diff options
Diffstat (limited to 'third_party/git/builtin/name-rev.c')
| -rw-r--r-- | third_party/git/builtin/name-rev.c | 636 |
1 files changed, 636 insertions, 0 deletions
diff --git a/third_party/git/builtin/name-rev.c b/third_party/git/builtin/name-rev.c new file mode 100644 index 000000000000..a9dcd25e4647 --- /dev/null +++ b/third_party/git/builtin/name-rev.c @@ -0,0 +1,636 @@ +#include "builtin.h" +#include "cache.h" +#include "repository.h" +#include "config.h" +#include "commit.h" +#include "tag.h" +#include "refs.h" +#include "parse-options.h" +#include "prio-queue.h" +#include "sha1-lookup.h" +#include "commit-slab.h" + +/* + * One day. See the 'name a rev shortly after epoch' test in t6120 when + * changing this value + */ +#define CUTOFF_DATE_SLOP 86400 + +struct rev_name { + char *tip_name; + timestamp_t taggerdate; + int generation; + int distance; + int from_tag; +}; + +define_commit_slab(commit_rev_name, struct rev_name); + +static timestamp_t cutoff = TIME_MAX; +static struct commit_rev_name rev_names; + +/* How many generations are maximally preferred over _one_ merge traversal? */ +#define MERGE_TRAVERSAL_WEIGHT 65535 + +static int is_valid_rev_name(const struct rev_name *name) +{ + return name && (name->generation || name->tip_name); +} + +static struct rev_name *get_commit_rev_name(const struct commit *commit) +{ + struct rev_name *name = commit_rev_name_peek(&rev_names, commit); + + return is_valid_rev_name(name) ? name : NULL; +} + +static int is_better_name(struct rev_name *name, + timestamp_t taggerdate, + int distance, + int from_tag) +{ + /* + * When comparing names based on tags, prefer names + * based on the older tag, even if it is farther away. + */ + if (from_tag && name->from_tag) + return (name->taggerdate > taggerdate || + (name->taggerdate == taggerdate && + name->distance > distance)); + + /* + * We know that at least one of them is a non-tag at this point. + * favor a tag over a non-tag. + */ + if (name->from_tag != from_tag) + return from_tag; + + /* + * We are now looking at two non-tags. Tiebreak to favor + * shorter hops. + */ + if (name->distance != distance) + return name->distance > distance; + + /* ... or tiebreak to favor older date */ + if (name->taggerdate != taggerdate) + return name->taggerdate > taggerdate; + + /* keep the current one if we cannot decide */ + return 0; +} + +static struct rev_name *create_or_update_name(struct commit *commit, + timestamp_t taggerdate, + int generation, int distance, + int from_tag) +{ + struct rev_name *name = commit_rev_name_at(&rev_names, commit); + + if (is_valid_rev_name(name)) { + if (!is_better_name(name, taggerdate, distance, from_tag)) + return NULL; + + /* + * This string might still be shared with ancestors + * (generation > 0). We can release it here regardless, + * because the new name that has just won will be better + * for them as well, so name_rev() will replace these + * stale pointers when it processes the parents. + */ + if (!name->generation) + free(name->tip_name); + } + + name->taggerdate = taggerdate; + name->generation = generation; + name->distance = distance; + name->from_tag = from_tag; + + return name; +} + +static char *get_parent_name(const struct rev_name *name, int parent_number) +{ + struct strbuf sb = STRBUF_INIT; + size_t len; + + strip_suffix(name->tip_name, "^0", &len); + if (name->generation > 0) { + strbuf_grow(&sb, len + + 1 + decimal_width(name->generation) + + 1 + decimal_width(parent_number)); + strbuf_addf(&sb, "%.*s~%d^%d", (int)len, name->tip_name, + name->generation, parent_number); + } else { + strbuf_grow(&sb, len + + 1 + decimal_width(parent_number)); + strbuf_addf(&sb, "%.*s^%d", (int)len, name->tip_name, + parent_number); + } + return strbuf_detach(&sb, NULL); +} + +static void name_rev(struct commit *start_commit, + const char *tip_name, timestamp_t taggerdate, + int from_tag, int deref) +{ + struct prio_queue queue; + struct commit *commit; + struct commit **parents_to_queue = NULL; + size_t parents_to_queue_nr, parents_to_queue_alloc = 0; + struct rev_name *start_name; + + parse_commit(start_commit); + if (start_commit->date < cutoff) + return; + + start_name = create_or_update_name(start_commit, taggerdate, 0, 0, + from_tag); + if (!start_name) + return; + if (deref) + start_name->tip_name = xstrfmt("%s^0", tip_name); + else + start_name->tip_name = xstrdup(tip_name); + + memset(&queue, 0, sizeof(queue)); /* Use the prio_queue as LIFO */ + prio_queue_put(&queue, start_commit); + + while ((commit = prio_queue_get(&queue))) { + struct rev_name *name = get_commit_rev_name(commit); + struct commit_list *parents; + int parent_number = 1; + + parents_to_queue_nr = 0; + + for (parents = commit->parents; + parents; + parents = parents->next, parent_number++) { + struct commit *parent = parents->item; + struct rev_name *parent_name; + int generation, distance; + + parse_commit(parent); + if (parent->date < cutoff) + continue; + + if (parent_number > 1) { + generation = 0; + distance = name->distance + MERGE_TRAVERSAL_WEIGHT; + } else { + generation = name->generation + 1; + distance = name->distance + 1; + } + + parent_name = create_or_update_name(parent, taggerdate, + generation, + distance, from_tag); + if (parent_name) { + if (parent_number > 1) + parent_name->tip_name = + get_parent_name(name, + parent_number); + else + parent_name->tip_name = name->tip_name; + ALLOC_GROW(parents_to_queue, + parents_to_queue_nr + 1, + parents_to_queue_alloc); + parents_to_queue[parents_to_queue_nr] = parent; + parents_to_queue_nr++; + } + } + + /* The first parent must come out first from the prio_queue */ + while (parents_to_queue_nr) + prio_queue_put(&queue, + parents_to_queue[--parents_to_queue_nr]); + } + + clear_prio_queue(&queue); + free(parents_to_queue); +} + +static int subpath_matches(const char *path, const char *filter) +{ + const char *subpath = path; + + while (subpath) { + if (!wildmatch(filter, subpath, 0)) + return subpath - path; + subpath = strchr(subpath, '/'); + if (subpath) + subpath++; + } + return -1; +} + +static const char *name_ref_abbrev(const char *refname, int shorten_unambiguous) +{ + if (shorten_unambiguous) + refname = shorten_unambiguous_ref(refname, 0); + else if (skip_prefix(refname, "refs/heads/", &refname)) + ; /* refname already advanced */ + else + skip_prefix(refname, "refs/", &refname); + return refname; +} + +struct name_ref_data { + int tags_only; + int name_only; + struct string_list ref_filters; + struct string_list exclude_filters; +}; + +static struct tip_table { + struct tip_table_entry { + struct object_id oid; + const char *refname; + struct commit *commit; + timestamp_t taggerdate; + unsigned int from_tag:1; + unsigned int deref:1; + } *table; + int nr; + int alloc; + int sorted; +} tip_table; + +static void add_to_tip_table(const struct object_id *oid, const char *refname, + int shorten_unambiguous, struct commit *commit, + timestamp_t taggerdate, int from_tag, int deref) +{ + refname = name_ref_abbrev(refname, shorten_unambiguous); + + ALLOC_GROW(tip_table.table, tip_table.nr + 1, tip_table.alloc); + oidcpy(&tip_table.table[tip_table.nr].oid, oid); + tip_table.table[tip_table.nr].refname = xstrdup(refname); + tip_table.table[tip_table.nr].commit = commit; + tip_table.table[tip_table.nr].taggerdate = taggerdate; + tip_table.table[tip_table.nr].from_tag = from_tag; + tip_table.table[tip_table.nr].deref = deref; + tip_table.nr++; + tip_table.sorted = 0; +} + +static int tipcmp(const void *a_, const void *b_) +{ + const struct tip_table_entry *a = a_, *b = b_; + return oidcmp(&a->oid, &b->oid); +} + +static int cmp_by_tag_and_age(const void *a_, const void *b_) +{ + const struct tip_table_entry *a = a_, *b = b_; + int cmp; + + /* Prefer tags. */ + cmp = b->from_tag - a->from_tag; + if (cmp) + return cmp; + + /* Older is better. */ + if (a->taggerdate < b->taggerdate) + return -1; + return a->taggerdate != b->taggerdate; +} + +static int name_ref(const char *path, const struct object_id *oid, int flags, void *cb_data) +{ + struct object *o = parse_object(the_repository, oid); + struct name_ref_data *data = cb_data; + int can_abbreviate_output = data->tags_only && data->name_only; + int deref = 0; + int from_tag = 0; + struct commit *commit = NULL; + timestamp_t taggerdate = TIME_MAX; + + if (data->tags_only && !starts_with(path, "refs/tags/")) + return 0; + + if (data->exclude_filters.nr) { + struct string_list_item *item; + + for_each_string_list_item(item, &data->exclude_filters) { + if (subpath_matches(path, item->string) >= 0) + return 0; + } + } + + if (data->ref_filters.nr) { + struct string_list_item *item; + int matched = 0; + + /* See if any of the patterns match. */ + for_each_string_list_item(item, &data->ref_filters) { + /* + * Check all patterns even after finding a match, so + * that we can see if a match with a subpath exists. + * When a user asked for 'refs/tags/v*' and 'v1.*', + * both of which match, the user is showing her + * willingness to accept a shortened output by having + * the 'v1.*' in the acceptable refnames, so we + * shouldn't stop when seeing 'refs/tags/v1.4' matches + * 'refs/tags/v*'. We should show it as 'v1.4'. + */ + switch (subpath_matches(path, item->string)) { + case -1: /* did not match */ + break; + case 0: /* matched fully */ + matched = 1; + break; + default: /* matched subpath */ + matched = 1; + can_abbreviate_output = 1; + break; + } + } + + /* If none of the patterns matched, stop now */ + if (!matched) + return 0; + } + + while (o && o->type == OBJ_TAG) { + struct tag *t = (struct tag *) o; + if (!t->tagged) + break; /* broken repository */ + o = parse_object(the_repository, &t->tagged->oid); + deref = 1; + taggerdate = t->date; + } + if (o && o->type == OBJ_COMMIT) { + commit = (struct commit *)o; + from_tag = starts_with(path, "refs/tags/"); + if (taggerdate == TIME_MAX) + taggerdate = commit->date; + } + + add_to_tip_table(oid, path, can_abbreviate_output, commit, taggerdate, + from_tag, deref); + return 0; +} + +static void name_tips(void) +{ + int i; + + /* + * Try to set better names first, so that worse ones spread + * less. + */ + QSORT(tip_table.table, tip_table.nr, cmp_by_tag_and_age); + for (i = 0; i < tip_table.nr; i++) { + struct tip_table_entry *e = &tip_table.table[i]; + if (e->commit) { + name_rev(e->commit, e->refname, e->taggerdate, + e->from_tag, e->deref); + } + } +} + +static const unsigned char *nth_tip_table_ent(size_t ix, void *table_) +{ + struct tip_table_entry *table = table_; + return table[ix].oid.hash; +} + +static const char *get_exact_ref_match(const struct object *o) +{ + int found; + + if (!tip_table.table || !tip_table.nr) + return NULL; + + if (!tip_table.sorted) { + QSORT(tip_table.table, tip_table.nr, tipcmp); + tip_table.sorted = 1; + } + + found = sha1_pos(o->oid.hash, tip_table.table, tip_table.nr, + nth_tip_table_ent); + if (0 <= found) + return tip_table.table[found].refname; + return NULL; +} + +/* may return a constant string or use "buf" as scratch space */ +static const char *get_rev_name(const struct object *o, struct strbuf *buf) +{ + struct rev_name *n; + const struct commit *c; + + if (o->type != OBJ_COMMIT) + return get_exact_ref_match(o); + c = (const struct commit *) o; + n = get_commit_rev_name(c); + if (!n) + return NULL; + + if (!n->generation) + return n->tip_name; + else { + strbuf_reset(buf); + strbuf_addstr(buf, n->tip_name); + strbuf_strip_suffix(buf, "^0"); + strbuf_addf(buf, "~%d", n->generation); + return buf->buf; + } +} + +static void show_name(const struct object *obj, + const char *caller_name, + int always, int allow_undefined, int name_only) +{ + const char *name; + const struct object_id *oid = &obj->oid; + struct strbuf buf = STRBUF_INIT; + + if (!name_only) + printf("%s ", caller_name ? caller_name : oid_to_hex(oid)); + name = get_rev_name(obj, &buf); + if (name) + printf("%s\n", name); + else if (allow_undefined) + printf("undefined\n"); + else if (always) + printf("%s\n", find_unique_abbrev(oid, DEFAULT_ABBREV)); + else + die("cannot describe '%s'", oid_to_hex(oid)); + strbuf_release(&buf); +} + +static char const * const name_rev_usage[] = { + N_("git name-rev [<options>] <commit>..."), + N_("git name-rev [<options>] --all"), + N_("git name-rev [<options>] --stdin"), + NULL +}; + +static void name_rev_line(char *p, struct name_ref_data *data) +{ + struct strbuf buf = STRBUF_INIT; + int counter = 0; + char *p_start; + const unsigned hexsz = the_hash_algo->hexsz; + + for (p_start = p; *p; p++) { +#define ishex(x) (isdigit((x)) || ((x) >= 'a' && (x) <= 'f')) + if (!ishex(*p)) + counter = 0; + else if (++counter == hexsz && + !ishex(*(p+1))) { + struct object_id oid; + const char *name = NULL; + char c = *(p+1); + int p_len = p - p_start + 1; + + counter = 0; + + *(p+1) = 0; + if (!get_oid(p - (hexsz - 1), &oid)) { + struct object *o = + lookup_object(the_repository, &oid); + if (o) + name = get_rev_name(o, &buf); + } + *(p+1) = c; + + if (!name) + continue; + + if (data->name_only) + printf("%.*s%s", p_len - hexsz, p_start, name); + else + printf("%.*s (%s)", p_len, p_start, name); + p_start = p + 1; + } + } + + /* flush */ + if (p_start != p) + fwrite(p_start, p - p_start, 1, stdout); + + strbuf_release(&buf); +} + +int cmd_name_rev(int argc, const char **argv, const char *prefix) +{ + struct object_array revs = OBJECT_ARRAY_INIT; + int all = 0, transform_stdin = 0, allow_undefined = 1, always = 0, peel_tag = 0; + struct name_ref_data data = { 0, 0, STRING_LIST_INIT_NODUP, STRING_LIST_INIT_NODUP }; + struct option opts[] = { + OPT_BOOL(0, "name-only", &data.name_only, N_("print only names (no SHA-1)")), + OPT_BOOL(0, "tags", &data.tags_only, N_("only use tags to name the commits")), + OPT_STRING_LIST(0, "refs", &data.ref_filters, N_("pattern"), + N_("only use refs matching <pattern>")), + OPT_STRING_LIST(0, "exclude", &data.exclude_filters, N_("pattern"), + N_("ignore refs matching <pattern>")), + OPT_GROUP(""), + OPT_BOOL(0, "all", &all, N_("list all commits reachable from all refs")), + OPT_BOOL(0, "stdin", &transform_stdin, N_("read from stdin")), + OPT_BOOL(0, "undefined", &allow_undefined, N_("allow to print `undefined` names (default)")), + OPT_BOOL(0, "always", &always, + N_("show abbreviated commit object as fallback")), + { + /* A Hidden OPT_BOOL */ + OPTION_SET_INT, 0, "peel-tag", &peel_tag, NULL, + N_("dereference tags in the input (internal use)"), + PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1, + }, + OPT_END(), + }; + + init_commit_rev_name(&rev_names); + git_config(git_default_config, NULL); + argc = parse_options(argc, argv, prefix, opts, name_rev_usage, 0); + if (all + transform_stdin + !!argc > 1) { + error("Specify either a list, or --all, not both!"); + usage_with_options(name_rev_usage, opts); + } + if (all || transform_stdin) + cutoff = 0; + + for (; argc; argc--, argv++) { + struct object_id oid; + struct object *object; + struct commit *commit; + + if (get_oid(*argv, &oid)) { + fprintf(stderr, "Could not get sha1 for %s. Skipping.\n", + *argv); + continue; + } + + commit = NULL; + object = parse_object(the_repository, &oid); + if (object) { + struct object *peeled = deref_tag(the_repository, + object, *argv, 0); + if (peeled && peeled->type == OBJ_COMMIT) + commit = (struct commit *)peeled; + } + + if (!object) { + fprintf(stderr, "Could not get object for %s. Skipping.\n", + *argv); + continue; + } + + if (commit) { + if (cutoff > commit->date) + cutoff = commit->date; + } + + if (peel_tag) { + if (!commit) { + fprintf(stderr, "Could not get commit for %s. Skipping.\n", + *argv); + continue; + } + object = (struct object *)commit; + } + add_object_array(object, *argv, &revs); + } + + if (cutoff) { + /* check for undeflow */ + if (cutoff > TIME_MIN + CUTOFF_DATE_SLOP) + cutoff = cutoff - CUTOFF_DATE_SLOP; + else + cutoff = TIME_MIN; + } + for_each_ref(name_ref, &data); + name_tips(); + + if (transform_stdin) { + char buffer[2048]; + + while (!feof(stdin)) { + char *p = fgets(buffer, sizeof(buffer), stdin); + if (!p) + break; + name_rev_line(p, &data); + } + } else if (all) { + int i, max; + + max = get_max_object_index(); + for (i = 0; i < max; i++) { + struct object *obj = get_indexed_object(i); + if (!obj || obj->type != OBJ_COMMIT) + continue; + show_name(obj, NULL, + always, allow_undefined, data.name_only); + } + } else { + int i; + for (i = 0; i < revs.nr; i++) + show_name(revs.objects[i].item, revs.objects[i].name, + always, allow_undefined, data.name_only); + } + + UNLEAK(revs); + return 0; +} |