--- /dev/null
+#==================================================================================\r
+\r
+# Copyright (c) 2018-2019 AT&T Intellectual Property.\r
+#\r
+# Licensed under the Apache License, Version 2.0 (the "License");\r
+# you may not use this file except in compliance with the License.\r
+# You may obtain a copy of the License at\r
+#\r
+# http://www.apache.org/licenses/LICENSE-2.0\r
+#\r
+# Unless required by applicable law or agreed to in writing, software\r
+# distributed under the License is distributed on an "AS IS" BASIS,\r
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
+# See the License for the specific language governing permissions and\r
+# limitations under the License.\r
+#==================================================================================\r
+\r
+\r
+This document gives an overview of the base class of a simple xAPP class. It is used to build the kpi-xapp executable\r
+\r
+Pre-requisitis : nanomsg libraries, nng libraries, hiredis libraries and ric messaging library + header must be installed and visible on standard library/include paths (via LD_LIBRARY_PATH, LIBRARY_PATH, CPATH)\r
+\r
+Usage Guidelines :\r
+The base XaPP class is defined in xapp_utils.hpp. An XaPP class object can be instantiated in a number of ways :\r
+\r
+1. XaPP(char *app_name, char *protocol, int redis_port, int message_size) : where \r
+ - app_name points to a char array to identify this xapp (e.g "my_app_1") \r
+ - protocol points to a char array to specify the protocol/port on which this xAPP listens for messages (e.g "tcp:4561")\r
+ - redis_port is the port to interact with Redis DB\r
+ - message_size is the maximum size of messages allowed to send ..\r
+\r
+ In this invocation, the number of listener threads (invoked when XaPP.Start() is called) is determined automatically based on hardware\r
+\r
+\r
+2. XaPP(char *app_name, char *protocol, int redis_port, int message_size, int num_threads) : (RECOMMENDED) where \r
+ - app_name points to a char array to identify this xapp (e.g "my_app_1") \r
+ - protocol points to a char array to specify the protocol/port on which this xAPP listens for messages (e.g "tcp:4561")\r
+ - redis_port is the port to interact with Redis DB\r
+ - message_size is the maximum size of messages allowed to send ..\r
+ - num_threads is the number of threads to invoke on which the XaPP listens for and processes messages\r
+\r
+\r
+3. The XaPP object can start listening to messages using the Start function, with two variants :\r
+\r
+ - 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 *). \r
+ 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.\r
+\r
+ - 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. \r
+\r
+\r
+4. The XaPP object can be used to send messages using the Send function with two variants :\r
+ - XaPP.Send(int message_type, int message_length, void *message_payload)\r
+ - XaPP.Send(rmr_mbuf_t * message);\r
+ They return true if message was sent successfuly and false if not\r
+\r
+\r
+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 guarantee which thread receives which message.\r
+\r
+\r
+ASN1 PDU Processing\r
+-------------------\r
+\r
+1. The basic CuCpResourceStatusReport processing is handled in KPI-Message-Handler which handles the decoding of the message and getting the IEs.\r
+\r
+\r
+Redis DB Store\r
+--------------\r
+\r
+1. The Redis DB store is done using the APIs provided by the hiredis libraries and handled in KPI-Monitoring.\r
+\r
+\r
+--- The kpi-xapp is a basic example to demonstrate RMR and DB store. The kpi-xapp just uses the basic xAPP class but with message processing done by message_processing.cc and store done by kpi_db.cc. \r
+\r
+It receives CuCpResourceStatusReport message over RMR, decodes it, extracts elements and stores the content in Redis DB.\r
Code Review / ric-app / kpimon.git / blobdiff