Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5
   6#define SEEN (1u << 0)
   7
   8static const char describe_usage[] =
   9"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
  10
  11static int all = 0;     /* Default to annotated tags only */
  12static int tags = 0;    /* But allow any tags if --tags is specified */
  13
  14#define DEFAULT_ABBREV 8 /* maybe too many */
  15static int abbrev = DEFAULT_ABBREV;
  16
  17static int names = 0, allocs = 0;
  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)
  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 == tag_type)
  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(struct commit *cmit)
 102{
 103        struct commit_list *list;
 104        static int initialized = 0;
 105        struct commit_name *n;
 106
 107        if (!initialized) {
 108                initialized = 1;
 109                for_each_ref(get_name);
 110                qsort(name_array, names, sizeof(*name_array), compare_names);
 111        }
 112
 113        n = match(cmit);
 114        if (n) {
 115                printf("%s\n", n->path);
 116                return;
 117        }
 118
 119        list = NULL;
 120        commit_list_insert(cmit, &list);
 121        while (list) {
 122                struct commit *c = pop_most_recent_commit(&list, SEEN);
 123                n = match(c);
 124                if (n) {
 125                        printf("%s-g%s\n", n->path,
 126                               find_unique_abbrev(cmit->object.sha1, abbrev));
 127                        break;
 128                }
 129        }
 130        clear_commit_marks(cmit, SEEN);
 131}
 132
 133int main(int argc, char **argv)
 134{
 135        int i;
 136
 137        for (i = 1; i < argc; i++) {
 138                const char *arg = argv[i];
 139                unsigned char sha1[20];
 140                struct commit *cmit;
 141
 142                if (!strcmp(arg, "--all")) {
 143                        all = 1;
 144                        continue;
 145                }
 146                if (!strcmp(arg, "--tags")) {
 147                        tags = 1;
 148                        continue;
 149                }
 150                if (!strncmp(arg, "--abbrev=", 9)) {
 151                        abbrev = strtoul(arg + 9, NULL, 10);
 152                        if (abbrev < 4 || 40 <= abbrev)
 153                                abbrev = DEFAULT_ABBREV;
 154                        continue;
 155                }
 156                if (get_sha1(arg, sha1) < 0)
 157                        usage(describe_usage);
 158                cmit = lookup_commit_reference(sha1);
 159                if (!cmit)
 160                        usage(describe_usage);
 161                describe(cmit);
 162        }
 163        return 0;
 164}