implemented MAV_CMD_REQUEST_MESSAGE for STORAGE_INFORMATION

src/modules/mavlink/mavlink_messages.cpp

@@ -5172,6 +5172,103 @@ protected:
 	}
 };
 
+#ifdef __PX4_DARWIN
+#include <sys/param.h>
+#include <sys/mount.h>
+#else
+#include <sys/statfs.h>
+#endif
+
+class MavlinkStreamStorageInformation : public MavlinkStream
+{
+public:
+	const char *get_name() const override
+	{
+		return MavlinkStreamStorageInformation::get_name_static();
+	}
+
+	static constexpr const char *get_name_static()
+	{
+		return "STORAGE_INFORMATION";
+	}
+
+	static constexpr uint16_t get_id_static()
+	{
+		return MAVLINK_MSG_ID_STORAGE_INFORMATION;
+	}
+
+	uint16_t get_id() override
+	{
+		return get_id_static();
+	}
+
+	static MavlinkStream *new_instance(Mavlink *mavlink)
+	{
+		return new MavlinkStreamStorageInformation(mavlink);
+	}
+
+	unsigned get_size() override
+	{
+		return MAVLINK_MSG_ID_STORAGE_INFORMATION_LEN + MAVLINK_NUM_NON_PAYLOAD_BYTES;
+	}
+
+	virtual bool request_message(float param1 = 0.0, float param2 = 0.0, float param3 = 0.0, float param4 = 0.0,
+				     float param5 = 0.0, float param6 = 0.0, float param7 = 0.0)
+	{
+		storage_id = (int)roundf(param2);
+		return send(hrt_absolute_time());
+	}
+private:
+	int storage_id = 0;
+
+	/* do not allow top copying this class */
+	MavlinkStreamStorageInformation(MavlinkStreamStorageInformation &) = delete;
+	MavlinkStreamStorageInformation &operator = (const MavlinkStreamStorageInformation &) = delete;
+
+
+protected:
+	explicit MavlinkStreamStorageInformation(Mavlink *mavlink) : MavlinkStream(mavlink)
+	{}
+
+	bool send(const hrt_abstime t) override
+	{
+		mavlink_storage_information_t storage_info{};
+		const char *microsd_dir = PX4_STORAGEDIR;
+
+		if (storage_id == 0 || storage_id == 1) { // request is for all or the first storage
+			storage_info.storage_id = storage_id; // replace by 1
+
+			struct statfs statfs_buf;
+			uint64_t total_bytes = 0;
+			uint64_t avail_bytes = 0;
+
+			if (statfs(microsd_dir, &statfs_buf) == 0) {
+				total_bytes = (uint64_t)statfs_buf.f_blocks * statfs_buf.f_bsize;
+				avail_bytes = (uint64_t)statfs_buf.f_bavail * statfs_buf.f_bsize;
+			}
+
+			if (total_bytes == 0) { // on NuttX we get 0 total bytes if no SD card is inserted
+				storage_info.storage_count = 0;
+				storage_info.status = 0; // not available
+
+			} else {
+				storage_info.storage_count = 1;
+				storage_info.status = 2; // available & formatted
+				storage_info.total_capacity = total_bytes / 1024. / 1024.;
+				storage_info.available_capacity = avail_bytes / 1024. / 1024.;
+				storage_info.used_capacity = (total_bytes - avail_bytes) / 1024. / 1024.;
+			}
+
+		} else {
+			return false; // results in MAV_RESULT_DENIED
+		}
+
+		storage_info.time_boot_ms = t / 1000;
+		mavlink_msg_storage_information_send_struct(_mavlink->get_channel(), &storage_info);
+		return true;
+	}
+};
+
 static const StreamListItem streams_list[] = {
 	create_stream_list_item<MavlinkStreamHeartbeat>(),
 	create_stream_list_item<MavlinkStreamStatustext>(),
@@ -5231,7 +5328,8 @@ static const StreamListItem streams_list[] = {
 	create_stream_list_item<MavlinkStreamGroundTruth>(),
 	create_stream_list_item<MavlinkStreamPing>(),
 	create_stream_list_item<MavlinkStreamOrbitStatus>(),
-	create_stream_list_item<MavlinkStreamObstacleDistance>()
+	create_stream_list_item<MavlinkStreamObstacleDistance>(),
+	create_stream_list_item<MavlinkStreamStorageInformation>()
 };
 
 const char *get_stream_name(const uint16_t msg_id)
@@ -5259,3 +5357,15 @@ MavlinkStream *create_mavlink_stream(const char *stream_name, Mavlink *mavlink)
 
 	return nullptr;
 }
+
+MavlinkStream *create_mavlink_stream(const uint16_t msg_id, Mavlink *mavlink)
+{
+	// search for stream with specified name in supported streams list
+	for (const auto &stream : streams_list) {
+		if (msg_id == stream.get_id()) {
+			return stream.new_instance(mavlink);
+		}
+	}
+
+	return nullptr;
+}