From: Jeff King <peff@peff.net>
To: git@vger.kernel.org
Subject: [PATCH 09/23] fsck: unify object-name code
Date: Fri, 18 Oct 2019 00:56:13 -0400 [thread overview]
Message-ID: <20191018045613.GI17879@sigill.intra.peff.net> (raw)
In-Reply-To: <20191018044103.GA17625@sigill.intra.peff.net>
Commit 90cf590f53 (fsck: optionally show more helpful info for broken
links, 2016-07-17) added a system for decorating objects with names. The
code is split across builtin/fsck.c (which gives the initial names) and
fsck.c (which adds to the names as it traverses the object graph). This
leads to some duplication, where both sites have near-identical
describe_object() functions (the difference being that the one in
builtin/fsck.c uses a circular array of buffers to allow multiple calls
in a single printf).
Let's provide a unified object_name API for fsck. That lets us drop the
duplication, as well as making the interface boundaries more clear
(which will let us refactor the implementation more in a future patch).
We'll leave describe_object() in builtin/fsck.c as a thin wrapper around
the new API, as it relies on a static global to make its many callers a
bit shorter.
We'll also convert the bare add_decoration() calls in builtin/fsck.c to
put_object_name(). This fixes two minor bugs:
1. We leak many small strings. add_decoration() has a last-one-wins
approach: it updates the decoration to the new string and returns
the old one. But we ignore the return value, leaking the old
string. This is quite common to trigger, since we look at reflogs:
the tip of any ref will be described both by looking at the actual
ref, as well as the latest reflog entry. So we'd always end up
leaking one of those strings.
2. The last-one-wins approach gives us lousy names. For instance, we
first look at all of the refs, and then all of the reflogs. So
rather than seeing "refs/heads/master", we're likely to overwrite
it with "HEAD@{12345678}". We're generally better off using the
first name we find.
And indeed, the test in t1450 expects this ugly HEAD@{} name. After
this patch, we've switched to using fsck_put_object_name()'s
first-one-wins semantics, and we output the more human-friendly
"refs/tags/julius" (and the test is updated accordingly).
Signed-off-by: Jeff King <peff@peff.net>
---
builtin/fsck.c | 50 ++++++++----------------------
fsck.c | 82 ++++++++++++++++++++++++++++++-------------------
fsck.h | 24 +++++++++++++++
t/t1450-fsck.sh | 2 +-
4 files changed, 89 insertions(+), 69 deletions(-)
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 18403a94fa..237643cc1d 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -52,24 +52,7 @@ static int name_objects;
static const char *describe_object(struct object *obj)
{
- static struct strbuf bufs[] = {
- STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
- };
- static int b = 0;
- struct strbuf *buf;
- char *name = NULL;
-
- if (name_objects)
- name = lookup_decoration(fsck_walk_options.object_names, obj);
-
- buf = bufs + b;
- b = (b + 1) % ARRAY_SIZE(bufs);
- strbuf_reset(buf);
- strbuf_addstr(buf, oid_to_hex(&obj->oid));
- if (name)
- strbuf_addf(buf, " (%s)", name);
-
- return buf->buf;
+ return fsck_describe_object(&fsck_walk_options, obj);
}
static const char *printable_type(struct object *obj)
@@ -499,10 +482,10 @@ static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
if (!is_null_oid(oid)) {
obj = lookup_object(the_repository, oid);
if (obj && (obj->flags & HAS_OBJ)) {
- if (timestamp && name_objects)
- add_decoration(fsck_walk_options.object_names,
- obj,
- xstrfmt("%s@{%"PRItime"}", refname, timestamp));
+ if (timestamp)
+ fsck_put_object_name(&fsck_walk_options, obj,
+ "%s@{%"PRItime"}",
+ refname, timestamp);
obj->flags |= USED;
mark_object_reachable(obj);
} else if (!is_promisor_object(oid)) {
@@ -566,9 +549,8 @@ static int fsck_handle_ref(const char *refname, const struct object_id *oid,
}
default_refs++;
obj->flags |= USED;
- if (name_objects)
- add_decoration(fsck_walk_options.object_names,
- obj, xstrdup(refname));
+ fsck_put_object_name(&fsck_walk_options,
+ obj, "%s", refname);
mark_object_reachable(obj);
return 0;
@@ -742,9 +724,7 @@ static int fsck_cache_tree(struct cache_tree *it)
return 1;
}
obj->flags |= USED;
- if (name_objects)
- add_decoration(fsck_walk_options.object_names,
- obj, xstrdup(":"));
+ fsck_put_object_name(&fsck_walk_options, obj, ":");
mark_object_reachable(obj);
if (obj->type != OBJ_TREE)
err |= objerror(obj, _("non-tree in cache-tree"));
@@ -830,8 +810,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
}
if (name_objects)
- fsck_walk_options.object_names =
- xcalloc(1, sizeof(struct decoration));
+ fsck_enable_object_names(&fsck_walk_options);
git_config(fsck_config, NULL);
@@ -890,9 +869,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
}
obj->flags |= USED;
- if (name_objects)
- add_decoration(fsck_walk_options.object_names,
- obj, xstrdup(arg));
+ fsck_put_object_name(&fsck_walk_options, obj,
+ "%s", arg);
mark_object_reachable(obj);
continue;
}
@@ -928,10 +906,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
continue;
obj = &blob->object;
obj->flags |= USED;
- if (name_objects)
- add_decoration(fsck_walk_options.object_names,
- obj,
- xstrfmt(":%s", active_cache[i]->name));
+ fsck_put_object_name(&fsck_walk_options, obj,
+ ":%s", active_cache[i]->name);
mark_object_reachable(obj);
}
if (active_cache_tree)
diff --git a/fsck.c b/fsck.c
index 347a0ef5c9..ecd5957362 100644
--- a/fsck.c
+++ b/fsck.c
@@ -312,15 +312,21 @@ static int report(struct fsck_options *options, struct object *object,
return result;
}
-static char *get_object_name(struct fsck_options *options, struct object *obj)
+void fsck_enable_object_names(struct fsck_options *options)
+{
+ if (!options->object_names)
+ options->object_names = xcalloc(1, sizeof(struct decoration));
+}
+
+const char *fsck_get_object_name(struct fsck_options *options, struct object *obj)
{
if (!options->object_names)
return NULL;
return lookup_decoration(options->object_names, obj);
}
-static void put_object_name(struct fsck_options *options, struct object *obj,
- const char *fmt, ...)
+void fsck_put_object_name(struct fsck_options *options, struct object *obj,
+ const char *fmt, ...)
{
va_list ap;
struct strbuf buf = STRBUF_INIT;
@@ -337,17 +343,27 @@ static void put_object_name(struct fsck_options *options, struct object *obj,
va_end(ap);
}
-static const char *describe_object(struct fsck_options *o, struct object *obj)
+const char *fsck_describe_object(struct fsck_options *options,
+ struct object *obj)
{
- static struct strbuf buf = STRBUF_INIT;
- char *name;
-
- strbuf_reset(&buf);
- strbuf_addstr(&buf, oid_to_hex(&obj->oid));
- if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
- strbuf_addf(&buf, " (%s)", name);
+ static struct strbuf bufs[] = {
+ STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT
+ };
+ static int b = 0;
+ struct strbuf *buf;
+ char *name = NULL;
+
+ if (options->object_names)
+ name = lookup_decoration(options->object_names, obj);
+
+ buf = bufs + b;
+ b = (b + 1) % ARRAY_SIZE(bufs);
+ strbuf_reset(buf);
+ strbuf_addstr(buf, oid_to_hex(&obj->oid));
+ if (name)
+ strbuf_addf(buf, " (%s)", name);
- return buf.buf;
+ return buf->buf;
}
static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
@@ -360,7 +376,7 @@ static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *op
if (parse_tree(tree))
return -1;
- name = get_object_name(options, &tree->object);
+ name = fsck_get_object_name(options, &tree->object);
if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
return -1;
while (tree_entry_gently(&desc, &entry)) {
@@ -373,20 +389,21 @@ static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *op
if (S_ISDIR(entry.mode)) {
obj = (struct object *)lookup_tree(the_repository, &entry.oid);
if (name && obj)
- put_object_name(options, obj, "%s%s/", name,
- entry.path);
+ fsck_put_object_name(options, obj, "%s%s/",
+ name, entry.path);
result = options->walk(obj, OBJ_TREE, data, options);
}
else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
obj = (struct object *)lookup_blob(the_repository, &entry.oid);
if (name && obj)
- put_object_name(options, obj, "%s%s", name,
- entry.path);
+ fsck_put_object_name(options, obj, "%s%s",
+ name, entry.path);
result = options->walk(obj, OBJ_BLOB, data, options);
}
else {
result = error("in tree %s: entry %s has bad mode %.6o",
- describe_object(options, &tree->object), entry.path, entry.mode);
+ fsck_describe_object(options, &tree->object),
+ entry.path, entry.mode);
}
if (result < 0)
return result;
@@ -407,10 +424,10 @@ static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_optio
if (parse_commit(commit))
return -1;
- name = get_object_name(options, &commit->object);
+ name = fsck_get_object_name(options, &commit->object);
if (name)
- put_object_name(options, &get_commit_tree(commit)->object,
- "%s:", name);
+ fsck_put_object_name(options, &get_commit_tree(commit)->object,
+ "%s:", name);
result = options->walk((struct object *)get_commit_tree(commit),
OBJ_TREE, data, options);
@@ -441,13 +458,15 @@ static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_optio
struct object *obj = &parents->item->object;
if (counter++)
- put_object_name(options, obj, "%s^%d",
- name, counter);
+ fsck_put_object_name(options, obj, "%s^%d",
+ name, counter);
else if (generation > 0)
- put_object_name(options, obj, "%.*s~%d",
- name_prefix_len, name, generation + 1);
+ fsck_put_object_name(options, obj, "%.*s~%d",
+ name_prefix_len, name,
+ generation + 1);
else
- put_object_name(options, obj, "%s^", name);
+ fsck_put_object_name(options, obj, "%s^",
+ name);
}
result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
if (result < 0)
@@ -461,12 +480,12 @@ static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_optio
static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
{
- char *name = get_object_name(options, &tag->object);
+ const char *name = fsck_get_object_name(options, &tag->object);
if (parse_tag(tag))
return -1;
if (name)
- put_object_name(options, tag->tagged, "%s", name);
+ fsck_put_object_name(options, tag->tagged, "%s", name);
return options->walk(tag->tagged, OBJ_ANY, data, options);
}
@@ -488,7 +507,8 @@ int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
case OBJ_TAG:
return fsck_walk_tag((struct tag *)obj, data, options);
default:
- error("Unknown object type for %s", describe_object(options, obj));
+ error("Unknown object type for %s",
+ fsck_describe_object(options, obj));
return -1;
}
}
@@ -962,10 +982,10 @@ int fsck_error_function(struct fsck_options *o,
struct object *obj, int msg_type, const char *message)
{
if (msg_type == FSCK_WARN) {
- warning("object %s: %s", describe_object(o, obj), message);
+ warning("object %s: %s", fsck_describe_object(o, obj), message);
return 0;
}
- error("object %s: %s", describe_object(o, obj), message);
+ error("object %s: %s", fsck_describe_object(o, obj), message);
return 1;
}
diff --git a/fsck.h b/fsck.h
index e479461075..f6f0c40060 100644
--- a/fsck.h
+++ b/fsck.h
@@ -67,4 +67,28 @@ int fsck_object(struct object *obj, void *data, unsigned long size,
*/
int fsck_finish(struct fsck_options *options);
+/*
+ * Subsystem for storing human-readable names for each object.
+ *
+ * If fsck_enable_object_names() has not been called, all other functions are
+ * noops.
+ *
+ * Use put_object_name() to seed initial names (e.g. from refnames); the fsck
+ * code will extend that while walking trees, etc.
+ *
+ * Use get_object_name() to get a single name (or NULL if none). Or the more
+ * convenient describe_object(), which always produces an output string with
+ * the oid combined with the name (if any). Note that the return value points
+ * to a rotating array of static buffers, and may be invalidated by a
+ * subsequent call.
+ */
+void fsck_enable_object_names(struct fsck_options *options);
+const char *fsck_get_object_name(struct fsck_options *options,
+ struct object *obj);
+__attribute__((format (printf,3,4)))
+void fsck_put_object_name(struct fsck_options *options, struct object *obj,
+ const char *fmt, ...);
+const char *fsck_describe_object(struct fsck_options *options,
+ struct object *obj);
+
#endif
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index 50d28e6fdb..7c7ff7e961 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -616,7 +616,7 @@ test_expect_success 'fsck --name-objects' '
remove_object $(git rev-parse julius:caesar.t) &&
test_must_fail git fsck --name-objects >out &&
tree=$(git rev-parse --verify julius:) &&
- test_i18ngrep -E "$tree \((refs/heads/master|HEAD)@\{[0-9]*\}:" out
+ test_i18ngrep "$tree (refs/tags/julius:" out
)
'
--
2.23.0.1228.gee29b05929
next prev parent reply other threads:[~2019-10-18 4:56 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 4:41 [PATCH 0/23] parsing and fsck cleanups Jeff King
2019-10-18 4:42 ` [PATCH 01/23] parse_commit_buffer(): treat lookup_commit() failure as parse error Jeff King
2019-10-24 3:37 ` Junio C Hamano
2019-10-24 18:01 ` Jeff King
2019-10-18 4:43 ` [PATCH 02/23] parse_commit_buffer(): treat lookup_tree() " Jeff King
2019-10-24 23:12 ` Jonathan Tan
2019-10-24 23:22 ` Jeff King
2019-10-18 4:45 ` [PATCH 03/23] parse_tag_buffer(): treat NULL tag pointer " Jeff King
2019-10-18 4:47 ` [PATCH 04/23] remember commit/tag parse failures Jeff King
2019-10-24 3:51 ` Junio C Hamano
2019-10-24 23:25 ` Jonathan Tan
2019-10-24 23:41 ` Jeff King
2019-10-18 4:48 ` [PATCH 05/23] fsck: stop checking commit->tree value Jeff King
2019-10-24 3:57 ` Junio C Hamano
2019-10-18 4:49 ` [PATCH 06/23] fsck: stop checking commit->parent counts Jeff King
2019-10-18 4:51 ` [PATCH 07/23] fsck: stop checking tag->tagged Jeff King
2019-10-18 4:54 ` [PATCH 08/23] fsck: require an actual buffer for non-blobs Jeff King
2019-10-18 4:56 ` Jeff King [this message]
2019-10-24 6:05 ` [PATCH 09/23] fsck: unify object-name code Junio C Hamano
2019-10-24 18:07 ` Jeff King
2019-10-25 3:23 ` Junio C Hamano
2019-10-25 21:20 ` Jeff King
2019-10-18 4:56 ` [PATCH 10/23] fsck_describe_object(): build on our get_object_name() primitive Jeff King
2019-10-24 6:06 ` Junio C Hamano
2019-10-18 4:57 ` [PATCH 11/23] fsck: use oids rather than objects for object_name API Jeff King
2019-10-18 4:58 ` [PATCH 12/23] fsck: don't require object structs for display functions Jeff King
2019-10-18 4:58 ` [PATCH 13/23] fsck: only provide oid/type in fsck_error callback Jeff King
2019-10-18 4:58 ` [PATCH 14/23] fsck: only require an oid for skiplist functions Jeff King
2019-10-18 4:59 ` [PATCH 15/23] fsck: don't require an object struct for report() Jeff King
2019-10-18 4:59 ` [PATCH 16/23] fsck: accept an oid instead of a "struct blob" for fsck_blob() Jeff King
2019-10-18 4:59 ` [PATCH 17/23] fsck: drop blob struct from fsck_finish() Jeff King
2019-10-18 5:00 ` [PATCH 18/23] fsck: don't require an object struct for fsck_ident() Jeff King
2019-10-18 5:00 ` [PATCH 19/23] fsck: don't require an object struct in verify_headers() Jeff King
2019-10-18 5:00 ` [PATCH 20/23] fsck: rename vague "oid" local variables Jeff King
2019-10-18 5:01 ` [PATCH 21/23] fsck: accept an oid instead of a "struct tag" for fsck_tag() Jeff King
2019-10-18 5:01 ` [PATCH 22/23] fsck: accept an oid instead of a "struct commit" for fsck_commit() Jeff King
2019-10-18 5:02 ` [PATCH 23/23] fsck: accept an oid instead of a "struct tree" for fsck_tree() Jeff King
2019-10-24 23:49 ` [PATCH 0/23] parsing and fsck cleanups Jonathan Tan
2019-10-25 3:11 ` Junio C Hamano
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