mie: name: implement parent-child maps and recursive name searches

mie/include/mie/name.h

@@ -3,13 +3,21 @@
 
 #include <blue/core/btree.h>
 #include <blue/core/queue.h>
+#include <mie/misc.h>
+#include <mie/parse/file-span.h>
 
 #define MIE_NAME_VALID(p) (((p)->n_str) != NULL)
 
 struct mie_name_map;
 
 enum mie_name_map_flags {
-	MIE_NAME_MAP_STRICT = 0x01u,
+	/* put(): take the name hint as the required name, and don't amend it
+	 * to ensure uniqueness. if the given name already exists, the operation
+	 * fails. */
+	MIE_NAME_MAP_F_STRICT = 0x01u,
+	/* get(): if the given name does not exist in the name map, recursively
+	 * search the parent map(s) until a result is found. */
+	MIE_NAME_MAP_F_RECURSIVE = 0x02u,
 };
 
 enum mie_name_map_entry_type {
@@ -31,6 +39,10 @@ struct mie_name {
 	struct mie_name_map_entry n_base;
 	struct mie_name_map *n_parent;
 	char *n_str;
+
+	/* if this name was read from a file, these structs can be used to
+	 * record the location within the file where the name is found. */
+	struct mie_file_span n_start, n_end;
 };
 
 struct mie_name_bucket {
@@ -39,13 +51,17 @@ struct mie_name_bucket {
 };
 
 struct mie_name_map {
+	const struct mie_name_map *m_parent;
 	b_btree m_entries;
 	size_t m_next_id;
 };
 
-extern struct mie_name_map *mie_name_map_create(void);
+extern struct mie_name_map *mie_name_map_create(const struct mie_name_map *parent);
 extern void mie_name_map_destroy(struct mie_name_map *map);
 
+extern const struct mie_name *mie_name_map_get(
+	const struct mie_name_map *map, const char *name,
+	enum mie_name_map_flags flags);
 extern struct mie_name *mie_name_map_put(
 	struct mie_name_map *map, struct mie_name *entry, const char *hint,
 	enum mie_name_map_flags flags);

mie/name.c

@@ -4,9 +4,10 @@
 #include <stdlib.h>
 #include <string.h>
 
-B_BTREE_DEFINE_SIMPLE_INSERT(struct mie_name_map_entry, e_node, e_hash, put_entry)
-B_BTREE_DEFINE_SIMPLE_GET(
-	struct mie_name_map_entry, uint64_t, e_node, e_hash, get_entry)
+static B_BTREE_DEFINE_SIMPLE_INSERT(
+	struct mie_name_map_entry, e_node, e_hash, put_entry);
+static B_BTREE_DEFINE_SIMPLE_GET(
+	struct mie_name_map_entry, uint64_t, e_node, e_hash, get_entry);
 
 static struct mie_name_bucket *create_bucket(void)
 {
@@ -36,7 +37,7 @@ static void destroy_bucket(struct mie_name_bucket *bucket)
 	free(bucket);
 }
 
-struct mie_name_map *mie_name_map_create(void)
+struct mie_name_map *mie_name_map_create(const struct mie_name_map *parent)
 {
 	struct mie_name_map *out = malloc(sizeof *out);
 	if (!out) {
@@ -44,6 +45,8 @@ struct mie_name_map *mie_name_map_create(void)
 	}
 
 	memset(out, 0x0, sizeof *out);
+	out->m_parent = parent;
+
 	return out;
 }
 
@@ -127,6 +130,80 @@ static b_status put_name(struct mie_name_map *map, struct mie_name *name)
 	return B_SUCCESS;
 }
 
+static bool check_name(const struct mie_name *name, const char *s, uint64_t hash)
+{
+	return name->n_base.e_hash == hash && !strcmp(name->n_str, s);
+}
+
+static const struct mie_name *find_name_in_bucket(
+	const struct mie_name_bucket *bucket, const char *s, uint64_t hash)
+{
+	b_queue_entry *entry = b_queue_first(&bucket->b_names);
+	while (entry) {
+		struct mie_name_map_entry *map_entry
+			= b_unbox(struct mie_name_map_entry, entry, e_entry);
+		struct mie_name *name = (struct mie_name *)map_entry;
+		if (check_name(name, s, hash)) {
+			return name;
+		}
+
+		entry = b_queue_next(entry);
+	}
+
+	return NULL;
+}
+
+static const struct mie_name *name_map_get(
+	const struct mie_name_map *map, const char *name, uint64_t name_hash)
+{
+	const struct mie_name_map_entry *entry
+		= get_entry(&map->m_entries, name_hash);
+	if (!entry) {
+		return NULL;
+	}
+
+	const struct mie_name *name_entry = NULL;
+	struct mie_name_bucket *bucket = NULL;
+
+	switch (entry->e_type) {
+	case MIE_NAME_MAP_E_NAME:
+		name_entry = (struct mie_name *)entry;
+		if (check_name(name_entry, name, name_hash)) {
+			return name_entry;
+		}
+		break;
+	case MIE_NAME_MAP_E_BUCKET:
+		bucket = (struct mie_name_bucket *)entry;
+		name_entry = find_name_in_bucket(bucket, name, name_hash);
+		if (name_entry) {
+			return name_entry;
+		}
+
+		break;
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+const struct mie_name *mie_name_map_get(
+	const struct mie_name_map *map, const char *name,
+	enum mie_name_map_flags flags)
+{
+	uint64_t name_hash = b_hash_cstr(name);
+	while (map) {
+		const struct mie_name *result = name_map_get(map, name, name_hash);
+		if (result) {
+			return result;
+		}
+
+		map = (flags & MIE_NAME_MAP_F_RECURSIVE) ? map->m_parent : NULL;
+	}
+
+	return NULL;
+}
+
 struct mie_name *mie_name_map_put(
 	struct mie_name_map *map, struct mie_name *entry, const char *hint,
 	enum mie_name_map_flags flags)
@@ -156,7 +233,7 @@ struct mie_name *mie_name_map_put(
 		}
 	}
 
-	if (flags & MIE_NAME_MAP_STRICT) {
+	if (flags & MIE_NAME_MAP_F_STRICT) {
 		/* the caller insists that `hint` be used as the name.
 		 * such a name already exists, so we can't help them */
 		return NULL;