Add simple header-only logger with macros

CMakeLists.txt

@@ -76,6 +76,11 @@ if(BUILD_CONNMAN)
     COMPONENT ${PROJECT_NAME}-dev)
 endif(BUILD_CONNMAN)
 
+install(
+  FILES ${CMAKE_CURRENT_SOURCE_DIR}/include/amarula/log.hpp
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/amarula
+  COMPONENT ${PROJECT_NAME}-dev)
+
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
   if(BUILD_TESTS)
     include(CTest)

examples/CMakeLists.txt

@@ -1,3 +1,5 @@
+add_compile_definitions(LCM_LOG_DEFAULT_ENABLED=1)
+
 if(BUILD_CONNMAN)
   add_executable(connmanctl_dbus connmanctl.cpp)
   target_link_libraries(connmanctl_dbus PRIVATE GConnmanDbus)

include/amarula/dbus/gproxy.hpp

@@ -5,6 +5,7 @@
 #include <glib.h>
 
 #include <amarula/dbus/gdbus.hpp>
+#include <amarula/log.hpp>
 #include <any>
 #include <array>
 #include <cstddef>
@@ -74,7 +75,7 @@ class DBusProxy : public std::enable_shared_from_this<DBusProxy<Properties>> {
             self->updateProperties(out_properties);
             g_variant_unref(out_properties);
         } else {
-            std::cerr << error->message << '\n';
+            LCM_LOG(error->message << '\n');
             g_error_free(error);
         }
         self->template executeCallBack<PropertiesCallback>(counter,
@@ -214,7 +215,7 @@ class DBusProxy : public std::enable_shared_from_this<DBusProxy<Properties>> {
 
         const auto success = finish(G_DBUS_PROXY(proxy), res, &error);
         if (!success) {
-            std::cerr << error->message << '\n';
+            LCM_LOG(error->message << '\n');
             g_error_free(error);
         }
 

include/amarula/log.hpp

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <atomic>
+#include <iostream>
+#include <mutex>
+#include <sstream>
+
+namespace Amarula {
+
+class Log {
+   public:
+    static void enable(bool enabled) {
+        state().store(enabled, std::memory_order_relaxed);
+    }
+
+    static auto isEnabled() -> bool {
+        return state().load(std::memory_order_relaxed);
+    }
+
+    static auto mutex() -> std::mutex& {
+        static std::mutex mutex;
+        return mutex;
+    }
+
+   private:
+    static auto state() -> std::atomic<bool>& {
+#ifdef LCM_LOG_DEFAULT_ENABLED
+        static std::atomic<bool> flag{true};
+#else
+        static std::atomic<bool> flag{false};
+#endif
+        return flag;
+    }
+};
+
+}  // namespace Amarula
+
+#ifndef LCM_LOG_STREAM
+#define LCM_LOG_STREAM std::cout
+#endif
+
+#define LCM_LOG(...)                                                         \
+    do {                                                                     \
+        if (::Amarula::Log::isEnabled()) {                                   \
+            std::ostringstream _lcm_oss;                                     \
+            _lcm_oss << __VA_ARGS__;                                         \
+            std::lock_guard<std::mutex> _lcm_guard(::Amarula::Log::mutex()); \
+            LCM_LOG_STREAM << _lcm_oss.str();                                \
+        }                                                                    \
+    } while (0)

src/dbus/gconnman_agent.cpp

@@ -3,6 +3,7 @@
 #include <glib.h>
 
 #include <amarula/dbus/connman/gagent.hpp>
+#include <amarula/log.hpp>
 #include <iostream>
 #include <stdexcept>
 #include <string>
@@ -114,7 +115,7 @@ void Agent::dispatch_method_call(GDBusMethodInvocation *invocation,
         service = g_variant_get_string(child_service, nullptr);
         error_str = g_variant_get_string(child_error, nullptr);
 
-        std::cerr << "ReportError:" << service << " " << error_str << "\n";
+        LCM_LOG("ReportError:" << service << " " << error_str << '\n');
 
         g_variant_unref(child_service);
         g_variant_unref(child_error);

src/dbus/gconnman_clock.cpp

@@ -3,6 +3,7 @@
 #include <amarula/dbus/connman/gclock.hpp>
 #include <amarula/dbus/gdbus.hpp>
 #include <amarula/dbus/gproxy.hpp>
+#include <amarula/log.hpp>
 #include <ctime>
 #include <iomanip>
 #include <iostream>
@@ -42,7 +43,7 @@ void ClockProperties::update(const gchar* key, GVariant* value) {
     } else if (g_strcmp0(key, TIMESERVERSYNCED_STR) == 0U) {
         time_server_synced_ = g_variant_get_boolean(value) == 1U;
     } else {
-        std::cerr << "Unknown property for Clock: " << key << '\n';
+        LCM_LOG("Unknown property for Clock: " << key << '\n');
     }
 }
 
@@ -97,24 +98,25 @@ void Clock::setTimeServers(const std::vector<std::string>& servers,
 }
 
 void ClockProperties::print() const {
-    std::cout << "@@@@@@@@@@ ClockProperties: @@@@@@@@@@@@@@@\n";
-    std::cout << TIME_STR << ": " << time_ << " (";
+    LCM_LOG("@@@@@@@@@@ ClockProperties: @@@@@@@@@@@@@@@\n");
+    LCM_LOG(TIME_STR << ": " << time_ << " (");
     const auto time_value = static_cast<std::time_t>(time_);
-    std::cout << std::put_time(std::localtime(&time_value), "%Y-%m-%d %H:%M:%S")
-              << ")\n";
-    std::cout << TIMEUPDATES_STR << ": "
-              << TIME_UPDATE_MAP.toString(time_updates_) << '\n';
-    std::cout << TIMEZONE_STR << ": " << timezone_ << '\n';
-    std::cout << TIMEZONEUPDATES_STR << ": "
-              << TIME_ZONE_UPDATE_MAP.toString(timezone_updates_) << '\n';
-    std::cout << TIMESERVERSYNCED_STR << ": " << std::boolalpha
-              << time_server_synced_ << '\n';
-    std::cout << TIMESERVERS_STR << ": ";
+    LCM_LOG(std::put_time(std::localtime(&time_value), "%Y-%m-%d %H:%M:%S")
+            << ")\n");
+    LCM_LOG(TIMEUPDATES_STR << ": " << TIME_UPDATE_MAP.toString(time_updates_)
+                            << '\n');
+    LCM_LOG(TIMEZONE_STR << ": " << timezone_ << '\n');
+    LCM_LOG(TIMEZONEUPDATES_STR
+            << ": " << TIME_ZONE_UPDATE_MAP.toString(timezone_updates_)
+            << '\n');
+    LCM_LOG(TIMESERVERSYNCED_STR << ": " << std::boolalpha
+                                 << time_server_synced_ << '\n');
+    LCM_LOG(TIMESERVERS_STR << ": ");
     for (const auto& server : time_servers_) {
-        std::cout << server << ' ';
+        LCM_LOG(server << ' ');
     }
-    std::cout << '\n';
-    std::cout << "@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n";
+    LCM_LOG('\n');
+    LCM_LOG("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\n");
 }
 
 }  // namespace Amarula::DBus::G::Connman

src/dbus/gconnman_manager.cpp

@@ -11,6 +11,7 @@
 #include <amarula/dbus/connman/gtechnology.hpp>
 #include <amarula/dbus/gdbus.hpp>
 #include <amarula/dbus/gproxy.hpp>
+#include <amarula/log.hpp>
 #include <iostream>
 #include <memory>
 #include <mutex>
@@ -36,7 +37,7 @@ void ManaProperties::update(const gchar* key, GVariant* value) {
     } else if (g_strcmp0(key, STATE_STR) == 0U) {
         state_ = STATE_MAP.fromString(g_variant_get_string(value, nullptr));
     } else {
-        std::cerr << "Unknown property for Manager: " << key << '\n';
+        LCM_LOG("Unknown property for Manager: " << key << '\n');
     }
 }
 
@@ -270,7 +271,7 @@ void Manager::get_proxies_cb(GObject* proxy, GAsyncResult* res,
         }
 
     } else {
-        std::cerr << error->message << '\n';
+        LCM_LOG(error->message << '\n');
         g_error_free(error);
     }
 }