rewrite wrapper

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

common.go

@@ -3,25 +3,12 @@ package wrapper
 import (
 	"database/sql/driver"
 	"errors"
+	"fmt"
 )
 
 // ErrUnsupported is an error returned when the underlying driver doesn't provide a given function.
 var ErrUnsupported = errors.New("operation unsupported by the underlying driver")
 
-/*
-// newSpan creates a new opentracing.Span instance from the given context.
-func (t *tracer) newSpan(ctx context.Context) opentracing.Span {
-	name := t.nameFunc(ctx)
-	var opts []opentracing.StartSpanOption
-	parent := opentracing.SpanFromContext(ctx)
-	if parent != nil {
-		opts = append(opts, opentracing.ChildOf(parent.Context()))
-	}
-	span := t.t.StartSpan(name, opts...)
-	return span
-}
-*/
-
 // namedValueToValue converts driver arguments of NamedValue format to Value format. Implemented in the same way as in
 // database/sql ctxutil.go.
 func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
@@ -34,3 +21,18 @@ func namedValueToValue(named []driver.NamedValue) ([]driver.Value, error) {
 	}
 	return dargs, nil
 }
+
+func namedValueToLabels(named []driver.NamedValue) []interface{} {
+	largs := make([]interface{}, len(named)*2)
+	var name string
+	for _, param := range named {
+		if param.Name != "" {
+			name = param.Name
+		} else {
+			name = fmt.Sprintf("$%d", param.Ordinal)
+		}
+
+		largs = append(largs, name, param.Value)
+	}
+	return largs
+}