From c765979f9ac446f2f2a230d2252a54e7da26e580 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 21 Apr 2016 16:11:21 +1000
Subject: [PATCH] DataFlash: expose the number of lost log messages

will be logged in PM message
---
 libraries/DataFlash/DataFlash.cpp       | 8 ++++++++
 libraries/DataFlash/DataFlash.h         | 3 +++
 libraries/DataFlash/DataFlash_Backend.h | 4 ++++
 3 files changed, 15 insertions(+)

diff --git a/libraries/DataFlash/DataFlash.cpp b/libraries/DataFlash/DataFlash.cpp
index e79b9144cf..24c1c1083c 100644
--- a/libraries/DataFlash/DataFlash.cpp
+++ b/libraries/DataFlash/DataFlash.cpp
@@ -203,6 +203,14 @@ void DataFlash_Class::Log_Write_Mission_Cmd(const AP_Mission &mission,
     FOR_EACH_BACKEND(Log_Write_Mission_Cmd(mission, cmd));
 }
 
+uint32_t DataFlash_Class::num_dropped() const
+{
+    if (_next_backend == 0) {
+        return 0;
+    }
+    return backends[0]->num_dropped();
+}
+
 
 // end functions pass straight through to backend
 
diff --git a/libraries/DataFlash/DataFlash.h b/libraries/DataFlash/DataFlash.h
index 16df684b8a..01f1471fa5 100644
--- a/libraries/DataFlash/DataFlash.h
+++ b/libraries/DataFlash/DataFlash.h
@@ -159,6 +159,9 @@ public:
 
     void periodic_tasks(); // may want to split this into GCS/non-GCS duties
 
+    // number of blocks that have been dropped
+    uint32_t num_dropped(void) const;
+    
     vehicle_startup_message_Log_Writer _vehicle_messages;
 
     // parameter support
diff --git a/libraries/DataFlash/DataFlash_Backend.h b/libraries/DataFlash/DataFlash_Backend.h
index 7a66e7c2d2..b172282190 100644
--- a/libraries/DataFlash/DataFlash_Backend.h
+++ b/libraries/DataFlash/DataFlash_Backend.h
@@ -94,6 +94,10 @@ public:
                              const AP_Param::ParamToken &token,
                              enum ap_var_type type);
 
+    uint32_t num_dropped(void) const {
+        return _dropped;
+    }
+    
 protected:
     uint32_t dropped;
     uint8_t internal_errors; // uint8_t - wishful thinking?