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