From 69cabd385f37f0aac5f273c08aa6b66211b1491e Mon Sep 17 00:00:00 2001
From: brunoherbelin <herbelin@Brunos-MacBook-Pro.local>
Date: Thu, 9 Jul 2020 12:22:30 +0200
Subject: [PATCH] Implementation of memory usage monitor.

---
 ImGuiToolkit.cpp  | 14 ++++++++------
 SystemToolkit.cpp | 27 +++++++++++++++++++++++++++
 SystemToolkit.h   |  6 ++++++
 3 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/ImGuiToolkit.cpp b/ImGuiToolkit.cpp
index b25a003..890f285 100644
--- a/ImGuiToolkit.cpp
+++ b/ImGuiToolkit.cpp
@@ -669,7 +669,7 @@ void ImGuiToolkit::Bar(float value, float in, float out, float min, float max, c
 
 
     ImVec2 pos0 = ImLerp(bb.Min, bb.Max, 0.1);
-    ImVec2 pos1 = ImLerp(bb.Min, bb.Max, 0.2);
+//    ImVec2 pos1 = ImLerp(bb.Min, bb.Max, 0.2);
     float step = (bb.Max.x - bb.Min.x) / 100.f;
     int i = 0;
     for (float tic = bb.Min.x; tic < bb.Max.x; tic += step, ++i) {
@@ -797,15 +797,17 @@ void ImGuiToolkit::ShowStats(bool *p_open, int* p_corner)
     {
 
         ImGuiToolkit::PushFont(ImGuiToolkit::FONT_MONO);
-        if (ImGui::IsMousePosValid())
-            ImGui::Text("Mouse  (%.1f,%.1f)", io.MousePos.x, io.MousePos.y);
-        else
-            ImGui::Text("Mouse  <invalid>");
+//        if (ImGui::IsMousePosValid())
+//            ImGui::Text("Mouse  (%.1f,%.1f)", io.MousePos.x, io.MousePos.y);
+//        else
+//            ImGui::Text("Mouse  <invalid>");
 
         ImGui::Text("Window  (%.1f,%.1f)", io.DisplaySize.x, io.DisplaySize.y);
-        ImGui::Text("HiDPI (retina) %s", io.DisplayFramebufferScale.x > 1.f ? "on" : "off");
+//        ImGui::Text("HiDPI (retina) %s", io.DisplayFramebufferScale.x > 1.f ? "on" : "off");
 //        ImGui::Text("DPI Scale (%.1f,%.1f)", io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
         ImGui::Text("Rendering %.1f FPS", io.Framerate);
+        ImGui::Text("Memory %s", SystemToolkit::byte_to_string( SystemToolkit::memory_usage()).c_str() );
+//        ImGui::Text("Memory %.ld MB", SystemToolkit::memory_usage());
         ImGui::PopFont();
 
         if (ImGui::BeginPopupContextWindow())
diff --git a/SystemToolkit.cpp b/SystemToolkit.cpp
index 7ebbb9f..648766d 100644
--- a/SystemToolkit.cpp
+++ b/SystemToolkit.cpp
@@ -14,6 +14,7 @@ using namespace std;
 #include <include/dirent.h>
 #define PATH_SEP '\\'
 #elif defined(LINUX) or defined(APPLE)
+#include <sys/resource.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <pwd.h>
@@ -33,6 +34,32 @@ using namespace std;
 #include "SystemToolkit.h"
 
 
+
+long SystemToolkit::memory_usage() {
+    struct rusage r_usage;
+    getrusage(RUSAGE_SELF,&r_usage);
+    return r_usage.ru_maxrss;
+//    return r_usage.ru_isrss;
+}
+
+string SystemToolkit::byte_to_string(long b)
+{
+    double numbytes = static_cast<double>(b);
+    ostringstream oss;
+
+    std::list<std::string> list = {" Bytes", " KB", " MB", " GB", " TB"};
+    std::list<std::string>::iterator i = list.begin();
+
+    while(numbytes >= 1024.0 && i != list.end())
+    {
+        i++;
+        numbytes /= 1024.0;
+    }
+    oss << std::fixed << std::setprecision(2) << numbytes << *i;
+    return oss.str();
+}
+
+
 string SystemToolkit::date_time_string()
 {
     chrono::system_clock::time_point now = chrono::system_clock::now();
diff --git a/SystemToolkit.h b/SystemToolkit.h
index 30d3303..4680d1e 100644
--- a/SystemToolkit.h
+++ b/SystemToolkit.h
@@ -50,6 +50,12 @@ namespace SystemToolkit
 
     // try to open the file with system
     void open(const std::string& path);
+
+    // (tries to) return maximum resident set size used (in kilobytes)
+    long memory_usage();
+
+    // get a string to display memory size with unit KB, MB, GB, TB
+    std::string byte_to_string(long b);
 }
 
 #endif // SYSTEMTOOLKIT_H