Merge branch 'js/attach'
[gitweb.git] / builtin-describe.c
index d65c7d286ddc6878a2d3936b9546839fec9ef997..165917e40db78e7105a16d6e7a1653862a29fdc5 100644 (file)
@@ -2,57 +2,41 @@
 #include "commit.h"
 #include "tag.h"
 #include "refs.h"
-#include "diff.h"
-#include "diffcore.h"
-#include "revision.h"
 #include "builtin.h"
 
+#define SEEN           (1u<<0)
+#define MAX_TAGS       (FLAG_BITS - 1)
+
 static const char describe_usage[] =
 "git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
 
+static int debug;      /* Display lots of verbose info */
 static int all;        /* Default to annotated tags only */
 static int tags;       /* But allow any tags if --tags is specified */
-
 static int abbrev = DEFAULT_ABBREV;
+static int max_candidates = 10;
 
-static int names, allocs;
-static struct commit_name {
-       struct commit *commit;
+struct commit_name {
        int prio; /* annotated tag = 2, tag = 1, head = 0 */
        char path[FLEX_ARRAY]; /* more */
-} **name_array = NULL;
-
-static struct commit_name *match(struct commit *cmit)
-{
-       int i = names;
-       struct commit_name **p = name_array;
-
-       while (i-- > 0) {
-               struct commit_name *n = *p++;
-               if (n->commit == cmit)
-                       return n;
-       }
-       return NULL;
-}
+};
+static const char *prio_names[] = {
+       "head", "lightweight", "annotated",
+};
 
 static void add_to_known_names(const char *path,
                               struct commit *commit,
                               int prio)
 {
-       int idx;
-       int len = strlen(path)+1;
-       struct commit_name *name = xmalloc(sizeof(struct commit_name) + len);
-
-       name->commit = commit;
-       name->prio = prio;
-       memcpy(name->path, path, len);
-       idx = names;
-       if (idx >= allocs) {
-               allocs = (idx + 50) * 3 / 2;
-               name_array = xrealloc(name_array, allocs*sizeof(*name_array));
+       struct commit_name *e = commit->util;
+       if (!e || e->prio < prio) {
+               size_t len = strlen(path)+1;
+               free(e);
+               e = xmalloc(sizeof(struct commit_name) + len);
+               e->prio = prio;
+               memcpy(e->path, path, len);
+               commit->util = e;
        }
-       name_array[idx] = name;
-       names = ++idx;
 }
 
 static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
@@ -68,7 +52,7 @@ static int get_name(const char *path, const unsigned char *sha1, int flag, void
         * If --tags, then any tags are used.
         * Otherwise only annotated tags are used.
         */
-       if (!strncmp(path, "refs/tags/", 10)) {
+       if (!prefixcmp(path, "refs/tags/")) {
                if (object->type == OBJ_TAG)
                        prio = 2;
                else
@@ -87,32 +71,69 @@ static int get_name(const char *path, const unsigned char *sha1, int flag, void
        return 0;
 }
 
-static int compare_names(const void *_a, const void *_b)
-{
-       struct commit_name *a = *(struct commit_name **)_a;
-       struct commit_name *b = *(struct commit_name **)_b;
-       unsigned long a_date = a->commit->date;
-       unsigned long b_date = b->commit->date;
-
-       if (a->prio != b->prio)
-               return b->prio - a->prio;
-       return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
-}
-
 struct possible_tag {
-       struct possible_tag *next;
        struct commit_name *name;
-       unsigned long depth;
+       int depth;
+       int found_order;
+       unsigned flag_within;
 };
 
+static int compare_pt(const void *a_, const void *b_)
+{
+       struct possible_tag *a = (struct possible_tag *)a_;
+       struct possible_tag *b = (struct possible_tag *)b_;
+       if (a->name->prio != b->name->prio)
+               return b->name->prio - a->name->prio;
+       if (a->depth != b->depth)
+               return a->depth - b->depth;
+       if (a->found_order != b->found_order)
+               return a->found_order - b->found_order;
+       return 0;
+}
+
+static unsigned long finish_depth_computation(
+       struct commit_list **list,
+       struct possible_tag *best)
+{
+       unsigned long seen_commits = 0;
+       while (*list) {
+               struct commit *c = pop_commit(list);
+               struct commit_list *parents = c->parents;
+               seen_commits++;
+               if (c->object.flags & best->flag_within) {
+                       struct commit_list *a = *list;
+                       while (a) {
+                               struct commit *i = a->item;
+                               if (!(i->object.flags & best->flag_within))
+                                       break;
+                               a = a->next;
+                       }
+                       if (!a)
+                               break;
+               } else
+                       best->depth++;
+               while (parents) {
+                       struct commit *p = parents->item;
+                       parse_commit(p);
+                       if (!(p->object.flags & SEEN))
+                               insert_by_date(p, list);
+                       p->object.flags |= c->object.flags;
+                       parents = parents->next;
+               }
+       }
+       return seen_commits;
+}
+
 static void describe(const char *arg, int last_one)
 {
        unsigned char sha1[20];
-       struct commit *cmit;
+       struct commit *cmit, *gave_up_on = NULL;
        struct commit_list *list;
        static int initialized = 0;
        struct commit_name *n;
-       struct possible_tag *all_matches, *min_match, *cur_match;
+       struct possible_tag all_matches[MAX_TAGS];
+       unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
+       unsigned long seen_commits = 0;
 
        if (get_sha1(arg, sha1))
                die("Not a valid object name %s", arg);
@@ -123,77 +144,99 @@ static void describe(const char *arg, int last_one)
        if (!initialized) {
                initialized = 1;
                for_each_ref(get_name, NULL);
-               qsort(name_array, names, sizeof(*name_array), compare_names);
        }
 
-       n = match(cmit);
+       n = cmit->util;
        if (n) {
                printf("%s\n", n->path);
                return;
        }
 
+       if (debug)
+               fprintf(stderr, "searching to describe %s\n", arg);
+
        list = NULL;
-       all_matches = NULL;
-       cur_match = NULL;
+       cmit->object.flags = SEEN;
        commit_list_insert(cmit, &list);
        while (list) {
                struct commit *c = pop_commit(&list);
-               n = match(c);
+               struct commit_list *parents = c->parents;
+               seen_commits++;
+               n = c->util;
                if (n) {
-                       struct possible_tag *p = xmalloc(sizeof(*p));
-                       p->name = n;
-                       p->next = NULL;
-                       if (cur_match)
-                               cur_match->next = p;
-                       else
-                               all_matches = p;
-                       cur_match = p;
-               } else {
-                       struct commit_list *parents = c->parents;
-                       while (parents) {
-                               struct commit *p = parents->item;
-                               parse_commit(p);
-                               if (!(p->object.flags & SEEN)) {
-                                       p->object.flags |= SEEN;
-                                       insert_by_date(p, &list);
-                               }
-                               parents = parents->next;
+                       if (match_cnt < max_candidates) {
+                               struct possible_tag *t = &all_matches[match_cnt++];
+                               t->name = n;
+                               t->depth = seen_commits - 1;
+                               t->flag_within = 1u << match_cnt;
+                               t->found_order = match_cnt;
+                               c->object.flags |= t->flag_within;
+                               if (n->prio == 2)
+                                       annotated_cnt++;
+                       }
+                       else {
+                               gave_up_on = c;
+                               break;
                        }
                }
+               for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+                       struct possible_tag *t = &all_matches[cur_match];
+                       if (!(c->object.flags & t->flag_within))
+                               t->depth++;
+               }
+               if (annotated_cnt && !list) {
+                       if (debug)
+                               fprintf(stderr, "finished search at %s\n",
+                                       sha1_to_hex(c->object.sha1));
+                       break;
+               }
+               while (parents) {
+                       struct commit *p = parents->item;
+                       parse_commit(p);
+                       if (!(p->object.flags & SEEN))
+                               insert_by_date(p, &list);
+                       p->object.flags |= c->object.flags;
+                       parents = parents->next;
+               }
        }
 
-       if (!all_matches)
+       if (!match_cnt)
                die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
 
-       min_match = NULL;
-       for (cur_match = all_matches; cur_match; cur_match = cur_match->next) {
-               struct rev_info revs;
-               struct commit *tagged = cur_match->name->commit;
+       qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 
-               clear_commit_marks(cmit, -1);
-               init_revisions(&revs, NULL);
-               tagged->object.flags |= UNINTERESTING;
-               add_pending_object(&revs, &tagged->object, NULL);
-               add_pending_object(&revs, &cmit->object, NULL);
-
-               prepare_revision_walk(&revs);
-               cur_match->depth = 0;
-               while ((!min_match || cur_match->depth < min_match->depth)
-                       && get_revision(&revs))
-                       cur_match->depth++;
-               if (!min_match || cur_match->depth < min_match->depth)
-                       min_match = cur_match;
+       if (gave_up_on) {
+               insert_by_date(gave_up_on, &list);
+               seen_commits--;
        }
-       printf("%s-g%s\n", min_match->name->path,
-                  find_unique_abbrev(cmit->object.sha1, abbrev));
+       seen_commits += finish_depth_computation(&list, &all_matches[0]);
+       free_commit_list(list);
 
-       if (!last_one) {
-               for (cur_match = all_matches; cur_match; cur_match = min_match) {
-                       min_match = cur_match->next;
-                       free(cur_match);
+       if (debug) {
+               for (cur_match = 0; cur_match < match_cnt; cur_match++) {
+                       struct possible_tag *t = &all_matches[cur_match];
+                       fprintf(stderr, " %-11s %8d %s\n",
+                               prio_names[t->name->prio],
+                               t->depth, t->name->path);
+               }
+               fprintf(stderr, "traversed %lu commits\n", seen_commits);
+               if (gave_up_on) {
+                       fprintf(stderr,
+                               "more than %i tags found; listed %i most recent\n"
+                               "gave up search at %s\n",
+                               max_candidates, max_candidates,
+                               sha1_to_hex(gave_up_on->object.sha1));
                }
-               clear_commit_marks(cmit, SEEN);
        }
+       if (abbrev == 0)
+               printf("%s\n", all_matches[0].name->path );
+       else
+               printf("%s-%d-g%s\n", all_matches[0].name->path,
+                      all_matches[0].depth,
+                      find_unique_abbrev(cmit->object.sha1, abbrev));
+
+       if (!last_one)
+               clear_commit_marks(cmit, -1);
 }
 
 int cmd_describe(int argc, const char **argv, const char *prefix)
@@ -205,15 +248,24 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 
                if (*arg != '-')
                        break;
+               else if (!strcmp(arg, "--debug"))
+                       debug = 1;
                else if (!strcmp(arg, "--all"))
                        all = 1;
                else if (!strcmp(arg, "--tags"))
                        tags = 1;
-               else if (!strncmp(arg, "--abbrev=", 9)) {
+               else if (!prefixcmp(arg, "--abbrev=")) {
                        abbrev = strtoul(arg + 9, NULL, 10);
-                       if (abbrev < MINIMUM_ABBREV || 40 < abbrev)
+                       if (abbrev != 0 && (abbrev < MINIMUM_ABBREV || 40 < abbrev))
                                abbrev = DEFAULT_ABBREV;
                }
+               else if (!prefixcmp(arg, "--candidates=")) {
+                       max_candidates = strtoul(arg + 13, NULL, 10);
+                       if (max_candidates < 1)
+                               max_candidates = 1;
+                       else if (max_candidates > MAX_TAGS)
+                               max_candidates = MAX_TAGS;
+               }
                else
                        usage(describe_usage);
        }