log: add support for trace level, exit on critical

log/README_ETHEREUM.md

@@ -2,3 +2,4 @@ This package is a fork of https://github.com/inconshreveable/log15, with some
 minor modifications required by the go-ethereum codebase:
 
  * Support for log level `trace`
+ * Modified behavior to exit on `critical` failure

log/format.go

@@ -58,6 +58,8 @@ func TerminalFormat() Format {
 			color = 32
 		case LvlDebug:
 			color = 36
+		case LvlTrace:
+			color = 34
 		}
 
 		b := &bytes.Buffer{}

log/logger.go

@@ -2,6 +2,7 @@ package log
 
 import (
 	"fmt"
+	"os"
 	"time"
 
 	"github.com/go-stack/stack"
@@ -20,11 +21,14 @@ const (
 	LvlWarn
 	LvlInfo
 	LvlDebug
+	LvlTrace
 )
 
 // Returns the name of a Lvl
 func (l Lvl) String() string {
 	switch l {
+	case LvlTrace:
+		return "trce"
 	case LvlDebug:
 		return "dbug"
 	case LvlInfo:
@@ -44,6 +48,8 @@ func (l Lvl) String() string {
 // Useful for parsing command line args and configuration files.
 func LvlFromString(lvlString string) (Lvl, error) {
 	switch lvlString {
+	case "trace", "trce":
+		return LvlTrace, nil
 	case "debug", "dbug":
 		return LvlDebug, nil
 	case "info":
@@ -87,6 +93,7 @@ type Logger interface {
 	SetHandler(h Handler)
 
 	// Log a message at the given level with context key/value pairs
+	Trace(msg string, ctx ...interface{})
 	Debug(msg string, ctx ...interface{})
 	Info(msg string, ctx ...interface{})
 	Warn(msg string, ctx ...interface{})
@@ -128,6 +135,10 @@ func newContext(prefix []interface{}, suffix []interface{}) []interface{} {
 	return newCtx
 }
 
+func (l *logger) Trace(msg string, ctx ...interface{}) {
+	l.write(msg, LvlTrace, ctx)
+}
+
 func (l *logger) Debug(msg string, ctx ...interface{}) {
 	l.write(msg, LvlDebug, ctx)
 }
@@ -146,6 +157,7 @@ func (l *logger) Error(msg string, ctx ...interface{}) {
 
 func (l *logger) Crit(msg string, ctx ...interface{}) {
 	l.write(msg, LvlCrit, ctx)
+	os.Exit(1)
 }
 
 func (l *logger) GetHandler() Handler {

log/root.go

@@ -41,6 +41,11 @@ func Root() Logger {
 // etc.) to keep the call depth the same for all paths to logger.write so
 // runtime.Caller(2) always refers to the call site in client code.
 
+// Trace is a convenient alias for Root().Trace
+func Trace(msg string, ctx ...interface{}) {
+	root.write(msg, LvlTrace, ctx)
+}
+
 // Debug is a convenient alias for Root().Debug
 func Debug(msg string, ctx ...interface{}) {
 	root.write(msg, LvlDebug, ctx)
@@ -64,4 +69,5 @@ func Error(msg string, ctx ...interface{}) {
 // Crit is a convenient alias for Root().Crit
 func Crit(msg string, ctx ...interface{}) {
 	root.write(msg, LvlCrit, ctx)
+	os.Exit(1)
 }

log/syslog.go

@@ -38,6 +38,8 @@ func sharedSyslog(fmtr Format, sysWr *syslog.Writer, err error) (Handler, error)
 			syslogFn = sysWr.Info
 		case LvlDebug:
 			syslogFn = sysWr.Debug
+		case LvlTrace:
+			syslogFn = func(m string) error { return nil } // There's no syslog level for trace
 		}
 
 		s := strings.TrimSpace(string(fmtr.Format(r)))