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
   7#define SEEN (1u << 0)
   8
   9static const char describe_usage[] =
  10"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
  11
  12static int all; /* Default to annotated tags only */
  13static int tags;        /* But allow any tags if --tags is specified */
  14
  15static int abbrev = DEFAULT_ABBREV;
  16
  17static int names, allocs;
  18static struct commit_name {
  19        const struct commit *commit;
  20        int prio; /* annotated tag = 2, tag = 1, head = 0 */
  21        char path[FLEX_ARRAY]; /* more */
  22} **name_array = NULL;
  23
  24static struct commit_name *match(struct commit *cmit)
  25{
  26        int i = names;
  27        struct commit_name **p = name_array;
  28
  29        while (i-- > 0) {
  30                struct commit_name *n = *p++;
  31                if (n->commit == cmit)
  32                        return n;
  33        }
  34        return NULL;
  35}
  36
  37static void add_to_known_names(const char *path,
  38                               const struct commit *commit,
  39                               int prio)
  40{
  41        int idx;
  42        int len = strlen(path)+1;
  43        struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
  44
  45        name->commit = commit;
  46        name->prio = prio;
  47        memcpy(name->path, path, len);
  48        idx = names;
  49        if (idx >= allocs) {
  50                allocs = (idx + 50) * 3 / 2;
  51                name_array = xrealloc(name_array, allocs*sizeof(*name_array));
  52        }
  53        name_array[idx] = name;
  54        names = ++idx;
  55}
  56
  57static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  58{
  59        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
  60        struct object *object;
  61        int prio;
  62
  63        if (!commit)
  64                return 0;
  65        object = parse_object(sha1);
  66        /* If --all, then any refs are used.
  67         * If --tags, then any tags are used.
  68         * Otherwise only annotated tags are used.
  69         */
  70        if (!strncmp(path, "refs/tags/", 10)) {
  71                if (object->type == OBJ_TAG)
  72                        prio = 2;
  73                else
  74                        prio = 1;
  75        }
  76        else
  77                prio = 0;
  78
  79        if (!all) {
  80                if (!prio)
  81                        return 0;
  82                if (!tags && prio < 2)
  83                        return 0;
  84        }
  85        add_to_known_names(all ? path + 5 : path + 10, commit, prio);
  86        return 0;
  87}
  88
  89static int compare_names(const void *_a, const void *_b)
  90{
  91        struct commit_name *a = *(struct commit_name **)_a;
  92        struct commit_name *b = *(struct commit_name **)_b;
  93        unsigned long a_date = a->commit->date;
  94        unsigned long b_date = b->commit->date;
  95
  96        if (a->prio != b->prio)
  97                return b->prio - a->prio;
  98        return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
  99}
 100
 101static void describe(const char *arg, int last_one)
 102{
 103        unsigned char sha1[20];
 104        struct commit *cmit;
 105        struct commit_list *list;
 106        static int initialized = 0;
 107        struct commit_name *n;
 108
 109        if (get_sha1(arg, sha1))
 110                die("Not a valid object name %s", arg);
 111        cmit = lookup_commit_reference(sha1);
 112        if (!cmit)
 113                die("%s is not a valid '%s' object", arg, commit_type);
 114
 115        if (!initialized) {
 116                initialized = 1;
 117                for_each_ref(get_name, NULL);
 118                qsort(name_array, names, sizeof(*name_array), compare_names);
 119        }
 120
 121        n = match(cmit);
 122        if (n) {
 123                printf("%s\n", n->path);
 124                return;
 125        }
 126
 127        list = NULL;
 128        commit_list_insert(cmit, &list);
 129        while (list) {
 130                struct commit *c = pop_most_recent_commit(&list, SEEN);
 131                n = match(c);
 132                if (n) {
 133                        printf("%s-g%s\n", n->path,
 134                               find_unique_abbrev(cmit->object.sha1, abbrev));
 135                        if (!last_one)
 136                                clear_commit_marks(cmit, SEEN);
 137                        return;
 138                }
 139        }
 140        die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 141}
 142
 143int cmd_describe(int argc, const char **argv, const char *prefix)
 144{
 145        int i;
 146
 147        for (i = 1; i < argc; i++) {
 148                const char *arg = argv[i];
 149
 150                if (*arg != '-')
 151                        break;
 152                else if (!strcmp(arg, "--all"))
 153                        all = 1;
 154                else if (!strcmp(arg, "--tags"))
 155                        tags = 1;
 156                else if (!strncmp(arg, "--abbrev=", 9)) {
 157                        abbrev = strtoul(arg + 9, NULL, 10);
 158                        if (abbrev < MINIMUM_ABBREV || 40 < abbrev)
 159                                abbrev = DEFAULT_ABBREV;
 160                }
 161                else
 162                        usage(describe_usage);
 163        }
 164
 165        save_commit_buffer = 0;
 166
 167        if (argc <= i)
 168                describe("HEAD", 1);
 169        else
 170                while (i < argc) {
 171                        describe(argv[i], (i == argc - 1));
 172                        i++;
 173                }
 174
 175        return 0;
 176}