Fix some GCC bugs, upgrade simpleapi and expand its examples

Author: biaks

CMakeLists.txt

@@ -2,7 +2,9 @@
 project(prometheus-cpp-lite)
 cmake_minimum_required(VERSION 2.6)
 
-if(WIN32) 
+option(PROMETHEUS_BUILD_EXAMPLES "Build with examples" OFF)
+
+if(WIN32)
 
   # This properties specifies the directories into which targets files should be built
   set(EXECUTABLE_OUTPUT_PATH         ${PROJECT_SOURCE_DIR}/bin) # Set old executable location variable
@@ -30,7 +32,8 @@ add_subdirectory("./core")
 
 add_subdirectory("./simpleapi")
 
-add_subdirectory("./examples")
-
+if(PROMETHEUS_BUILD_EXAMPLES)
+  add_subdirectory("./examples")
+endif()
 
 

core/CMakeLists.txt

@@ -10,3 +10,8 @@ target_include_directories(${PROJECT_NAME}     INTERFACE ${CMAKE_CURRENT_SOURCE_
 add_custom_target         (${PROJECT_NAME}-ide SOURCES   ${PROMETHEUS_CPP_LITE_HEADERS})
 
 set                       (${PROJECT_NAME}_INCLUDE ${CMAKE_CURRENT_SOURCE_DIR}/include PARENT_SCOPE)
+
+if(NOT WIN32)
+  find_package(Threads)
+  target_link_libraries(${PROJECT_NAME} INTERFACE ${CMAKE_THREAD_LIBS_INIT})
+endif()

core/include/prometheus/builder.h

@@ -1,3 +1,4 @@
+#pragma once
 
 #include <string>
 #include <map>
@@ -13,7 +14,7 @@ namespace prometheus {
     std::string help_;
 
   public:
-    Builder& Labels(const std::map<std::string, std::string>& labels) {
+    Builder& Labels(const std::map<const std::string, const std::string>& labels) {
       labels_ = labels;
       return *this;
     }

core/include/prometheus/family.h

@@ -239,11 +239,11 @@ namespace prometheus {
 
           ClientMetric collected = metric_pair.second->Collect();
           for (const Label& constant_label : constant_labels)
-            collected.label.push_back(std::move(ClientMetric::Label(constant_label.first, constant_label.second)));
+            collected.label.emplace_back(ClientMetric::Label(constant_label.first, constant_label.second));
 
           const Labels& metric_labels = labels.at(metric_pair.first);
           for (const Label& metric_label : metric_labels)
-            collected.label.push_back(std::move(ClientMetric::Label(metric_label.first, metric_label.second)));
+            collected.label.emplace_back(ClientMetric::Label(metric_label.first, metric_label.second));
 
           family.metric.push_back(std::move(collected));
 
@@ -346,7 +346,7 @@ namespace prometheus {
       /// Register(Registry&).
       template <typename Registry>
       static CustomFamily& Build(Registry& registry, const std::string& name, const std::string& help, const Family::Labels& labels = Family::Labels()) {
-        return registry.Add<CustomFamily>(name, help, labels);
+        return registry.template Add<CustomFamily>(name, help, labels);
       }
 
   };

core/include/prometheus/gauge.h

@@ -52,7 +52,7 @@ namespace prometheus {
         value = static_cast<Value>(time);
       }
       void Set(const Value& val) { value = val; }        ///< \brief Set the gauge to the given value.
-      const Value& Get() const { return value; }         ///< \brief Get the current value of the gauge.
+      const Value Get() const { return value; }          ///< \brief Get the current value of the gauge.
 
       virtual ClientMetric Collect() const {             ///< \brief Get the current value of the gauge. Collect is called by the Registry when collecting metrics.
         ClientMetric metric;

core/include/prometheus/save_to_file.h

@@ -15,17 +15,21 @@ namespace prometheus {
     std::thread          worker_thread { &SaveToFile::worker_function, this };
     Registry*            registry_ptr { nullptr };
 
+    void save_data() {
+      if (registry_ptr) {
+        std::fstream out_file_stream;
+        out_file_stream.open(filename, std::fstream::out | std::fstream::binary);
+        if (out_file_stream.is_open()) {
+          TextSerializer::Serialize(out_file_stream, registry_ptr->Collect());
+          out_file_stream.close();
+        }
+      }
+    }
+
     void worker_function() {
       for (;;) {
         std::this_thread::sleep_for(period);
-        if (registry_ptr) {
-          std::fstream out_file_stream;
-          out_file_stream.open(filename, std::fstream::out | std::fstream::binary);
-          if (out_file_stream.is_open()) {
-            TextSerializer::Serialize(out_file_stream, registry_ptr->Collect());
-            out_file_stream.close();
-          }
-        }
+        save_data();
       }
     }
 
@@ -35,6 +39,8 @@ namespace prometheus {
     ~SaveToFile() {
       if (worker_thread.joinable())
         worker_thread.detach();
+      // save last data before finish
+      save_data();
     }
 
     SaveToFile(Registry& registry_, const std::chrono::seconds& period_, const std::string& filename_) {

examples/CMakeLists.txt

@@ -18,5 +18,8 @@ add_executable       (save_to_file_example           "save_to_file_example.cpp"
 target_link_libraries(save_to_file_example           prometheus-cpp-lite-core)
 
 
-add_executable       (simpleapi_example              "simpleapi_use_in_class_example.cpp")
+add_executable       (simpleapi_example              "simpleapi_example.cpp")
 target_link_libraries(simpleapi_example              prometheus-cpp-simpleapi)
+
+add_executable       (simpleapi_use_in_class_example "simpleapi_use_in_class_example.cpp")
+target_link_libraries(simpleapi_use_in_class_example prometheus-cpp-simpleapi)

examples/modern_example.cpp

@@ -53,7 +53,7 @@ int main() {
     if (random_value & 8) udp_tx_counter += 0.7;
 
     const std::array<std::string, 4> methods = { "GET", "PUT", "POST", "HEAD" };
-    const std::string& method = methods.at(random_value % methods.size());
+    const std::string& method = methods.at(static_cast<std::size_t>(random_value) % methods.size());
 
     // dynamically calling Family<T>.Add() works but is slow and should be avoided
     http_requests_counter.Add({ {"method", method} }) += 10;
@@ -62,7 +62,4 @@ int main() {
     text_serializer.Serialize(std::cout, registry.Collect());
 
   }
-
-  return 0;
-
-}
+}

examples/original_example.cpp

@@ -56,14 +56,12 @@ int main() {
     if (random_value & 8) udp_tx_counter.Increment(10);
 
     const std::array<std::string, 4> methods = { "GET", "PUT", "POST", "HEAD" };
-    auto method = methods.at(random_value % methods.size());
+    auto method = methods.at(static_cast<std::size_t>(random_value) % methods.size());
     // dynamically calling Family<T>.Add() works but is slow and should be avoided
     http_requests_counter.Add({ {"method", method} }).Increment();
 
     TextSerializer text_serializer;
     text_serializer.Serialize(std::cout, registry->Collect());
 
   }
-
-  return 0;
-}
+}

examples/save_to_file_example.cpp

@@ -40,7 +40,4 @@ int main() {
     const int random_value = std::rand();
     metric += random_value % 10;
   }
-
-  return 0;
-
-}
+}