Andrew's git - gitweb.git/blob - builtin-describe.c

   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "builtin.h"
   6#include "exec_cmd.h"
   7#include "parse-options.h"
   8
   9#define SEEN            (1u<<0)
  10#define MAX_TAGS        (FLAG_BITS - 1)
  11
  12static const char * const describe_usage[] = {
  13        "git-describe [options] <committish>*",
  14        NULL
  15};
  16
  17static int debug;       /* Display lots of verbose info */
  18static int all; /* Default to annotated tags only */
  19static int tags;        /* But allow any tags if --tags is specified */
  20static int abbrev = DEFAULT_ABBREV;
  21static int max_candidates = 10;
  22const char *pattern = NULL;
  23
  24struct commit_name {
  25        int prio; /* annotated tag = 2, tag = 1, head = 0 */
  26        char path[FLEX_ARRAY]; /* more */
  27};
  28static const char *prio_names[] = {
  29        "head", "lightweight", "annotated",
  30};
  31
  32static void add_to_known_names(const char *path,
  33                               struct commit *commit,
  34                               int prio)
  35{
  36        struct commit_name *e = commit->util;
  37        if (!e || e->prio < prio) {
  38                size_t len = strlen(path)+1;
  39                free(e);
  40                e = xmalloc(sizeof(struct commit_name) + len);
  41                e->prio = prio;
  42                memcpy(e->path, path, len);
  43                commit->util = e;
  44        }
  45}
  46
  47static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  48{
  49        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
  50        struct object *object;
  51        int prio;
  52
  53        if (!commit)
  54                return 0;
  55        object = parse_object(sha1);
  56        /* If --all, then any refs are used.
  57         * If --tags, then any tags are used.
  58         * Otherwise only annotated tags are used.
  59         */
  60        if (!prefixcmp(path, "refs/tags/")) {
  61                if (object->type == OBJ_TAG) {
  62                        prio = 2;
  63                        if (pattern && fnmatch(pattern, path + 10, 0))
  64                                prio = 0;
  65                } else
  66                        prio = 1;
  67        }
  68        else
  69                prio = 0;
  70
  71        if (!all) {
  72                if (!prio)
  73                        return 0;
  74                if (!tags && prio < 2)
  75                        return 0;
  76        }
  77        add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  78        return 0;
  79}
  80
  81struct possible_tag {
  82        struct commit_name *name;
  83        int depth;
  84        int found_order;
  85        unsigned flag_within;
  86};
  87
  88static int compare_pt(const void *a_, const void *b_)
  89{
  90        struct possible_tag *a = (struct possible_tag *)a_;
  91        struct possible_tag *b = (struct possible_tag *)b_;
  92        if (a->name->prio != b->name->prio)
  93                return b->name->prio - a->name->prio;
  94        if (a->depth != b->depth)
  95                return a->depth - b->depth;
  96        if (a->found_order != b->found_order)
  97                return a->found_order - b->found_order;
  98        return 0;
  99}
 100
 101static unsigned long finish_depth_computation(
 102        struct commit_list **list,
 103        struct possible_tag *best)
 104{
 105        unsigned long seen_commits = 0;
 106        while (*list) {
 107                struct commit *c = pop_commit(list);
 108                struct commit_list *parents = c->parents;
 109                seen_commits++;
 110                if (c->object.flags & best->flag_within) {
 111                        struct commit_list *a = *list;
 112                        while (a) {
 113                                struct commit *i = a->item;
 114                                if (!(i->object.flags & best->flag_within))
 115                                        break;
 116                                a = a->next;
 117                        }
 118                        if (!a)
 119                                break;
 120                } else
 121                        best->depth++;
 122                while (parents) {
 123                        struct commit *p = parents->item;
 124                        parse_commit(p);
 125                        if (!(p->object.flags & SEEN))
 126                                insert_by_date(p, list);
 127                        p->object.flags |= c->object.flags;
 128                        parents = parents->next;
 129                }
 130        }
 131        return seen_commits;
 132}
 133
 134static void describe(const char *arg, int last_one)
 135{
 136        unsigned char sha1[20];
 137        struct commit *cmit, *gave_up_on = NULL;
 138        struct commit_list *list;
 139        static int initialized = 0;
 140        struct commit_name *n;
 141        struct possible_tag all_matches[MAX_TAGS];
 142        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 143        unsigned long seen_commits = 0;
 144
 145        if (get_sha1(arg, sha1))
 146                die("Not a valid object name %s", arg);
 147        cmit = lookup_commit_reference(sha1);
 148        if (!cmit)
 149                die("%s is not a valid '%s' object", arg, commit_type);
 150
 151        if (!initialized) {
 152                initialized = 1;
 153                for_each_ref(get_name, NULL);
 154        }
 155
 156        n = cmit->util;
 157        if (n) {
 158                printf("%s\n", n->path);
 159                return;
 160        }
 161
 162        if (debug)
 163                fprintf(stderr, "searching to describe %s\n", arg);
 164
 165        list = NULL;
 166        cmit->object.flags = SEEN;
 167        commit_list_insert(cmit, &list);
 168        while (list) {
 169                struct commit *c = pop_commit(&list);
 170                struct commit_list *parents = c->parents;
 171                seen_commits++;
 172                n = c->util;
 173                if (n) {
 174                        if (match_cnt < max_candidates) {
 175                                struct possible_tag *t = &all_matches[match_cnt++];
 176                                t->name = n;
 177                                t->depth = seen_commits - 1;
 178                                t->flag_within = 1u << match_cnt;
 179                                t->found_order = match_cnt;
 180                                c->object.flags |= t->flag_within;
 181                                if (n->prio == 2)
 182                                        annotated_cnt++;
 183                        }
 184                        else {
 185                                gave_up_on = c;
 186                                break;
 187                        }
 188                }
 189                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 190                        struct possible_tag *t = &all_matches[cur_match];
 191                        if (!(c->object.flags & t->flag_within))
 192                                t->depth++;
 193                }
 194                if (annotated_cnt && !list) {
 195                        if (debug)
 196                                fprintf(stderr, "finished search at %s\n",
 197                                        sha1_to_hex(c->object.sha1));
 198                        break;
 199                }
 200                while (parents) {
 201                        struct commit *p = parents->item;
 202                        parse_commit(p);
 203                        if (!(p->object.flags & SEEN))
 204                                insert_by_date(p, &list);
 205                        p->object.flags |= c->object.flags;
 206                        parents = parents->next;
 207                }
 208        }
 209
 210        if (!match_cnt)
 211                die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 212
 213        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 214
 215        if (gave_up_on) {
 216                insert_by_date(gave_up_on, &list);
 217                seen_commits--;
 218        }
 219        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 220        free_commit_list(list);
 221
 222        if (debug) {
 223                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 224                        struct possible_tag *t = &all_matches[cur_match];
 225                        fprintf(stderr, " %-11s %8d %s\n",
 226                                prio_names[t->name->prio],
 227                                t->depth, t->name->path);
 228                }
 229                fprintf(stderr, "traversed %lu commits\n", seen_commits);
 230                if (gave_up_on) {
 231                        fprintf(stderr,
 232                                "more than %i tags found; listed %i most recent\n"
 233                                "gave up search at %s\n",
 234                                max_candidates, max_candidates,
 235                                sha1_to_hex(gave_up_on->object.sha1));
 236                }
 237        }
 238        if (abbrev == 0)
 239                printf("%s\n", all_matches[0].name->path );
 240        else
 241                printf("%s-%d-g%s\n", all_matches[0].name->path,
 242                       all_matches[0].depth,
 243                       find_unique_abbrev(cmit->object.sha1, abbrev));
 244
 245        if (!last_one)
 246                clear_commit_marks(cmit, -1);
 247}
 248
 249int cmd_describe(int argc, const char **argv, const char *prefix)
 250{
 251        int contains = 0;
 252        struct option options[] = {
 253                OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
 254                OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
 255                OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
 256                OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
 257                OPT__ABBREV(&abbrev),
 258                OPT_INTEGER(0, "candidates", &max_candidates,
 259                            "consider <n> most recent tags (default: 10)"),
 260                OPT_STRING(0, "match",       &pattern, "pattern",
 261                           "only consider tags matching <pattern>"),
 262                OPT_END(),
 263        };
 264
 265        argc = parse_options(argc, argv, options, describe_usage, 0);
 266        if (max_candidates < 1)
 267                max_candidates = 1;
 268        else if (max_candidates > MAX_TAGS)
 269                max_candidates = MAX_TAGS;
 270
 271        save_commit_buffer = 0;
 272
 273        if (contains) {
 274                const char **args = xmalloc((6 + argc) * sizeof(char*));
 275                int i = 0;
 276                args[i++] = "name-rev";
 277                args[i++] = "--name-only";
 278                args[i++] = "--no-undefined";
 279                if (!all) {
 280                        args[i++] = "--tags";
 281                        if (pattern) {
 282                                char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 283                                sprintf(s, "--refs=refs/tags/%s", pattern);
 284                                args[i++] = s;
 285                        }
 286                }
 287                memcpy(args + i, argv, argc * sizeof(char*));
 288                args[i + argc] = NULL;
 289                return cmd_name_rev(i + argc, args, prefix);
 290        }
 291
 292        if (argc == 0) {
 293                describe("HEAD", 1);
 294        } else {
 295                while (argc-- > 0) {
 296                        describe(*argv++, argc == 0);
 297                }
 298        }
 299        return 0;
 300}