Merge pull request #3554 from vladpaiu/json_merge_func

Add json_merge script function

lib/cJSON.c

@@ -2528,3 +2528,73 @@ void cJSON_Minify(char *json)
     /* and null-terminate. */
     *into = '\0';
 }
+
+cjbool cJSON_IsObject(const cJSON * const item)
+{
+    if (item == NULL)
+    {
+        return false;
+    }
+
+    return (item->type & 0xFF) == cJSON_Object;
+}
+
+cjbool cJSON_IsNull(const cJSON * const item)
+{
+    if (item == NULL)
+    {
+        return false;
+    }
+
+    return (item->type & 0xFF) == cJSON_NULL;
+}
+
+
+static cJSON *merge_patch(cJSON *target, const cJSON * const patch)
+{
+    cJSON *patch_child = NULL;
+
+    if (!cJSON_IsObject(patch))
+    {
+        /* scalar value, array or NULL, just duplicate */
+        cJSON_Delete(target);
+        return cJSON_Duplicate(patch, 1);
+    }
+
+    if (!cJSON_IsObject(target))
+    {
+        cJSON_Delete(target);
+        target = cJSON_CreateObject();
+    }
+
+    patch_child = patch->child;
+    while (patch_child != NULL)
+    {
+        if (cJSON_IsNull(patch_child))
+        {
+            cJSON_DeleteItemFromObject(target, patch_child->string);
+        }
+        else
+        {
+            cJSON *replace_me = NULL;
+            cJSON *replacement = NULL;
+
+            replace_me = cJSON_DetachItemFromObject(target, patch_child->string);
+
+            replacement = merge_patch(replace_me, patch_child);
+            if (replacement == NULL)
+            {
+                return NULL;
+            }
+
+            cJSON_AddItemToObject(target, patch_child->string, replacement);
+        }
+        patch_child = patch_child->next;
+    }
+    return target;
+}
+
+cJSON * cJSONUtils_MergePatch(cJSON *target, const cJSON * const patch)
+{
+    return merge_patch(target, patch);
+}

lib/cJSON.h

@@ -258,6 +258,8 @@ int cJSON_NumberIsInt(cJSON *item);
 /* Macro for iterating over an array */
 #define cJSON_ArrayForEach(pos, head) for(pos = (head)->child; pos != NULL; pos = pos->next)
 
+cJSON * cJSONUtils_MergePatch(cJSON *target, const cJSON * const patch);
+
 #ifdef __cplusplus
 }
 #endif

modules/json/README

@@ -24,6 +24,9 @@ JSON Module
         1.5. Exported Functions
 
               1.5.1. json_link($json(dest_id), $json(source_id))
+              1.5.2.
+                      json_merge(main_json_var,patch_json_var,output
+                      _var))
 
    2. Contributors
 
@@ -57,6 +60,7 @@ JSON Module
    1.12. Adding a json to another json
    1.13. Creating a reference
    1.14. [LOGICAL ERROR] Creating a circular reference
+   1.15. Using json_merge
 
 Chapter 1. Admin Guide
 
@@ -406,6 +410,29 @@ xlog("\nTest link :\n$json(stub)\n$json(b)\n\n");
 
 ...
 
+1.5.2.  json_merge(main_json_var,patch_json_var,output_var))
+
+   The function can be used to patch merge patch_json_var into
+   main_json_var and the output will be populated into the
+   output_var
+
+   Example 1.15. Using json_merge
+...
+
+$json(val1) := "{}";
+$json(val1/test1) = "test_val1";
+$json(val1/common_val) = "val_from1";
+
+$json(val2) := "{}";
+$json(val2/test2) = "test_val2";
+$json(val1/common_val) = "val_from2";
+
+json_merge($json(val1),$json(val2),$var(merged_json));
+xlog("we merged and got $var(merged_json) \n");
+# will print :
+# we merged and got {"test1":"test_val1","common_val":"val_from2","test2
+":"test_val2"}
+
 Chapter 2. Contributors
 
 2.1. By Commit Statistics

modules/json/doc/json_admin.xml

@@ -539,12 +539,36 @@ xlog("\nTest link :\n$json(stub)\n$json(b)\n\n");
 
 		</section>
 
-
-	</section>
+		<section id="func_json_merge" xreflabel="json_merge()">
+			<title>
+			<function moreinfo="none">
+				json_merge(main_json_var,patch_json_var,output_var))
+				</function>
+			</title>
+			<para>
+				The function can be used to patch merge patch_json_var into main_json_var and the output will be populated into the output_var
+			</para>
 
-
+			<example>
+			<title>Using json_merge </title>
+			<programlisting format="linespecific">
+...
 
+$json(val1) := "{}";
+$json(val1/test1) = "test_val1";
+$json(val1/common_val) = "val_from1";
 
+$json(val2) := "{}";
+$json(val2/test2) = "test_val2";
+$json(val1/common_val) = "val_from2";
 
+json_merge($json(val1),$json(val2),$var(merged_json));
+xlog("we merged and got $var(merged_json) \n");
+# will print : 
+# we merged and got {"test1":"test_val1","common_val":"val_from2","test2":"test_val2"} 
+			</programlisting>
+			</example>
+		</section>
+	</section>
 </chapter>
 

modules/json/json.c

@@ -118,14 +118,20 @@ static int pv_parse_json_index(pv_spec_p sp, const str *in);
 static pv_json_t * get_pv_json (pv_param_t* );
 static int pv_add_json ( pv_param_t* , json_t * );
 static int expand_tag_list( struct sip_msg*, json_tag *);
-
+static int w_merge_json(struct sip_msg *msg, str *j1, str* j2, pv_spec_t *res);
 
 static const cmd_export_t cmds[]={
 	{"json_link",    (cmd_function)json_bind, {
 		{CMD_PARAM_VAR, fixup_json_bind, 0},
 		{CMD_PARAM_VAR, fixup_json_bind, 0}, {0,0,0}},
 		REQUEST_ROUTE|ONREPLY_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE|
 		LOCAL_ROUTE|STARTUP_ROUTE|TIMER_ROUTE|EVENT_ROUTE},
+	{"json_merge",(cmd_function)w_merge_json, {
+		{CMD_PARAM_STR, 0, 0}, 
+		{CMD_PARAM_STR, 0, 0}, 
+		{CMD_PARAM_VAR, 0, 0}, 
+		{0,0,0}},
+		ALL_ROUTES},
 	{0,0,{{0,0,0}},0}
 };
 
@@ -1068,3 +1074,60 @@ void mod_destroy(void)
 {
 
 }
+
+int w_merge_json(struct sip_msg *msg, str *j1, str* j2, pv_spec_t *res)
+{
+	cJSON *in1, *in2, *out;
+	char *p;
+	pv_value_t pv_val;
+
+	in1 = cJSON_Parse(j1->s);
+	if (!in1) {
+		LM_ERR("Failed to parse first param \n");
+		return -1;
+	}
+
+	in2 = cJSON_Parse(j2->s);
+	if (!in2) {
+		LM_ERR("Failed to parse second param \n");
+		cJSON_Delete(in1);
+		return -1;
+	}
+
+	out = cJSONUtils_MergePatch(in1,in2);
+	if (!out) {
+		LM_ERR("Failed to merge the two jsons \n");
+		cJSON_Delete(in1);
+		cJSON_Delete(in2);
+		return -1;
+	}
+
+	p = cJSON_Print(out);
+	if (!p) {
+		LM_ERR("Failed to merge the two jsons \n");
+		cJSON_Delete(in1);
+		cJSON_Delete(in2);
+		return -1;
+	}
+
+	cJSON_Minify(p);
+
+	pv_val.flags = PV_VAL_STR;
+	pv_val.rs.s = p;
+	pv_val.rs.len = strlen(p);
+
+
+	if (pv_set_value( msg, res, 0, &pv_val) != 0) {
+		LM_ERR("SET output value failed \n");
+		pkg_free(p);
+		cJSON_Delete(in1);
+		cJSON_Delete(in2);
+		return -1;
+	}
+
+	pkg_free(p);
+	cJSON_Delete(in1);
+	cJSON_Delete(in2);
+
+	return 1;
+}