tvl-depot/third_party/git/builtin/name-rev.c
Vincent Ambo f4609b896f merge(3p/git): Merge git subtree at v2.29.2
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
2020-11-21 19:45:56 +01:00

636 lines
16 KiB
C

#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 ref-based names (no object names)")),
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;
}