Merge branch 'bc/hash-transition-part-15'
[git] / builtin / name-rev.c
1 #include "builtin.h"
2 #include "cache.h"
3 #include "repository.h"
4 #include "config.h"
5 #include "commit.h"
6 #include "tag.h"
7 #include "refs.h"
8 #include "parse-options.h"
9 #include "sha1-lookup.h"
10 #include "commit-slab.h"
11
12 #define CUTOFF_DATE_SLOP 86400 /* one day */
13
14 typedef struct rev_name {
15         const char *tip_name;
16         timestamp_t taggerdate;
17         int generation;
18         int distance;
19         int from_tag;
20 } rev_name;
21
22 define_commit_slab(commit_rev_name, struct rev_name *);
23
24 static timestamp_t cutoff = TIME_MAX;
25 static struct commit_rev_name rev_names;
26
27 /* How many generations are maximally preferred over _one_ merge traversal? */
28 #define MERGE_TRAVERSAL_WEIGHT 65535
29
30 static struct rev_name *get_commit_rev_name(struct commit *commit)
31 {
32         struct rev_name **slot = commit_rev_name_peek(&rev_names, commit);
33
34         return slot ? *slot : NULL;
35 }
36
37 static void set_commit_rev_name(struct commit *commit, struct rev_name *name)
38 {
39         *commit_rev_name_at(&rev_names, commit) = name;
40 }
41
42 static int is_better_name(struct rev_name *name,
43                           const char *tip_name,
44                           timestamp_t taggerdate,
45                           int generation,
46                           int distance,
47                           int from_tag)
48 {
49         /*
50          * When comparing names based on tags, prefer names
51          * based on the older tag, even if it is farther away.
52          */
53         if (from_tag && name->from_tag)
54                 return (name->taggerdate > taggerdate ||
55                         (name->taggerdate == taggerdate &&
56                          name->distance > distance));
57
58         /*
59          * We know that at least one of them is a non-tag at this point.
60          * favor a tag over a non-tag.
61          */
62         if (name->from_tag != from_tag)
63                 return from_tag;
64
65         /*
66          * We are now looking at two non-tags.  Tiebreak to favor
67          * shorter hops.
68          */
69         if (name->distance != distance)
70                 return name->distance > distance;
71
72         /* ... or tiebreak to favor older date */
73         if (name->taggerdate != taggerdate)
74                 return name->taggerdate > taggerdate;
75
76         /* keep the current one if we cannot decide */
77         return 0;
78 }
79
80 static void name_rev(struct commit *commit,
81                 const char *tip_name, timestamp_t taggerdate,
82                 int generation, int distance, int from_tag,
83                 int deref)
84 {
85         struct rev_name *name = get_commit_rev_name(commit);
86         struct commit_list *parents;
87         int parent_number = 1;
88         char *to_free = NULL;
89
90         parse_commit(commit);
91
92         if (commit->date < cutoff)
93                 return;
94
95         if (deref) {
96                 tip_name = to_free = xstrfmt("%s^0", tip_name);
97
98                 if (generation)
99                         die("generation: %d, but deref?", generation);
100         }
101
102         if (name == NULL) {
103                 name = xmalloc(sizeof(rev_name));
104                 set_commit_rev_name(commit, name);
105                 goto copy_data;
106         } else if (is_better_name(name, tip_name, taggerdate,
107                                   generation, distance, from_tag)) {
108 copy_data:
109                 name->tip_name = tip_name;
110                 name->taggerdate = taggerdate;
111                 name->generation = generation;
112                 name->distance = distance;
113                 name->from_tag = from_tag;
114         } else {
115                 free(to_free);
116                 return;
117         }
118
119         for (parents = commit->parents;
120                         parents;
121                         parents = parents->next, parent_number++) {
122                 if (parent_number > 1) {
123                         size_t len;
124                         char *new_name;
125
126                         strip_suffix(tip_name, "^0", &len);
127                         if (generation > 0)
128                                 new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
129                                                    generation, parent_number);
130                         else
131                                 new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
132                                                    parent_number);
133
134                         name_rev(parents->item, new_name, taggerdate, 0,
135                                  distance + MERGE_TRAVERSAL_WEIGHT,
136                                  from_tag, 0);
137                 } else {
138                         name_rev(parents->item, tip_name, taggerdate,
139                                  generation + 1, distance + 1,
140                                  from_tag, 0);
141                 }
142         }
143 }
144
145 static int subpath_matches(const char *path, const char *filter)
146 {
147         const char *subpath = path;
148
149         while (subpath) {
150                 if (!wildmatch(filter, subpath, 0))
151                         return subpath - path;
152                 subpath = strchr(subpath, '/');
153                 if (subpath)
154                         subpath++;
155         }
156         return -1;
157 }
158
159 static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous)
160 {
161         if (shorten_unambiguous)
162                 refname = shorten_unambiguous_ref(refname, 0);
163         else if (starts_with(refname, "refs/heads/"))
164                 refname = refname + 11;
165         else if (starts_with(refname, "refs/"))
166                 refname = refname + 5;
167         return refname;
168 }
169
170 struct name_ref_data {
171         int tags_only;
172         int name_only;
173         struct string_list ref_filters;
174         struct string_list exclude_filters;
175 };
176
177 static struct tip_table {
178         struct tip_table_entry {
179                 struct object_id oid;
180                 const char *refname;
181         } *table;
182         int nr;
183         int alloc;
184         int sorted;
185 } tip_table;
186
187 static void add_to_tip_table(const struct object_id *oid, const char *refname,
188                              int shorten_unambiguous)
189 {
190         refname = name_ref_abbrev(refname, shorten_unambiguous);
191
192         ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc);
193         oidcpy(&tip_table.table[tip_table.nr].oid, oid);
194         tip_table.table[tip_table.nr].refname = xstrdup(refname);
195         tip_table.nr++;
196         tip_table.sorted = 0;
197 }
198
199 static int tipcmp(const void *a_, const void *b_)
200 {
201         const struct tip_table_entry *a = a_, *b = b_;
202         return oidcmp(&a->oid, &b->oid);
203 }
204
205 static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data)
206 {
207         struct object *o = parse_object(the_repository, oid);
208         struct name_ref_data *data = cb_data;
209         int can_abbreviate_output = data->tags_only && data->name_only;
210         int deref = 0;
211         timestamp_t taggerdate = TIME_MAX;
212
213         if (data->tags_only && !starts_with(path, "refs/tags/"))
214                 return 0;
215
216         if (data->exclude_filters.nr) {
217                 struct string_list_item *item;
218
219                 for_each_string_list_item(item, &data->exclude_filters) {
220                         if (subpath_matches(path, item->string) >= 0)
221                                 return 0;
222                 }
223         }
224
225         if (data->ref_filters.nr) {
226                 struct string_list_item *item;
227                 int matched = 0;
228
229                 /* See if any of the patterns match. */
230                 for_each_string_list_item(item, &data->ref_filters) {
231                         /*
232                          * Check all patterns even after finding a match, so
233                          * that we can see if a match with a subpath exists.
234                          * When a user asked for 'refs/tags/v*' and 'v1.*',
235                          * both of which match, the user is showing her
236                          * willingness to accept a shortened output by having
237                          * the 'v1.*' in the acceptable refnames, so we
238                          * shouldn't stop when seeing 'refs/tags/v1.4' matches
239                          * 'refs/tags/v*'.  We should show it as 'v1.4'.
240                          */
241                         switch (subpath_matches(path, item->string)) {
242                         case -1: /* did not match */
243                                 break;
244                         case 0: /* matched fully */
245                                 matched = 1;
246                                 break;
247                         default: /* matched subpath */
248                                 matched = 1;
249                                 can_abbreviate_output = 1;
250                                 break;
251                         }
252                 }
253
254                 /* If none of the patterns matched, stop now */
255                 if (!matched)
256                         return 0;
257         }
258
259         add_to_tip_table(oid, path, can_abbreviate_output);
260
261         while (o && o->type == OBJ_TAG) {
262                 struct tag *t = (struct tag *) o;
263                 if (!t->tagged)
264                         break; /* broken repository */
265                 o = parse_object(the_repository, &t->tagged->oid);
266                 deref = 1;
267                 taggerdate = t->date;
268         }
269         if (o && o->type == OBJ_COMMIT) {
270                 struct commit *commit = (struct commit *)o;
271                 int from_tag = starts_with(path, "refs/tags/");
272
273                 if (taggerdate == TIME_MAX)
274                         taggerdate = ((struct commit *)o)->date;
275                 path = name_ref_abbrev(path, can_abbreviate_output);
276                 name_rev(commit, xstrdup(path), taggerdate, 0, 0,
277                          from_tag, deref);
278         }
279         return 0;
280 }
281
282 static const unsigned char *nth_tip_table_ent(size_t ix, void *table_)
283 {
284         struct tip_table_entry *table = table_;
285         return table[ix].oid.hash;
286 }
287
288 static const char *get_exact_ref_match(const struct object *o)
289 {
290         int found;
291
292         if (!tip_table.table || !tip_table.nr)
293                 return NULL;
294
295         if (!tip_table.sorted) {
296                 QSORT(tip_table.table, tip_table.nr, tipcmp);
297                 tip_table.sorted = 1;
298         }
299
300         found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr,
301                          nth_tip_table_ent);
302         if (0 <= found)
303                 return tip_table.table[found].refname;
304         return NULL;
305 }
306
307 /* may return a constant string or use "buf" as scratch space */
308 static const char *get_rev_name(const struct object *o, struct strbuf *buf)
309 {
310         struct rev_name *n;
311         struct commit *c;
312
313         if (o->type != OBJ_COMMIT)
314                 return get_exact_ref_match(o);
315         c = (struct commit *) o;
316         n = get_commit_rev_name(c);
317         if (!n)
318                 return NULL;
319
320         if (!n->generation)
321                 return n->tip_name;
322         else {
323                 int len = strlen(n->tip_name);
324                 if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
325                         len -= 2;
326                 strbuf_reset(buf);
327                 strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
328                 return buf->buf;
329         }
330 }
331
332 static void show_name(const struct object *obj,
333                       const char *caller_name,
334                       int always, int allow_undefined, int name_only)
335 {
336         const char *name;
337         const struct object_id *oid = &obj->oid;
338         struct strbuf buf = STRBUF_INIT;
339
340         if (!name_only)
341                 printf("%s ", caller_name ? caller_name : oid_to_hex(oid));
342         name = get_rev_name(obj, &buf);
343         if (name)
344                 printf("%s\n", name);
345         else if (allow_undefined)
346                 printf("undefined\n");
347         else if (always)
348                 printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV));
349         else
350                 die("cannot describe '%s'", oid_to_hex(oid));
351         strbuf_release(&buf);
352 }
353
354 static char const * const name_rev_usage[] = {
355         N_("git name-rev [<options>] <commit>..."),
356         N_("git name-rev [<options>] --all"),
357         N_("git name-rev [<options>] --stdin"),
358         NULL
359 };
360
361 static void name_rev_line(char *p, struct name_ref_data *data)
362 {
363         struct strbuf buf = STRBUF_INIT;
364         int forty = 0;
365         char *p_start;
366         for (p_start = p; *p; p++) {
367 #define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f'))
368                 if (!ishex(*p))
369                         forty = 0;
370                 else if (++forty == GIT_SHA1_HEXSZ &&
371                          !ishex(*(p+1))) {
372                         struct object_id oid;
373                         const char *name = NULL;
374                         char c = *(p+1);
375                         int p_len = p - p_start + 1;
376
377                         forty = 0;
378
379                         *(p+1) = 0;
380                         if (!get_oid(p - (GIT_SHA1_HEXSZ - 1), &oid)) {
381                                 struct object *o =
382                                         lookup_object(the_repository,
383                                                       oid.hash);
384                                 if (o)
385                                         name = get_rev_name(o, &buf);
386                         }
387                         *(p+1) = c;
388
389                         if (!name)
390                                 continue;
391
392                         if (data->name_only)
393                                 printf("%.*s%s", p_len - GIT_SHA1_HEXSZ, p_start, name);
394                         else
395                                 printf("%.*s (%s)", p_len, p_start, name);
396                         p_start = p + 1;
397                 }
398         }
399
400         /* flush */
401         if (p_start != p)
402                 fwrite(p_start, p - p_start, 1, stdout);
403
404         strbuf_release(&buf);
405 }
406
407 int cmd_name_rev(int argc, const char **argv, const char *prefix)
408 {
409         struct object_array revs = OBJECT_ARRAY_INIT;
410         int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0;
411         struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP };
412         struct option opts[] = {
413                 OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")),
414                 OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")),
415                 OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"),
416                                    N_("only use refs matching <pattern>")),
417                 OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"),
418                                    N_("ignore refs matching <pattern>")),
419                 OPT_GROUP(""),
420                 OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")),
421                 OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")),
422                 OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")),
423                 OPT_BOOL(0, "always",     &always,
424                            N_("show abbreviated commit object as fallback")),
425                 {
426                         /* A Hidden OPT_BOOL */
427                         OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL,
428                         N_("dereference tags in the input (internal use)"),
429                         PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1,
430                 },
431                 OPT_END(),
432         };
433
434         init_commit_rev_name(&rev_names);
435         git_config(git_default_config, NULL);
436         argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0);
437         if (all + transform_stdin + !!argc > 1) {
438                 error("Specify either a list, or --all, not both!");
439                 usage_with_options(name_rev_usage, opts);
440         }
441         if (all || transform_stdin)
442                 cutoff = 0;
443
444         for (; argc; argc--, argv++) {
445                 struct object_id oid;
446                 struct object *object;
447                 struct commit *commit;
448
449                 if (get_oid(*argv, &oid)) {
450                         fprintf(stderr, "Could not get sha1 for %s. Skipping.\n",
451                                         *argv);
452                         continue;
453                 }
454
455                 commit = NULL;
456                 object = parse_object(the_repository, &oid);
457                 if (object) {
458                         struct object *peeled = deref_tag(the_repository,
459                                                           object, *argv, 0);
460                         if (peeled && peeled->type == OBJ_COMMIT)
461                                 commit = (struct commit *)peeled;
462                 }
463
464                 if (!object) {
465                         fprintf(stderr, "Could not get object for %s. Skipping.\n",
466                                         *argv);
467                         continue;
468                 }
469
470                 if (commit) {
471                         if (cutoff > commit->date)
472                                 cutoff = commit->date;
473                 }
474
475                 if (peel_tag) {
476                         if (!commit) {
477                                 fprintf(stderr, "Could not get commit for %s. Skipping.\n",
478                                         *argv);
479                                 continue;
480                         }
481                         object = (struct object *)commit;
482                 }
483                 add_object_array(object, *argv, &revs);
484         }
485
486         if (cutoff)
487                 cutoff = cutoff - CUTOFF_DATE_SLOP;
488         for_each_ref(name_ref, &data);
489
490         if (transform_stdin) {
491                 char buffer[2048];
492
493                 while (!feof(stdin)) {
494                         char *p = fgets(buffer, sizeof(buffer), stdin);
495                         if (!p)
496                                 break;
497                         name_rev_line(p, &data);
498                 }
499         } else if (all) {
500                 int i, max;
501
502                 max = get_max_object_index();
503                 for (i = 0; i < max; i++) {
504                         struct object *obj = get_indexed_object(i);
505                         if (!obj || obj->type != OBJ_COMMIT)
506                                 continue;
507                         show_name(obj, NULL,
508                                   always, allow_undefined, data.name_only);
509                 }
510         } else {
511                 int i;
512                 for (i = 0; i < revs.nr; i++)
513                         show_name(revs.objects[i].item, revs.objects[i].name,
514                                   always, allow_undefined, data.name_only);
515         }
516
517         UNLEAK(revs);
518         return 0;
519 }