Logger interface and tmLogger impl based on go-kit

log/logger.go

@@ -0,0 +1,27 @@
+package log
+
+import (
+	"fmt"
+
+	kitlog "github.com/go-kit/kit/log"
+)
+
+// Logger is what any Tendermint library should take.
+type Logger interface {
+	Debug(msg string, keyvals ...interface{}) error
+	Info(msg string, keyvals ...interface{}) error
+	Error(msg string, keyvals ...interface{}) error
+}
+
+// With returns a new contextual logger with keyvals prepended to those passed
+// to calls to Info, Debug or Error.
+func With(logger Logger, keyvals ...interface{}) Logger {
+	switch logger.(type) {
+	case *tmLogger:
+		return &tmLogger{kitlog.With(logger.(*tmLogger).srcLogger, keyvals...)}
+	case *nopLogger:
+		return logger
+	default:
+		panic(fmt.Sprintf("Unexpected logger of type %T", logger))
+	}
+}