builtin-branch: factor out merge_filter matching
[gitweb.git] / builtin-describe.c
index ad3b469f372c6c62b3b6ba2c36c2a80874743e6d..ec404c839b6542deb4e15ca342fd3c0afbbedd2e 100644 (file)
@@ -3,75 +3,90 @@
 #include "tag.h"
 #include "refs.h"
 #include "builtin.h"
+#include "exec_cmd.h"
+#include "parse-options.h"
 
-#define SEEN (1u << 0)
+#define SEEN           (1u<<0)
+#define MAX_TAGS       (FLAG_BITS - 1)
 
-static const char describe_usage[] =
-"git-describe [--all] [--tags] [--abbrev=<n>] <committish>*";
+static const char * const describe_usage[] = {
+       "git describe [options] <committish>*",
+       NULL
+};
 
+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 longformat;
 static int abbrev = DEFAULT_ABBREV;
+static int max_candidates = 10;
+static const char *pattern;
+static int always;
 
-static int names, allocs;
-static struct commit_name {
-       const struct commit *commit;
+struct commit_name {
+       struct tag *tag;
        int prio; /* annotated tag = 2, tag = 1, head = 0 */
+       unsigned char sha1[20];
        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,
-                              const struct commit *commit,
-                              int prio)
+                              struct commit *commit,
+                              int prio,
+                              const unsigned char *sha1)
 {
-       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->tag = NULL;
+               e->prio = prio;
+               hashcpy(e->sha1, sha1);
+               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)
 {
-       struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+       int might_be_tag = !prefixcmp(path, "refs/tags/");
+       struct commit *commit;
        struct object *object;
-       int prio;
+       unsigned char peeled[20];
+       int is_tag, prio;
 
-       if (!commit)
+       if (!all && !might_be_tag)
                return 0;
-       object = parse_object(sha1);
+
+       if (!peel_ref(path, peeled) && !is_null_sha1(peeled)) {
+               commit = lookup_commit_reference_gently(peeled, 1);
+               if (!commit)
+                       return 0;
+               is_tag = !!hashcmp(sha1, commit->object.sha1);
+       } else {
+               commit = lookup_commit_reference_gently(sha1, 1);
+               object = parse_object(sha1);
+               if (!commit || !object)
+                       return 0;
+               is_tag = object->type == OBJ_TAG;
+       }
+
        /* If --all, then any refs are used.
         * If --tags, then any tags are used.
         * Otherwise only annotated tags are used.
         */
-       if (!strncmp(path, "refs/tags/", 10)) {
-               if (object->type == OBJ_TAG)
+       if (might_be_tag) {
+               if (is_tag)
                        prio = 2;
                else
                        prio = 1;
+
+               if (pattern && fnmatch(pattern, path + 10, 0))
+                       prio = 0;
        }
        else
                prio = 0;
@@ -82,29 +97,94 @@ static int get_name(const char *path, const unsigned char *sha1, int flag, void
                if (!tags && prio < 2)
                        return 0;
        }
-       add_to_known_names(all ? path + 5 : path + 10, commit, prio);
+       add_to_known_names(all ? path + 5 : path + 10, commit, prio, sha1);
+       return 0;
+}
+
+struct possible_tag {
+       struct commit_name *name;
+       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 int compare_names(const void *_a, const void *_b)
+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 display_name(struct commit_name *n)
+{
+       if (n->prio == 2 && !n->tag) {
+               n->tag = lookup_tag(n->sha1);
+               if (!n->tag || parse_tag(n->tag) || !n->tag->tag)
+                       die("annotated tag %s not available", n->path);
+               if (strcmp(n->tag->tag, n->path))
+                       warning("tag '%s' is really '%s' here", n->tag->tag, n->path);
+       }
+
+       if (n->tag)
+               printf("%s", n->tag->tag);
+       else
+               printf("%s", n->path);
+}
+
+static void show_suffix(int depth, const unsigned char *sha1)
 {
-       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;
+       printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 }
 
 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[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);
@@ -115,62 +195,173 @@ 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);
+               /*
+                * Exact match to an existing ref.
+                */
+               display_name(n);
+               if (longformat)
+                       show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
+               printf("\n");
                return;
        }
 
+       if (!max_candidates)
+               die("no tag exactly matches '%s'", sha1_to_hex(cmit->object.sha1));
+       if (debug)
+               fprintf(stderr, "searching to describe %s\n", arg);
+
        list = NULL;
+       cmit->object.flags = SEEN;
        commit_list_insert(cmit, &list);
        while (list) {
-               struct commit *c = pop_most_recent_commit(&list, SEEN);
-               n = match(c);
+               struct commit *c = pop_commit(&list);
+               struct commit_list *parents = c->parents;
+               seen_commits++;
+               n = c->util;
                if (n) {
-                       printf("%s-g%s\n", n->path,
-                              find_unique_abbrev(cmit->object.sha1, abbrev));
-                       if (!last_one)
-                               clear_commit_marks(cmit, SEEN);
+                       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 (!match_cnt) {
+               const unsigned char *sha1 = cmit->object.sha1;
+               if (always) {
+                       printf("%s\n", find_unique_abbrev(sha1, abbrev));
                        return;
                }
+               die("cannot describe '%s'", sha1_to_hex(sha1));
+       }
+
+       qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
+
+       if (gave_up_on) {
+               insert_by_date(gave_up_on, &list);
+               seen_commits--;
+       }
+       seen_commits += finish_depth_computation(&list, &all_matches[0]);
+       free_commit_list(list);
+
+       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));
+               }
        }
-       die("cannot describe '%s'", sha1_to_hex(cmit->object.sha1));
+
+       display_name(all_matches[0].name);
+       if (abbrev)
+               show_suffix(all_matches[0].depth, cmit->object.sha1);
+       printf("\n");
+
+       if (!last_one)
+               clear_commit_marks(cmit, -1);
 }
 
 int cmd_describe(int argc, const char **argv, const char *prefix)
 {
-       int i;
+       int contains = 0;
+       struct option options[] = {
+               OPT_BOOLEAN(0, "contains",   &contains, "find the tag that comes after the commit"),
+               OPT_BOOLEAN(0, "debug",      &debug, "debug search strategy on stderr"),
+               OPT_BOOLEAN(0, "all",        &all, "use any ref in .git/refs"),
+               OPT_BOOLEAN(0, "tags",       &tags, "use any tag in .git/refs/tags"),
+               OPT_BOOLEAN(0, "long",       &longformat, "always use long format"),
+               OPT__ABBREV(&abbrev),
+               OPT_SET_INT(0, "exact-match", &max_candidates,
+                           "only output exact matches", 0),
+               OPT_INTEGER(0, "candidates", &max_candidates,
+                           "consider <n> most recent tags (default: 10)"),
+               OPT_STRING(0, "match",       &pattern, "pattern",
+                          "only consider tags matching <pattern>"),
+               OPT_BOOLEAN(0, "always",     &always,
+                          "show abbreviated commit object as fallback"),
+               OPT_END(),
+       };
 
-       for (i = 1; i < argc; i++) {
-               const char *arg = argv[i];
+       argc = parse_options(argc, argv, options, describe_usage, 0);
+       if (max_candidates < 0)
+               max_candidates = 0;
+       else if (max_candidates > MAX_TAGS)
+               max_candidates = MAX_TAGS;
 
-               if (*arg != '-')
-                       break;
-               else if (!strcmp(arg, "--all"))
-                       all = 1;
-               else if (!strcmp(arg, "--tags"))
-                       tags = 1;
-               else if (!strncmp(arg, "--abbrev=", 9)) {
-                       abbrev = strtoul(arg + 9, NULL, 10);
-                       if (abbrev < MINIMUM_ABBREV || 40 < abbrev)
-                               abbrev = DEFAULT_ABBREV;
+       save_commit_buffer = 0;
+
+       if (longformat && abbrev == 0)
+               die("--long is incompatible with --abbrev=0");
+
+       if (contains) {
+               const char **args = xmalloc((7 + argc) * sizeof(char*));
+               int i = 0;
+               args[i++] = "name-rev";
+               args[i++] = "--name-only";
+               args[i++] = "--no-undefined";
+               if (always)
+                       args[i++] = "--always";
+               if (!all) {
+                       args[i++] = "--tags";
+                       if (pattern) {
+                               char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
+                               sprintf(s, "--refs=refs/tags/%s", pattern);
+                               args[i++] = s;
+                       }
                }
-               else
-                       usage(describe_usage);
+               memcpy(args + i, argv, argc * sizeof(char*));
+               args[i + argc] = NULL;
+               return cmd_name_rev(i + argc, args, prefix);
        }
 
-       save_commit_buffer = 0;
-
-       if (argc <= i)
+       if (argc == 0) {
                describe("HEAD", 1);
-       else
-               while (i < argc) {
-                       describe(argv[i], (i == argc - 1));
-                       i++;
+       } else {
+               while (argc-- > 0) {
+                       describe(*argv++, argc == 0);
                }
-
+       }
        return 0;
 }