Merge pull request #505 from AllenX2018/recursive_object_update

Recursive object update

doc/apiref.rst

@@ -708,6 +708,12 @@ allowed in object keys.
 
    .. versionadded:: 2.3
 
+.. function:: int json_object_update_recursive(json_t *object, json_t *other)
+
+   Like :func:`json_object_update()`, but object values in *other* are
+   recursively merged with the corresponding values in *object* if they are also
+   objects, instead of overwriting them. Returns 0 on success or -1 on error.
+
 .. function:: json_object_foreach(object, key, value)
 
    Iterate over every key-value pair of ``object``, running the block

src/jansson.def

@@ -41,6 +41,7 @@ EXPORTS
     json_object_update
     json_object_update_existing
     json_object_update_missing
+    json_object_update_recursive
     json_object_iter
     json_object_iter_at
     json_object_iter_next

src/jansson.h

@@ -199,6 +199,7 @@ int json_object_clear(json_t *object);
 int json_object_update(json_t *object, json_t *other);
 int json_object_update_existing(json_t *object, json_t *other);
 int json_object_update_missing(json_t *object, json_t *other);
+int json_object_update_recursive(json_t *object, json_t *other);
 void *json_object_iter(json_t *object);
 void *json_object_iter_at(json_t *object, const char *key);
 void *json_object_key_to_iter(const char *key);

src/value.c

@@ -37,7 +37,7 @@ static JSON_INLINE int isnan(double x) { return x != x; }
 static JSON_INLINE int isinf(double x) { return !isnan(x) && isnan(x - x); }
 #endif
 
-json_t *do_deep_copy(const json_t *, hashtable_t *);
+json_t *do_deep_copy(const json_t *json, hashtable_t *parents);
 
 static JSON_INLINE void json_init(json_t *json, json_type type)
 {
@@ -214,6 +214,58 @@ int json_object_update_missing(json_t *object, json_t *other)
     return 0;
 }
 
+int do_object_update_recursive(json_t *object, json_t *other, hashtable_t *parents)
+{
+    const char *key;
+    json_t *value;
+    char loop_key[LOOP_KEY_LEN];
+    int res = 0;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    if(jsonp_loop_check(parents, other, loop_key, sizeof(loop_key)))
+        return -1;
+
+    json_object_foreach(other, key, value) {
+        json_t *v = json_object_get(object, key);
+
+        if(json_is_object(v) && json_is_object(value))
+        {
+            if(do_object_update_recursive(v, value, parents))
+            {
+                res = -1;
+                break;
+            }
+        }
+        else
+        {
+            if(json_object_set_nocheck(object, key, value))
+            {
+                res = -1;
+                break;
+            }
+        }
+    }
+
+    hashtable_del(parents, loop_key);
+
+    return res;
+}
+
+int json_object_update_recursive(json_t *object, json_t *other)
+{
+    int res;
+    hashtable_t parents_set;
+
+    if (hashtable_init(&parents_set))
+        return -1;
+    res = do_object_update_recursive(object, other, &parents_set);
+    hashtable_close(&parents_set);
+
+    return res;
+}
+
 void *json_object_iter(json_t *json)
 {
     json_object_t *object;
@@ -329,7 +381,7 @@ static json_t *json_object_deep_copy(const json_t *object, hashtable_t *parents)
 
     result = json_object();
     if(!result)
-        return NULL;
+        goto out;
 
     /* Cannot use json_object_foreach because object has to be cast
        non-const */
@@ -348,6 +400,8 @@ static json_t *json_object_deep_copy(const json_t *object, hashtable_t *parents)
         }
         iter = json_object_iter_next((json_t *)object, iter);
     }
+
+out:
     hashtable_del(parents, loop_key);
 
     return result;
@@ -648,7 +702,7 @@ static json_t *json_array_deep_copy(const json_t *array, hashtable_t *parents)
 
     result = json_array();
     if(!result)
-        return NULL;
+        goto out;
 
     for(i = 0; i < json_array_size(array); i++)
     {
@@ -659,6 +713,8 @@ static json_t *json_array_deep_copy(const json_t *array, hashtable_t *parents)
             break;
         }
     }
+
+out:
     hashtable_del(parents, loop_key);
 
     return result;

test/suites/api/test_object.c

@@ -207,6 +207,86 @@ static void test_conditional_updates()
     json_decref(other);
 }
 
+static void test_recursive_updates()
+{
+    json_t *invalid, *object, *other, *barBefore, *barAfter;
+
+    invalid = json_integer(42);
+
+    object = json_pack("{sis{si}}", "foo", 1, "bar", "baz", 2);
+    other = json_pack("{sisisi}", "foo", 3, "bar", 4, "baz", 5);
+
+    if(!json_object_update_recursive(invalid, other))
+        fail("json_object_update_recursive accepted non-object argument");
+
+    json_decref(invalid);
+
+    if(json_object_update_recursive(object, other))
+        fail("json_object_update_recursive failed");
+
+    if(json_object_size(object) != 3)
+        fail("invalid size after update");
+
+    if(json_integer_value(json_object_get(object, "foo")) != 3)
+        fail("json_object_update_recursive failed to update existing key");
+
+    if(json_integer_value(json_object_get(object, "bar")) != 4)
+        fail("json_object_update_recursive failed to overwrite object");
+
+    if(json_integer_value(json_object_get(object, "baz")) != 5)
+        fail("json_object_update_recursive didn't add new item");
+
+    json_decref(object);
+    json_decref(other);
+
+    object = json_pack("{sis{si}}", "foo", 1, "bar", "baz", 2);
+    other = json_pack("{s{si}}", "bar", "baz", 3);
+    barBefore = json_object_get(object, "bar");
+
+    if(!barBefore)
+        fail("can't get bar object before json_object_update_recursive");
+
+    if(json_object_update_recursive(object, other))
+        fail("json_object_update_recursive failed");
+
+    if(json_object_size(object) != 2)
+        fail("invalid size after update");
+
+    if(!json_object_get(object, "foo"))
+        fail("json_object_update_recursive removed existing key");
+
+    if(json_integer_value(json_object_get(json_object_get(object, "bar"), "baz")) != 3)
+        fail("json_object_update_recursive failed to update nested value");
+
+    barAfter = json_object_get(object, "bar");
+    if(!barAfter)
+        fail("can't get bar object after json_object_update_recursive");
+
+    if(barBefore != barAfter)
+        fail("bar object reference changed after json_object_update_recursive");
+
+    json_decref(object);
+    json_decref(other);
+
+    /* check circular reference */
+    object = json_pack("{s{s{s{si}}}}", "foo", "bar", "baz", "xxx", 2);
+    other = json_pack("{s{s{si}}}", "foo", "bar", "baz", 2);
+    json_object_set(json_object_get(json_object_get(other, "foo"), "bar"), "baz",
+                    json_object_get(other, "foo"));
+
+    if(!json_object_update_recursive(object, other))
+        fail("json_object_update_recursive update a circular reference!");
+
+    json_object_set_new(json_object_get(json_object_get(other, "foo"), "bar"), "baz",
+                        json_integer(1));
+
+    if(json_object_update_recursive(object, other))
+        fail("json_object_update_recursive failed!");
+
+    json_decref(object);
+    json_decref(other);
+}
+
 static void test_circular()
 {
     json_t *object1, *object2;
@@ -667,6 +747,7 @@ static void run_tests()
     test_update();
     test_set_many_keys();
     test_conditional_updates();
+    test_recursive_updates();
     test_circular();
     test_set_nocheck();
     test_iterators();