Skip to content

Commit

Permalink
Merge branch 'sg/name-rev-wo-recursion'
Browse files Browse the repository at this point in the history 
Redo "git name-rev" to avoid recursive calls.

* sg/name-rev-wo-recursion:
  name-rev: cleanup name_ref()
  name-rev: eliminate recursion in name_rev()
  name-rev: use 'name->tip_name' instead of 'tip_name'
  name-rev: drop name_rev()'s 'generation' and 'distance' parameters
  name-rev: restructure creating/updating 'struct rev_name' instances
  name-rev: restructure parsing commits and applying date cutoff
  name-rev: pull out deref handling from the recursion
  name-rev: extract creating/updating a 'struct name_rev' into a helper
  t6120: add a test to cover inner conditions in 'git name-rev's name_rev()
  name-rev: use sizeof(*ptr) instead of sizeof(type) in allocation
  name-rev: avoid unnecessary cast in name_ref()
  name-rev: use strbuf_strip_suffix() in get_rev_name()
  t6120-describe: modernize the 'check_describe' helper
  t6120-describe: correct test repo history graph in comment
  • Loading branch information
@gitster
gitster committed Dec 25, 2019
2 parents 6514ad4 + 2866fd2 commit f3c520e
Show file tree
Hide file tree
Showing 2 changed files with 153 additions and 66 deletions.
147 changes: 97 additions & 50 deletions builtin/name-rev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
#include "tag.h"
#include "refs.h"
#include "parse-options.h"
#include "prio-queue.h"
#include "sha1-lookup.h"
#include "commit-slab.h"

Expand Down Expand Up @@ -79,30 +80,16 @@ static int is_better_name(struct rev_name *name,
return 0;
}

static void name_rev(struct commit *commit,
const char *tip_name, timestamp_t taggerdate,
int generation, int distance, int from_tag,
int deref)
static struct rev_name *create_or_update_name(struct commit *commit,
const char *tip_name,
timestamp_t taggerdate,
int generation, int distance,
int from_tag)
{
struct rev_name *name = get_commit_rev_name(commit);
struct commit_list *parents;
int parent_number = 1;
char *to_free = NULL;

parse_commit(commit);

if (commit->date < cutoff)
return;

if (deref) {
tip_name = to_free = xstrfmt("%s^0", tip_name);

if (generation)
die("generation: %d, but deref?", generation);
}

if (name == NULL) {
name = xmalloc(sizeof(rev_name));
name = xmalloc(sizeof(*name));
set_commit_rev_name(commit, name);
goto copy_data;
} else if (is_better_name(name, taggerdate, distance, from_tag)) {
Expand All @@ -112,35 +99,97 @@ static void name_rev(struct commit *commit,
name->generation = generation;
name->distance = distance;
name->from_tag = from_tag;
} else {

return name;
} else
return 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;
char *to_free = NULL;

parse_commit(start_commit);
if (start_commit->date < cutoff)
return;

if (deref)
tip_name = to_free = xstrfmt("%s^0", tip_name);

if (!create_or_update_name(start_commit, tip_name, taggerdate, 0, 0,
from_tag)) {
free(to_free);
return;
}

for (parents = commit->parents;
parents;
parents = parents->next, parent_number++) {
if (parent_number > 1) {
size_t len;
char *new_name;

strip_suffix(tip_name, "^0", &len);
if (generation > 0)
new_name = xstrfmt("%.*s~%d^%d", (int)len, tip_name,
generation, parent_number);
else
new_name = xstrfmt("%.*s^%d", (int)len, tip_name,
parent_number);

name_rev(parents->item, new_name, taggerdate, 0,
distance + MERGE_TRAVERSAL_WEIGHT,
from_tag, 0);
} else {
name_rev(parents->item, tip_name, taggerdate,
generation + 1, distance + 1,
from_tag, 0);
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;
const char *new_name;
int generation, distance;

parse_commit(parent);
if (parent->date < cutoff)
continue;

if (parent_number > 1) {
size_t len;

strip_suffix(name->tip_name, "^0", &len);
if (name->generation > 0)
new_name = xstrfmt("%.*s~%d^%d",
(int)len,
name->tip_name,
name->generation,
parent_number);
else
new_name = xstrfmt("%.*s^%d", (int)len,
name->tip_name,
parent_number);
generation = 0;
distance = name->distance + MERGE_TRAVERSAL_WEIGHT;
} else {
new_name = name->tip_name;
generation = name->generation + 1;
distance = name->distance + 1;
}

if (create_or_update_name(parent, new_name, taggerdate,
generation, distance,
from_tag)) {
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)
Expand Down Expand Up @@ -272,10 +321,9 @@ static int name_ref(const char *path, const struct object_id *oid, int flags, vo
int from_tag = starts_with(path, "refs/tags/");

if (taggerdate == TIME_MAX)
taggerdate = ((struct commit *)o)->date;
taggerdate = commit->date;
path = name_ref_abbrev(path, can_abbreviate_output);
name_rev(commit, xstrdup(path), taggerdate, 0, 0,
from_tag, deref);
name_rev(commit, xstrdup(path), taggerdate, from_tag, deref);
}
return 0;
}
Expand Down Expand Up @@ -321,11 +369,10 @@ static const char *get_rev_name(const struct object *o, struct strbuf *buf)
if (!n->generation)
return n->tip_name;
else {
int len = strlen(n->tip_name);
if (len > 2 && !strcmp(n->tip_name + len - 2, "^0"))
len -= 2;
strbuf_reset(buf);
strbuf_addf(buf, "%.*s~%d", len, n->tip_name, n->generation);
strbuf_addstr(buf, n->tip_name);
strbuf_strip_suffix(buf, "^0");
strbuf_addf(buf, "~%d", n->generation);
return buf->buf;
}
}
Expand Down
72 changes: 56 additions & 16 deletions t/t6120-describe.sh
View file
Original file line number Diff line number Diff line change
@@ -1,28 +1,27 @@
#!/bin/sh

test_description='test describe
test_description='test describe'

# o---o-----o----o----o-------o----x
# \ D,R e /
# \---o-------------o-'
# \ B /
# `-o----o----o-'
# A c
#
# First parent of a merge commit is on the same line, second parent below.

B
.--------------o----o----o----x
/ / /
o----o----o----o----o----. /
\ A c /
.------------o---o---o
D,R e
'
. ./test-lib.sh

check_describe () {
expect="$1"
shift
R=$(git describe "$@" 2>err.actual)
S=$?
cat err.actual >&3
test_expect_success "describe $*" '
test $S = 0 &&
describe_opts="$@"
test_expect_success "describe $describe_opts" '
R=$(git describe $describe_opts 2>err.actual) &&
case "$R" in
$expect) echo happy ;;
*) echo "Oops - $R is not $expect";
*) echo "Oops - $R is not $expect" &&
false ;;
esac
'
Expand Down Expand Up @@ -382,7 +381,7 @@ test_expect_success 'describe tag object' '
test_i18ngrep "fatal: test-blob-1 is neither a commit nor blob" actual
'

test_expect_failure ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '
test_expect_success ULIMIT_STACK_SIZE 'name-rev works in a deep repo' '
i=1 &&
while test $i -lt 8000
do
Expand Down Expand Up @@ -439,4 +438,45 @@ test_expect_success 'name-rev a rev shortly after epoch' '
test_cmp expect actual
'

# A--------------master
# \ /
# \----------M2
# \ /
# \---M1-C
# \ /
# B
test_expect_success 'name-rev covers all conditions while looking at parents' '
git init repo &&
(
cd repo &&
echo A >file &&
git add file &&
git commit -m A &&
A=$(git rev-parse HEAD) &&
git checkout --detach &&
echo B >file &&
git commit -m B file &&
B=$(git rev-parse HEAD) &&
git checkout $A &&
git merge --no-ff $B && # M1
echo C >file &&
git commit -m C file &&
git checkout $A &&
git merge --no-ff HEAD@{1} && # M2
git checkout master &&
git merge --no-ff HEAD@{1} &&
echo "$B master^2^2~1^2" >expect &&
git name-rev $B >actual &&
test_cmp expect actual
)
'

test_done

0 comments on commit f3c520e

Please sign in to comment.