1 files changed, 126 insertions, 0 deletions
diff --git a/louloulibs/logger/logger.hpp b/louloulibs/logger/logger.hpp
new file mode 100644
index 0000000..0893c77
--- /dev/null
+++ b/louloulibs/logger/logger.hpp
@@ -0,0 +1,126 @@
+#pragma once
+
+
+/**
+ * Singleton used in logger macros to write into files or stdout, with
+ * various levels of severity.
+ * Only the macros should be used.
+ * @class Logger
+ */
+
+#include <memory>
+#include <iostream>
+#include <fstream>
+
+#define debug_lvl 0
+#define info_lvl 1
+#define warning_lvl 2
+#define error_lvl 3
+
+#include "louloulibs.h"
+#ifdef SYSTEMD_FOUND
+# include <systemd/sd-daemon.h>
+#else
+# define SD_DEBUG    "[DEBUG]: "
+# define SD_INFO     "[INFO]: "
+# define SD_WARNING  "[WARNING]: "
+# define SD_ERR      "[ERROR]: "
+#endif
+
+// Macro defined to get the filename instead of the full path. But if it is
+// not properly defined by the build system, we fallback to __FILE__
+#ifndef __FILENAME__
+# define __FILENAME__ __FILE__
+#endif
+
+/**
+ * Juste a structure representing a stream doing nothing with its input.
+ */
+class nullstream: public std::ostream
+{
+public:
+  nullstream():
+    std::ostream(0)
+  { }
+};
+
+class Logger
+{
+public:
+  static std::unique_ptr<Logger>& instance();
+  std::ostream& get_stream(const int);
+  Logger(const int log_level, const std::string& log_file);
+  Logger(const int log_level);
+
+  Logger(const Logger&) = delete;
+  Logger& operator=(const Logger&) = delete;
+  Logger(Logger&&) = delete;
+  Logger& operator=(Logger&&) = delete;
+
+private:
+  const int log_level;
+  std::ofstream ofstream;
+  nullstream null_stream;
+  std::ostream stream;
+};
+
+#define WHERE __FILENAME__, ":", __LINE__, ":\t"
+
+namespace logging_details
+{
+  template <typename T>
+  void log(std::ostream& os, const T& arg)
+  {
+    os << arg << std::endl;
+  }
+
+  template <typename T, typename... U>
+  void log(std::ostream& os, const T& first, U&&... rest)
+  {
+    os << first;
+    log(os, std::forward<U>(rest)...);
+  }
+
+  template <typename... U>
+  void log_debug(U&&... args)
+  {
+    auto& os = Logger::instance()->get_stream(debug_lvl);
+    os << SD_DEBUG;
+    log(os, std::forward<U>(args)...);
+  }
+
+  template <typename... U>
+  void log_info(U&&... args)
+  {
+    auto& os = Logger::instance()->get_stream(info_lvl);
+    os << SD_INFO;
+    log(os, std::forward<U>(args)...);
+  }
+
+  template <typename... U>
+  void log_warning(U&&... args)
+  {
+    auto& os = Logger::instance()->get_stream(warning_lvl);
+    os << SD_WARNING;
+    log(os, std::forward<U>(args)...);
+  }
+
+  template <typename... U>
+  void log_error(U&&... args)
+  {
+    auto& os = Logger::instance()->get_stream(error_lvl);
+    os << SD_ERR;
+    log(os, std::forward<U>(args)...);
+  }
+}
+
+#define log_info(...) logging_details::log_info(WHERE, __VA_ARGS__)
+
+#define log_warning(...) logging_details::log_warning(WHERE, __VA_ARGS__)
+
+#define log_error(...) logging_details::log_error(WHERE, __VA_ARGS__)
+
+#define log_debug(...) logging_details::log_debug(WHERE, __VA_ARGS__)
+
+
+