From c21b6b4a164f571cb960651271b0b737b3d6e9a6 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Wed, 30 Dec 2020 17:23:27 +1100
Subject: [PATCH] AP_HAL_SITL: use ExpandingString class

---
 libraries/AP_HAL_SITL/CANSocketIface.cpp | 65 +++++++++++-------------
 libraries/AP_HAL_SITL/CANSocketIface.h   |  2 +-
 2 files changed, 32 insertions(+), 35 deletions(-)

diff --git a/libraries/AP_HAL_SITL/CANSocketIface.cpp b/libraries/AP_HAL_SITL/CANSocketIface.cpp
index 602eb7b784..03ca3d2a66 100644
--- a/libraries/AP_HAL_SITL/CANSocketIface.cpp
+++ b/libraries/AP_HAL_SITL/CANSocketIface.cpp
@@ -39,6 +39,8 @@
 #include <cstring>
 #include "Scheduler.h"
 #include <AP_CANManager/AP_CANManager.h>
+#include <AP_Common/ExpandingString.h>
+
 extern const AP_HAL::HAL& hal;
 
 using namespace HALSITL;
@@ -576,41 +578,36 @@ bool CANIface::CANSocketEventSource::wait(uint64_t duration, AP_HAL::EventHandle
     return true;
 }
 
-uint32_t CANIface::get_stats(char* data, uint32_t max_size)
+void CANIface::get_stats(ExpandingString &str)
 {
-    if (data == nullptr) {
-        return 0;
-    }
-    uint32_t ret = snprintf(data, max_size,
-                            "tx_requests:    %u\n"
-                            "tx_write_fail:  %u\n"
-                            "tx_full:        %u\n"
-                            "tx_confirmed:   %u\n"
-                            "tx_success:     %u\n"
-                            "tx_timedout:    %u\n"
-                            "rx_received:    %u\n"
-                            "rx_errors:      %u\n"
-                            "num_downs:      %u\n"
-                            "num_rx_poll_req:  %u\n"
-                            "num_tx_poll_req:  %u\n"
-                            "num_poll_waits:   %u\n"
-                            "num_poll_tx_events: %u\n"
-                            "num_poll_rx_events: %u\n",
-                            stats.tx_requests,
-                            stats.tx_write_fail,
-                            stats.tx_full,
-                            stats.tx_confirmed,
-                            stats.tx_success,
-                            stats.tx_timedout,
-                            stats.rx_received,
-                            stats.rx_errors,
-                            stats.num_downs,
-                            stats.num_rx_poll_req,
-                            stats.num_tx_poll_req,
-                            stats.num_poll_waits,
-                            stats.num_poll_tx_events,
-                            stats.num_poll_rx_events);
-    return ret;
+    str.printf("tx_requests:    %u\n"
+               "tx_write_fail:  %u\n"
+               "tx_full:        %u\n"
+               "tx_confirmed:   %u\n"
+               "tx_success:     %u\n"
+               "tx_timedout:    %u\n"
+               "rx_received:    %u\n"
+               "rx_errors:      %u\n"
+               "num_downs:      %u\n"
+               "num_rx_poll_req:  %u\n"
+               "num_tx_poll_req:  %u\n"
+               "num_poll_waits:   %u\n"
+               "num_poll_tx_events: %u\n"
+               "num_poll_rx_events: %u\n",
+               stats.tx_requests,
+               stats.tx_write_fail,
+               stats.tx_full,
+               stats.tx_confirmed,
+               stats.tx_success,
+               stats.tx_timedout,
+               stats.rx_received,
+               stats.rx_errors,
+               stats.num_downs,
+               stats.num_rx_poll_req,
+               stats.num_tx_poll_req,
+               stats.num_poll_waits,
+               stats.num_poll_tx_events,
+               stats.num_poll_rx_events);
 }
 
 #endif
diff --git a/libraries/AP_HAL_SITL/CANSocketIface.h b/libraries/AP_HAL_SITL/CANSocketIface.h
index 4c17105a9c..34916523b1 100644
--- a/libraries/AP_HAL_SITL/CANSocketIface.h
+++ b/libraries/AP_HAL_SITL/CANSocketIface.h
@@ -113,7 +113,7 @@ public:
 
     // fetch stats text and return the size of the same,
     // results available via @SYS/can0_stats.txt or @SYS/can1_stats.txt 
-    uint32_t get_stats(char* data, uint32_t max_size) override;
+    void get_stats(ExpandingString &str) override;
 
     class CANSocketEventSource : public AP_HAL::EventSource {
         friend class CANIface;