From 00e475c43478f8fe8522218d8da8c58938a31450 Mon Sep 17 00:00:00 2001
From: Helmut Schaa <helmut.schaa@googlemail.com>
Date: Wed, 13 Jan 2016 15:40:02 +0100
Subject: [PATCH] Add utility function for comparing json_objects

---
 json_object.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++
 json_object.h | 20 +++++++++++++
 2 files changed, 101 insertions(+)

diff --git a/json_object.c b/json_object.c
index e611103..38e69c6 100644
--- a/json_object.c
+++ b/json_object.c
@@ -992,3 +992,84 @@ struct json_object* json_object_array_get_idx(const struct json_object *jso,
 	return (struct json_object*)array_list_get_idx(jso->o.c_array, idx);
 }
 
+static int json_array_equal(struct json_object* jso1,
+			    struct json_object* jso2)
+{
+	int len, i;
+
+	len = json_object_array_length(jso1);
+	if (len != json_object_array_length(jso2))
+		return 0;
+
+	for (i = 0; i < len; i++) {
+		if (!json_object_equal(json_object_array_get_idx(jso1, i),
+				       json_object_array_get_idx(jso2, i)))
+			return 0;
+	}
+	return 1;
+}
+
+static int json_object_all_values_equal(struct json_object* jso1,
+					struct json_object* jso2)
+{
+	struct json_object_iter iter;
+	struct json_object *sub;
+
+	/* Iterate over jso1 keys and see if they exist and are equal in jso2 */
+        json_object_object_foreachC(jso1, iter) {
+		if (!lh_table_lookup_ex(jso1->o.c_object, (void*)iter.key,
+					(void**)&sub))
+			return 0;
+		if (!json_object_equal(iter.val, sub))
+			return 0;
+        }
+
+	/* Iterate over jso2 keys to see if any exist that are not in jso1 */
+        json_object_object_foreachC(jso2, iter) {
+		if (!lh_table_lookup_ex(jso1->o.c_object, (void*)iter.key,
+					(void**)&sub))
+			return 0;
+        }
+
+	return 1;
+}
+
+int json_object_equal(struct json_object* jso1, struct json_object* jso2)
+{
+	if (jso1 == jso2)
+		return 1;
+
+	if (!jso1 || !jso2)
+		return 0;
+
+	if (jso1->o_type != jso2->o_type)
+		return 0;
+
+	switch(jso1->o_type) {
+		case json_type_boolean:
+			return (jso1->o.c_boolean == jso2->o.c_boolean);
+
+		case json_type_double:
+			return (jso1->o.c_double == jso2->o.c_double);
+
+		case json_type_int:
+			return (jso1->o.c_int64 == jso2->o.c_int64);
+
+		case json_type_string:
+			return (jso1->o.c_string.len == jso2->o.c_string.len &&
+				memcmp(get_string_component(jso1),
+				       get_string_component(jso2),
+				       jso1->o.c_string.len) == 0);
+
+		case json_type_object:
+			return json_object_all_values_equal(jso1, jso2);
+
+		case json_type_array:
+			return json_array_equal(jso1, jso2);
+
+		case json_type_null:
+			return 1;
+	};
+
+	return 0;
+}
diff --git a/json_object.h b/json_object.h
index 99b8edf..ee53524 100644
--- a/json_object.h
+++ b/json_object.h
@@ -691,6 +691,26 @@ extern const char* json_object_get_string(struct json_object *obj);
  */
 extern int json_object_get_string_len(const struct json_object *obj);
 
+/** Check if two json_object's are equal
+ *
+ * If the passed objects are equal 1 will be returned.
+ * Equality is defined as follows:
+ * - json_objects of different types are never equal
+ * - json_objects of the same primitive type are equal if the
+ *   c-representation of their value is equal
+ * - json-arrays are considered equal if all values at the same
+ *   indices are equal (same order)
+ * - Complex json_objects are considered equal if all
+ *   contained objects referenced by their key are equal,
+ *   regardless their order.
+ *
+ * @param obj1 the first json_object instance
+ * @param obj2 the second json_object instance
+ * @returns whether both objects are equal or not
+ */
+extern int json_object_equal(struct json_object *obj1,
+			     struct json_object *obj2);
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.40.0