Add user guide

[ric-plt/xapp-frame-cpp.git] / examples / xapp_t2.cpp

diff --git a/examples/xapp_t2.cpp b/examples/xapp_t2.cpp
index dd24d2b..67aa72f 100644 (file)
--- a/examples/xapp_t2.cpp
+++ b/examples/xapp_t2.cpp
@@ -26,8 +26,13 @@
 
        Date:           18 March 2020
        Author:         E. Scott Daniels
-               
+
+       Caution:        This example code is pulled directly into one or more of the documents
+                               (starting from the "start-example" tag below.  Use caution with
+                               line lengths and contents because of the requirement that this
+                               be documentation as well as working code.
 */
+// start-example
 
 #include <stdio.h>
 #include <string.h>
@@ -38,14 +43,13 @@
 
 #include "ricxfcpp/xapp.hpp"
 
-// ----------------------------------------------------------
-
 extern int main( int argc, char** argv ) {
        std::unique_ptr<Xapp> xfw;
        std::unique_ptr<Message> msg;
-       Msg_component payload;                          // special type of unique pointer to the payload 
+       Msg_component payload;                          // special type of unique pointer to the payload
 
        int     sz;
+       int len;
        int i;
        int ai;
        int response_to = 0;                            // max timeout wating for a response
@@ -53,26 +57,29 @@ extern int main( int argc, char** argv ) {
        int     mtype = 0;
        int rmtype;                                                     // received message type
        int delay = 1000000;                            // mu-sec delay; default 1s
-       
 
-       ai = 1;
-       while( ai < argc ) {                            // very simple flag processing (no bounds/error checking)
+
+       // very simple flag processing (no bounds/error checking)
+       while( ai < argc ) {
                if( argv[ai][0] != '-' )  {
                        break;
                }
 
-               switch( argv[ai][1] ) {                 // we only support -x so -xy must be -x -y
-                       case 'd':                                       // delay between messages (mu-sec)
+               // we only support -x so -xy must be -x -y
+               switch( argv[ai][1] ) {
+                       // delay between messages (mu-sec)
+                       case 'd':
                                delay = atoi( argv[ai+1] );
                                ai++;
                                break;
-                               
-                       case 'p': 
-                               port = argv[ai+1];      
+
+                       case 'p':
+                               port = argv[ai+1];
                                ai++;
                                break;
 
-                       case 't':                                       // timeout in seconds; we need to convert to ms for rmr calls
+                       // timeout in seconds; we need to convert to ms for rmr calls
+                       case 't':
                                response_to = atoi( argv[ai+1] ) * 1000;
                                ai++;
                                break;
@@ -83,7 +90,8 @@ extern int main( int argc, char** argv ) {
        fprintf( stderr, "<XAPP> response timeout set to: %d\n", response_to );
        fprintf( stderr, "<XAPP> listening on port: %s\n", port );
 
-       xfw = std::unique_ptr<Xapp>( new Xapp( port, true ) );          // new xAPP thing; wait for a route table
+       // get an instance and wait for a route table to be loaded
+       xfw = std::unique_ptr<Xapp>( new Xapp( port, true ) );
        msg = xfw->Alloc_msg( 2048 );
 
        for( i = 0; i < 100; i++ ) {
@@ -92,27 +100,27 @@ extern int main( int argc, char** argv ) {
                        mtype = 0;
                }
 
-               sz = msg->Get_available_size();                 // we'll reuse a message if we received one back; ensure it's big enough
-               if( sz < 2048 ) {
-                       fprintf( stderr, "<SNDR> fail: message returned did not have enough size: %d [%d]\n", sz, i );
-                       exit( 1 );
-               }
+               // we'll reuse a received message; get max size
+               sz = msg->Get_available_size();
 
-               payload = msg->Get_payload();                                                                                   // direct access to payload
-               snprintf( (char *) payload.get(), 2048, "This is message %d\n", i );    // something silly to send
+               // direct access to payload; add something silly
+               payload = msg->Get_payload();
+               len = snprintf( (char *) payload.get(), sz, "This is message %d\n", i );
 
-               // payload updated in place, nothing to copy from, so payload parm is nil
-               if ( ! msg->Send_msg( mtype, Message::NO_SUBID, strlen( (char *) payload.get() )+1, NULL )) {
+               // payload updated in place, prevent copy by passing nil
+               if ( ! msg->Send_msg( mtype, Message::NO_SUBID,  len, NULL )) {
                        fprintf( stderr, "<SNDR> send failed: %d\n", i );
                }
 
+               // receive anything that might come back
                msg = xfw->Receive( response_to );
                if( msg != NULL ) {
                        rmtype = msg->Get_mtype();
                        payload = msg->Get_payload();
-                       fprintf( stderr, "got: mtype=%d payload=(%s)\n", rmtype, (char *) payload.get() );
+                       fprintf( stderr, "got: mtype=%d payload=(%s)\n",
+                               rmtype, (char *) payload.get() );
                } else {
-                       msg = xfw->Alloc_msg( 2048 );                           // nothing back, need a new message to send
+                       msg = xfw->Alloc_msg( 2048 );
                }
 
                if( delay > 0 ) {