Make logs more efficient by avoiding argument evaluation for LOG* if

it's not needed at the current level

Author: robertswiecki

cmdline.cc

@@ -555,13 +555,13 @@ std::unique_ptr<nsjconf_t> parseArgs(int argc, char* argv[]) {
 			nsjconf->daemonize = true;
 			break;
 		case 'v':
-			logs::logLevel(logs::DEBUG);
+			logs::setLogLevel(logs::DEBUG);
 			break;
 		case 'q':
-			logs::logLevel(logs::WARNING);
+			logs::setLogLevel(logs::WARNING);
 			break;
 		case 'Q':
-			logs::logLevel(logs::FATAL);
+			logs::setLogLevel(logs::FATAL);
 			break;
 		case 'e':
 			nsjconf->keep_env = true;

config.cc

@@ -102,19 +102,19 @@ static bool configParseInternal(nsjconf_t* nsjconf, const nsjail::NsJailConfig&
 	if (njc.has_log_level()) {
 		switch (njc.log_level()) {
 		case nsjail::LogLevel::DEBUG:
-			logs::logLevel(logs::DEBUG);
+			logs::setLogLevel(logs::DEBUG);
 			break;
 		case nsjail::LogLevel::INFO:
-			logs::logLevel(logs::INFO);
+			logs::setLogLevel(logs::INFO);
 			break;
 		case nsjail::LogLevel::WARNING:
-			logs::logLevel(logs::WARNING);
+			logs::setLogLevel(logs::WARNING);
 			break;
 		case nsjail::LogLevel::ERROR:
-			logs::logLevel(logs::ERROR);
+			logs::setLogLevel(logs::ERROR);
 			break;
 		case nsjail::LogLevel::FATAL:
-			logs::logLevel(logs::FATAL);
+			logs::setLogLevel(logs::FATAL);
 			break;
 		default:
 			LOG_E("Unknown log_level: %d", njc.log_level());

logs.cc

@@ -70,10 +70,14 @@ bool logSet() {
 	return _log_set;
 }
 
-void logLevel(enum llevel_t ll) {
+void setLogLevel(enum llevel_t ll) {
 	_log_level = ll;
 }
 
+enum llevel_t getLogLevel(void) {
+	return _log_level;
+}
+
 void logFile(const std::string& log_file, int log_fd) {
 	_log_set = true;
 	int newlogfd = -1;

logs.h

@@ -33,17 +33,47 @@ namespace logs {
 #define LOG_HELP_BOLD(...) \
 	logs::logMsg(logs::HELP_BOLD, __FUNCTION__, __LINE__, false, __VA_ARGS__);
 
-#define LOG_D(...) logs::logMsg(logs::DEBUG, __FUNCTION__, __LINE__, false, __VA_ARGS__);
-#define LOG_I(...) logs::logMsg(logs::INFO, __FUNCTION__, __LINE__, false, __VA_ARGS__);
-#define LOG_W(...) logs::logMsg(logs::WARNING, __FUNCTION__, __LINE__, false, __VA_ARGS__);
-#define LOG_E(...) logs::logMsg(logs::ERROR, __FUNCTION__, __LINE__, false, __VA_ARGS__);
-#define LOG_F(...) logs::logMsg(logs::FATAL, __FUNCTION__, __LINE__, false, __VA_ARGS__);
-
-#define PLOG_D(...) logs::logMsg(logs::DEBUG, __FUNCTION__, __LINE__, true, __VA_ARGS__);
-#define PLOG_I(...) logs::logMsg(logs::INFO, __FUNCTION__, __LINE__, true, __VA_ARGS__);
-#define PLOG_W(...) logs::logMsg(logs::WARNING, __FUNCTION__, __LINE__, true, __VA_ARGS__);
-#define PLOG_E(...) logs::logMsg(logs::ERROR, __FUNCTION__, __LINE__, true, __VA_ARGS__);
-#define PLOG_F(...) logs::logMsg(logs::FATAL, __FUNCTION__, __LINE__, true, __VA_ARGS__);
+#define LOG_D(...)                                                                     \
+	if (logs::getLogLevel() <= logs::DEBUG) {                                      \
+		logs::logMsg(logs::DEBUG, __FUNCTION__, __LINE__, false, __VA_ARGS__); \
+	}
+#define LOG_I(...)                                                                    \
+	if (logs::getLogLevel() <= logs::INFO) {                                      \
+		logs::logMsg(logs::INFO, __FUNCTION__, __LINE__, false, __VA_ARGS__); \
+	}
+#define LOG_W(...)                                                                       \
+	if (logs::getLogLevel() <= logs::WARNING) {                                      \
+		logs::logMsg(logs::WARNING, __FUNCTION__, __LINE__, false, __VA_ARGS__); \
+	}
+#define LOG_E(...)                                                                     \
+	if (logs::getLogLevel() <= logs::ERROR) {                                      \
+		logs::logMsg(logs::ERROR, __FUNCTION__, __LINE__, false, __VA_ARGS__); \
+	}
+#define LOG_F(...)                                                                     \
+	if (logs::getLogLevel() <= logs::FATAL) {                                      \
+		logs::logMsg(logs::FATAL, __FUNCTION__, __LINE__, false, __VA_ARGS__); \
+	}
+
+#define PLOG_D(...)                                                                   \
+	if (logs::getLogLevel() <= logs::DEBUG) {                                     \
+		logs::logMsg(logs::DEBUG, __FUNCTION__, __LINE__, true, __VA_ARGS__); \
+	}
+#define PLOG_I(...)                                                                  \
+	if (logs::getLogLevel() <= logs::INFO) {                                     \
+		logs::logMsg(logs::INFO, __FUNCTION__, __LINE__, true, __VA_ARGS__); \
+	}
+#define PLOG_W(...)                                                                     \
+	if (logs::getLogLevel() <= logs::WARNING) {                                     \
+		logs::logMsg(logs::WARNING, __FUNCTION__, __LINE__, true, __VA_ARGS__); \
+	}
+#define PLOG_E(...)                                                                   \
+	if (logs::getLogLevel() <= logs::ERROR) {                                     \
+		logs::logMsg(logs::ERROR, __FUNCTION__, __LINE__, true, __VA_ARGS__); \
+	}
+#define PLOG_F(...)                                                                   \
+	if (logs::getLogLevel() <= logs::FATAL) {                                     \
+		logs::logMsg(logs::FATAL, __FUNCTION__, __LINE__, true, __VA_ARGS__); \
+	}
 
 enum llevel_t {
 	DEBUG = 0,
@@ -58,7 +88,8 @@ enum llevel_t {
 void logMsg(enum llevel_t ll, const char* fn, int ln, bool perr, const char* fmt, ...)
     __attribute__((format(printf, 5, 6)));
 void logStop(int sig);
-void logLevel(enum llevel_t ll);
+void setLogLevel(enum llevel_t ll);
+enum llevel_t getLogLevel(void);
 void logFile(const std::string& log_file, int log_fd);
 bool logSet();