Add routines for querying the log module state.

Unless you have very good reason to do so, there should be no reason to
actually call these ever, since the log messages are only generated if
they will result in output being written to a log file.

common/log/log.go

@@ -41,13 +41,20 @@ import (
 const (
 	elidedAddr = "[scrubbed]"
 
-	levelError = iota
-	levelWarn
-	levelInfo
-	levelDebug
+	// LevelError is the ERROR log level (NOTICE/ERROR).
+	LevelError = iota
+
+	// LevelWarn is the WARN log level,  (NOTICE/ERROR/WARN).
+	LevelWarn
+
+	// LevelInfo is the INFO log level, (NOTICE/ERROR/WARN/INFO).
+	LevelInfo
+
+	// LevelDebug is the DEBUG log level, (NOTICE/ERROR/WARN/INFO/DEBUG).
+	LevelDebug
 )
 
-var logLevel = levelInfo
+var logLevel = LevelInfo
 var enableLogging bool
 var unsafeLogging bool
 
@@ -66,18 +73,34 @@ func Init(enable bool, logFilePath string, unsafe bool) error {
 	return nil
 }
 
+// Enabled returns if logging is enabled.
+func Enabled() bool {
+	return enableLogging
+}
+
+// Unsafe returns if unsafe logging is allowed (the caller MAY skip eliding
+// addresses and other bits of sensitive information).
+func Unsafe() bool {
+	return unsafeLogging
+}
+
+// Level returns the current log level.
+func Level() int {
+	return logLevel
+}
+
 // SetLogLevel sets the log level to the value indicated by the given string
 // (case-insensitive).
 func SetLogLevel(logLevelStr string) error {
 	switch strings.ToUpper(logLevelStr) {
 	case "ERROR":
-		logLevel = levelError
+		logLevel = LevelError
 	case "WARN":
-		logLevel = levelWarn
+		logLevel = LevelWarn
 	case "INFO":
-		logLevel = levelInfo
+		logLevel = LevelInfo
 	case "DEBUG":
-		logLevel = levelDebug
+		logLevel = LevelDebug
 	default:
 		return fmt.Errorf("invalid log level '%s'", logLevelStr)
 	}
@@ -85,6 +108,7 @@ func SetLogLevel(logLevelStr string) error {
 }
 
 // Noticef logs the given format string/arguments at the NOTICE log level.
+// Unless logging is disabled, Noticef logs are always emitted.
 func Noticef(format string, a ...interface{}) {
 	if enableLogging {
 		msg := fmt.Sprintf(format, a...)
@@ -94,7 +118,7 @@ func Noticef(format string, a ...interface{}) {
 
 // Errorf logs the given format string/arguments at the ERROR log level.
 func Errorf(format string, a ...interface{}) {
-	if enableLogging && logLevel >= levelError {
+	if enableLogging && logLevel >= LevelError {
 		msg := fmt.Sprintf(format, a...)
 		log.Print("[ERROR]: " + msg)
 	}
@@ -102,7 +126,7 @@ func Errorf(format string, a ...interface{}) {
 
 // Warnf logs the given format string/arguments at the WARN log level.
 func Warnf(format string, a ...interface{}) {
-	if enableLogging && logLevel >= levelWarn {
+	if enableLogging && logLevel >= LevelWarn {
 		msg := fmt.Sprintf(format, a...)
 		log.Print("[WARN]: " + msg)
 	}
@@ -110,7 +134,7 @@ func Warnf(format string, a ...interface{}) {
 
 // Infof logs the given format string/arguments at the INFO log level.
 func Infof(format string, a ...interface{}) {
-	if enableLogging && logLevel >= levelInfo {
+	if enableLogging && logLevel >= LevelInfo {
 		msg := fmt.Sprintf(format, a...)
 		log.Print("[INFO]: " + msg)
 	}
@@ -118,7 +142,7 @@ func Infof(format string, a ...interface{}) {
 
 // Debugf logs the given format string/arguments at the INFO log level.
 func Debugf(format string, a ...interface{}) {
-	if enableLogging && logLevel >= levelDebug {
+	if enableLogging && logLevel >= LevelDebug {
 		msg := fmt.Sprintf(format, a...)
 		log.Print("[DEBUG]: " + msg)
 	}