// Copyright 2018 Google Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package state import ( "fmt" "io" "io/ioutil" "strings" "github.com/golang/protobuf/proto" pb "gvisor.googlesource.com/gvisor/pkg/state/object_go_proto" ) // format formats a single object, for pretty-printing. func format(graph uint64, depth int, object *pb.Object, html bool) (string, bool) { switch x := object.GetValue().(type) { case *pb.Object_BoolValue: return fmt.Sprintf("%t", x.BoolValue), x.BoolValue != false case *pb.Object_StringValue: return fmt.Sprintf("\"%s\"", x.StringValue), x.StringValue != "" case *pb.Object_Int64Value: return fmt.Sprintf("%d", x.Int64Value), x.Int64Value != 0 case *pb.Object_Uint64Value: return fmt.Sprintf("%du", x.Uint64Value), x.Uint64Value != 0 case *pb.Object_DoubleValue: return fmt.Sprintf("%f", x.DoubleValue), x.DoubleValue != 0.0 case *pb.Object_RefValue: if x.RefValue == 0 { return "nil", false } ref := fmt.Sprintf("g%dr%d", graph, x.RefValue) if html { ref = fmt.Sprintf("%s", ref, ref) } return ref, true case *pb.Object_SliceValue: if x.SliceValue.RefValue == 0 { return "nil", false } ref := fmt.Sprintf("g%dr%d", graph, x.SliceValue.RefValue) if html { ref = fmt.Sprintf("%s", ref, ref) } return fmt.Sprintf("%s[:%d:%d]", ref, x.SliceValue.Length, x.SliceValue.Capacity), true case *pb.Object_ArrayValue: if len(x.ArrayValue.Contents) == 0 { return "[]", false } items := make([]string, 0, len(x.ArrayValue.Contents)+2) zeros := make([]string, 0) // used to eliminate zero entries. items = append(items, "[") tabs := "\n" + strings.Repeat("\t", depth) for i := 0; i < len(x.ArrayValue.Contents); i++ { item, ok := format(graph, depth+1, x.ArrayValue.Contents[i], html) if ok { if len(zeros) > 0 { items = append(items, zeros...) zeros = nil } items = append(items, fmt.Sprintf("\t%s,", item)) } else { zeros = append(zeros, fmt.Sprintf("\t%s,", item)) } } if len(zeros) > 0 { items = append(items, fmt.Sprintf("\t... (%d zero),", len(zeros))) } items = append(items, "]") return strings.Join(items, tabs), len(zeros) < len(x.ArrayValue.Contents) case *pb.Object_StructValue: if len(x.StructValue.Fields) == 0 { return "struct{}", false } items := make([]string, 0, len(x.StructValue.Fields)+2) items = append(items, "struct{") tabs := "\n" + strings.Repeat("\t", depth) allZero := true for _, field := range x.StructValue.Fields { element, ok := format(graph, depth+1, field.Value, html) allZero = allZero && !ok items = append(items, fmt.Sprintf("\t%s: %s,", field.Name, element)) } items = append(items, "}") return strings.Join(items, tabs), !allZero case *pb.Object_MapValue: if len(x.MapValue.Keys) == 0 { return "map{}", false } items := make([]string, 0, len(x.MapValue.Keys)+2) items = append(items, "map{") tabs := "\n" + strings.Repeat("\t", depth) for i := 0; i < len(x.MapValue.Keys); i++ { key, _ := format(graph, depth+1, x.MapValue.Keys[i], html) value, _ := format(graph, depth+1, x.MapValue.Values[i], html) items = append(items, fmt.Sprintf("\t%s: %s,", key, value)) } items = append(items, "}") return strings.Join(items, tabs), true case *pb.Object_InterfaceValue: if x.InterfaceValue.Type == "" { return "interface(nil){}", false } element, _ := format(graph, depth+1, x.InterfaceValue.Value, html) return fmt.Sprintf("interface(\"%s\"){%s}", x.InterfaceValue.Type, element), true } // Should not happen, but tolerate. return fmt.Sprintf("(unknown proto type: %T)", object.GetValue()), true } // PrettyPrint reads the state stream from r, and pretty prints to w. func PrettyPrint(w io.Writer, r io.Reader, html bool) error { var ( // current graph ID. graph uint64 // current object ID. id uint64 ) if html { fmt.Fprintf(w, "
")
		defer fmt.Fprintf(w, "
") } for { // Find the first object to begin generation. length, object, err := ReadHeader(r) if err == io.EOF { // Nothing else to do. break } else if err != nil { return err } if !object { // Increment the graph number & reset the ID. graph++ id = 0 if length > 0 { fmt.Fprintf(w, "(%d bytes non-object data)\n", length) io.Copy(ioutil.Discard, &io.LimitedReader{ R: r, N: int64(length), }) } continue } // Read & unmarshal the object. buf := make([]byte, length) for done := 0; done < len(buf); { n, err := r.Read(buf[done:]) done += n if n == 0 && err != nil { return err } } obj := new(pb.Object) if err := proto.Unmarshal(buf, obj); err != nil { return err } id++ // First object must be one. str, _ := format(graph, 0, obj, html) tag := fmt.Sprintf("g%dr%d", graph, id) if html { tag = fmt.Sprintf("%s", tag, tag) } if _, err := fmt.Fprintf(w, "%s = %s\n", tag, str); err != nil { return err } } return nil }