[PATCH v3 3/3] oidmap: return oidmap_entry pointers

[Abhishek Kumar <abhishekkumar8222@gmail.com>]

oidmap_entry is usually embedded as first member of user data
structures. Since oidmap is unaware of structure, it returns an void
pointer for oidmap_get(), oidmap_put() and oidmap_remove().

This pointer is rather a pointer to a oidmap entry. Teach the functions
to return a oidmap_entry pointer and add helper macros to return
pointers to container struct.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
---
 list-objects-filter.c  |  8 +++++---
 oidmap.c               | 21 ++++++++++++---------
 oidmap.h               | 42 ++++++++++++++++++++++++++++++++++++------
 replace-object.c       |  7 ++++---
 sequencer.c            | 28 ++++++++++++++++++----------
 t/helper/test-oidmap.c |  8 +++++---
 6 files changed, 80 insertions(+), 34 deletions(-)

diff --git a/list-objects-filter.c b/list-objects-filter.c
index 1e8d4e763d..16b45d913e 100644
--- a/list-objects-filter.c
+++ b/list-objects-filter.c
@@ -183,13 +183,15 @@ static enum list_objects_filter_result filter_trees_depth(
 		return include_it ? LOFR_MARK_SEEN | LOFR_DO_SHOW : LOFR_ZERO;
 
 	case LOFS_BEGIN_TREE:
-		seen_info = oidmap_get(
-			&filter_data->seen_at_depth, &obj->oid);
+		oidmap_get_entry(seen_info, base, &filter_data->seen_at_depth,
+				 &obj->oid);
+
 		if (!seen_info) {
 			seen_info = xcalloc(1, sizeof(*seen_info));
 			oidcpy(&seen_info->base.oid, &obj->oid);
 			seen_info->depth = filter_data->current_depth;
-			oidmap_put(&filter_data->seen_at_depth, seen_info);
+			oidmap_put_entry(seen_info, base,
+					 &filter_data->seen_at_depth);
 			already_seen = 0;
 		} else {
 			already_seen =
diff --git a/oidmap.c b/oidmap.c
index 44345a8cf2..0e64c0e8a2 100644
--- a/oidmap.c
+++ b/oidmap.c
@@ -33,15 +33,18 @@ void oidmap_free(struct oidmap *map, int free_entries)
 		hashmap_free(&map->map);
 }
 
-void *oidmap_get(const struct oidmap *map, const struct object_id *key)
+struct oidmap_entry *oidmap_get(const struct oidmap *map,
+		const struct object_id *key)
 {
 	if (!map->map.cmpfn)
 		return NULL;
 
-	return hashmap_get_from_hash(&map->map, oidhash(key), key);
+	return oidmap_entry_from_hashmap_entry(
+		hashmap_get_from_hash(&map->map, oidhash(key), key));
 }
 
-void *oidmap_remove(struct oidmap *map, const struct object_id *key)
+struct oidmap_entry *oidmap_remove(struct oidmap *map,
+		const struct object_id *key)
 {
 	struct hashmap_entry entry;
 
@@ -49,16 +52,16 @@ void *oidmap_remove(struct oidmap *map, const struct object_id *key)
 		oidmap_init(map, 0);
 
 	hashmap_entry_init(&entry, oidhash(key));
-	return hashmap_remove(&map->map, &entry, key);
+	return oidmap_entry_from_hashmap_entry(
+		hashmap_remove(&map->map, &entry, key));
 }
 
-void *oidmap_put(struct oidmap *map, void *entry)
+struct oidmap_entry *oidmap_put(struct oidmap *map, struct oidmap_entry *entry)
 {
-	struct oidmap_entry *to_put = entry;
-
 	if (!map->map.cmpfn)
 		oidmap_init(map, 0);
 
-	hashmap_entry_init(&to_put->internal_entry, oidhash(&to_put->oid));
-	return hashmap_put(&map->map, &to_put->internal_entry);
+	hashmap_entry_init(&entry->internal_entry, oidhash(&entry->oid));
+	return oidmap_entry_from_hashmap_entry(
+		hashmap_put(&map->map, &entry->internal_entry));
 }
diff --git a/oidmap.h b/oidmap.h
index d79b087ab0..f250f0bf87 100644
--- a/oidmap.h
+++ b/oidmap.h
@@ -46,25 +46,55 @@ void oidmap_free(struct oidmap *map, int free_entries);
 /*
  * Returns the oidmap entry for the specified oid, or NULL if not found.
  */
-void *oidmap_get(const struct oidmap *map,
+struct oidmap_entry *oidmap_get(const struct oidmap *map,
 		 const struct object_id *key);
 
+/*
+ * Returns pointer to container struct of the oidmap entry for the
+ * specified oid, or NULL if not found.
+ */
+#define oidmap_get_entry(var, member, map, key) \
+	var = container_of_or_null_offset( \
+		oidmap_get(map, key), \
+		OFFSETOF_VAR(var, member))
 /*
  * Adds or replaces an oidmap entry.
  *
- * ((struct oidmap_entry *) entry)->internal_entry will be populated by this
- * function.
- *
  * Returns the replaced entry, or NULL if not found (i.e. the entry was added).
  */
-void *oidmap_put(struct oidmap *map, void *entry);
+struct oidmap_entry *oidmap_put(struct oidmap *map, struct oidmap_entry *entry);
+
+/*
+ * Adds or replaces an oidmap entry.
+ *
+ * Returns pointer to container struct of replaced entry, or NULL if
+ * not found (i.e. the entry was added).
+ *
+ * The struct type of @var contains a "struct oidmap_entry" @member.
+ */
+#define oidmap_put_entry(var, member, map) \
+	container_of_or_null_offset( \
+		oidmap_put(map, &var->member), \
+		OFFSETOF_VAR(var, member))
 
 /*
  * Removes an oidmap entry matching the specified oid.
  *
  * Returns the removed entry, or NULL if not found.
  */
-void *oidmap_remove(struct oidmap *map, const struct object_id *key);
+struct oidmap_entry *oidmap_remove(struct oidmap *map,
+		const struct object_id *key);
+
+/*
+ * Removes an oidmap entry matching the specified oid.
+ *
+ * Returns pointer to container struct of the removed entry, or NULL if
+ * not found.
+ */
+#define oidmap_remove_entry(var, member, map, key) \
+	var = container_of_or_null_offset( \
+		oidmap_remove(map, key), \
+		OFFSETOF_VAR(var, member))
 
 #define oidmap_entry_from_hashmap_entry(entry) \
 	container_of_or_null(entry, struct oidmap_entry, internal_entry)
diff --git a/replace-object.c b/replace-object.c
index 7bd9aba6ee..ab0354db7a 100644
--- a/replace-object.c
+++ b/replace-object.c
@@ -26,7 +26,7 @@ static int register_replace_ref(struct repository *r,
 	oidcpy(&repl_obj->replacement, oid);
 
 	/* Register new object */
-	if (oidmap_put(r->objects->replace_map, repl_obj))
+	if (oidmap_put_entry(repl_obj, original, r->objects->replace_map))
 		die(_("duplicate replace ref: %s"), refname);
 
 	return 0;
@@ -73,8 +73,9 @@ const struct object_id *do_lookup_replace_object(struct repository *r,
 
 	/* Try to recursively replace the object */
 	while (depth-- > 0) {
-		struct replace_object *repl_obj =
-			oidmap_get(r->objects->replace_map, cur);
+		struct replace_object *repl_obj;
+		oidmap_get_entry(repl_obj, original, r->objects->replace_map,
+				 cur);
 		if (!repl_obj)
 			return cur;
 		cur = &repl_obj->replacement;
diff --git a/sequencer.c b/sequencer.c
index f30bb73c70..012e7865db 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -4506,7 +4506,8 @@ static const char *label_oid(struct object_id *oid, const char *label,
 	struct object_id dummy;
 	int i;
 
-	string_entry = oidmap_get(&state->commit2label, oid);
+	oidmap_get_entry(string_entry, entry, &state->commit2label, oid);
+
 	if (string_entry)
 		return string_entry->string;
 
@@ -4606,7 +4607,7 @@ static const char *label_oid(struct object_id *oid, const char *label,
 
 	FLEX_ALLOC_STR(string_entry, string, label);
 	oidcpy(&string_entry->entry.oid, oid);
-	oidmap_put(&state->commit2label, string_entry);
+	oidmap_put_entry(string_entry, entry, &state->commit2label);
 
 	return string_entry->string;
 }
@@ -4645,7 +4646,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 		struct object_id *oid = &revs->cmdline.rev[0].item->oid;
 		FLEX_ALLOC_STR(entry, string, "onto");
 		oidcpy(&entry->entry.oid, oid);
-		oidmap_put(&state.commit2label, entry);
+		oidmap_put_entry(entry, entry, /* member name */
+				 &state.commit2label);
 
 		FLEX_ALLOC_STR(onto_label_entry, label, "onto");
 		hashmap_entry_init(&onto_label_entry->entry, strihash("onto"));
@@ -4689,7 +4691,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 			FLEX_ALLOC_STR(entry, string, buf.buf);
 			oidcpy(&entry->entry.oid, &commit->object.oid);
-			oidmap_put(&commit2todo, entry);
+			oidmap_put_entry(entry, entry, /* member name */
+					 &commit2todo);
 
 			continue;
 		}
@@ -4731,7 +4734,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 		FLEX_ALLOC_STR(entry, string, buf.buf);
 		oidcpy(&entry->entry.oid, &commit->object.oid);
-		oidmap_put(&commit2todo, entry);
+		oidmap_put_entry(entry, entry, /* member name */
+				 &commit2todo);
 	}
 
 	/*
@@ -4769,7 +4773,9 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 		commit = iter->item;
 		if (oidset_contains(&shown, &commit->object.oid))
 			continue;
-		entry = oidmap_get(&state.commit2label, &commit->object.oid);
+
+		oidmap_get_entry(entry, entry /* member name */,
+				 &state.commit2label, &commit->object.oid);
 
 		if (entry)
 			strbuf_addf(out, "\n%c Branch %s\n", comment_line_char, entry->string);
@@ -4793,8 +4799,8 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 		else {
 			const char *to = NULL;
 
-			entry = oidmap_get(&state.commit2label,
-					   &commit->object.oid);
+			oidmap_get_entry(entry, entry /* member name */,
+					 &state.commit2label, &commit->object.oid);
 			if (entry)
 				to = entry->string;
 			else if (!rebase_cousins)
@@ -4813,11 +4819,13 @@ static int make_script_with_merges(struct pretty_print_context *pp,
 
 		for (iter2 = list; iter2; iter2 = iter2->next) {
 			struct object_id *oid = &iter2->item->object.oid;
-			entry = oidmap_get(&commit2todo, oid);
+			oidmap_get_entry(entry, entry /* member name */,
+					 &commit2todo, oid);
 			/* only show if not already upstream */
 			if (entry)
 				strbuf_addf(out, "%s\n", entry->string);
-			entry = oidmap_get(&state.commit2label, oid);
+			oidmap_get_entry(entry, entry /* member name */,
+					 &state.commit2label, oid);
 			if (entry)
 				strbuf_addf(out, "%s %s\n",
 					    cmd_label, entry->string);
diff --git a/t/helper/test-oidmap.c b/t/helper/test-oidmap.c
index 3f599b21b8..fc19c1cb8e 100644
--- a/t/helper/test-oidmap.c
+++ b/t/helper/test-oidmap.c
@@ -59,7 +59,7 @@ int cmd__oidmap(int argc, const char **argv)
 			oidcpy(&entry->entry.oid, &oid);
 
 			/* add / replace entry */
-			entry = oidmap_put(&map, entry);
+			entry = oidmap_put_entry(entry, entry, /* member name */ &map);
 
 			/* print and free replaced entry, if any */
 			puts(entry ? entry->name : "NULL");
@@ -73,7 +73,8 @@ int cmd__oidmap(int argc, const char **argv)
 			}
 
 			/* lookup entry in oidmap */
-			entry = oidmap_get(&map, &oid);
+			oidmap_get_entry(entry, entry /* member name */,
+					&map, &oid);
 
 			/* print result */
 			puts(entry ? entry->name : "NULL");
@@ -86,7 +87,8 @@ int cmd__oidmap(int argc, const char **argv)
 			}
 
 			/* remove entry from oidmap */
-			entry = oidmap_remove(&map, &oid);
+			oidmap_remove_entry(entry, entry, /* member name */
+				      &map, &oid);
 
 			/* print result and free entry*/
 			puts(entry ? entry->name : "NULL");
-- 
2.26.0