* implement --loglevel option

Daemon.cpp

@@ -110,10 +110,11 @@ namespace i2p
 					logfile_path.append("\\i2pd.log");
 #endif
 					StartLog (logfile_path);
-				}
-				else
+				} else {
 					StartLog (""); // write to stdout
 				}
+				g_Log->SetLogLevel(i2p::util::config::GetArg("-loglevel", "info"));
+			}
 
 			LogPrint(eLogInfo, "Daemon: staring HTTP Server");
 			d.httpServer = std::unique_ptr<i2p::util::HTTPServer>(new i2p::util::HTTPServer(i2p::util::config::GetArg("-httpaddress", "127.0.0.1"), i2p::util::config::GetArg("-httpport", 7070)));

Log.cpp

@@ -55,6 +55,19 @@ void Log::SetLogFile (const std::string& fullFilePath)
 		delete logFile;
 }
 
+void Log::SetLogLevel (const std::string& level)
+{
+  if      (level == "error") { m_MinLevel = eLogError; }
+  else if (level == "warn")  { m_MinLevel = eLogWarning;  }
+  else if (level == "info")  { m_MinLevel = eLogInfo;  }
+  else if (level == "debug") { m_MinLevel = eLogDebug; }
+  else {
+		LogPrint(eLogError, "Log: Unknown loglevel: ", level);
+		return;
+  }
+  LogPrint(eLogInfo, "Log: min msg level set to ", level);
+}
+
 void Log::SetLogStream (std::ostream * logStream)
 {
 	if (m_LogStream) delete m_LogStream;	

Log.h

@@ -38,9 +38,11 @@ class Log: public i2p::util::MsgQueue<LogMsg>
 		~Log () { delete m_LogStream; };
 
 		void SetLogFile (const std::string& fullFilePath);
+		void SetLogLevel (const std::string& level);
 		void SetLogStream (std::ostream * logStream);
 		std::ostream * GetLogStream () const { return m_LogStream; };	
 		const std::string& GetTimestamp ();
+		LogLevel GetLogLevel () { return m_MinLevel; };
 
 	private:
 
@@ -49,6 +51,7 @@ class Log: public i2p::util::MsgQueue<LogMsg>
 	private:
 		
 		std::ostream * m_LogStream;
+		enum LogLevel m_MinLevel;
 		std::string m_Timestamp;
 #if (__GNUC__ == 4) && (__GNUC_MINOR__ <= 6) && !defined(__clang__) // gcc 4.6
 		std::chrono::monotonic_clock::time_point m_LastTimestampUpdate;
@@ -108,13 +111,14 @@ void LogPrint (std::stringstream& s, TValue arg, TArgs... args)
 template<typename... TArgs>
 void LogPrint (LogLevel level, TArgs... args) 
 {
+	if (g_Log && level > g_Log->GetLogLevel ())
+		return;
 	LogMsg * msg = new LogMsg (g_Log, level);
 	LogPrint (msg->s, args...);
 	msg->s << std::endl;
-	if (g_Log)	
+	if (g_Log) {
 		g_Log->Put (msg);
-	else
-	{
+	} else {
 		msg->Process ();
 		delete msg;
 	}

docs/configuration.md

@@ -6,6 +6,7 @@ i2pd cmdline options
 * --httpaddress=        - The address to listen on (HTTP server)
 * --httpport=           - The port to listen on (HTTP server)
 * --log=                - Enable or disable logging to file. 1 for yes, 0 for no.
+* --loglevel=           - Log messages above this level (debug, *info, warn, error)
 * --daemon=             - Enable or disable daemon mode. 1 for yes, 0 for no.
 * --service=            - 1 if uses system folders (/var/run/i2pd.pid, /var/log/i2pd.log, /var/lib/i2pd).
 * --v6=                 - 1 if supports communication through ipv6, off by default