free_fn,
1320 };
1321
1322 static struct stream_filter null_filter_singleton = {
1323 &null_vtbl,
1324 };
1325
1326 int is_null_stream_filter(struct stream_filter *filter)
1327 {
1328 return filter == &null_filter_singleton;
1329 }
1330
1331
1332 /*
1333 * LF-to-CRLF filter
1334 */
1335
1336 struct lf_to_crlf_filter {
1337 struct stream_filter filter;
1338 unsigned has_held:1;
1339 char held;
1340 };
1341
1342 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
1343 const char *input, size_t *isize_p,
1344 char *output, size_t *osize_p)
1345 {
1346 size_t count, o = 0;
1347 struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
1348
1349 /*
1350 * We may be holding onto the CR to see if it is followed by a
1351 * LF, in which case we would need to go to the main loop.
1352 * Otherwise, just emit it to the output stream.
1353 */
1354 if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
1355 output[o++] = lf_to_crlf->held;
1356 lf_to_crlf->has_held = 0;
1357 }
1358
1359 /* We are told to drain */
1360 if (!input) {
1361 *osize_p -= o;
1362 return 0;
1363 }
1364
1365 count = *isize_p;
1366 if (count || lf_to_crlf->has_held) {
1367 size_t i;
1368 int was_cr = 0;
1369
1370 if (lf_to_crlf->has_held) {
1371 was_cr = 1;
1372 lf_to_crlf->has_held = 0;
1373 }
1374
1375 for (i = 0; o < *osize_p && i < count; i++) {
1376 char ch = input[i];
1377
1378 if (ch == '\n') {
1379 output[o++] = '\r';
1380 } else if (was_cr) {
1381 /*
1382 * Previous round saw CR and it is not followed
1383 * by a LF; emit the CR before processing the
1384 * current character.
1385 */
1386 output[o++] = '\r';
1387 }
1388
1389 /*
1390 * We may have consumed the last output slot,
1391 * in which case we need to break out of this
1392 * loop; hold the current character before
1393 * returning.
1394 */
1395 if (*osize_p <= o) {
1396 lf_to_crlf->has_held = 1;
1397 lf_to_crlf->held = ch;
1398 continue; /* break but increment i */
1399 }
1400
1401 if (ch == '\r') {
1402 was_cr = 1;
1403 continue;
1404 }
1405
1406 was_cr = 0;
1407 output[o++] = ch;
1408 }
1409
1410 *osize_p -= o;
1411 *isize_p -= i;
1412
1413 if (!lf_to_crlf->has_held && was_cr) {
1414 lf_to_crlf->has_held = 1;
1415 lf_to_crlf->held = '\r';
1416 }
1417 }
1418 return 0;
1419 }
1420
1421 static void lf_to_crlf_free_fn(struct stream_filter *filter)
1422 {
1423 free(filter);
1424 }
1425
1426 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
1427 lf_to_crlf_filter_fn,
1428 lf_to_crlf_free_fn,
1429 };
1430
1431 static struct stream_filter *lf_to_crlf_filter(void)
1432 {
1433 struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
1434
1435 lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
1436 return (struct stream_filter *)lf_to_crlf;
1437 }
1438
1439 /*
1440 * Cascade filter
1441 */
1442 #define FILTER_BUFFER 1024
1443 struct cascade_filter {
1444 struct stream_filter filter;
1445 struct stream_filter *one;
1446 struct stream_filter *two;
1447 char buf[FILTER_BUFFER];
1448 int end, ptr;
1449 };
1450
1451 static int cascade_filter_fn(struct stream_filter *filter,
1452 const char *input, size_t *isize_p,
1453 char *output, size_t *osize_p)
1454 {
1455 struct cascade_filter *cas = (struct cascade_filter *) filter;
1456 size_t filled = 0;
1457 size_t sz = *osize_p;
1458 size_t to_feed, remaining;
1459
1460 /*
1461 * input -- (one) --> buf -- (two) --> output
1462 */
1463 while (filled < sz) {
1464 remaining = sz - filled;
1465
1466 /* do we already have something to feed two with? */
1467 if (cas->ptr < cas->end) {
1468 to_feed = cas->end - cas->ptr;
1469 if (stream_filter(cas->two,
1470 cas->buf + cas->ptr, &to_feed,
1471 output + filled, &remaining))
1472 return -1;
1473 cas->ptr += (cas->end - cas->ptr) - to_feed;
1474 filled = sz - remaining;
1475 continue;
1476 }
1477
1478 /* feed one from upstream and have it emit into our buffer */
1479 to_feed = input ? *isize_p : 0;
1480 if (input && !to_feed)
1481 break;
1482 remaining = sizeof(cas->buf);
1483 if (stream_filter(cas->one,
1484 input, &to_feed,
1485 cas->buf, &remaining))
1486 return -1;
1487 cas->end = sizeof(cas->buf) - remaining;
1488 cas->ptr = 0;
1489 if (input) {
1490 size_t fed = *isize_p - to_feed;
1491 *isize_p -= fed;
1492 input += fed;
1493 }
1494
1495 /* do we know that we drained one completely? */
1496 if (input || cas->end)
1497 continue;
1498
1499 /* tell two to drain; we have nothing more to give it */
1500 to_feed = 0;
1501 remaining = sz - filled;
1502 if (stream_filter(cas->two,
1503 NULL, &to_feed,
1504 output + filled, &remaining))
1505 return -1;
1506 if (remaining == (sz - filled))
1507 break; /* completely drained two */
1508 filled = sz - remaining;
1509 }
1510 *osize_p -= filled;
1511 return 0;
1512 }
1513
1514 static void cascade_free_fn(struct stream_filter *filter)
1515 {
1516 struct cascade_filter *cas = (struct cascade_filter *)filter;
1517 free_stream_filter(cas->one);
1518 free_stream_filter(cas->two);
1519 free(filter);
1520 }
1521
1522 static struct stream_filter_vtbl cascade_vtbl = {
1523 cascade_filter_fn,
1524 cascade_free_fn,
1525 };
1526
1527 static struct stream_filter *cascade_filter(struct stream_filter *one,
1528 struct stream_filter *two)
1529 {
1530 struct cascade_filter *cascade;
1531
1532 if (!one || is_null_stream_filter(one))
1533 return two;
1534 if (!two || is_null_stream_filter(two))
1535 return one;
1536
1537 cascade = xmalloc(sizeof(*cascade));
1538 cascade->one = one;
1539 cascade->two = two;
1540 cascade->end = cascade->ptr = 0;
1541 cascade->filter.vtbl = &cascade_vtbl;
1542 return (struct stream_filter *)cascade;
1543 }
1544
1545 /*
1546 * ident filter
1547 */
1548 #define IDENT_DRAINING (-1)
1549 #define IDENT_SKIPPING (-2)
1550 struct ident_filter {
1551 struct stream_filter filter;
1552 struct strbuf left;
1553 int state;
1554 char ident[45]; /* ": x40 $" */
1555 };
1556
1557 static int is_foreign_ident(const char *str)
1558 {
1559 int i;
1560
1561 if (!skip_prefix(str, "$Id: ", &str))
1562 return 0;
1563 for (i = 0; str[i]; i++) {
1564 if (isspace(str[i]) && str[i+1] != '$')
1565 return 1;
1566 }
1567 return 0;
1568 }
1569
1570 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1571 {
1572 size_t to_drain = ident->left.len;
1573
1574 if (*osize_p < to_drain)
1575 to_drain = *osize_p;
1576 if (to_drain) {
1577 memcpy(*output_p, ident->left.buf, to_drain);
1578 strbuf_remove(&ident->left, 0, to_drain);
1579 *output_p += to_drain;
1580 *osize_p -= to_drain;
1581 }
1582 if (!ident->left.len)
1583 ident->state = 0;
1584 }
1585
1586 static int ident_filter_fn(struct stream_filter *filter,
1587 const char *input, size_t *isize_p,
1588 char *output, size_t *osize_p)
1589 {
1590 struct ident_filter *ident = (struct ident_filter *)filter;
1591 static const char head[] = "$Id";
1592
1593 if (!input) {
1594 /* drain upon eof */
1595 switch (ident->state) {
1596 default:
1597 strbuf_add(&ident->left, head, ident->state);
1598 case IDENT_SKIPPING:
1599 /* fallthru */
1600 case IDENT_DRAINING:
1601 ident_drain(ident, &output, osize_p);
1602 }
1603 return 0;
1604 }
1605
1606 while (*isize_p || (ident->state == IDENT_DRAINING)) {
1607 int ch;
1608
1609 if (ident->state == IDENT_DRAINING) {
1610 ident_drain(ident, &output, osize_p);
1611 if (!*osize_p)
1612 break;
1613 continue;
1614 }
1615
1616 ch = *(input++);
1617 (*isize_p)--;
1618
1619 if (ident->state == IDENT_SKIPPING) {
1620 /*
1621 * Skipping until '$' or LF, but keeping them
1622 * in case it is a foreign ident.
1623 */
1624 strbuf_addch(&ident->left, ch);
1625 if (ch != '\n' && ch != '$')
1626 continue;
1627 if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1628 strbuf_setlen(&ident->left, sizeof(head) - 1);
1629 strbuf_addstr(&ident->left, ident->ident);
1630 }
1631 ident->state = IDENT_DRAINING;
1632 continue;
1633 }
1634
1635 if (ident->state < sizeof(head) &&
1636 head[ident->state] == ch) {
1637 ident->state++;
1638 continue;
1639 }
1640
1641 if (ident->state)
1642 strbuf_add(&ident->left, head, ident->state);
1643 if (ident->state == sizeof(head) - 1) {
1644 if (ch != ':' && ch != '$') {
1645 strbuf_addch(&ident->left, ch);
1646 ident->state = 0;
1647 continue;
1648 }
1649
1650 if (ch == ':') {
1651 strbuf_addch(&ident->left, ch);
1652 ident->state = IDENT_SKIPPING;
1653 } else {
1654 strbuf_addstr(&ident->left, ident->ident);
1655 ident->state = IDENT_DRAINING;
1656 }
1657 continue;
1658 }
1659
1660 strbuf_addch(&ident->left, ch);
1661 ident->state = IDENT_DRAINING;
1662 }
1663 return 0;
1664 }
1665
1666 static void ident_free_fn(struct stream_filter *filter)
1667 {
1668 struct ident_filter *ident = (struct ident_filter *)filter;
1669 strbuf_release(&ident->left);
1670 free(filter);
1671 }
1672
1673 static struct stream_filter_vtbl ident_vtbl = {
1674 ident_filter_fn,
1675 ident_free_fn,
1676 };
1677
1678 static struct stream_filter *ident_filter(const unsigned char *sha1)
1679 {
1680 struct ident_filter *ident = xmalloc(sizeof(*ident));
1681
1682 xsnprintf(ident->ident, sizeof(ident->ident),
1683 ": %s $", sha1_to_hex(sha1));
1684 strbuf_init(&ident->left, 0);
1685 ident->filter.vtbl = &ident_vtbl;
1686 ident->state = 0;
1687 return (struct stream_filter *)ident;
1688 }
1689
1690 /*
1691 * Return an appropriately constructed filter for the path, or NULL if
1692 * the contents cannot be filtered without reading the whole thing
1693 * in-core.
1694 *
1695 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1696 * large binary blob you would want us not to slurp into the memory!
1697 */
1698 struct stream_filter *get_stream_filter(const char *path, const unsigned char *sha1)
1699 {
1700 struct conv_attrs ca;
1701 struct stream_filter *filter = NULL;
1702
1703 convert_attrs(&ca, path);
1704 if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
1705 return NULL;
1706
1707 if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
1708 return NULL;
1709
1710 if (ca.ident)
1711 filter = ident_filter(sha1);
1712
1713 if (output_eol(ca.crlf_action) == EOL_CRLF)
1714 filter = cascade_filter(filter, lf_to_crlf_filter());
1715 else
1716 filter = cascade_filter(filter, &null_filter_singleton);
1717
1718 return filter;
1719 }
1720
1721 void free_stream_filter(struct stream_filter *filter)
1722 {
1723 filter->vtbl->free(filter);
1724 }
1725
1726 int stream_filter(struct stream_filter *filter,
1727 const char *input, size_t *isize_p,
1728 char *output, size_t *osize_p)
1729 {
1730 return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
1731 }
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