replace default json serializer to improve readability

common/rs-config.cpp

@@ -6,6 +6,7 @@
 #include <librealsense2/rs.h>
 #include <rsutils/os/special-folder.h>
 #include <rsutils/json.h>
+#include <rsutils/json-config.h>
 #include <fstream>
 
 using json = rsutils::json;
@@ -69,7 +70,7 @@ void config_file::save(const char* filename)
     try
     {
         std::ofstream out(filename);
-        out << _j.dump( 2 );
+        out << std::setw( 2 ) << _j;
         out.close();
     }
     catch (...)
@@ -89,9 +90,8 @@ config_file::config_file( std::string const & filename )
 {
     try
     {
-        std::ifstream t(_filename);
-        if (!t.good()) return;
-        _j = json::parse( t );
+        if( auto j = rsutils::json_config::load_from_file( filename ) )
+            _j = std::move( j );
     }
     catch(...)
     {

src/dds/rs-dds-device-info.cpp

@@ -34,7 +34,7 @@ std::string dds_device_info::get_address() const
 void dds_device_info::to_stream( std::ostream & os ) const
 {
     os << "DDS device (" << _dev->participant()->print( _dev->guid() ) << " on domain "
-       << _dev->participant()->get()->get_domain_id() << "):" << _dev->device_info().to_json().dump( 4 );
+       << _dev->participant()->get()->get_domain_id() << "):" << std::setw( 4 ) << _dev->device_info().to_json();
 }
 
 

third-party/realdds/src/dds-device-broadcaster.cpp

@@ -155,7 +155,7 @@ void dds_device_broadcaster::broadcast() const
     try
     {
         topics::flexible_msg msg( _device_info.to_json() );
-        LOG_DEBUG( "[" << _device_info.debug_name() << "] broadcasting device-info " << _device_info.to_json().dump(4) );
+        LOG_DEBUG( "[" << _device_info.debug_name() << "] broadcasting device-info " << std::setw( 4 ) << _device_info.to_json() );
         std::move( msg ).write_to( *_writer );
 
         // If a broadcast callback is asked for, we wait for acks and call it on the first broadcast (and never again)

third-party/realdds/src/dds-device-impl.cpp

@@ -307,7 +307,7 @@ void dds_device::impl::on_query_options( json const & j, dds_sample const & )
     if( ! option_values.is_object() )
         throw std::runtime_error( "missing option-values" );
 
-    //LOG_DEBUG( "[" << debug_name() << "] got query-options: " << option_values.dump(4) );
+    //LOG_DEBUG( "[" << debug_name() << "] got query-options: " << std::setw( 4 ) << option_values );
     for( auto it = option_values.begin(); it != option_values.end(); ++it )
     {
         if( it->is_object() )

third-party/realdds/src/dds-device-watcher.cpp

@@ -78,7 +78,7 @@ dds_device_watcher::dds_device_watcher( std::shared_ptr< dds_participant > const
                             // Old device coming back to life
                             device.writer_guid = guid;
                             LOG_DEBUG( "[" << device.alive->debug_name() << "] device (from "
-                                           << _participant->print( guid ) << ") back to life: " << j.dump( 4 ) );
+                                           << _participant->print( guid ) << ") back to life: " << std::setw( 4 ) << j );
                             topics::device_info device_info = topics::device_info::from_json( j );
                             static_cast< dds_discovery_sink * >( device.alive.get() )
                                 ->on_discovery_restored( device_info );
@@ -97,7 +97,7 @@ dds_device_watcher::dds_device_watcher( std::shared_ptr< dds_participant > const
                     }
                 }
 
-                LOG_DEBUG( "DDS device (from " << _participant->print( guid ) << ") detected: " << j.dump( 4 ) );
+                LOG_DEBUG( "DDS device (from " << _participant->print( guid ) << ") detected: " << std::setw( 4 ) << j );
                 topics::device_info device_info = topics::device_info::from_json( j );
 
                 // Add a new device record into our dds devices map

third-party/rsutils/include/rsutils/json-fwd.h

@@ -2,6 +2,11 @@
 // Copyright(c) 2023 Intel Corporation. All Rights Reserved.
 #pragma once
 
+// Turn off normal JSON I/O (operator<<) serialization
+// This disables a few things like json::parse, but we do it because of conflict between our operator<< and the built-in
+// one by json. Otherwise (if we do not need custom stream serialization) it's not needed...
+#define JSON_NO_IO
+
 #include <nlohmann/json_fwd.hpp>
 
 
@@ -73,4 +78,8 @@ extern json const empty_json_string;
 extern json const empty_json_object;
 
 
+std::ostream & operator<<( std::ostream &, const json & );
+
+
+
 }  // namespace rsutils