uorb: allow for more than 255 uORB messages

Increased size for ORB_ID from uint8_t to uint16_t

Created a type: orb_id_size_t = uint16_t.
There are still a couple of places where the size
of the ORB_ID is assumed to be less than 16-bits.
The places that I have found are commented regarding
this and can be found with a search on orb_id_size_t.

Tools/msg/templates/uorb/msg.cpp.em

@@ -77,7 +77,7 @@ topic_fields = ["%s %s" % (convert_type(field.type, True), field.name) for field
 constexpr char __orb_@(name_snake_case)_fields[] = "@( ";".join(topic_fields) );";
 
 @[for topic in topics]@
-ORB_DEFINE(@topic, struct @uorb_struct, @(struct_size-padding_end_size), __orb_@(name_snake_case)_fields, static_cast<uint8_t>(ORB_ID::@topic));
+ORB_DEFINE(@topic, struct @uorb_struct, @(struct_size-padding_end_size), __orb_@(name_snake_case)_fields, static_cast<orb_id_size_t>(ORB_ID::@topic));
 @[end for]
 
 void print_message(const orb_metadata *meta, const @uorb_struct& message)

Tools/msg/templates/uorb/uORBTopics.cpp.em

@@ -76,5 +76,5 @@ const struct orb_metadata *get_orb_meta(ORB_ID id)
 		return nullptr;
 	}
 
-	return uorb_topics_list[static_cast<uint8_t>(id)];
+	return uorb_topics_list[static_cast<orb_id_size_t>(id)];
 }

Tools/msg/templates/uorb/uORBTopics.hpp.em

@@ -62,7 +62,7 @@ static constexpr size_t orb_topics_count() { return ORB_TOPICS_COUNT; }
  */
 extern const struct orb_metadata *const *orb_get_topics() __EXPORT;
 
-enum class ORB_ID : uint8_t {
+enum class ORB_ID : orb_id_size_t {
 @[for idx, topic_name in enumerate(topic_names_all)]@
 	@(topic_name) = @(idx),
 @[end for]

platforms/common/uORB/uORB.h

@@ -42,16 +42,17 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+typedef uint16_t orb_id_size_t;
 
 /**
  * Object metadata.
  */
 struct orb_metadata {
-	const char *o_name;		/**< unique object name */
-	const uint16_t o_size;		/**< object size */
-	const uint16_t o_size_no_padding;	/**< object size w/o padding at the end (for logger) */
-	const char *o_fields;		/**< semicolon separated list of fields (with type) */
-	uint8_t o_id;			/**< ORB_ID enum */
+	const char    *o_name;              /**< unique object name */
+	const uint16_t o_size;              /**< object size */
+	const uint16_t o_size_no_padding;   /**< object size w/o padding at the end (for logger) */
+	const char    *o_fields;            /**< semicolon separated list of fields (with type) */
+	orb_id_size_t  o_id;                /**< ORB_ID enum */
 };
 
 typedef const struct orb_metadata *orb_id_t;

platforms/common/uORB/uORBDeviceMaster.cpp

@@ -150,7 +150,7 @@ int uORB::DeviceMaster::advertise(const struct orb_metadata *meta, bool is_adver
 
 			// add to the node map.
 			_node_list.add(node);
-			_node_exists[node->get_instance()].set((uint8_t)node->id(), true);
+			_node_exists[node->get_instance()].set((orb_id_size_t)node->id(), true);
 		}
 
 		group_tries++;

platforms/common/uORB/uORBDeviceMaster.hpp

@@ -98,7 +98,7 @@ public:
 			return false;
 		}
 
-		return _node_exists[instance][(uint8_t)id];
+		return _node_exists[instance][(orb_id_size_t)id];
 	}
 
 	/**

src/modules/logger/logged_topics.h

@@ -88,7 +88,7 @@ public:
 		RequestedSubscription sub[MAX_TOPICS_NUM];
 		int count{0};
 
-		uint8_t excluded_optional_topic_ids[MAX_EXCLUDED_OPTIONAL_TOPICS_NUM];
+		orb_id_size_t excluded_optional_topic_ids[MAX_EXCLUDED_OPTIONAL_TOPICS_NUM];
 		int num_excluded_optional_topic_ids{0};
 	};
 

src/modules/logger/logger.h

@@ -365,7 +365,7 @@ private:
 	uint16_t 					_event_sequence_offset{0}; ///< event sequence offset to account for skipped (not logged) messages
 	uint16_t 					_event_sequence_offset_mission{0};
 
-	uint8_t						_excluded_optional_topic_ids[LoggedTopics::MAX_EXCLUDED_OPTIONAL_TOPICS_NUM];
+	orb_id_size_t  					_excluded_optional_topic_ids[LoggedTopics::MAX_EXCLUDED_OPTIONAL_TOPICS_NUM];
 	int						_num_excluded_optional_topic_ids{0};
 
 	LogWriter					_writer;

src/modules/uxrce_dds_client/utilities.hpp

@@ -10,8 +10,16 @@
 
 uxrObjectId topic_id_from_orb(ORB_ID orb_id, uint8_t instance = 0)
 {
-	if (orb_id != ORB_ID::INVALID) {
-		uint16_t id = static_cast<uint8_t>(orb_id) + (instance * UINT8_MAX);
+	// Note that the uxrObjectId.id is a uint16_t so we need to cap the ID.
+	// orb_id_size_t is currently uint16_t (MAX = 65535) and a max # of instances as either 4 or 10.
+	// We want to use half of the available id's for writers and half for readers,
+	// so this works as long as orb_id < 3276.
+	// Unfortunately, limits does not appear to be available. So hard-coding for uint16_t.
+	if (orb_id != ORB_ID::INVALID &&
+	    //(orb_id_size_t) orb_id < (std::numeric_limits<orb_id_size_t> / (2*ORB_MULTI_MAX_INSTANCES) )
+	    (orb_id_size_t) orb_id < (65535U / (2U * (uint16_t)ORB_MULTI_MAX_INSTANCES))
+	   ) {
+		uint16_t id = static_cast<orb_id_size_t>(orb_id) + (instance * ORB_TOPICS_COUNT);
 		uxrObjectId topic_id = uxr_object_id(id, UXR_TOPIC_ID);
 		return topic_id;
 	}
@@ -94,8 +102,9 @@ static bool create_data_reader(uxrSession *session, uxrStreamId reliable_out_str
 		return false;
 	}
 
-	uint16_t id = index + 1000;
-
+	// Use the second half of the available ID space.
+	// Add 1 so that we get a nice hex starting number: 0x8000 instead of 0x7fff.
+	uint16_t id = index + (65535U / 2U) + 1;
 
 	uxrObjectId topic_id = uxr_object_id(id, UXR_TOPIC_ID);
 	uint16_t topic_req = uxr_buffer_create_topic_bin(session, reliable_out_stream_id, topic_id, participant_id, topic_name,