Andrew's git - gitweb.git/blob

ee38f5f5d8791646cd6ca0f1d2570d793afa78a9
   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        char path[];
  21} **name_array = NULL;
  22
  23static struct commit_name *match(struct commit *cmit)
  24{
  25        int i = names;
  26        struct commit_name **p = name_array;
  27
  28        while (i-- > 0) {
  29                struct commit_name *n = *p++;
  30                if (n->commit == cmit)
  31                        return n;
  32        }
  33        return NULL;
  34}
  35
  36static void add_to_known_names(const char *path, const struct commit *commit)
  37{
  38        int idx;
  39        int len = strlen(path)+1;
  40        struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
  41
  42        name->commit = commit;
  43        memcpy(name->path, path, len);
  44        idx = names;
  45        if (idx >= allocs) {
  46                allocs = (idx + 50) * 3 / 2;
  47                name_array = xrealloc(name_array, allocs*sizeof(*name_array));
  48        }
  49        name_array[idx] = name;
  50        names = ++idx;
  51}
  52
  53static int get_name(const char *path, const unsigned char *sha1)
  54{
  55        struct commit *commit = lookup_commit_reference_gently(sha1, 1);
  56        if (!commit)
  57                return 0;
  58        /* If --all, then any refs are used.
  59         * If --tags, then any tags are used.
  60         * Otherwise only annotated tags are used.
  61         */
  62        if (!all) {
  63                if (strncmp(path, "refs/tags/", 10))
  64                        return 0;
  65                if (!tags) {
  66                        struct object *object;
  67                        object = parse_object(sha1);
  68                        if (object->type != tag_type)
  69                                return 0;
  70                }
  71        }
  72        add_to_known_names(all ? path : path + 10, commit);
  73        return 0;
  74}
  75
  76static int compare_names(const void *_a, const void *_b)
  77{
  78        struct commit_name *a = *(struct commit_name **)_a;
  79        struct commit_name *b = *(struct commit_name **)_b;
  80        unsigned long a_date = a->commit->date;
  81        unsigned long b_date = b->commit->date;
  82        return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
  83}
  84
  85static void describe(struct commit *cmit)
  86{
  87        struct commit_list *list;
  88        static int initialized = 0;
  89        struct commit_name *n;
  90
  91        if (!initialized) {
  92                initialized = 1;
  93                for_each_ref(get_name);
  94                qsort(name_array, names, sizeof(*name_array), compare_names);
  95        }
  96
  97        n = match(cmit);
  98        if (n) {
  99                printf("%s\n", n->path);
 100                return;
 101        }
 102
 103        list = NULL;
 104        commit_list_insert(cmit, &list);
 105        while (list) {
 106                struct commit *c = pop_most_recent_commit(&list, SEEN);
 107                n = match(c);
 108                if (n) {
 109                        printf("%s-g%s\n", n->path,
 110                               find_unique_abbrev(cmit->object.sha1, abbrev));
 111                        return;
 112                }
 113        }
 114}
 115
 116int main(int argc, char **argv)
 117{
 118        int i;
 119
 120        for (i = 1; i < argc; i++) {
 121                const char *arg = argv[i];
 122                unsigned char sha1[20];
 123                struct commit *cmit;
 124
 125                if (!strcmp(arg, "--all")) {
 126                        all = 1;
 127                        continue;
 128                }
 129                if (!strcmp(arg, "--tags")) {
 130                        tags = 1;
 131                        continue;
 132                }
 133                if (!strncmp(arg, "--abbrev=", 9)) {
 134                        abbrev = strtoul(arg + 9, NULL, 10);
 135                        if (abbrev < 4 || 40 <= abbrev)
 136                                abbrev = DEFAULT_ABBREV;
 137                        continue;
 138                }
 139                if (get_sha1(arg, sha1) < 0)
 140                        usage(describe_usage);
 141                cmit = lookup_commit_reference(sha1);
 142                if (!cmit)
 143                        usage(describe_usage);
 144                describe(cmit);
 145        }
 146        return 0;
 147}