Add UA_Server_read and UA_Server_write to give complete access to the read and write services

include/ua_server.h

@@ -214,6 +214,21 @@ UA_Server_removeRepeatedJob(UA_Server *server, UA_Guid jobId);
  * - UserWriteMask
  * - UserAccessLevel
  * - UserExecutable */
+/* Read an attribute of a node. The specialized functions below provide a more
+ * concise syntax.
+ *
+ * @param server The server object.
+ * @param item ReadValueIds contain the NodeId of the target node, the id of the
+ *             attribute to read and (optionally) an index range to read parts
+ *             of an array only. See the section on NumericRange for the format
+ *             used for array ranges.
+ * @param timestamps Which timestamps to return for the attribute.
+ * @return Returns a DataValue that contains either an error code, or a variant
+ *         with the attribute value and the timestamps. */
+UA_DataValue UA_EXPORT
+UA_Server_read(UA_Server *server, const UA_ReadValueId *item,
+               UA_TimestampsToReturn timestamps);
+    
 /* Don't use this function. There are typed versions for every supported
  * attribute. */
 UA_StatusCode UA_EXPORT
@@ -376,6 +391,19 @@ UA_Server_readExecutable(UA_Server *server, const UA_NodeId nodeId,
  * - ArrayDimensions
  *
  * Historizing is currently unsupported */
+/* Overwrite an attribute of a node. The specialized functions below provide a
+ * more concise syntax.
+ *
+ * @param server The server object.
+ * @param value WriteValues contain the NodeId of the target node, the id of the
+ *              attribute to overwritten, the actual value and (optionally) an
+ *              index range to replace parts of an array only. of an array only.
+ *              See the section on NumericRange for the format used for array
+ *              ranges.
+ * @return Returns a status code. */
+UA_StatusCode UA_EXPORT
+UA_Server_write(UA_Server *server, const UA_WriteValue *value);
+
 /* Don't use this function. There are typed versions with no additional
  * overhead. */
 UA_StatusCode UA_EXPORT

src/server/ua_services_attribute.c

@@ -481,19 +481,28 @@ void Service_Read(UA_Server *server, UA_Session *session,
 #endif
 }
 
+UA_DataValue
+UA_Server_read(UA_Server *server, const UA_ReadValueId *item,
+               UA_TimestampsToReturn timestamps) {
+    UA_DataValue dv;
+    UA_DataValue_init(&dv);
+    UA_RCU_LOCK();
+    Service_Read_single(server, &adminSession, timestamps, item, &dv);
+    UA_RCU_UNLOCK();
+    return dv;
+}
+
 UA_StatusCode
 __UA_Server_read(UA_Server *server, const UA_NodeId *nodeId,
                  const UA_AttributeId attributeId, void *v) {
+    /* Call the read service */
     UA_ReadValueId item;
     UA_ReadValueId_init(&item);
     item.nodeId = *nodeId;
     item.attributeId = attributeId;
-    UA_DataValue dv;
-    UA_DataValue_init(&dv);
-    UA_RCU_LOCK();
-    Service_Read_single(server, &adminSession, UA_TIMESTAMPSTORETURN_NEITHER,
-                        &item, &dv);
-    UA_RCU_UNLOCK();
+    UA_DataValue dv = UA_Server_read(server, &item, UA_TIMESTAMPSTORETURN_NEITHER);
+
+    /* Check the return value */
     UA_StatusCode retval = UA_STATUSCODE_GOOD;
     if(dv.hasStatus)
         retval = dv.hasStatus;
@@ -503,19 +512,28 @@ __UA_Server_read(UA_Server *server, const UA_NodeId *nodeId,
         UA_DataValue_deleteMembers(&dv);
         return retval;
     }
-    if(attributeId == UA_ATTRIBUTEID_VALUE ||
-       attributeId == UA_ATTRIBUTEID_ARRAYDIMENSIONS)
-        memcpy(v, &dv.value, sizeof(UA_Variant));
-    else if(attributeId == UA_ATTRIBUTEID_DATATYPE) {
-        UA_copy(dv.value.data, v, dv.value.type);
-        UA_DataValue_deleteMembers(&dv);
-    } else {
-        memcpy(v, dv.value.data, dv.value.type->memSize);
-        dv.value.data = NULL;
-        dv.value.arrayLength = 0;
-        UA_Variant_deleteMembers(&dv.value);
+
+    /* Prepare the result */
+     if(attributeId == UA_ATTRIBUTEID_VALUE ||
+        attributeId == UA_ATTRIBUTEID_ARRAYDIMENSIONS) {
+         /* Return the entire variant */
+         if(dv.value.storageType == UA_VARIANT_DATA_NODELETE) {
+             retval = UA_Variant_copy(dv.value.data, v);
+         } else { /* storageType is UA_VARIANT_DATA */
+             memcpy(v, &dv.value, sizeof(UA_Variant));
+         }
+     }  else {
+         /* Return the variant content only */
+         if(dv.value.storageType == UA_VARIANT_DATA_NODELETE) {
+             retval = UA_copy(dv.value.data, v, dv.value.type);
+         } else { /* storageType is UA_VARIANT_DATA */
+             /* Copy the content of the type (including pointers and all)*/
+             memcpy(v, dv.value.data, dv.value.type->memSize);
+             /* Delete the "carrier" in the variant */
+             UA_free(dv.value.data);
+         }
     }
-    return UA_STATUSCODE_GOOD;
+    return retval;
 }
 
 /*******************/
@@ -836,6 +854,12 @@ void Service_Write(UA_Server *server, UA_Session *session, const UA_WriteRequest
     }
 }
 
+UA_StatusCode UA_Server_write(UA_Server *server, const UA_WriteValue *value) {
+    UA_RCU_LOCK();
+    return Service_Write_single(server, &adminSession, value);
+    UA_RCU_UNLOCK();
+}
+
 UA_StatusCode
 __UA_Server_write(UA_Server *server, const UA_NodeId *nodeId,
                   const UA_AttributeId attributeId, const UA_DataType *attr_type,
@@ -853,8 +877,6 @@ __UA_Server_write(UA_Server *server, const UA_NodeId *nodeId,
         wvalue.value.value = *(const UA_Variant*)value;
     }
     wvalue.value.hasValue = true;
-    UA_RCU_LOCK();
-    UA_StatusCode retval = Service_Write_single(server, &adminSession, &wvalue);
-    UA_RCU_UNLOCK();
+    UA_StatusCode retval = UA_Server_write(server, &wvalue);
     return retval;
 }