logger: add wrapper support

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

logger/wrapper.go

@@ -0,0 +1,68 @@
+package logger
+
+import (
+	"context"
+	"reflect"
+
+	rutil "github.com/unistack-org/micro/v3/util/reflect"
+)
+
+// LogFunc function used for Log method
+type LogFunc func(ctx context.Context, level Level, args ...interface{})
+
+// LogfFunc function used for Logf method
+type LogfFunc func(ctx context.Context, level Level, msg string, args ...interface{})
+
+type Wrapper interface {
+	// Log logs message with needed level
+	Log(LogFunc) LogFunc
+	//	Log(ctx context.Context, level Level, args ...interface{})
+	// Logf logs message with needed level
+	Logf(LogfFunc) LogfFunc
+	//Logf(ctx context.Context, level Level, msg string, args ...interface{})
+}
+
+type OmitWrapper struct{}
+
+func NewOmitWrapper() Wrapper {
+	return &OmitWrapper{}
+}
+
+func getArgs(args []interface{}) []interface{} {
+	nargs := make([]interface{}, 0, len(args))
+	var err error
+	for _, arg := range args {
+		val := reflect.ValueOf(arg)
+		switch val.Kind() {
+		case reflect.Ptr:
+			val = val.Elem()
+		}
+		narg := arg
+		if val.Kind() == reflect.Struct {
+			if narg, err = rutil.Zero(arg); err == nil {
+				rutil.CopyDefaults(narg, arg)
+				if flds, ferr := rutil.StructFields(narg); ferr == nil {
+					for _, fld := range flds {
+						if tv, ok := fld.Field.Tag.Lookup("logger"); ok && tv == "omit" {
+							fld.Value.Set(reflect.Zero(fld.Value.Type()))
+						}
+					}
+				}
+			}
+		}
+		nargs = append(nargs, narg)
+	}
+	return nargs
+}
+
+func (w *OmitWrapper) Log(fn LogFunc) LogFunc {
+	return func(ctx context.Context, level Level, args ...interface{}) {
+		fn(ctx, level, getArgs(args)...)
+	}
+}
+
+func (w *OmitWrapper) Logf(fn LogfFunc) LogfFunc {
+	return func(ctx context.Context, level Level, msg string, args ...interface{}) {
+		fn(ctx, level, msg, getArgs(args)...)
+	}
+}