diff mbox series

[4/6] refs: drop unused params from the reflog iterator callback

Message ID be512ef268b910852ff11df181d89c483ffc18ab.1708353264.git.ps@pks.im (mailing list archive)
State Superseded
Commit d629221144249cd7db33f32f3adce14dac5c2c96
Headers show
Series reflog: introduce subcommand to list reflogs | expand

Commit Message

Patrick Steinhardt Feb. 19, 2024, 2:35 p.m. UTC
The ref and reflog iterators share much of the same underlying code to
iterate over the corresponding entries. This results in some weird code
because the reflog iterator also exposes an object ID as well as a flag
to the callback function. Neither of these fields do refer to the reflog
though -- they refer to the corresponding ref with the same name. This
is quite misleading. In practice at least the object ID cannot really be
implemented in any other way as a reflog does not have a specific object
ID in the first place. This is further stressed by the fact that none of
the callbacks except for our test helper make use of these fields.

Split up the infrastucture so that ref and reflog iterators use separate
callback signatures. This allows us to drop the nonsensical fields from
the reflog iterator.

Note that internally, the backends still use the same shared infra to
iterate over both types. As the backends should never end up being
called directly anyway, this is not much of a problem and thus kept
as-is for simplicity's sake.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 builtin/fsck.c                 |  4 +---
 builtin/reflog.c               |  3 +--
 refs.c                         | 23 +++++++++++++++++++----
 refs.h                         | 11 +++++++++--
 refs/files-backend.c           |  8 +-------
 refs/reftable-backend.c        |  8 +-------
 revision.c                     |  4 +---
 t/helper/test-ref-store.c      | 18 ++++++++++++------
 t/t0600-reffiles-backend.sh    | 24 ++++++++++++------------
 t/t1405-main-ref-store.sh      |  8 ++++----
 t/t1406-submodule-ref-store.sh |  8 ++++----
 11 files changed, 65 insertions(+), 54 deletions(-)

Comments

Junio C Hamano Feb. 20, 2024, 12:14 a.m. UTC | #1
Patrick Steinhardt <ps@pks.im> writes:

> The ref and reflog iterators share much of the same underlying code to
> iterate over the corresponding entries. This results in some weird code
> because the reflog iterator also exposes an object ID as well as a flag
> to the callback function. Neither of these fields do refer to the reflog
> though -- they refer to the corresponding ref with the same name. This
> is quite misleading. In practice at least the object ID cannot really be
> implemented in any other way as a reflog does not have a specific object
> ID in the first place. This is further stressed by the fact that none of
> the callbacks except for our test helper make use of these fields.

Interesting observation.  Of course this will make the callstack
longer by another level of indirection ...

> +struct do_for_each_reflog_help {
> +	each_reflog_fn *fn;
> +	void *cb_data;
> +};
> +
> +static int do_for_each_reflog_helper(struct repository *r UNUSED,
> +				     const char *refname,
> +				     const struct object_id *oid UNUSED,
> +				     int flags,
> +				     void *cb_data)
> +{
> +	struct do_for_each_reflog_help *hp = cb_data;
> +	return hp->fn(refname, hp->cb_data);
> +}

... but I think it would be worth it.

> +/*
> + * The signature for the callback function for the {refs_,}for_each_reflog()
> + * functions below. The memory pointed to by the refname argument is only
> + * guaranteed to be valid for the duration of a single callback invocation.
> + */
> +typedef int each_reflog_fn(const char *refname, void *cb_data);
> +
>  /*
>   * Calls the specified function for each reflog file until it returns nonzero,
>   * and returns the value. Reflog file order is unspecified.
>   */
> -int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
> -int for_each_reflog(each_ref_fn fn, void *cb_data);
> +int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data);
> +int for_each_reflog(each_reflog_fn fn, void *cb_data);

Nice simplification.
Patrick Steinhardt Feb. 20, 2024, 8:34 a.m. UTC | #2
On Mon, Feb 19, 2024 at 04:14:16PM -0800, Junio C Hamano wrote:
> Patrick Steinhardt <ps@pks.im> writes:
> 
> > The ref and reflog iterators share much of the same underlying code to
> > iterate over the corresponding entries. This results in some weird code
> > because the reflog iterator also exposes an object ID as well as a flag
> > to the callback function. Neither of these fields do refer to the reflog
> > though -- they refer to the corresponding ref with the same name. This
> > is quite misleading. In practice at least the object ID cannot really be
> > implemented in any other way as a reflog does not have a specific object
> > ID in the first place. This is further stressed by the fact that none of
> > the callbacks except for our test helper make use of these fields.
> 
> Interesting observation.  Of course this will make the callstack
> longer by another level of indirection ...

It actually doesn't -- the old code had a `do_for_each_ref_helper()`
that did the same wrapping, so the level of indirection is exactly the
same. Over there we have it to drop the unused `struct repository`
parameter.

Patrick

> > +struct do_for_each_reflog_help {
> > +	each_reflog_fn *fn;
> > +	void *cb_data;
> > +};
> > +
> > +static int do_for_each_reflog_helper(struct repository *r UNUSED,
> > +				     const char *refname,
> > +				     const struct object_id *oid UNUSED,
> > +				     int flags,
> > +				     void *cb_data)
> > +{
> > +	struct do_for_each_reflog_help *hp = cb_data;
> > +	return hp->fn(refname, hp->cb_data);
> > +}
> 
> ... but I think it would be worth it.
> 
> > +/*
> > + * The signature for the callback function for the {refs_,}for_each_reflog()
> > + * functions below. The memory pointed to by the refname argument is only
> > + * guaranteed to be valid for the duration of a single callback invocation.
> > + */
> > +typedef int each_reflog_fn(const char *refname, void *cb_data);
> > +
> >  /*
> >   * Calls the specified function for each reflog file until it returns nonzero,
> >   * and returns the value. Reflog file order is unspecified.
> >   */
> > -int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
> > -int for_each_reflog(each_ref_fn fn, void *cb_data);
> > +int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data);
> > +int for_each_reflog(each_reflog_fn fn, void *cb_data);
> 
> Nice simplification.
diff mbox series

Patch

diff --git a/builtin/fsck.c b/builtin/fsck.c
index a7cf94f67e..f892487c9b 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -509,9 +509,7 @@  static int fsck_handle_reflog_ent(struct object_id *ooid, struct object_id *noid
 	return 0;
 }
 
-static int fsck_handle_reflog(const char *logname,
-			      const struct object_id *oid UNUSED,
-			      int flag UNUSED, void *cb_data)
+static int fsck_handle_reflog(const char *logname, void *cb_data)
 {
 	struct strbuf refname = STRBUF_INIT;
 
diff --git a/builtin/reflog.c b/builtin/reflog.c
index a5a4099f61..3a0c4d4322 100644
--- a/builtin/reflog.c
+++ b/builtin/reflog.c
@@ -60,8 +60,7 @@  struct worktree_reflogs {
 	struct string_list reflogs;
 };
 
-static int collect_reflog(const char *ref, const struct object_id *oid UNUSED,
-			  int flags UNUSED, void *cb_data)
+static int collect_reflog(const char *ref, void *cb_data)
 {
 	struct worktree_reflogs *cb = cb_data;
 	struct worktree *worktree = cb->worktree;
diff --git a/refs.c b/refs.c
index fff343c256..6d76000f13 100644
--- a/refs.c
+++ b/refs.c
@@ -2516,18 +2516,33 @@  int refs_verify_refname_available(struct ref_store *refs,
 	return ret;
 }
 
-int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
+struct do_for_each_reflog_help {
+	each_reflog_fn *fn;
+	void *cb_data;
+};
+
+static int do_for_each_reflog_helper(struct repository *r UNUSED,
+				     const char *refname,
+				     const struct object_id *oid UNUSED,
+				     int flags,
+				     void *cb_data)
+{
+	struct do_for_each_reflog_help *hp = cb_data;
+	return hp->fn(refname, hp->cb_data);
+}
+
+int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data)
 {
 	struct ref_iterator *iter;
-	struct do_for_each_ref_help hp = { fn, cb_data };
+	struct do_for_each_reflog_help hp = { fn, cb_data };
 
 	iter = refs->be->reflog_iterator_begin(refs);
 
 	return do_for_each_repo_ref_iterator(the_repository, iter,
-					     do_for_each_ref_helper, &hp);
+					     do_for_each_reflog_helper, &hp);
 }
 
-int for_each_reflog(each_ref_fn fn, void *cb_data)
+int for_each_reflog(each_reflog_fn fn, void *cb_data)
 {
 	return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
 }
diff --git a/refs.h b/refs.h
index 303c5fac4d..895579aeb7 100644
--- a/refs.h
+++ b/refs.h
@@ -534,12 +534,19 @@  int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_dat
 /* youngest entry first */
 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
 
+/*
+ * The signature for the callback function for the {refs_,}for_each_reflog()
+ * functions below. The memory pointed to by the refname argument is only
+ * guaranteed to be valid for the duration of a single callback invocation.
+ */
+typedef int each_reflog_fn(const char *refname, void *cb_data);
+
 /*
  * Calls the specified function for each reflog file until it returns nonzero,
  * and returns the value. Reflog file order is unspecified.
  */
-int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
-int for_each_reflog(each_ref_fn fn, void *cb_data);
+int refs_for_each_reflog(struct ref_store *refs, each_reflog_fn fn, void *cb_data);
+int for_each_reflog(each_reflog_fn fn, void *cb_data);
 
 #define REFNAME_ALLOW_ONELEVEL 1
 #define REFNAME_REFSPEC_PATTERN 2
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 2ffc63185f..2b3c99b00d 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -2116,10 +2116,8 @@  static int files_for_each_reflog_ent(struct ref_store *ref_store,
 
 struct files_reflog_iterator {
 	struct ref_iterator base;
-
 	struct ref_store *ref_store;
 	struct dir_iterator *dir_iterator;
-	struct object_id oid;
 };
 
 static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
@@ -2130,8 +2128,6 @@  static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 	int ok;
 
 	while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
-		int flags;
-
 		if (!S_ISREG(diter->st.st_mode))
 			continue;
 		if (diter->basename[0] == '.')
@@ -2141,14 +2137,12 @@  static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 
 		if (!refs_resolve_ref_unsafe(iter->ref_store,
 					     diter->relative_path, 0,
-					     &iter->oid, &flags)) {
+					     NULL, NULL)) {
 			error("bad ref for %s", diter->path.buf);
 			continue;
 		}
 
 		iter->base.refname = diter->relative_path;
-		iter->base.oid = &iter->oid;
-		iter->base.flags = flags;
 		return ITER_OK;
 	}
 
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index a14f2ad7f4..889bb1f1ba 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1637,7 +1637,6 @@  struct reftable_reflog_iterator {
 	struct reftable_ref_store *refs;
 	struct reftable_iterator iter;
 	struct reftable_log_record log;
-	struct object_id oid;
 	char *last_name;
 	int err;
 };
@@ -1648,8 +1647,6 @@  static int reftable_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 		(struct reftable_reflog_iterator *)ref_iterator;
 
 	while (!iter->err) {
-		int flags;
-
 		iter->err = reftable_iterator_next_log(&iter->iter, &iter->log);
 		if (iter->err)
 			break;
@@ -1663,7 +1660,7 @@  static int reftable_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 			continue;
 
 		if (!refs_resolve_ref_unsafe(&iter->refs->base, iter->log.refname,
-					     0, &iter->oid, &flags)) {
+					     0, NULL, NULL)) {
 			error(_("bad ref for %s"), iter->log.refname);
 			continue;
 		}
@@ -1671,8 +1668,6 @@  static int reftable_reflog_iterator_advance(struct ref_iterator *ref_iterator)
 		free(iter->last_name);
 		iter->last_name = xstrdup(iter->log.refname);
 		iter->base.refname = iter->log.refname;
-		iter->base.oid = &iter->oid;
-		iter->base.flags = flags;
 
 		break;
 	}
@@ -1725,7 +1720,6 @@  static struct reftable_reflog_iterator *reflog_iterator_for_stack(struct reftabl
 	iter = xcalloc(1, sizeof(*iter));
 	base_ref_iterator_init(&iter->base, &reftable_reflog_iterator_vtable, 1);
 	iter->refs = refs;
-	iter->base.oid = &iter->oid;
 
 	ret = refs->err;
 	if (ret)
diff --git a/revision.c b/revision.c
index 2424c9bd67..ac45c6d8f2 100644
--- a/revision.c
+++ b/revision.c
@@ -1686,9 +1686,7 @@  static int handle_one_reflog_ent(struct object_id *ooid, struct object_id *noid,
 	return 0;
 }
 
-static int handle_one_reflog(const char *refname_in_wt,
-			     const struct object_id *oid UNUSED,
-			     int flag UNUSED, void *cb_data)
+static int handle_one_reflog(const char *refname_in_wt, void *cb_data)
 {
 	struct all_refs_cb *cb = cb_data;
 	struct strbuf refname = STRBUF_INIT;
diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
index 702ec1f128..7a0f6cac53 100644
--- a/t/helper/test-ref-store.c
+++ b/t/helper/test-ref-store.c
@@ -221,15 +221,21 @@  static int cmd_verify_ref(struct ref_store *refs, const char **argv)
 	return ret;
 }
 
+static int each_reflog(const char *refname, void *cb_data UNUSED)
+{
+	printf("%s\n", refname);
+	return 0;
+}
+
 static int cmd_for_each_reflog(struct ref_store *refs,
 			       const char **argv UNUSED)
 {
-	return refs_for_each_reflog(refs, each_ref, NULL);
+	return refs_for_each_reflog(refs, each_reflog, NULL);
 }
 
-static int each_reflog(struct object_id *old_oid, struct object_id *new_oid,
-		       const char *committer, timestamp_t timestamp,
-		       int tz, const char *msg, void *cb_data UNUSED)
+static int each_reflog_ent(struct object_id *old_oid, struct object_id *new_oid,
+			   const char *committer, timestamp_t timestamp,
+			   int tz, const char *msg, void *cb_data UNUSED)
 {
 	printf("%s %s %s %" PRItime " %+05d%s%s", oid_to_hex(old_oid),
 	       oid_to_hex(new_oid), committer, timestamp, tz,
@@ -241,14 +247,14 @@  static int cmd_for_each_reflog_ent(struct ref_store *refs, const char **argv)
 {
 	const char *refname = notnull(*argv++, "refname");
 
-	return refs_for_each_reflog_ent(refs, refname, each_reflog, refs);
+	return refs_for_each_reflog_ent(refs, refname, each_reflog_ent, refs);
 }
 
 static int cmd_for_each_reflog_ent_reverse(struct ref_store *refs, const char **argv)
 {
 	const char *refname = notnull(*argv++, "refname");
 
-	return refs_for_each_reflog_ent_reverse(refs, refname, each_reflog, refs);
+	return refs_for_each_reflog_ent_reverse(refs, refname, each_reflog_ent, refs);
 }
 
 static int cmd_reflog_exists(struct ref_store *refs, const char **argv)
diff --git a/t/t0600-reffiles-backend.sh b/t/t0600-reffiles-backend.sh
index 4f860285cc..56a3196b83 100755
--- a/t/t0600-reffiles-backend.sh
+++ b/t/t0600-reffiles-backend.sh
@@ -287,23 +287,23 @@  test_expect_success 'for_each_reflog()' '
 	mkdir -p     .git/worktrees/wt/logs/refs/bisect &&
 	echo $ZERO_OID > .git/worktrees/wt/logs/refs/bisect/wt-random &&
 
-	$RWT for-each-reflog | cut -d" " -f 2- >actual &&
+	$RWT for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
-	PSEUDO-WT 0x0
-	refs/bisect/wt-random 0x0
-	refs/heads/main 0x0
-	refs/heads/wt-main 0x0
+	HEAD
+	PSEUDO-WT
+	refs/bisect/wt-random
+	refs/heads/main
+	refs/heads/wt-main
 	EOF
 	test_cmp expected actual &&
 
-	$RMAIN for-each-reflog | cut -d" " -f 2- >actual &&
+	$RMAIN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
-	PSEUDO-MAIN 0x0
-	refs/bisect/random 0x0
-	refs/heads/main 0x0
-	refs/heads/wt-main 0x0
+	HEAD
+	PSEUDO-MAIN
+	refs/bisect/random
+	refs/heads/main
+	refs/heads/wt-main
 	EOF
 	test_cmp expected actual
 '
diff --git a/t/t1405-main-ref-store.sh b/t/t1405-main-ref-store.sh
index cfb583f544..3eee758bce 100755
--- a/t/t1405-main-ref-store.sh
+++ b/t/t1405-main-ref-store.sh
@@ -74,11 +74,11 @@  test_expect_success 'verify_ref(new-main)' '
 '
 
 test_expect_success 'for_each_reflog()' '
-	$RUN for-each-reflog | cut -d" " -f 2- >actual &&
+	$RUN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
-	refs/heads/main 0x0
-	refs/heads/new-main 0x0
+	HEAD
+	refs/heads/main
+	refs/heads/new-main
 	EOF
 	test_cmp expected actual
 '
diff --git a/t/t1406-submodule-ref-store.sh b/t/t1406-submodule-ref-store.sh
index 40332e23cc..c01f0f14a1 100755
--- a/t/t1406-submodule-ref-store.sh
+++ b/t/t1406-submodule-ref-store.sh
@@ -63,11 +63,11 @@  test_expect_success 'verify_ref(new-main)' '
 '
 
 test_expect_success 'for_each_reflog()' '
-	$RUN for-each-reflog | cut -d" " -f 2- >actual &&
+	$RUN for-each-reflog >actual &&
 	cat >expected <<-\EOF &&
-	HEAD 0x1
-	refs/heads/main 0x0
-	refs/heads/new-main 0x0
+	HEAD
+	refs/heads/main
+	refs/heads/new-main
 	EOF
 	test_cmp expected actual
 '