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pkt-line: annotate packet_writel with LAST_ARG_MUST_BE_NULL
[git.git] / convert.c
blob0f1b5a634043debb8c4793e9f12576d5ea431ad3
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 void read_multi_file_filter_status(int fd, struct strbuf *status)
525 {
526 struct strbuf **pair;
527 char *line;
528 for (;;) {
529 line = packet_read_line(fd, NULL);
530 if (!line)
531 break;
532 pair = strbuf_split_str(line, '=', 2);
533 if (pair[0] && pair[0]->len && pair[1]) {
534 /* the last "status=<foo>" line wins */
535 if (!strcmp(pair[0]->buf, "status=")) {
536 strbuf_reset(status);
537 strbuf_addbuf(status, pair[1]);
538 }
539 }
540 strbuf_list_free(pair);
541 }
542 }
543
544 static void kill_multi_file_filter(struct hashmap *hashmap, struct cmd2process *entry)
545 {
546 if (!entry)
547 return;
548
549 entry->process.clean_on_exit = 0;
550 kill(entry->process.pid, SIGTERM);
551 finish_command(&entry->process);
552
553 hashmap_remove(hashmap, entry, NULL);
554 free(entry);
555 }
556
557 static void stop_multi_file_filter(struct child_process *process)
558 {
559 sigchain_push(SIGPIPE, SIG_IGN);
560 /* Closing the pipe signals the filter to initiate a shutdown. */
561 close(process->in);
562 close(process->out);
563 sigchain_pop(SIGPIPE);
564 /* Finish command will wait until the shutdown is complete. */
565 finish_command(process);
566 }
567
568 static struct cmd2process *start_multi_file_filter(struct hashmap *hashmap, const char *cmd)
569 {
570 int err;
571 struct cmd2process *entry;
572 struct child_process *process;
573 const char *argv[] = { cmd, NULL };
574 struct string_list cap_list = STRING_LIST_INIT_NODUP;
575 char *cap_buf;
576 const char *cap_name;
577
578 entry = xmalloc(sizeof(*entry));
579 entry->cmd = cmd;
580 entry->supported_capabilities = 0;
581 process = &entry->process;
582
583 child_process_init(process);
584 process->argv = argv;
585 process->use_shell = 1;
586 process->in = -1;
587 process->out = -1;
588 process->clean_on_exit = 1;
589 process->clean_on_exit_handler = stop_multi_file_filter;
590
591 if (start_command(process)) {
592 error("cannot fork to run external filter '%s'", cmd);
593 return NULL;
594 }
595
596 hashmap_entry_init(entry, strhash(cmd));
597
598 sigchain_push(SIGPIPE, SIG_IGN);
599
600 err = packet_writel(process->in, "git-filter-client", "version=2", NULL);
601 if (err)
602 goto done;
603
604 err = strcmp(packet_read_line(process->out, NULL), "git-filter-server");
605 if (err) {
606 error("external filter '%s' does not support filter protocol version 2", cmd);
607 goto done;
608 }
609 err = strcmp(packet_read_line(process->out, NULL), "version=2");
610 if (err)
611 goto done;
612 err = packet_read_line(process->out, NULL) != NULL;
613 if (err)
614 goto done;
615
616 err = packet_writel(process->in, "capability=clean", "capability=smudge", NULL);
617
618 for (;;) {
619 cap_buf = packet_read_line(process->out, NULL);
620 if (!cap_buf)
621 break;
622 string_list_split_in_place(&cap_list, cap_buf, '=', 1);
623
624 if (cap_list.nr != 2 || strcmp(cap_list.items[0].string, "capability"))
625 continue;
626
627 cap_name = cap_list.items[1].string;
628 if (!strcmp(cap_name, "clean")) {
629 entry->supported_capabilities |= CAP_CLEAN;
630 } else if (!strcmp(cap_name, "smudge")) {
631 entry->supported_capabilities |= CAP_SMUDGE;
632 } else {
633 warning(
634 "external filter '%s' requested unsupported filter capability '%s'",
635 cmd, cap_name
636 );
637 }
638
639 string_list_clear(&cap_list, 0);
640 }
641
642 done:
643 sigchain_pop(SIGPIPE);
644
645 if (err) {
646 error("initialization for external filter '%s' failed", cmd);
647 kill_multi_file_filter(hashmap, entry);
648 return NULL;
649 }
650
651 hashmap_add(hashmap, entry);
652 return entry;
653 }
654
655 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
656 int fd, struct strbuf *dst, const char *cmd,
657 const unsigned int wanted_capability)
658 {
659 int err;
660 struct cmd2process *entry;
661 struct child_process *process;
662 struct strbuf nbuf = STRBUF_INIT;
663 struct strbuf filter_status = STRBUF_INIT;
664 const char *filter_type;
665
666 if (!cmd_process_map_initialized) {
667 cmd_process_map_initialized = 1;
668 hashmap_init(&cmd_process_map, (hashmap_cmp_fn) cmd2process_cmp, 0);
669 entry = NULL;
670 } else {
671 entry = find_multi_file_filter_entry(&cmd_process_map, cmd);
672 }
673
674 fflush(NULL);
675
676 if (!entry) {
677 entry = start_multi_file_filter(&cmd_process_map, cmd);
678 if (!entry)
679 return 0;
680 }
681 process = &entry->process;
682
683 if (!(wanted_capability & entry->supported_capabilities))
684 return 0;
685
686 if (CAP_CLEAN & wanted_capability)
687 filter_type = "clean";
688 else if (CAP_SMUDGE & wanted_capability)
689 filter_type = "smudge";
690 else
691 die("unexpected filter type");
692
693 sigchain_push(SIGPIPE, SIG_IGN);
694
695 assert(strlen(filter_type) < LARGE_PACKET_DATA_MAX - strlen("command=\n"));
696 err = packet_write_fmt_gently(process->in, "command=%s\n", filter_type);
697 if (err)
698 goto done;
699
700 err = strlen(path) > LARGE_PACKET_DATA_MAX - strlen("pathname=\n");
701 if (err) {
702 error("path name too long for external filter");
703 goto done;
704 }
705
706 err = packet_write_fmt_gently(process->in, "pathname=%s\n", path);
707 if (err)
708 goto done;
709
710 err = packet_flush_gently(process->in);
711 if (err)
712 goto done;
713
714 if (fd >= 0)
715 err = write_packetized_from_fd(fd, process->in);
716 else
717 err = write_packetized_from_buf(src, len, process->in);
718 if (err)
719 goto done;
720
721 read_multi_file_filter_status(process->out, &filter_status);
722 err = strcmp(filter_status.buf, "success");
723 if (err)
724 goto done;
725
726 err = read_packetized_to_strbuf(process->out, &nbuf) < 0;
727 if (err)
728 goto done;
729
730 read_multi_file_filter_status(process->out, &filter_status);
731 err = strcmp(filter_status.buf, "success");
732
733 done:
734 sigchain_pop(SIGPIPE);
735
736 if (err) {
737 if (!strcmp(filter_status.buf, "error")) {
738 /* The filter signaled a problem with the file. */
739 } else if (!strcmp(filter_status.buf, "abort")) {
740 /*
741 * The filter signaled a permanent problem. Don't try to filter
742 * files with the same command for the lifetime of the current
743 * Git process.
744 */
745 entry->supported_capabilities &= ~wanted_capability;
746 } else {
747 /*
748 * Something went wrong with the protocol filter.
749 * Force shutdown and restart if another blob requires filtering.
750 */
751 error("external filter '%s' failed", cmd);
752 kill_multi_file_filter(&cmd_process_map, entry);
753 }
754 } else {
755 strbuf_swap(dst, &nbuf);
756 }
757 strbuf_release(&nbuf);
758 return !err;
759 }
760
761 static struct convert_driver {
762 const char *name;
763 struct convert_driver *next;
764 const char *smudge;
765 const char *clean;
766 const char *process;
767 int required;
768 } *user_convert, **user_convert_tail;
769
770 static int apply_filter(const char *path, const char *src, size_t len,
771 int fd, struct strbuf *dst, struct convert_driver *drv,
772 const unsigned int wanted_capability)
773 {
774 const char *cmd = NULL;
775
776 if (!drv)
777 return 0;
778
779 if (!dst)
780 return 1;
781
782 if ((CAP_CLEAN & wanted_capability) && !drv->process && drv->clean)
783 cmd = drv->clean;
784 else if ((CAP_SMUDGE & wanted_capability) && !drv->process && drv->smudge)
785 cmd = drv->smudge;
786
787 if (cmd && *cmd)
788 return apply_single_file_filter(path, src, len, fd, dst, cmd);
789 else if (drv->process && *drv->process)
790 return apply_multi_file_filter(path, src, len, fd, dst, drv->process, wanted_capability);
791
792 return 0;
793 }
794
795 static int read_convert_config(const char *var, const char *value, void *cb)
796 {
797 const char *key, *name;
798 int namelen;
799 struct convert_driver *drv;
800
801 /*
802 * External conversion drivers are configured using
803 * "filter.<name>.variable".
804 */
805 if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
806 return 0;
807 for (drv = user_convert; drv; drv = drv->next)
808 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
809 break;
810 if (!drv) {
811 drv = xcalloc(1, sizeof(struct convert_driver));
812 drv->name = xmemdupz(name, namelen);
813 *user_convert_tail = drv;
814 user_convert_tail = &(drv->next);
815 }
816
817 /*
818 * filter.<name>.smudge and filter.<name>.clean specifies
819 * the command line:
820 *
821 * command-line
822 *
823 * The command-line will not be interpolated in any way.
824 */
825
826 if (!strcmp("smudge", key))
827 return git_config_string(&drv->smudge, var, value);
828
829 if (!strcmp("clean", key))
830 return git_config_string(&drv->clean, var, value);
831
832 if (!strcmp("process", key))
833 return git_config_string(&drv->process, var, value);
834
835 if (!strcmp("required", key)) {
836 drv->required = git_config_bool(var, value);
837 return 0;
838 }
839
840 return 0;
841 }
842
843 static int count_ident(const char *cp, unsigned long size)
844 {
845 /*
846 * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
847 */
848 int cnt = 0;
849 char ch;
850
851 while (size) {
852 ch = *cp++;
853 size--;
854 if (ch != '$')
855 continue;
856 if (size < 3)
857 break;
858 if (memcmp("Id", cp, 2))
859 continue;
860 ch = cp[2];
861 cp += 3;
862 size -= 3;
863 if (ch == '$')
864 cnt++; /* $Id$ */
865 if (ch != ':')
866 continue;
867
868 /*
869 * "$Id: ... "; scan up to the closing dollar sign and discard.
870 */
871 while (size) {
872 ch = *cp++;
873 size--;
874 if (ch == '$') {
875 cnt++;
876 break;
877 }
878 if (ch == '\n')
879 break;
880 }
881 }
882 return cnt;
883 }
884
885 static int ident_to_git(const char *path, const char *src, size_t len,
886 struct strbuf *buf, int ident)
887 {
888 char *dst, *dollar;
889
890 if (!ident || (src && !count_ident(src, len)))
891 return 0;
892
893 if (!buf)
894 return 1;
895
896 /* only grow if not in place */
897 if (strbuf_avail(buf) + buf->len < len)
898 strbuf_grow(buf, len - buf->len);
899 dst = buf->buf;
900 for (;;) {
901 dollar = memchr(src, '$', len);
902 if (!dollar)
903 break;
904 memmove(dst, src, dollar + 1 - src);
905 dst += dollar + 1 - src;
906 len -= dollar + 1 - src;
907 src = dollar + 1;
908
909 if (len > 3 && !memcmp(src, "Id:", 3)) {
910 dollar = memchr(src + 3, '$', len - 3);
911 if (!dollar)
912 break;
913 if (memchr(src + 3, '\n', dollar - src - 3)) {
914 /* Line break before the next dollar. */
915 continue;
916 }
917
918 memcpy(dst, "Id$", 3);
919 dst += 3;
920 len -= dollar + 1 - src;
921 src = dollar + 1;
922 }
923 }
924 memmove(dst, src, len);
925 strbuf_setlen(buf, dst + len - buf->buf);
926 return 1;
927 }
928
929 static int ident_to_worktree(const char *path, const char *src, size_t len,
930 struct strbuf *buf, int ident)
931 {
932 unsigned char sha1[20];
933 char *to_free = NULL, *dollar, *spc;
934 int cnt;
935
936 if (!ident)
937 return 0;
938
939 cnt = count_ident(src, len);
940 if (!cnt)
941 return 0;
942
943 /* are we "faking" in place editing ? */
944 if (src == buf->buf)
945 to_free = strbuf_detach(buf, NULL);
946 hash_sha1_file(src, len, "blob", sha1);
947
948 strbuf_grow(buf, len + cnt * 43);
949 for (;;) {
950 /* step 1: run to the next '$' */
951 dollar = memchr(src, '$', len);
952 if (!dollar)
953 break;
954 strbuf_add(buf, src, dollar + 1 - src);
955 len -= dollar + 1 - src;
956 src = dollar + 1;
957
958 /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
959 if (len < 3 || memcmp("Id", src, 2))
960 continue;
961
962 /* step 3: skip over Id$ or Id:xxxxx$ */
963 if (src[2] == '$') {
964 src += 3;
965 len -= 3;
966 } else if (src[2] == ':') {
967 /*
968 * It's possible that an expanded Id has crept its way into the
969 * repository, we cope with that by stripping the expansion out.
970 * This is probably not a good idea, since it will cause changes
971 * on checkout, which won't go away by stash, but let's keep it
972 * for git-style ids.
973 */
974 dollar = memchr(src + 3, '$', len - 3);
975 if (!dollar) {
976 /* incomplete keyword, no more '$', so just quit the loop */
977 break;
978 }
979
980 if (memchr(src + 3, '\n', dollar - src - 3)) {
981 /* Line break before the next dollar. */
982 continue;
983 }
984
985 spc = memchr(src + 4, ' ', dollar - src - 4);
986 if (spc && spc < dollar-1) {
987 /* There are spaces in unexpected places.
988 * This is probably an id from some other
989 * versioning system. Keep it for now.
990 */
991 continue;
992 }
993
994 len -= dollar + 1 - src;
995 src = dollar + 1;
996 } else {
997 /* it wasn't a "Id$" or "Id:xxxx$" */
998 continue;
999 }
1000
1001 /* step 4: substitute */
1002 strbuf_addstr(buf, "Id: ");
1003 strbuf_add(buf, sha1_to_hex(sha1), 40);
1004 strbuf_addstr(buf, " $");
1005 }
1006 strbuf_add(buf, src, len);
1007
1008 free(to_free);
1009 return 1;
1010 }
1011
1012 static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
1013 {
1014 const char *value = check->value;
1015
1016 if (ATTR_TRUE(value))
1017 return CRLF_TEXT;
1018 else if (ATTR_FALSE(value))
1019 return CRLF_BINARY;
1020 else if (ATTR_UNSET(value))
1021 ;
1022 else if (!strcmp(value, "input"))
1023 return CRLF_TEXT_INPUT;
1024 else if (!strcmp(value, "auto"))
1025 return CRLF_AUTO;
1026 return CRLF_UNDEFINED;
1027 }
1028
1029 static enum eol git_path_check_eol(struct attr_check_item *check)
1030 {
1031 const char *value = check->value;
1032
1033 if (ATTR_UNSET(value))
1034 ;
1035 else if (!strcmp(value, "lf"))
1036 return EOL_LF;
1037 else if (!strcmp(value, "crlf"))
1038 return EOL_CRLF;
1039 return EOL_UNSET;
1040 }
1041
1042 static struct convert_driver *git_path_check_convert(struct attr_check_item *check)
1043 {
1044 const char *value = check->value;
1045 struct convert_driver *drv;
1046
1047 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1048 return NULL;
1049 for (drv = user_convert; drv; drv = drv->next)
1050 if (!strcmp(value, drv->name))
1051 return drv;
1052 return NULL;
1053 }
1054
1055 static int git_path_check_ident(struct attr_check_item *check)
1056 {
1057 const char *value = check->value;
1058
1059 return !!ATTR_TRUE(value);
1060 }
1061
1062 struct conv_attrs {
1063 struct convert_driver *drv;
1064 enum crlf_action attr_action; /* What attr says */
1065 enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
1066 int ident;
1067 };
1068
1069 static void convert_attrs(struct conv_attrs *ca, const char *path)
1070 {
1071 static struct attr_check *check;
1072
1073 if (!check) {
1074 check = attr_check_initl("crlf", "ident", "filter",
1075 "eol", "text", NULL);
1076 user_convert_tail = &user_convert;
1077 git_config(read_convert_config, NULL);
1078 }
1079
1080 if (!git_check_attr(path, check)) {
1081 struct attr_check_item *ccheck = check->items;
1082 ca->crlf_action = git_path_check_crlf(ccheck + 4);
1083 if (ca->crlf_action == CRLF_UNDEFINED)
1084 ca->crlf_action = git_path_check_crlf(ccheck + 0);
1085 ca->attr_action = ca->crlf_action;
1086 ca->ident = git_path_check_ident(ccheck + 1);
1087 ca->drv = git_path_check_convert(ccheck + 2);
1088 if (ca->crlf_action != CRLF_BINARY) {
1089 enum eol eol_attr = git_path_check_eol(ccheck + 3);
1090 if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF)
1091 ca->crlf_action = CRLF_AUTO_INPUT;
1092 else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF)
1093 ca->crlf_action = CRLF_AUTO_CRLF;
1094 else if (eol_attr == EOL_LF)
1095 ca->crlf_action = CRLF_TEXT_INPUT;
1096 else if (eol_attr == EOL_CRLF)
1097 ca->crlf_action = CRLF_TEXT_CRLF;
1098 }
1099 ca->attr_action = ca->crlf_action;
1100 } else {
1101 ca->drv = NULL;
1102 ca->crlf_action = CRLF_UNDEFINED;
1103 ca->ident = 0;
1104 }
1105 if (ca->crlf_action == CRLF_TEXT)
1106 ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
1107 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
1108 ca->crlf_action = CRLF_BINARY;
1109 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE)
1110 ca->crlf_action = CRLF_AUTO_CRLF;
1111 if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT)
1112 ca->crlf_action = CRLF_AUTO_INPUT;
1113 }
1114
1115 int would_convert_to_git_filter_fd(const char *path)
1116 {
1117 struct conv_attrs ca;
1118
1119 convert_attrs(&ca, path);
1120 if (!ca.drv)
1121 return 0;
1122
1123 /*
1124 * Apply a filter to an fd only if the filter is required to succeed.
1125 * We must die if the filter fails, because the original data before
1126 * filtering is not available.
1127 */
1128 if (!ca.drv->required)
1129 return 0;
1130
1131 return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN);
1132 }
1133
1134 const char *get_convert_attr_ascii(const char *path)
1135 {
1136 struct conv_attrs ca;
1137
1138 convert_attrs(&ca, path);
1139 switch (ca.attr_action) {
1140 case CRLF_UNDEFINED:
1141 return "";
1142 case CRLF_BINARY:
1143 return "-text";
1144 case CRLF_TEXT:
1145 return "text";
1146 case CRLF_TEXT_INPUT:
1147 return "text eol=lf";
1148 case CRLF_TEXT_CRLF:
1149 return "text eol=crlf";
1150 case CRLF_AUTO:
1151 return "text=auto";
1152 case CRLF_AUTO_CRLF:
1153 return "text=auto eol=crlf";
1154 case CRLF_AUTO_INPUT:
1155 return "text=auto eol=lf";
1156 }
1157 return "";
1158 }
1159
1160 int convert_to_git(const char *path, const char *src, size_t len,
1161 struct strbuf *dst, enum safe_crlf checksafe)
1162 {
1163 int ret = 0;
1164 struct conv_attrs ca;
1165
1166 convert_attrs(&ca, path);
1167
1168 ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN);
1169 if (!ret && ca.drv && ca.drv->required)
1170 die("%s: clean filter '%s' failed", path, ca.drv->name);
1171
1172 if (ret && dst) {
1173 src = dst->buf;
1174 len = dst->len;
1175 }
1176 ret |= crlf_to_git(path, src, len, dst, ca.crlf_action, checksafe);
1177 if (ret && dst) {
1178 src = dst->buf;
1179 len = dst->len;
1180 }
1181 return ret | ident_to_git(path, src, len, dst, ca.ident);
1182 }
1183
1184 void convert_to_git_filter_fd(const char *path, int fd, struct strbuf *dst,
1185 enum safe_crlf checksafe)
1186 {
1187 struct conv_attrs ca;
1188 convert_attrs(&ca, path);
1189
1190 assert(ca.drv);
1191 assert(ca.drv->clean || ca.drv->process);
1192
1193 if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN))
1194 die("%s: clean filter '%s' failed", path, ca.drv->name);
1195
1196 crlf_to_git(path, dst->buf, dst->len, dst, ca.crlf_action, checksafe);
1197 ident_to_git(path, dst->buf, dst->len, dst, ca.ident);
1198 }
1199
1200 static int convert_to_working_tree_internal(const char *path, const char *src,
1201 size_t len, struct strbuf *dst,
1202 int normalizing)
1203 {
1204 int ret = 0, ret_filter = 0;
1205 struct conv_attrs ca;
1206
1207 convert_attrs(&ca, path);
1208
1209 ret |= ident_to_worktree(path, src, len, dst, ca.ident);
1210 if (ret) {
1211 src = dst->buf;
1212 len = dst->len;
1213 }
1214 /*
1215 * CRLF conversion can be skipped if normalizing, unless there
1216 * is a smudge or process filter (even if the process filter doesn't
1217 * support smudge). The filters might expect CRLFs.
1218 */
1219 if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
1220 ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
1221 if (ret) {
1222 src = dst->buf;
1223 len = dst->len;
1224 }
1225 }
1226
1227 ret_filter = apply_filter(path, src, len, -1, dst, ca.drv, CAP_SMUDGE);
1228 if (!ret_filter && ca.drv && ca.drv->required)
1229 die("%s: smudge filter %s failed", path, ca.drv->name);
1230
1231 return ret | ret_filter;
1232 }
1233
1234 int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
1235 {
1236 return convert_to_working_tree_internal(path, src, len, dst, 0);
1237 }
1238
1239 int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst)
1240 {
1241 int ret = convert_to_working_tree_internal(path, src, len, dst, 1);
1242 if (ret) {
1243 src = dst->buf;
1244 len = dst->len;
1245 }
1246 return ret | convert_to_git(path, src, len, dst, SAFE_CRLF_RENORMALIZE);
1247 }
1248
1249 /*****************************************************************
1250 *
1251 * Streaming conversion support
1252 *
1253 *****************************************************************/
1254
1255 typedef int (*filter_fn)(struct stream_filter *,
1256 const char *input, size_t *isize_p,
1257 char *output, size_t *osize_p);
1258 typedef void (*free_fn)(struct stream_filter *);
1259
1260 struct stream_filter_vtbl {
1261 filter_fn filter;
1262 free_fn free;
1263 };
1264
1265 struct stream_filter {
1266 struct stream_filter_vtbl *vtbl;
1267 };
1268
1269 static int null_filter_fn(struct stream_filter *filter,
1270 const char *input, size_t *isize_p,
1271 char *output, size_t *osize_p)
1272 {
1273 size_t count;
1274
1275 if (!input)
1276 return 0; /* we do not keep any states */
1277 count = *isize_p;
1278 if (*osize_p < count)
1279 count = *osize_p;
1280 if (count) {
1281 memmove(output, input, count);
1282 *isize_p -= count;
1283 *osize_p -= count;
1284 }
1285 return 0;
1286 }
1287
1288 static void null_free_fn(struct stream_filter *filter)
1289 {
1290 ; /* nothing -- null instances are shared */
1291 }
1292
1293 static struct stream_filter_vtbl null_vtbl = {
1294 null_filter_fn,
1295 null_free_fn,
1296 };
1297
1298 static struct stream_filter null_filter_singleton = {
1299 &null_vtbl,
1300 };
1301
1302 int is_null_stream_filter(struct stream_filter *filter)
1303 {
1304 return filter == &null_filter_singleton;
1305 }
1306
1307
1308 /*
1309 * LF-to-CRLF filter
1310 */
1311
1312 struct lf_to_crlf_filter {
1313 struct stream_filter filter;
1314 unsigned has_held:1;
1315 char held;
1316 };
1317
1318 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
1319 const char *input, size_t *isize_p,
1320 char *output, size_t *osize_p)
1321 {
1322 size_t count, o = 0;
1323 struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
1324
1325 /*
1326 * We may be holding onto the CR to see if it is followed by a
1327 * LF, in which case we would need to go to the main loop.
1328 * Otherwise, just emit it to the output stream.
1329 */
1330 if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
1331 output[o++] = lf_to_crlf->held;
1332 lf_to_crlf->has_held = 0;
1333 }
1334
1335 /* We are told to drain */
1336 if (!input) {
1337 *osize_p -= o;
1338 return 0;
1339 }
1340
1341 count = *isize_p;
1342 if (count || lf_to_crlf->has_held) {
1343 size_t i;
1344 int was_cr = 0;
1345
1346 if (lf_to_crlf->has_held) {
1347 was_cr = 1;
1348 lf_to_crlf->has_held = 0;
1349 }
1350
1351 for (i = 0; o < *osize_p && i < count; i++) {
1352 char ch = input[i];
1353
1354 if (ch == '\n') {
1355 output[o++] = '\r';
1356 } else if (was_cr) {
1357 /*
1358 * Previous round saw CR and it is not followed
1359 * by a LF; emit the CR before processing the
1360 * current character.
1361 */
1362 output[o++] = '\r';
1363 }
1364
1365 /*
1366 * We may have consumed the last output slot,
1367 * in which case we need to break out of this
1368 * loop; hold the current character before
1369 * returning.
1370 */
1371 if (*osize_p <= o) {
1372 lf_to_crlf->has_held = 1;
1373 lf_to_crlf->held = ch;
1374 continue; /* break but increment i */
1375 }
1376
1377 if (ch == '\r') {
1378 was_cr = 1;
1379 continue;
1380 }
1381
1382 was_cr = 0;
1383 output[o++] = ch;
1384 }
1385
1386 *osize_p -= o;
1387 *isize_p -= i;
1388
1389 if (!lf_to_crlf->has_held && was_cr) {
1390 lf_to_crlf->has_held = 1;
1391 lf_to_crlf->held = '\r';
1392 }
1393 }
1394 return 0;
1395 }
1396
1397 static void lf_to_crlf_free_fn(struct stream_filter *filter)
1398 {
1399 free(filter);
1400 }
1401
1402 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
1403 lf_to_crlf_filter_fn,
1404 lf_to_crlf_free_fn,
1405 };
1406
1407 static struct stream_filter *lf_to_crlf_filter(void)
1408 {
1409 struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
1410
1411 lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
1412 return (struct stream_filter *)lf_to_crlf;
1413 }
1414
1415 /*
1416 * Cascade filter
1417 */
1418 #define FILTER_BUFFER 1024
1419 struct cascade_filter {
1420 struct stream_filter filter;
1421 struct stream_filter *one;
1422 struct stream_filter *two;
1423 char buf[FILTER_BUFFER];
1424 int end, ptr;
1425 };
1426
1427 static int cascade_filter_fn(struct stream_filter *filter,
1428 const char *input, size_t *isize_p,
1429 char *output, size_t *osize_p)
1430 {
1431 struct cascade_filter *cas = (struct cascade_filter *) filter;
1432 size_t filled = 0;
1433 size_t sz = *osize_p;
1434 size_t to_feed, remaining;
1435
1436 /*
1437 * input -- (one) --> buf -- (two) --> output
1438 */
1439 while (filled < sz) {
1440 remaining = sz - filled;
1441
1442 /* do we already have something to feed two with? */
1443 if (cas->ptr < cas->end) {
1444 to_feed = cas->end - cas->ptr;
1445 if (stream_filter(cas->two,
1446 cas->buf + cas->ptr, &to_feed,
1447 output + filled, &remaining))
1448 return -1;
1449 cas->ptr += (cas->end - cas->ptr) - to_feed;
1450 filled = sz - remaining;
1451 continue;
1452 }
1453
1454 /* feed one from upstream and have it emit into our buffer */
1455 to_feed = input ? *isize_p : 0;
1456 if (input && !to_feed)
1457 break;
1458 remaining = sizeof(cas->buf);
1459 if (stream_filter(cas->one,
1460 input, &to_feed,
1461 cas->buf, &remaining))
1462 return -1;
1463 cas->end = sizeof(cas->buf) - remaining;
1464 cas->ptr = 0;
1465 if (input) {
1466 size_t fed = *isize_p - to_feed;
1467 *isize_p -= fed;
1468 input += fed;
1469 }
1470
1471 /* do we know that we drained one completely? */
1472 if (input || cas->end)
1473 continue;
1474
1475 /* tell two to drain; we have nothing more to give it */
1476 to_feed = 0;
1477 remaining = sz - filled;
1478 if (stream_filter(cas->two,
1479 NULL, &to_feed,
1480 output + filled, &remaining))
1481 return -1;
1482 if (remaining == (sz - filled))
1483 break; /* completely drained two */
1484 filled = sz - remaining;
1485 }
1486 *osize_p -= filled;
1487 return 0;
1488 }
1489
1490 static void cascade_free_fn(struct stream_filter *filter)
1491 {
1492 struct cascade_filter *cas = (struct cascade_filter *)filter;
1493 free_stream_filter(cas->one);
1494 free_stream_filter(cas->two);
1495 free(filter);
1496 }
1497
1498 static struct stream_filter_vtbl cascade_vtbl = {
1499 cascade_filter_fn,
1500 cascade_free_fn,
1501 };
1502
1503 static struct stream_filter *cascade_filter(struct stream_filter *one,
1504 struct stream_filter *two)
1505 {
1506 struct cascade_filter *cascade;
1507
1508 if (!one || is_null_stream_filter(one))
1509 return two;
1510 if (!two || is_null_stream_filter(two))
1511 return one;
1512
1513 cascade = xmalloc(sizeof(*cascade));
1514 cascade->one = one;
1515 cascade->two = two;
1516 cascade->end = cascade->ptr = 0;
1517 cascade->filter.vtbl = &cascade_vtbl;
1518 return (struct stream_filter *)cascade;
1519 }
1520
1521 /*
1522 * ident filter
1523 */
1524 #define IDENT_DRAINING (-1)
1525 #define IDENT_SKIPPING (-2)
1526 struct ident_filter {
1527 struct stream_filter filter;
1528 struct strbuf left;
1529 int state;
1530 char ident[45]; /* ": x40 $" */
1531 };
1532
1533 static int is_foreign_ident(const char *str)
1534 {
1535 int i;
1536
1537 if (!skip_prefix(str, "$Id: ", &str))
1538 return 0;
1539 for (i = 0; str[i]; i++) {
1540 if (isspace(str[i]) && str[i+1] != '$')
1541 return 1;
1542 }
1543 return 0;
1544 }
1545
1546 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1547 {
1548 size_t to_drain = ident->left.len;
1549
1550 if (*osize_p < to_drain)
1551 to_drain = *osize_p;
1552 if (to_drain) {
1553 memcpy(*output_p, ident->left.buf, to_drain);
1554 strbuf_remove(&ident->left, 0, to_drain);
1555 *output_p += to_drain;
1556 *osize_p -= to_drain;
1557 }
1558 if (!ident->left.len)
1559 ident->state = 0;
1560 }
1561
1562 static int ident_filter_fn(struct stream_filter *filter,
1563 const char *input, size_t *isize_p,
1564 char *output, size_t *osize_p)
1565 {
1566 struct ident_filter *ident = (struct ident_filter *)filter;
1567 static const char head[] = "$Id";
1568
1569 if (!input) {
1570 /* drain upon eof */
1571 switch (ident->state) {
1572 default:
1573 strbuf_add(&ident->left, head, ident->state);
1574 case IDENT_SKIPPING:
1575 /* fallthru */
1576 case IDENT_DRAINING:
1577 ident_drain(ident, &output, osize_p);
1578 }
1579 return 0;
1580 }
1581
1582 while (*isize_p || (ident->state == IDENT_DRAINING)) {
1583 int ch;
1584
1585 if (ident->state == IDENT_DRAINING) {
1586 ident_drain(ident, &output, osize_p);
1587 if (!*osize_p)
1588 break;
1589 continue;
1590 }
1591
1592 ch = *(input++);
1593 (*isize_p)--;
1594
1595 if (ident->state == IDENT_SKIPPING) {
1596 /*
1597 * Skipping until '$' or LF, but keeping them
1598 * in case it is a foreign ident.
1599 */
1600 strbuf_addch(&ident->left, ch);
1601 if (ch != '\n' && ch != '$')
1602 continue;
1603 if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1604 strbuf_setlen(&ident->left, sizeof(head) - 1);
1605 strbuf_addstr(&ident->left, ident->ident);
1606 }
1607 ident->state = IDENT_DRAINING;
1608 continue;
1609 }
1610
1611 if (ident->state < sizeof(head) &&
1612 head[ident->state] == ch) {
1613 ident->state++;
1614 continue;
1615 }
1616
1617 if (ident->state)
1618 strbuf_add(&ident->left, head, ident->state);
1619 if (ident->state == sizeof(head) - 1) {
1620 if (ch != ':' && ch != '$') {
1621 strbuf_addch(&ident->left, ch);
1622 ident->state = 0;
1623 continue;
1624 }
1625
1626 if (ch == ':') {
1627 strbuf_addch(&ident->left, ch);
1628 ident->state = IDENT_SKIPPING;
1629 } else {
1630 strbuf_addstr(&ident->left, ident->ident);
1631 ident->state = IDENT_DRAINING;
1632 }
1633 continue;
1634 }
1635
1636 strbuf_addch(&ident->left, ch);
1637 ident->state = IDENT_DRAINING;
1638 }
1639 return 0;
1640 }
1641
1642 static void ident_free_fn(struct stream_filter *filter)
1643 {
1644 struct ident_filter *ident = (struct ident_filter *)filter;
1645 strbuf_release(&ident->left);
1646 free(filter);
1647 }
1648
1649 static struct stream_filter_vtbl ident_vtbl = {
1650 ident_filter_fn,
1651 ident_free_fn,
1652 };
1653
1654 static struct stream_filter *ident_filter(const unsigned char *sha1)
1655 {
1656 struct ident_filter *ident = xmalloc(sizeof(*ident));
1657
1658 xsnprintf(ident->ident, sizeof(ident->ident),
1659 ": %s $", sha1_to_hex(sha1));
1660 strbuf_init(&ident->left, 0);
1661 ident->filter.vtbl = &ident_vtbl;
1662 ident->state = 0;
1663 return (struct stream_filter *)ident;
1664 }
1665
1666 /*
1667 * Return an appropriately constructed filter for the path, or NULL if
1668 * the contents cannot be filtered without reading the whole thing
1669 * in-core.
1670 *
1671 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1672 * large binary blob you would want us not to slurp into the memory!
1673 */
1674 struct stream_filter *get_stream_filter(const char *path, const unsigned char *sha1)
1675 {
1676 struct conv_attrs ca;
1677 struct stream_filter *filter = NULL;
1678
1679 convert_attrs(&ca, path);
1680 if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
1681 return NULL;
1682
1683 if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
1684 return NULL;
1685
1686 if (ca.ident)
1687 filter = ident_filter(sha1);
1688
1689 if (output_eol(ca.crlf_action) == EOL_CRLF)
1690 filter = cascade_filter(filter, lf_to_crlf_filter());
1691 else
1692 filter = cascade_filter(filter, &null_filter_singleton);
1693
1694 return filter;
1695 }
1696
1697 void free_stream_filter(struct stream_filter *filter)
1698 {
1699 filter->vtbl->free(filter);
1700 }
1701
1702 int stream_filter(struct stream_filter *filter,
1703 const char *input, size_t *isize_p,
1704 char *output, size_t *osize_p)
1705 {
1706 return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
1707 }
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