From f8f0027c7f62bf8a91f13920281811c11ef28368 Mon Sep 17 00:00:00 2001
From: "DrZiplok@gmail.com"
 <DrZiplok@gmail.com@f9c3cf11-9bcb-44bc-f272-b75c42450872>
Date: Wed, 16 Feb 2011 07:01:17 +0000
Subject: [PATCH] Add a little code to track the amount of memory used by
 AP_Var subclasses.

git-svn-id: https://arducopter.googlecode.com/svn/trunk@1661 f9c3cf11-9bcb-44bc-f272-b75c42450872
---
 libraries/AP_Common/AP_Var.cpp |  6 +++++-
 libraries/AP_Common/AP_Var.h   | 20 +++++++++++++++++++-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/libraries/AP_Common/AP_Var.cpp b/libraries/AP_Common/AP_Var.cpp
index 53e00fd816..ebec37afa3 100644
--- a/libraries/AP_Common/AP_Var.cpp
+++ b/libraries/AP_Common/AP_Var.cpp
@@ -28,12 +28,12 @@ AP_Float AP_Float_unity         ( 1.0, AP_Var::k_key_none, NULL, AP_Var::k_flag_
 AP_Float AP_Float_negative_unity(-1.0, AP_Var::k_key_none, NULL, AP_Var::k_flag_unlisted);
 AP_Float AP_Float_zero          ( 0.0, AP_Var::k_key_none, NULL, AP_Var::k_flag_unlisted);
 
-
 // Static member variables for AP_Var.
 //
 AP_Var      *AP_Var::_variables;
 AP_Var      *AP_Var::_grouped_variables;
 uint16_t    AP_Var::_tail_sentinel;
+uint16_t    AP_Var::_bytes_in_use;
 
 // Constructor for standalone variables
 //
@@ -172,6 +172,8 @@ bool AP_Var::save(void)
         return _group->save();
     }
 
+    debug("save: %S", _name ? _name : PSTR("??"));
+
     // locate the variable in EEPROM, allocating space as required
     if (!_EEPROM_locate(true)) {
         debug("locate failed");
@@ -202,6 +204,8 @@ bool AP_Var::load(void)
         return _group->load();
     }
 
+    debug("load: %S", _name ? _name : PSTR("??"));
+
     // locate the variable in EEPROM, but do not allocate space
     if (!_EEPROM_locate(false)) {
         debug("locate failed");
diff --git a/libraries/AP_Common/AP_Var.h b/libraries/AP_Common/AP_Var.h
index 2d2850b3b4..14dd0142e2 100644
--- a/libraries/AP_Common/AP_Var.h
+++ b/libraries/AP_Common/AP_Var.h
@@ -347,6 +347,16 @@ public:
     ///
     virtual float cast_to_float() const;
 
+    /// Report the amount of memory being used by AP_Var subclasses.
+    ///
+    /// @return             The sum of sizeof(*this) for all constructed AP_Var subclass instances.
+    ///
+    static uint16_t     get_memory_use() { return _bytes_in_use; }
+
+protected:
+    // Memory statistics
+    static uint16_t     _bytes_in_use;
+
 private:
     AP_Var_group        *_group;            ///< Group that the variable may be a member of
     AP_Var              *_link;             ///< linked list pointer to next variable
@@ -363,7 +373,6 @@ private:
 
     static const uint16_t k_EEPROM_size = 4096;    ///< XXX avr-libc doesn't consistently export this
 
-
     /// Scan the EEPROM and assign addresses to any known variables
     /// that have entries there.
     ///
@@ -409,6 +418,7 @@ public:
     AP_Var_group(Key key = k_key_none, const prog_char *name = NULL, Flags flags = k_flags_none) :
         AP_Var(key, name, flags | k_flag_is_group)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     /// Serialize the group.
@@ -478,6 +488,7 @@ public:
         AP_Var(key, name, flags),
         _value(initial_value)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     /// Constructor for grouped variable.
@@ -500,6 +511,7 @@ public:
         AP_Var(group, index, name, flags),
         _value(initial_value)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     // serialize _value into the buffer, but only if it is big enough.
@@ -608,6 +620,7 @@ public:
                 Flags flags = k_flags_none) :
         AP_Var(key, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     /// Constructor for a grouped structure variable.
@@ -627,6 +640,7 @@ public:
                 Flags flags = k_flags_none) :
         AP_Var(group, index, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     // serialize _value into the buffer, but only if it is big enough.
@@ -716,6 +730,7 @@ public:
                   Flags flags = k_flags_none) :
         AP_Var(key, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     /// Constructor for a grouped array.
@@ -735,6 +750,7 @@ public:
                   Flags flags = k_flags_none) :
         AP_Var(group, index, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     // serialize _value into the buffer, but only if it is big enough.
@@ -829,6 +845,7 @@ public:
                Flags flags = k_flags_none) :
         AP_Float(initial_value, key, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }
 
     AP_Float16(AP_Var_group *group,
@@ -838,6 +855,7 @@ public:
                Flags flags = k_flags_none) :
         AP_Float(group, index, initial_value, name, flags)
     {
+        _bytes_in_use += sizeof(*this);
     }