--- /dev/null
+#==================================================================================
+
+# Copyright (c) 2018-2019 AT&T Intellectual Property.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#==================================================================================
+
+
+This document gives an overview of the base class of a simple xAPP class. It is used to build the adm-ctrl-xapp executable
+
+Pre-requisitis : nanomsg libraries, nng libraries and ric messaging library + header must be installed and visible on standard library/include paths (via LD_LIBRARY_PATH, LIBRARY_PATH, CPATH)
+
+Usage Guidelines :
+The base XaPP class is defined in xapp_utils.hpp. An XaPP class object can be instantiated in a number of ways :
+
+1. XaPP(char *app_name, char *protocol, int message_size) : where
+ - app_name points to a char array to identify this xapp (e.g "my_app_1")
+ - protocol points to a char array to specify the protocol/port on which this xAPP listens for messages (e.g "tcp:4561")
+ - message_size is the maximum size of messages allowed to send ..
+
+ In this invocation, the number of listener threads (invoked when XaPP.Start() is called) is determined automatically based on hardware
+
+
+2. XaPP(char *app_name, char *protocol, int message_size, int num_threads) : (RECOMMENDED) where
+ - app_name points to a char array to identify this xapp (e.g "my_app_1")
+ - protocol points to a char array to specify the protocol/port on which this xAPP listens for messages (e.g "tcp:4561")
+ - message_size is the maximum size of messages allowed to send ..
+ - num_threads is the number of threads to invoke on which the XaPP listens for and processes messages
+
+
+3. The XaPP object can start listening to messages using the Start function, with two variants :
+
+ - XaPP.Start(message_handler) : in this invocation, any message received by the XaPP is passed on the message_handler function which must have the signature bool *(rmr_mbuf_t *).
+ If the message handler wishes to respond, it must modify the message buffer in place and respond with a true value, else respond with false.
+
+ - XaPP.Start(message_handler, error_handler) : in this invocation, the user can specify an error_handler function, which must have the signature void *(rmr_mubf_t *) if the sending of a message (processed by message_handler) fails.
+
+
+4. The XaPP object can be used to send messages using the Send function with two variants :
+ - XaPP.Send(int message_type, int message_length, void *message_payload)
+ - XaPP.Send(rmr_mbuf_t * message);
+ They return true if message was sent successfuly and false if not
+
+
+If the XaPP is started with multiple listening threads, they all share the same RMR context and invoke the same message handler/error handler user functions. Hence these are expected to be thread safe. Since all threads will listen to RMR, there is no gaurantee on which thread receives which message.
+
+
+ASN1 PDU Processing
+-------------------
+
+1. The basic X2AP builder class (which is responsible for encoding/decoding and setting the X2AP-ELEMENTARY-PROCEDURE) is in x2ap_pdu_builder.hpp
+2. Any other IE requires own code for processing. Currently ResourceStatusRequest builder is under ResourceStatuRequest_builder.hpp and ResourceStatusResponse builder under ResourceStatusResponse_builder.hpp
+
+
+
+--- The adm-ctrl-xapp is a basic example to demonstrate RMR. The adm-ctrl-xapp just uses the basic xAPP class but with message processing done by message_processing.cc.
+
+It receives ResourceStatusRequest message over RMR (message type defined in RMR_services.h), decodes it, extracts elements and responds with a ResourceStatusResponse message (message type defined in RMR_services.h). As an example for verification, it subtracts 1 from the received enb1 and enb2 ids before inserting in response ...
Code Review / ric-app / admin.git / blobdiff