// Protocol Buffers for Go with Gadgets // // Copyright (c) 2013, The GoGo Authors. All rights reserved. // http://github.com/gogo/protobuf // // Go support for Protocol Buffers - Google's data interchange format // // Copyright 2010 The Go Authors. All rights reserved. // https://github.com/golang/protobuf // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. package proto // Functions for writing the text protocol buffer format. import ( "bufio" "bytes" "encoding" "errors" "fmt" "io" "log" "math" "reflect" "sort" "strings" "sync" ) var ( newline = []byte("\n") spaces = []byte(" ") gtNewline = []byte(">\n") endBraceNewline = []byte("}\n") backslashN = []byte{'\\', 'n'} backslashR = []byte{'\\', 'r'} backslashT = []byte{'\\', 't'} backslashDQ = []byte{'\\', '"'} backslashBS = []byte{'\\', '\\'} posInf = []byte("inf") negInf = []byte("-inf") nan = []byte("nan") ) type writer interface { io.Writer WriteByte(byte) error } // textWriter is an io.Writer that tracks its indentation level. type textWriter struct { ind int complete bool // if the current position is a complete line compact bool // whether to write out as a one-liner w writer } func (w *textWriter) WriteString(s string) (n int, err error) { if !strings.Contains(s, "\n") { if !w.compact && w.complete { w.writeIndent() } w.complete = false return io.WriteString(w.w, s) } // WriteString is typically called without newlines, so this // codepath and its copy are rare. We copy to avoid // duplicating all of Write's logic here. return w.Write([]byte(s)) } func (w *textWriter) Write(p []byte) (n int, err error) { newlines := bytes.Count(p, newline) if newlines == 0 { if !w.compact && w.complete { w.writeIndent() } n, err = w.w.Write(p) w.complete = false return n, err } frags := bytes.SplitN(p, newline, newlines+1) if w.compact { for i, frag := range frags { if i > 0 { if err := w.w.WriteByte(' '); err != nil { return n, err } n++ } nn, err := w.w.Write(frag) n += nn if err != nil { return n, err } } return n, nil } for i, frag := range frags { if w.complete { w.writeIndent() } nn, err := w.w.Write(frag) n += nn if err != nil { return n, err } if i+1 < len(frags) { if err := w.w.WriteByte('\n'); err != nil { return n, err } n++ } } w.complete = len(frags[len(frags)-1]) == 0 return n, nil } func (w *textWriter) WriteByte(c byte) error { if w.compact && c == '\n' { c = ' ' } if !w.compact && w.complete { w.writeIndent() } err := w.w.WriteByte(c) w.complete = c == '\n' return err } func (w *textWriter) indent() { w.ind++ } func (w *textWriter) unindent() { if w.ind == 0 { log.Print("proto: textWriter unindented too far") return } w.ind-- } func writeName(w *textWriter, props *Properties) error { if _, err := w.WriteString(props.OrigName); err != nil { return err } if props.Wire != "group" { return w.WriteByte(':') } return nil } // raw is the interface satisfied by RawMessage. type raw interface { Bytes() []byte } func writeStruct(w *textWriter, sv reflect.Value) error { st := sv.Type() sprops := GetProperties(st) for i := 0; i < sv.NumField(); i++ { fv := sv.Field(i) props := sprops.Prop[i] name := st.Field(i).Name if strings.HasPrefix(name, "XXX_") { // There are two XXX_ fields: // XXX_unrecognized []byte // XXX_extensions map[int32]proto.Extension // The first is handled here; // the second is handled at the bottom of this function. if name == "XXX_unrecognized" && !fv.IsNil() { if err := writeUnknownStruct(w, fv.Interface().([]byte)); err != nil { return err } } continue } if fv.Kind() == reflect.Ptr && fv.IsNil() { // Field not filled in. This could be an optional field or // a required field that wasn't filled in. Either way, there // isn't anything we can show for it. continue } if fv.Kind() == reflect.Slice && fv.IsNil() { // Repeated field that is empty, or a bytes field that is unused. continue } if props.Repeated && fv.Kind() == reflect.Slice { // Repeated field. for j := 0; j < fv.Len(); j++ { if err := writeName(w, props); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } v := fv.Index(j) if v.Kind() == reflect.Ptr && v.IsNil() { // A nil message in a repeated field is not valid, // but we can handle that more gracefully than panicking. if _, err := w.Write([]byte("<nil>\n")); err != nil { return err } continue } if len(props.Enum) > 0 { if err := writeEnum(w, v, props); err != nil { return err } } else if err := writeAny(w, v, props); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } } continue } if fv.Kind() == reflect.Map { // Map fields are rendered as a repeated struct with key/value fields. keys := fv.MapKeys() sort.Sort(mapKeys(keys)) for _, key := range keys { val := fv.MapIndex(key) if err := writeName(w, props); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } // open struct if err := w.WriteByte('<'); err != nil { return err } if !w.compact { if err := w.WriteByte('\n'); err != nil { return err } } w.indent() // key if _, err := w.WriteString("key:"); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } if err := writeAny(w, key, props.mkeyprop); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } // nil values aren't legal, but we can avoid panicking because of them. if val.Kind() != reflect.Ptr || !val.IsNil() { // value if _, err := w.WriteString("value:"); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } if err := writeAny(w, val, props.mvalprop); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } } // close struct w.unindent() if err := w.WriteByte('>'); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } } continue } if props.proto3 && fv.Kind() == reflect.Slice && fv.Len() == 0 { // empty bytes field continue } if props.proto3 && fv.Kind() != reflect.Ptr && fv.Kind() != reflect.Slice { // proto3 non-repeated scalar field; skip if zero value if isProto3Zero(fv) { continue } } if fv.Kind() == reflect.Interface { // Check if it is a oneof. if st.Field(i).Tag.Get("protobuf_oneof") != "" { // fv is nil, or holds a pointer to generated struct. // That generated struct has exactly one field, // which has a protobuf struct tag. if fv.IsNil() { continue } inner := fv.Elem().Elem() // interface -> *T -> T tag := inner.Type().Field(0).Tag.Get("protobuf") props = new(Properties) // Overwrite the outer props var, but not its pointee. props.Parse(tag) // Write the value in the oneof, not the oneof itself. fv = inner.Field(0) // Special case to cope with malformed messages gracefully: // If the value in the oneof is a nil pointer, don't panic // in writeAny. if fv.Kind() == reflect.Ptr && fv.IsNil() { // Use errors.New so writeAny won't render quotes. msg := errors.New("/* nil */") fv = reflect.ValueOf(&msg).Elem() } } } if err := writeName(w, props); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } if b, ok := fv.Interface().(raw); ok { if err := writeRaw(w, b.Bytes()); err != nil { return err } continue } if len(props.Enum) > 0 { if err := writeEnum(w, fv, props); err != nil { return err } } else if err := writeAny(w, fv, props); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } } // Extensions (the XXX_extensions field). pv := sv if pv.CanAddr() { pv = sv.Addr() } else { pv = reflect.New(sv.Type()) pv.Elem().Set(sv) } if pv.Type().Implements(extensionRangeType) { if err := writeExtensions(w, pv); err != nil { return err } } return nil } // writeRaw writes an uninterpreted raw message. func writeRaw(w *textWriter, b []byte) error { if err := w.WriteByte('<'); err != nil { return err } if !w.compact { if err := w.WriteByte('\n'); err != nil { return err } } w.indent() if err := writeUnknownStruct(w, b); err != nil { return err } w.unindent() if err := w.WriteByte('>'); err != nil { return err } return nil } // writeAny writes an arbitrary field. func writeAny(w *textWriter, v reflect.Value, props *Properties) error { v = reflect.Indirect(v) if props != nil && len(props.CustomType) > 0 { custom, ok := v.Interface().(Marshaler) if ok { data, err := custom.Marshal() if err != nil { return err } if err := writeString(w, string(data)); err != nil { return err } return nil } } // Floats have special cases. if v.Kind() == reflect.Float32 || v.Kind() == reflect.Float64 { x := v.Float() var b []byte switch { case math.IsInf(x, 1): b = posInf case math.IsInf(x, -1): b = negInf case math.IsNaN(x): b = nan } if b != nil { _, err := w.Write(b) return err } // Other values are handled below. } // We don't attempt to serialise every possible value type; only those // that can occur in protocol buffers. switch v.Kind() { case reflect.Slice: // Should only be a []byte; repeated fields are handled in writeStruct. if err := writeString(w, string(v.Bytes())); err != nil { return err } case reflect.String: if err := writeString(w, v.String()); err != nil { return err } case reflect.Struct: // Required/optional group/message. var bra, ket byte = '<', '>' if props != nil && props.Wire == "group" { bra, ket = '{', '}' } if err := w.WriteByte(bra); err != nil { return err } if !w.compact { if err := w.WriteByte('\n'); err != nil { return err } } w.indent() if tm, ok := v.Interface().(encoding.TextMarshaler); ok { text, err := tm.MarshalText() if err != nil { return err } if _, err = w.Write(text); err != nil { return err } } else if err := writeStruct(w, v); err != nil { return err } w.unindent() if err := w.WriteByte(ket); err != nil { return err } default: _, err := fmt.Fprint(w, v.Interface()) return err } return nil } // equivalent to C's isprint. func isprint(c byte) bool { return c >= 0x20 && c < 0x7f } // writeString writes a string in the protocol buffer text format. // It is similar to strconv.Quote except we don't use Go escape sequences, // we treat the string as a byte sequence, and we use octal escapes. // These differences are to maintain interoperability with the other // languages' implementations of the text format. func writeString(w *textWriter, s string) error { // use WriteByte here to get any needed indent if err := w.WriteByte('"'); err != nil { return err } // Loop over the bytes, not the runes. for i := 0; i < len(s); i++ { var err error // Divergence from C++: we don't escape apostrophes. // There's no need to escape them, and the C++ parser // copes with a naked apostrophe. switch c := s[i]; c { case '\n': _, err = w.w.Write(backslashN) case '\r': _, err = w.w.Write(backslashR) case '\t': _, err = w.w.Write(backslashT) case '"': _, err = w.w.Write(backslashDQ) case '\\': _, err = w.w.Write(backslashBS) default: if isprint(c) { err = w.w.WriteByte(c) } else { _, err = fmt.Fprintf(w.w, "\\%03o", c) } } if err != nil { return err } } return w.WriteByte('"') } func writeUnknownStruct(w *textWriter, data []byte) (err error) { if !w.compact { if _, err := fmt.Fprintf(w, "/* %d unknown bytes */\n", len(data)); err != nil { return err } } b := NewBuffer(data) for b.index < len(b.buf) { x, err := b.DecodeVarint() if err != nil { _, ferr := fmt.Fprintf(w, "/* %v */\n", err) return ferr } wire, tag := x&7, x>>3 if wire == WireEndGroup { w.unindent() if _, werr := w.Write(endBraceNewline); werr != nil { return werr } continue } if _, ferr := fmt.Fprint(w, tag); ferr != nil { return ferr } if wire != WireStartGroup { if err = w.WriteByte(':'); err != nil { return err } } if !w.compact || wire == WireStartGroup { if err = w.WriteByte(' '); err != nil { return err } } switch wire { case WireBytes: buf, e := b.DecodeRawBytes(false) if e == nil { _, err = fmt.Fprintf(w, "%q", buf) } else { _, err = fmt.Fprintf(w, "/* %v */", e) } case WireFixed32: x, err = b.DecodeFixed32() err = writeUnknownInt(w, x, err) case WireFixed64: x, err = b.DecodeFixed64() err = writeUnknownInt(w, x, err) case WireStartGroup: err = w.WriteByte('{') w.indent() case WireVarint: x, err = b.DecodeVarint() err = writeUnknownInt(w, x, err) default: _, err = fmt.Fprintf(w, "/* unknown wire type %d */", wire) } if err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } } return nil } func writeUnknownInt(w *textWriter, x uint64, err error) error { if err == nil { _, err = fmt.Fprint(w, x) } else { _, err = fmt.Fprintf(w, "/* %v */", err) } return err } type int32Slice []int32 func (s int32Slice) Len() int { return len(s) } func (s int32Slice) Less(i, j int) bool { return s[i] < s[j] } func (s int32Slice) Swap(i, j int) { s[i], s[j] = s[j], s[i] } // writeExtensions writes all the extensions in pv. // pv is assumed to be a pointer to a protocol message struct that is extendable. func writeExtensions(w *textWriter, pv reflect.Value) error { emap := extensionMaps[pv.Type().Elem()] e := pv.Interface().(Message) var m map[int32]Extension var mu sync.Locker if em, ok := e.(extensionsBytes); ok { eb := em.GetExtensions() var err error m, err = BytesToExtensionsMap(*eb) if err != nil { return err } mu = notLocker{} } else if _, ok := e.(extendableProto); ok { ep, _ := extendable(e) m, mu = ep.extensionsRead() if m == nil { return nil } } // Order the extensions by ID. // This isn't strictly necessary, but it will give us // canonical output, which will also make testing easier. mu.Lock() ids := make([]int32, 0, len(m)) for id := range m { ids = append(ids, id) } sort.Sort(int32Slice(ids)) mu.Unlock() for _, extNum := range ids { ext := m[extNum] var desc *ExtensionDesc if emap != nil { desc = emap[extNum] } if desc == nil { // Unknown extension. if err := writeUnknownStruct(w, ext.enc); err != nil { return err } continue } pb, err := GetExtension(e, desc) if err != nil { return fmt.Errorf("failed getting extension: %v", err) } // Repeated extensions will appear as a slice. if !desc.repeated() { if err := writeExtension(w, desc.Name, pb); err != nil { return err } } else { v := reflect.ValueOf(pb) for i := 0; i < v.Len(); i++ { if err := writeExtension(w, desc.Name, v.Index(i).Interface()); err != nil { return err } } } } return nil } func writeExtension(w *textWriter, name string, pb interface{}) error { if _, err := fmt.Fprintf(w, "[%s]:", name); err != nil { return err } if !w.compact { if err := w.WriteByte(' '); err != nil { return err } } if err := writeAny(w, reflect.ValueOf(pb), nil); err != nil { return err } if err := w.WriteByte('\n'); err != nil { return err } return nil } func (w *textWriter) writeIndent() { if !w.complete { return } remain := w.ind * 2 for remain > 0 { n := remain if n > len(spaces) { n = len(spaces) } w.w.Write(spaces[:n]) remain -= n } w.complete = false } // TextMarshaler is a configurable text format marshaler. type TextMarshaler struct { Compact bool // use compact text format (one line). } // Marshal writes a given protocol buffer in text format. // The only errors returned are from w. func (m *TextMarshaler) Marshal(w io.Writer, pb Message) error { val := reflect.ValueOf(pb) if pb == nil || val.IsNil() { w.Write([]byte("<nil>")) return nil } var bw *bufio.Writer ww, ok := w.(writer) if !ok { bw = bufio.NewWriter(w) ww = bw } aw := &textWriter{ w: ww, complete: true, compact: m.Compact, } if tm, ok := pb.(encoding.TextMarshaler); ok { text, err := tm.MarshalText() if err != nil { return err } if _, err = aw.Write(text); err != nil { return err } if bw != nil { return bw.Flush() } return nil } // Dereference the received pointer so we don't have outer < and >. v := reflect.Indirect(val) if err := writeStruct(aw, v); err != nil { return err } if bw != nil { return bw.Flush() } return nil } // Text is the same as Marshal, but returns the string directly. func (m *TextMarshaler) Text(pb Message) string { var buf bytes.Buffer m.Marshal(&buf, pb) return buf.String() } var ( defaultTextMarshaler = TextMarshaler{} compactTextMarshaler = TextMarshaler{Compact: true} ) // TODO: consider removing some of the Marshal functions below. // MarshalText writes a given protocol buffer in text format. // The only errors returned are from w. func MarshalText(w io.Writer, pb Message) error { return defaultTextMarshaler.Marshal(w, pb) } // MarshalTextString is the same as MarshalText, but returns the string directly. func MarshalTextString(pb Message) string { return defaultTextMarshaler.Text(pb) } // CompactText writes a given protocol buffer in compact text format (one line). func CompactText(w io.Writer, pb Message) error { return compactTextMarshaler.Marshal(w, pb) } // CompactTextString is the same as CompactText, but returns the string directly. func CompactTextString(pb Message) string { return compactTextMarshaler.Text(pb) }