device: combine debug and info log levels into 'verbose'

There are very few cases, if any, in which a user only wants one of
these levels, so combine it into a single level.

While we're at it, reduce indirection on the loggers by using an empty
function rather than a nil function pointer. It's not like we have
retpolines anyway, and we were always calling through a function with a
branch prior, so this seems like a net gain.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 9 insertions, 29 deletions

diff --git a/device/logger.go b/device/logger.go
index 6869a24..7601929 100644
--- a/device/logger.go
+++ b/device/logger.go
@@ -16,53 +16,33 @@ import (
 // They do not require a trailing newline in the format.
 // If nil, that level of logging will be silent.
 type Logger struct {
-	Debugf func(format string, args ...interface{})
-	Infof  func(format string, args ...interface{})
-	Errorf func(format string, args ...interface{})
+	Verbosef func(format string, args ...interface{})
+	Errorf   func(format string, args ...interface{})
 }
 
 // Log levels for use with NewLogger.
 const (
 	LogLevelSilent = iota
 	LogLevelError
-	LogLevelInfo
-	LogLevelDebug
+	LogLevelVerbose
 )
 
+// Function for use in Logger for discarding logged lines.
+func DiscardLogf(format string, args ...interface{}) {}
+
 // NewLogger constructs a Logger that writes to stdout.
 // It logs at the specified log level and above.
 // It decorates log lines with the log level, date, time, and prepend.
 func NewLogger(level int, prepend string) *Logger {
-	logger := new(Logger)
+	logger := &Logger{DiscardLogf, DiscardLogf}
 	logf := func(prefix string) func(string, ...interface{}) {
 		return log.New(os.Stdout, prefix+": "+prepend, log.Ldate|log.Ltime).Printf
 	}
-	if level >= LogLevelDebug {
-		logger.Debugf = logf("DEBUG")
-	}
-	if level >= LogLevelInfo {
-		logger.Infof = logf("INFO")
+	if level >= LogLevelVerbose {
+		logger.Verbosef = logf("DEBUG")
 	}
 	if level >= LogLevelError {
 		logger.Errorf = logf("ERROR")
 	}
 	return logger
 }
-
-func (device *Device) debugf(format string, args ...interface{}) {
-	if device.log.Debugf != nil {
-		device.log.Debugf(format, args...)
-	}
-}
-
-func (device *Device) infof(format string, args ...interface{}) {
-	if device.log.Infof != nil {
-		device.log.Infof(format, args...)
-	}
-}
-
-func (device *Device) errorf(format string, args ...interface{}) {
-	if device.log.Errorf != nil {
-		device.log.Errorf(format, args...)
-	}
-}