webserver 1.12: Added graphical statistics page (gnuplot generated)

2 files changed, 49 insertions, 3 deletions

diff --git a/plugins/statistics/Makefile b/plugins/statistics/Makefile
index 8e8a6f7..34c0229 100644
--- a/plugins/statistics/Makefile
+++ b/plugins/statistics/Makefile
@@ -28,8 +28,8 @@ SRC=$(PROGSRC)
 
 all: $(PROJECTNAME).so
 
-$(PROJECTNAME).so: $(SRC:.cpp=.o)
-	$(CXX) $(CXXFLAGS) $^ -shared $(LIBS) -o $@
+$(PROJECTNAME).so: ../../libcommon/libcommon.a $(SRC:.cpp=.o)
+	$(CXX) $(LDFLAGS) $^ -shared $(LDLIBS) $(LIBS) -o $@
 
 ../../libcommon/libcommon.a:
 	cd ../.. && $(MAKE) libcommon/libcommon.a
diff --git a/plugins/statistics/statistics.cpp b/plugins/statistics/statistics.cpp
index b1778f7..415369d 100644
--- a/plugins/statistics/statistics.cpp
+++ b/plugins/statistics/statistics.cpp
@@ -1,5 +1,8 @@
 #include "statistics.h"
 
+#include "libcommon/file.h"
+#include "libcommon/tempfile.h"
+
 #include <boost/algorithm/string/predicate.hpp>
 #include <boost/algorithm/string/split.hpp>
 #include <boost/coroutine2/coroutine.hpp>
@@ -23,9 +26,48 @@ namespace {
  {
   SetResponseHeader("status", status);
   SetResponseHeader("content_type", "text/html");
+
   return status + " " + message;
  }
 
+ std::string statsPng(std::function<std::string(const std::string& key)>& GetServerParam,
+                      std::function<plugin_interface_setter_type>& SetResponseHeader)
+ {
+  // Create PNG statistics via Gnuplot
+  std::string statistics{GetServerParam("statistics")};
+
+  Tempfile tempStats{".txt"}; // input data
+  File::setFile(tempStats.GetPath(), statistics);
+  
+  Tempfile tempPng{".png"}; // output
+  
+  Tempfile tempGnuplot{".gnuplot"};
+  std::stringstream s;
+  s << "set terminal png truecolor\n";
+  s << "set output " << tempPng.GetPath() << "\n"; // quotes added automatically for paths
+  s << "set title \"Webserver Throughput\"\n";
+  s << "set xlabel \"Time\"\n";
+  s << "set timefmt \"%s\"\n";
+  s << "set format x \"%Y-%m-%d\"\n";
+  s << "set xdata time\n";
+  s << "set xtics rotate by 45 right\n";
+  s << "set ylabel \"Bytes\"\n";
+  s << "set datafile separator \",\"\n";
+  s << "set grid\n";
+  s << "set style fill solid\n";
+  s << "plot " << tempStats.GetPath() << " using 1:($4+$5) with boxes title \"Bytes I/O\" lt rgb \"#1132A7\"\n";
+  File::setFile(tempGnuplot.GetPath(), s.str());
+
+  int exit_code{system(("gnuplot "s + tempGnuplot.GetPath().generic_string()).c_str())};
+  if (exit_code) {
+   std::cerr << "Error: gnuplot returned " << std::to_string(exit_code) << std::endl;
+   return HttpStatus("500", "Statistics error"s, SetResponseHeader);
+  }
+  
+  SetResponseHeader("content_type", "image/png");
+  return File::getFile(tempPng.GetPath());
+ }
+
  // returns sum over specified column
  uint64_t getSum(const std::string& stats, size_t column)
  {
@@ -95,9 +137,12 @@ std::string statistics_plugin::generate_page(
   if (target.size() && target.back() != '/' && fs::is_directory(path)) {
    std::string location{GetRequestParam("location") + "/"s};
    SetResponseHeader("location", location);
-   return HttpStatus("301", "Correcting directory path", SetResponseHeader);
+   return HttpStatus("301", "Correcting directory path", SetResponseHeader); // 301 Moved Permanently
   }
 
+  if (path.filename() == "stats.png")
+   return statsPng(GetServerParam, SetResponseHeader);
+
   try {
    SetResponseHeader("content_type", "text/html");
 
@@ -122,6 +167,7 @@ std::string statistics_plugin::generate_page(
    result += "<p>IPv6 fraction by bytes: "s + std::to_string(ipv6_fraction_by_bytes * 100) + "%</p>";
    result += "<p>HTTPS fraction by requests: "s + std::to_string(https_fraction_by_requests * 100) + "%</p>";
    result += "<p>HTTPS fraction by bytes: "s + std::to_string(https_fraction_by_bytes * 100) + "%</p>";
+   result += "<p><img src=\"stats.png\"/></p>";
    result += "<pre>"s + statistics + "</pre>"s;
 
    result += footer;