dir.h: move struct exclude declaration to top level
[git.git] / convert.c
blobcb5fbb45ea04cead65316ecf6b44730b17108122
1 #include "cache.h"
2 #include "attr.h"
3 #include "run-command.h"
4 #include "quote.h"
5 #include "sigchain.h"
7 /*
8 * convert.c - convert a file when checking it out and checking it in.
10 * This should use the pathname to decide on whether it wants to do some
11 * more interesting conversions (automatic gzip/unzip, general format
12 * conversions etc etc), but by default it just does automatic CRLF<->LF
13 * translation when the "text" attribute or "auto_crlf" option is set.
16 enum crlf_action {
17 CRLF_GUESS = -1,
18 CRLF_BINARY = 0,
19 CRLF_TEXT,
20 CRLF_INPUT,
21 CRLF_CRLF,
22 CRLF_AUTO
25 struct text_stat {
26 /* NUL, CR, LF and CRLF counts */
27 unsigned nul, cr, lf, crlf;
29 /* These are just approximations! */
30 unsigned printable, nonprintable;
33 static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
35 unsigned long i;
37 memset(stats, 0, sizeof(*stats));
39 for (i = 0; i < size; i++) {
40 unsigned char c = buf[i];
41 if (c == '\r') {
42 stats->cr++;
43 if (i+1 < size && buf[i+1] == '\n')
44 stats->crlf++;
45 continue;
47 if (c == '\n') {
48 stats->lf++;
49 continue;
51 if (c == 127)
52 /* DEL */
53 stats->nonprintable++;
54 else if (c < 32) {
55 switch (c) {
56 /* BS, HT, ESC and FF */
57 case '\b': case '\t': case '\033': case '\014':
58 stats->printable++;
59 break;
60 case 0:
61 stats->nul++;
62 /* fall through */
63 default:
64 stats->nonprintable++;
67 else
68 stats->printable++;
71 /* If file ends with EOF then don't count this EOF as non-printable. */
72 if (size >= 1 && buf[size-1] == '\032')
73 stats->nonprintable--;
77 * The same heuristics as diff.c::mmfile_is_binary()
79 static int is_binary(unsigned long size, struct text_stat *stats)
82 if (stats->nul)
83 return 1;
84 if ((stats->printable >> 7) < stats->nonprintable)
85 return 1;
87 * Other heuristics? Average line length might be relevant,
88 * as might LF vs CR vs CRLF counts..
90 * NOTE! It might be normal to have a low ratio of CRLF to LF
91 * (somebody starts with a LF-only file and edits it with an editor
92 * that adds CRLF only to lines that are added..). But do we
93 * want to support CR-only? Probably not.
95 return 0;
98 static enum eol output_eol(enum crlf_action crlf_action)
100 switch (crlf_action) {
101 case CRLF_BINARY:
102 return EOL_UNSET;
103 case CRLF_CRLF:
104 return EOL_CRLF;
105 case CRLF_INPUT:
106 return EOL_LF;
107 case CRLF_GUESS:
108 if (!auto_crlf)
109 return EOL_UNSET;
110 /* fall through */
111 case CRLF_TEXT:
112 case CRLF_AUTO:
113 if (auto_crlf == AUTO_CRLF_TRUE)
114 return EOL_CRLF;
115 else if (auto_crlf == AUTO_CRLF_INPUT)
116 return EOL_LF;
117 else if (core_eol == EOL_UNSET)
118 return EOL_NATIVE;
120 return core_eol;
123 static void check_safe_crlf(const char *path, enum crlf_action crlf_action,
124 struct text_stat *stats, enum safe_crlf checksafe)
126 if (!checksafe)
127 return;
129 if (output_eol(crlf_action) == EOL_LF) {
131 * CRLFs would not be restored by checkout:
132 * check if we'd remove CRLFs
134 if (stats->crlf) {
135 if (checksafe == SAFE_CRLF_WARN)
136 warning("CRLF will be replaced by LF in %s.\nThe file will have its original line endings in your working directory.", path);
137 else /* i.e. SAFE_CRLF_FAIL */
138 die("CRLF would be replaced by LF in %s.", path);
140 } else if (output_eol(crlf_action) == EOL_CRLF) {
142 * CRLFs would be added by checkout:
143 * check if we have "naked" LFs
145 if (stats->lf != stats->crlf) {
146 if (checksafe == SAFE_CRLF_WARN)
147 warning("LF will be replaced by CRLF in %s.\nThe file will have its original line endings in your working directory.", path);
148 else /* i.e. SAFE_CRLF_FAIL */
149 die("LF would be replaced by CRLF in %s", path);
154 static int has_cr_in_index(const char *path)
156 unsigned long sz;
157 void *data;
158 int has_cr;
160 data = read_blob_data_from_cache(path, &sz);
161 if (!data)
162 return 0;
163 has_cr = memchr(data, '\r', sz) != NULL;
164 free(data);
165 return has_cr;
168 static int crlf_to_git(const char *path, const char *src, size_t len,
169 struct strbuf *buf,
170 enum crlf_action crlf_action, enum safe_crlf checksafe)
172 struct text_stat stats;
173 char *dst;
175 if (crlf_action == CRLF_BINARY ||
176 (crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE) ||
177 (src && !len))
178 return 0;
181 * If we are doing a dry-run and have no source buffer, there is
182 * nothing to analyze; we must assume we would convert.
184 if (!buf && !src)
185 return 1;
187 gather_stats(src, len, &stats);
189 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
191 * We're currently not going to even try to convert stuff
192 * that has bare CR characters. Does anybody do that crazy
193 * stuff?
195 if (stats.cr != stats.crlf)
196 return 0;
199 * And add some heuristics for binary vs text, of course...
201 if (is_binary(len, &stats))
202 return 0;
204 if (crlf_action == CRLF_GUESS) {
206 * If the file in the index has any CR in it, do not convert.
207 * This is the new safer autocrlf handling.
209 if (has_cr_in_index(path))
210 return 0;
214 check_safe_crlf(path, crlf_action, &stats, checksafe);
216 /* Optimization: No CR? Nothing to convert, regardless. */
217 if (!stats.cr)
218 return 0;
221 * At this point all of our source analysis is done, and we are sure we
222 * would convert. If we are in dry-run mode, we can give an answer.
224 if (!buf)
225 return 1;
227 /* only grow if not in place */
228 if (strbuf_avail(buf) + buf->len < len)
229 strbuf_grow(buf, len - buf->len);
230 dst = buf->buf;
231 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
233 * If we guessed, we already know we rejected a file with
234 * lone CR, and we can strip a CR without looking at what
235 * follow it.
237 do {
238 unsigned char c = *src++;
239 if (c != '\r')
240 *dst++ = c;
241 } while (--len);
242 } else {
243 do {
244 unsigned char c = *src++;
245 if (! (c == '\r' && (1 < len && *src == '\n')))
246 *dst++ = c;
247 } while (--len);
249 strbuf_setlen(buf, dst - buf->buf);
250 return 1;
253 static int crlf_to_worktree(const char *path, const char *src, size_t len,
254 struct strbuf *buf, enum crlf_action crlf_action)
256 char *to_free = NULL;
257 struct text_stat stats;
259 if (!len || output_eol(crlf_action) != EOL_CRLF)
260 return 0;
262 gather_stats(src, len, &stats);
264 /* No LF? Nothing to convert, regardless. */
265 if (!stats.lf)
266 return 0;
268 /* Was it already in CRLF format? */
269 if (stats.lf == stats.crlf)
270 return 0;
272 if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
273 if (crlf_action == CRLF_GUESS) {
274 /* If we have any CR or CRLF line endings, we do not touch it */
275 /* This is the new safer autocrlf-handling */
276 if (stats.cr > 0 || stats.crlf > 0)
277 return 0;
280 /* If we have any bare CR characters, we're not going to touch it */
281 if (stats.cr != stats.crlf)
282 return 0;
284 if (is_binary(len, &stats))
285 return 0;
288 /* are we "faking" in place editing ? */
289 if (src == buf->buf)
290 to_free = strbuf_detach(buf, NULL);
292 strbuf_grow(buf, len + stats.lf - stats.crlf);
293 for (;;) {
294 const char *nl = memchr(src, '\n', len);
295 if (!nl)
296 break;
297 if (nl > src && nl[-1] == '\r') {
298 strbuf_add(buf, src, nl + 1 - src);
299 } else {
300 strbuf_add(buf, src, nl - src);
301 strbuf_addstr(buf, "\r\n");
303 len -= nl + 1 - src;
304 src = nl + 1;
306 strbuf_add(buf, src, len);
308 free(to_free);
309 return 1;
312 struct filter_params {
313 const char *src;
314 unsigned long size;
315 const char *cmd;
316 const char *path;
319 static int filter_buffer(int in, int out, void *data)
322 * Spawn cmd and feed the buffer contents through its stdin.
324 struct child_process child_process;
325 struct filter_params *params = (struct filter_params *)data;
326 int write_err, status;
327 const char *argv[] = { NULL, NULL };
329 /* apply % substitution to cmd */
330 struct strbuf cmd = STRBUF_INIT;
331 struct strbuf path = STRBUF_INIT;
332 struct strbuf_expand_dict_entry dict[] = {
333 { "f", NULL, },
334 { NULL, NULL, },
337 /* quote the path to preserve spaces, etc. */
338 sq_quote_buf(&path, params->path);
339 dict[0].value = path.buf;
341 /* expand all %f with the quoted path */
342 strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
343 strbuf_release(&path);
345 argv[0] = cmd.buf;
347 memset(&child_process, 0, sizeof(child_process));
348 child_process.argv = argv;
349 child_process.use_shell = 1;
350 child_process.in = -1;
351 child_process.out = out;
353 if (start_command(&child_process))
354 return error("cannot fork to run external filter %s", params->cmd);
356 sigchain_push(SIGPIPE, SIG_IGN);
358 write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
359 if (close(child_process.in))
360 write_err = 1;
361 if (write_err)
362 error("cannot feed the input to external filter %s", params->cmd);
364 sigchain_pop(SIGPIPE);
366 status = finish_command(&child_process);
367 if (status)
368 error("external filter %s failed %d", params->cmd, status);
370 strbuf_release(&cmd);
371 return (write_err || status);
374 static int apply_filter(const char *path, const char *src, size_t len,
375 struct strbuf *dst, const char *cmd)
378 * Create a pipeline to have the command filter the buffer's
379 * contents.
381 * (child --> cmd) --> us
383 int ret = 1;
384 struct strbuf nbuf = STRBUF_INIT;
385 struct async async;
386 struct filter_params params;
388 if (!cmd)
389 return 0;
391 if (!dst)
392 return 1;
394 memset(&async, 0, sizeof(async));
395 async.proc = filter_buffer;
396 async.data = &params;
397 async.out = -1;
398 params.src = src;
399 params.size = len;
400 params.cmd = cmd;
401 params.path = path;
403 fflush(NULL);
404 if (start_async(&async))
405 return 0; /* error was already reported */
407 if (strbuf_read(&nbuf, async.out, len) < 0) {
408 error("read from external filter %s failed", cmd);
409 ret = 0;
411 if (close(async.out)) {
412 error("read from external filter %s failed", cmd);
413 ret = 0;
415 if (finish_async(&async)) {
416 error("external filter %s failed", cmd);
417 ret = 0;
420 if (ret) {
421 strbuf_swap(dst, &nbuf);
423 strbuf_release(&nbuf);
424 return ret;
427 static struct convert_driver {
428 const char *name;
429 struct convert_driver *next;
430 const char *smudge;
431 const char *clean;
432 int required;
433 } *user_convert, **user_convert_tail;
435 static int read_convert_config(const char *var, const char *value, void *cb)
437 const char *key, *name;
438 int namelen;
439 struct convert_driver *drv;
442 * External conversion drivers are configured using
443 * "filter.<name>.variable".
445 if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
446 return 0;
447 for (drv = user_convert; drv; drv = drv->next)
448 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
449 break;
450 if (!drv) {
451 drv = xcalloc(1, sizeof(struct convert_driver));
452 drv->name = xmemdupz(name, namelen);
453 *user_convert_tail = drv;
454 user_convert_tail = &(drv->next);
458 * filter.<name>.smudge and filter.<name>.clean specifies
459 * the command line:
461 * command-line
463 * The command-line will not be interpolated in any way.
466 if (!strcmp("smudge", key))
467 return git_config_string(&drv->smudge, var, value);
469 if (!strcmp("clean", key))
470 return git_config_string(&drv->clean, var, value);
472 if (!strcmp("required", key)) {
473 drv->required = git_config_bool(var, value);
474 return 0;
477 return 0;
480 static int count_ident(const char *cp, unsigned long size)
483 * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
485 int cnt = 0;
486 char ch;
488 while (size) {
489 ch = *cp++;
490 size--;
491 if (ch != '$')
492 continue;
493 if (size < 3)
494 break;
495 if (memcmp("Id", cp, 2))
496 continue;
497 ch = cp[2];
498 cp += 3;
499 size -= 3;
500 if (ch == '$')
501 cnt++; /* $Id$ */
502 if (ch != ':')
503 continue;
506 * "$Id: ... "; scan up to the closing dollar sign and discard.
508 while (size) {
509 ch = *cp++;
510 size--;
511 if (ch == '$') {
512 cnt++;
513 break;
515 if (ch == '\n')
516 break;
519 return cnt;
522 static int ident_to_git(const char *path, const char *src, size_t len,
523 struct strbuf *buf, int ident)
525 char *dst, *dollar;
527 if (!ident || (src && !count_ident(src, len)))
528 return 0;
530 if (!buf)
531 return 1;
533 /* only grow if not in place */
534 if (strbuf_avail(buf) + buf->len < len)
535 strbuf_grow(buf, len - buf->len);
536 dst = buf->buf;
537 for (;;) {
538 dollar = memchr(src, '$', len);
539 if (!dollar)
540 break;
541 memmove(dst, src, dollar + 1 - src);
542 dst += dollar + 1 - src;
543 len -= dollar + 1 - src;
544 src = dollar + 1;
546 if (len > 3 && !memcmp(src, "Id:", 3)) {
547 dollar = memchr(src + 3, '$', len - 3);
548 if (!dollar)
549 break;
550 if (memchr(src + 3, '\n', dollar - src - 3)) {
551 /* Line break before the next dollar. */
552 continue;
555 memcpy(dst, "Id$", 3);
556 dst += 3;
557 len -= dollar + 1 - src;
558 src = dollar + 1;
561 memmove(dst, src, len);
562 strbuf_setlen(buf, dst + len - buf->buf);
563 return 1;
566 static int ident_to_worktree(const char *path, const char *src, size_t len,
567 struct strbuf *buf, int ident)
569 unsigned char sha1[20];
570 char *to_free = NULL, *dollar, *spc;
571 int cnt;
573 if (!ident)
574 return 0;
576 cnt = count_ident(src, len);
577 if (!cnt)
578 return 0;
580 /* are we "faking" in place editing ? */
581 if (src == buf->buf)
582 to_free = strbuf_detach(buf, NULL);
583 hash_sha1_file(src, len, "blob", sha1);
585 strbuf_grow(buf, len + cnt * 43);
586 for (;;) {
587 /* step 1: run to the next '$' */
588 dollar = memchr(src, '$', len);
589 if (!dollar)
590 break;
591 strbuf_add(buf, src, dollar + 1 - src);
592 len -= dollar + 1 - src;
593 src = dollar + 1;
595 /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
596 if (len < 3 || memcmp("Id", src, 2))
597 continue;
599 /* step 3: skip over Id$ or Id:xxxxx$ */
600 if (src[2] == '$') {
601 src += 3;
602 len -= 3;
603 } else if (src[2] == ':') {
605 * It's possible that an expanded Id has crept its way into the
606 * repository, we cope with that by stripping the expansion out.
607 * This is probably not a good idea, since it will cause changes
608 * on checkout, which won't go away by stash, but let's keep it
609 * for git-style ids.
611 dollar = memchr(src + 3, '$', len - 3);
612 if (!dollar) {
613 /* incomplete keyword, no more '$', so just quit the loop */
614 break;
617 if (memchr(src + 3, '\n', dollar - src - 3)) {
618 /* Line break before the next dollar. */
619 continue;
622 spc = memchr(src + 4, ' ', dollar - src - 4);
623 if (spc && spc < dollar-1) {
624 /* There are spaces in unexpected places.
625 * This is probably an id from some other
626 * versioning system. Keep it for now.
628 continue;
631 len -= dollar + 1 - src;
632 src = dollar + 1;
633 } else {
634 /* it wasn't a "Id$" or "Id:xxxx$" */
635 continue;
638 /* step 4: substitute */
639 strbuf_addstr(buf, "Id: ");
640 strbuf_add(buf, sha1_to_hex(sha1), 40);
641 strbuf_addstr(buf, " $");
643 strbuf_add(buf, src, len);
645 free(to_free);
646 return 1;
649 static enum crlf_action git_path_check_crlf(const char *path, struct git_attr_check *check)
651 const char *value = check->value;
653 if (ATTR_TRUE(value))
654 return CRLF_TEXT;
655 else if (ATTR_FALSE(value))
656 return CRLF_BINARY;
657 else if (ATTR_UNSET(value))
659 else if (!strcmp(value, "input"))
660 return CRLF_INPUT;
661 else if (!strcmp(value, "auto"))
662 return CRLF_AUTO;
663 return CRLF_GUESS;
666 static enum eol git_path_check_eol(const char *path, struct git_attr_check *check)
668 const char *value = check->value;
670 if (ATTR_UNSET(value))
672 else if (!strcmp(value, "lf"))
673 return EOL_LF;
674 else if (!strcmp(value, "crlf"))
675 return EOL_CRLF;
676 return EOL_UNSET;
679 static struct convert_driver *git_path_check_convert(const char *path,
680 struct git_attr_check *check)
682 const char *value = check->value;
683 struct convert_driver *drv;
685 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
686 return NULL;
687 for (drv = user_convert; drv; drv = drv->next)
688 if (!strcmp(value, drv->name))
689 return drv;
690 return NULL;
693 static int git_path_check_ident(const char *path, struct git_attr_check *check)
695 const char *value = check->value;
697 return !!ATTR_TRUE(value);
700 static enum crlf_action input_crlf_action(enum crlf_action text_attr, enum eol eol_attr)
702 if (text_attr == CRLF_BINARY)
703 return CRLF_BINARY;
704 if (eol_attr == EOL_LF)
705 return CRLF_INPUT;
706 if (eol_attr == EOL_CRLF)
707 return CRLF_CRLF;
708 return text_attr;
711 struct conv_attrs {
712 struct convert_driver *drv;
713 enum crlf_action crlf_action;
714 enum eol eol_attr;
715 int ident;
718 static const char *conv_attr_name[] = {
719 "crlf", "ident", "filter", "eol", "text",
721 #define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
723 static void convert_attrs(struct conv_attrs *ca, const char *path)
725 int i;
726 static struct git_attr_check ccheck[NUM_CONV_ATTRS];
728 if (!ccheck[0].attr) {
729 for (i = 0; i < NUM_CONV_ATTRS; i++)
730 ccheck[i].attr = git_attr(conv_attr_name[i]);
731 user_convert_tail = &user_convert;
732 git_config(read_convert_config, NULL);
735 if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
736 ca->crlf_action = git_path_check_crlf(path, ccheck + 4);
737 if (ca->crlf_action == CRLF_GUESS)
738 ca->crlf_action = git_path_check_crlf(path, ccheck + 0);
739 ca->ident = git_path_check_ident(path, ccheck + 1);
740 ca->drv = git_path_check_convert(path, ccheck + 2);
741 ca->eol_attr = git_path_check_eol(path, ccheck + 3);
742 } else {
743 ca->drv = NULL;
744 ca->crlf_action = CRLF_GUESS;
745 ca->eol_attr = EOL_UNSET;
746 ca->ident = 0;
750 int convert_to_git(const char *path, const char *src, size_t len,
751 struct strbuf *dst, enum safe_crlf checksafe)
753 int ret = 0;
754 const char *filter = NULL;
755 int required = 0;
756 struct conv_attrs ca;
758 convert_attrs(&ca, path);
759 if (ca.drv) {
760 filter = ca.drv->clean;
761 required = ca.drv->required;
764 ret |= apply_filter(path, src, len, dst, filter);
765 if (!ret && required)
766 die("%s: clean filter '%s' failed", path, ca.drv->name);
768 if (ret && dst) {
769 src = dst->buf;
770 len = dst->len;
772 ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
773 ret |= crlf_to_git(path, src, len, dst, ca.crlf_action, checksafe);
774 if (ret && dst) {
775 src = dst->buf;
776 len = dst->len;
778 return ret | ident_to_git(path, src, len, dst, ca.ident);
781 static int convert_to_working_tree_internal(const char *path, const char *src,
782 size_t len, struct strbuf *dst,
783 int normalizing)
785 int ret = 0, ret_filter = 0;
786 const char *filter = NULL;
787 int required = 0;
788 struct conv_attrs ca;
790 convert_attrs(&ca, path);
791 if (ca.drv) {
792 filter = ca.drv->smudge;
793 required = ca.drv->required;
796 ret |= ident_to_worktree(path, src, len, dst, ca.ident);
797 if (ret) {
798 src = dst->buf;
799 len = dst->len;
802 * CRLF conversion can be skipped if normalizing, unless there
803 * is a smudge filter. The filter might expect CRLFs.
805 if (filter || !normalizing) {
806 ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
807 ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
808 if (ret) {
809 src = dst->buf;
810 len = dst->len;
814 ret_filter = apply_filter(path, src, len, dst, filter);
815 if (!ret_filter && required)
816 die("%s: smudge filter %s failed", path, ca.drv->name);
818 return ret | ret_filter;
821 int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
823 return convert_to_working_tree_internal(path, src, len, dst, 0);
826 int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst)
828 int ret = convert_to_working_tree_internal(path, src, len, dst, 1);
829 if (ret) {
830 src = dst->buf;
831 len = dst->len;
833 return ret | convert_to_git(path, src, len, dst, SAFE_CRLF_FALSE);
836 /*****************************************************************
838 * Streaming conversion support
840 *****************************************************************/
842 typedef int (*filter_fn)(struct stream_filter *,
843 const char *input, size_t *isize_p,
844 char *output, size_t *osize_p);
845 typedef void (*free_fn)(struct stream_filter *);
847 struct stream_filter_vtbl {
848 filter_fn filter;
849 free_fn free;
852 struct stream_filter {
853 struct stream_filter_vtbl *vtbl;
856 static int null_filter_fn(struct stream_filter *filter,
857 const char *input, size_t *isize_p,
858 char *output, size_t *osize_p)
860 size_t count;
862 if (!input)
863 return 0; /* we do not keep any states */
864 count = *isize_p;
865 if (*osize_p < count)
866 count = *osize_p;
867 if (count) {
868 memmove(output, input, count);
869 *isize_p -= count;
870 *osize_p -= count;
872 return 0;
875 static void null_free_fn(struct stream_filter *filter)
877 ; /* nothing -- null instances are shared */
880 static struct stream_filter_vtbl null_vtbl = {
881 null_filter_fn,
882 null_free_fn,
885 static struct stream_filter null_filter_singleton = {
886 &null_vtbl,
889 int is_null_stream_filter(struct stream_filter *filter)
891 return filter == &null_filter_singleton;
896 * LF-to-CRLF filter
899 struct lf_to_crlf_filter {
900 struct stream_filter filter;
901 unsigned has_held:1;
902 char held;
905 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
906 const char *input, size_t *isize_p,
907 char *output, size_t *osize_p)
909 size_t count, o = 0;
910 struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
913 * We may be holding onto the CR to see if it is followed by a
914 * LF, in which case we would need to go to the main loop.
915 * Otherwise, just emit it to the output stream.
917 if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
918 output[o++] = lf_to_crlf->held;
919 lf_to_crlf->has_held = 0;
922 /* We are told to drain */
923 if (!input) {
924 *osize_p -= o;
925 return 0;
928 count = *isize_p;
929 if (count || lf_to_crlf->has_held) {
930 size_t i;
931 int was_cr = 0;
933 if (lf_to_crlf->has_held) {
934 was_cr = 1;
935 lf_to_crlf->has_held = 0;
938 for (i = 0; o < *osize_p && i < count; i++) {
939 char ch = input[i];
941 if (ch == '\n') {
942 output[o++] = '\r';
943 } else if (was_cr) {
945 * Previous round saw CR and it is not followed
946 * by a LF; emit the CR before processing the
947 * current character.
949 output[o++] = '\r';
953 * We may have consumed the last output slot,
954 * in which case we need to break out of this
955 * loop; hold the current character before
956 * returning.
958 if (*osize_p <= o) {
959 lf_to_crlf->has_held = 1;
960 lf_to_crlf->held = ch;
961 continue; /* break but increment i */
964 if (ch == '\r') {
965 was_cr = 1;
966 continue;
969 was_cr = 0;
970 output[o++] = ch;
973 *osize_p -= o;
974 *isize_p -= i;
976 if (!lf_to_crlf->has_held && was_cr) {
977 lf_to_crlf->has_held = 1;
978 lf_to_crlf->held = '\r';
981 return 0;
984 static void lf_to_crlf_free_fn(struct stream_filter *filter)
986 free(filter);
989 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
990 lf_to_crlf_filter_fn,
991 lf_to_crlf_free_fn,
994 static struct stream_filter *lf_to_crlf_filter(void)
996 struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
998 lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
999 return (struct stream_filter *)lf_to_crlf;
1003 * Cascade filter
1005 #define FILTER_BUFFER 1024
1006 struct cascade_filter {
1007 struct stream_filter filter;
1008 struct stream_filter *one;
1009 struct stream_filter *two;
1010 char buf[FILTER_BUFFER];
1011 int end, ptr;
1014 static int cascade_filter_fn(struct stream_filter *filter,
1015 const char *input, size_t *isize_p,
1016 char *output, size_t *osize_p)
1018 struct cascade_filter *cas = (struct cascade_filter *) filter;
1019 size_t filled = 0;
1020 size_t sz = *osize_p;
1021 size_t to_feed, remaining;
1024 * input -- (one) --> buf -- (two) --> output
1026 while (filled < sz) {
1027 remaining = sz - filled;
1029 /* do we already have something to feed two with? */
1030 if (cas->ptr < cas->end) {
1031 to_feed = cas->end - cas->ptr;
1032 if (stream_filter(cas->two,
1033 cas->buf + cas->ptr, &to_feed,
1034 output + filled, &remaining))
1035 return -1;
1036 cas->ptr += (cas->end - cas->ptr) - to_feed;
1037 filled = sz - remaining;
1038 continue;
1041 /* feed one from upstream and have it emit into our buffer */
1042 to_feed = input ? *isize_p : 0;
1043 if (input && !to_feed)
1044 break;
1045 remaining = sizeof(cas->buf);
1046 if (stream_filter(cas->one,
1047 input, &to_feed,
1048 cas->buf, &remaining))
1049 return -1;
1050 cas->end = sizeof(cas->buf) - remaining;
1051 cas->ptr = 0;
1052 if (input) {
1053 size_t fed = *isize_p - to_feed;
1054 *isize_p -= fed;
1055 input += fed;
1058 /* do we know that we drained one completely? */
1059 if (input || cas->end)
1060 continue;
1062 /* tell two to drain; we have nothing more to give it */
1063 to_feed = 0;
1064 remaining = sz - filled;
1065 if (stream_filter(cas->two,
1066 NULL, &to_feed,
1067 output + filled, &remaining))
1068 return -1;
1069 if (remaining == (sz - filled))
1070 break; /* completely drained two */
1071 filled = sz - remaining;
1073 *osize_p -= filled;
1074 return 0;
1077 static void cascade_free_fn(struct stream_filter *filter)
1079 struct cascade_filter *cas = (struct cascade_filter *)filter;
1080 free_stream_filter(cas->one);
1081 free_stream_filter(cas->two);
1082 free(filter);
1085 static struct stream_filter_vtbl cascade_vtbl = {
1086 cascade_filter_fn,
1087 cascade_free_fn,
1090 static struct stream_filter *cascade_filter(struct stream_filter *one,
1091 struct stream_filter *two)
1093 struct cascade_filter *cascade;
1095 if (!one || is_null_stream_filter(one))
1096 return two;
1097 if (!two || is_null_stream_filter(two))
1098 return one;
1100 cascade = xmalloc(sizeof(*cascade));
1101 cascade->one = one;
1102 cascade->two = two;
1103 cascade->end = cascade->ptr = 0;
1104 cascade->filter.vtbl = &cascade_vtbl;
1105 return (struct stream_filter *)cascade;
1109 * ident filter
1111 #define IDENT_DRAINING (-1)
1112 #define IDENT_SKIPPING (-2)
1113 struct ident_filter {
1114 struct stream_filter filter;
1115 struct strbuf left;
1116 int state;
1117 char ident[45]; /* ": x40 $" */
1120 static int is_foreign_ident(const char *str)
1122 int i;
1124 if (!skip_prefix(str, "$Id: ", &str))
1125 return 0;
1126 for (i = 0; str[i]; i++) {
1127 if (isspace(str[i]) && str[i+1] != '$')
1128 return 1;
1130 return 0;
1133 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1135 size_t to_drain = ident->left.len;
1137 if (*osize_p < to_drain)
1138 to_drain = *osize_p;
1139 if (to_drain) {
1140 memcpy(*output_p, ident->left.buf, to_drain);
1141 strbuf_remove(&ident->left, 0, to_drain);
1142 *output_p += to_drain;
1143 *osize_p -= to_drain;
1145 if (!ident->left.len)
1146 ident->state = 0;
1149 static int ident_filter_fn(struct stream_filter *filter,
1150 const char *input, size_t *isize_p,
1151 char *output, size_t *osize_p)
1153 struct ident_filter *ident = (struct ident_filter *)filter;
1154 static const char head[] = "$Id";
1156 if (!input) {
1157 /* drain upon eof */
1158 switch (ident->state) {
1159 default:
1160 strbuf_add(&ident->left, head, ident->state);
1161 case IDENT_SKIPPING:
1162 /* fallthru */
1163 case IDENT_DRAINING:
1164 ident_drain(ident, &output, osize_p);
1166 return 0;
1169 while (*isize_p || (ident->state == IDENT_DRAINING)) {
1170 int ch;
1172 if (ident->state == IDENT_DRAINING) {
1173 ident_drain(ident, &output, osize_p);
1174 if (!*osize_p)
1175 break;
1176 continue;
1179 ch = *(input++);
1180 (*isize_p)--;
1182 if (ident->state == IDENT_SKIPPING) {
1184 * Skipping until '$' or LF, but keeping them
1185 * in case it is a foreign ident.
1187 strbuf_addch(&ident->left, ch);
1188 if (ch != '\n' && ch != '$')
1189 continue;
1190 if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1191 strbuf_setlen(&ident->left, sizeof(head) - 1);
1192 strbuf_addstr(&ident->left, ident->ident);
1194 ident->state = IDENT_DRAINING;
1195 continue;
1198 if (ident->state < sizeof(head) &&
1199 head[ident->state] == ch) {
1200 ident->state++;
1201 continue;
1204 if (ident->state)
1205 strbuf_add(&ident->left, head, ident->state);
1206 if (ident->state == sizeof(head) - 1) {
1207 if (ch != ':' && ch != '$') {
1208 strbuf_addch(&ident->left, ch);
1209 ident->state = 0;
1210 continue;
1213 if (ch == ':') {
1214 strbuf_addch(&ident->left, ch);
1215 ident->state = IDENT_SKIPPING;
1216 } else {
1217 strbuf_addstr(&ident->left, ident->ident);
1218 ident->state = IDENT_DRAINING;
1220 continue;
1223 strbuf_addch(&ident->left, ch);
1224 ident->state = IDENT_DRAINING;
1226 return 0;
1229 static void ident_free_fn(struct stream_filter *filter)
1231 struct ident_filter *ident = (struct ident_filter *)filter;
1232 strbuf_release(&ident->left);
1233 free(filter);
1236 static struct stream_filter_vtbl ident_vtbl = {
1237 ident_filter_fn,
1238 ident_free_fn,
1241 static struct stream_filter *ident_filter(const unsigned char *sha1)
1243 struct ident_filter *ident = xmalloc(sizeof(*ident));
1245 sprintf(ident->ident, ": %s $", sha1_to_hex(sha1));
1246 strbuf_init(&ident->left, 0);
1247 ident->filter.vtbl = &ident_vtbl;
1248 ident->state = 0;
1249 return (struct stream_filter *)ident;
1253 * Return an appropriately constructed filter for the path, or NULL if
1254 * the contents cannot be filtered without reading the whole thing
1255 * in-core.
1257 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1258 * large binary blob you would want us not to slurp into the memory!
1260 struct stream_filter *get_stream_filter(const char *path, const unsigned char *sha1)
1262 struct conv_attrs ca;
1263 enum crlf_action crlf_action;
1264 struct stream_filter *filter = NULL;
1266 convert_attrs(&ca, path);
1268 if (ca.drv && (ca.drv->smudge || ca.drv->clean))
1269 return filter;
1271 if (ca.ident)
1272 filter = ident_filter(sha1);
1274 crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
1276 if ((crlf_action == CRLF_BINARY) || (crlf_action == CRLF_INPUT) ||
1277 (crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE))
1278 filter = cascade_filter(filter, &null_filter_singleton);
1280 else if (output_eol(crlf_action) == EOL_CRLF &&
1281 !(crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS))
1282 filter = cascade_filter(filter, lf_to_crlf_filter());
1284 return filter;
1287 void free_stream_filter(struct stream_filter *filter)
1289 filter->vtbl->free(filter);
1292 int stream_filter(struct stream_filter *filter,
1293 const char *input, size_t *isize_p,
1294 char *output, size_t *osize_p)
1296 return filter->vtbl->filter(filter, input, isize_p, output, osize_p);