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Diffstat (limited to 'src/pkg/encoding/xml/marshal.go')
-rw-r--r--src/pkg/encoding/xml/marshal.go380
1 files changed, 380 insertions, 0 deletions
diff --git a/src/pkg/encoding/xml/marshal.go b/src/pkg/encoding/xml/marshal.go
new file mode 100644
index 000000000..7a05a1bb1
--- /dev/null
+++ b/src/pkg/encoding/xml/marshal.go
@@ -0,0 +1,380 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xml
+
+import (
+ "bufio"
+ "bytes"
+ "fmt"
+ "io"
+ "reflect"
+ "strconv"
+ "strings"
+)
+
+const (
+ // A generic XML header suitable for use with the output of Marshal.
+ // This is not automatically added to any output of this package,
+ // it is provided as a convenience.
+ Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"
+)
+
+// Marshal returns the XML encoding of v.
+//
+// Marshal handles an array or slice by marshalling each of the elements.
+// Marshal handles a pointer by marshalling the value it points at or, if the
+// pointer is nil, by writing nothing. Marshal handles an interface value by
+// marshalling the value it contains or, if the interface value is nil, by
+// writing nothing. Marshal handles all other data by writing one or more XML
+// elements containing the data.
+//
+// The name for the XML elements is taken from, in order of preference:
+// - the tag on the XMLName field, if the data is a struct
+// - the value of the XMLName field of type xml.Name
+// - the tag of the struct field used to obtain the data
+// - the name of the struct field used to obtain the data
+// - the name of the marshalled type
+//
+// The XML element for a struct contains marshalled elements for each of the
+// exported fields of the struct, with these exceptions:
+// - the XMLName field, described above, is omitted.
+// - a field with tag "-" is omitted.
+// - a field with tag "name,attr" becomes an attribute with
+// the given name in the XML element.
+// - a field with tag ",attr" becomes an attribute with the
+// field name in the in the XML element.
+// - a field with tag ",chardata" is written as character data,
+// not as an XML element.
+// - a field with tag ",innerxml" is written verbatim, not subject
+// to the usual marshalling procedure.
+// - a field with tag ",comment" is written as an XML comment, not
+// subject to the usual marshalling procedure. It must not contain
+// the "--" string within it.
+//
+// If a field uses a tag "a>b>c", then the element c will be nested inside
+// parent elements a and b. Fields that appear next to each other that name
+// the same parent will be enclosed in one XML element. For example:
+//
+// type Result struct {
+// XMLName xml.Name `xml:"result"`
+// Id int `xml:"id,attr"`
+// FirstName string `xml:"person>name>first"`
+// LastName string `xml:"person>name>last"`
+// Age int `xml:"person>age"`
+// }
+//
+// xml.Marshal(&Result{Id: 13, FirstName: "John", LastName: "Doe", Age: 42})
+//
+// would be marshalled as:
+//
+// <result>
+// <person id="13">
+// <name>
+// <first>John</first>
+// <last>Doe</last>
+// </name>
+// <age>42</age>
+// </person>
+// </result>
+//
+// Marshal will return an error if asked to marshal a channel, function, or map.
+func Marshal(v interface{}) ([]byte, error) {
+ var b bytes.Buffer
+ if err := NewEncoder(&b).Encode(v); err != nil {
+ return nil, err
+ }
+ return b.Bytes(), nil
+}
+
+// An Encoder writes XML data to an output stream.
+type Encoder struct {
+ printer
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+ return &Encoder{printer{bufio.NewWriter(w)}}
+}
+
+// Encode writes the XML encoding of v to the stream.
+//
+// See the documentation for Marshal for details about the conversion
+// of Go values to XML.
+func (enc *Encoder) Encode(v interface{}) error {
+ err := enc.marshalValue(reflect.ValueOf(v), nil)
+ enc.Flush()
+ return err
+}
+
+type printer struct {
+ *bufio.Writer
+}
+
+func (p *printer) marshalValue(val reflect.Value, finfo *fieldInfo) error {
+ if !val.IsValid() {
+ return nil
+ }
+
+ kind := val.Kind()
+ typ := val.Type()
+
+ // Drill into pointers/interfaces
+ if kind == reflect.Ptr || kind == reflect.Interface {
+ if val.IsNil() {
+ return nil
+ }
+ return p.marshalValue(val.Elem(), finfo)
+ }
+
+ // Slices and arrays iterate over the elements. They do not have an enclosing tag.
+ if (kind == reflect.Slice || kind == reflect.Array) && typ.Elem().Kind() != reflect.Uint8 {
+ for i, n := 0, val.Len(); i < n; i++ {
+ if err := p.marshalValue(val.Index(i), finfo); err != nil {
+ return err
+ }
+ }
+ return nil
+ }
+
+ tinfo, err := getTypeInfo(typ)
+ if err != nil {
+ return err
+ }
+
+ // Precedence for the XML element name is:
+ // 1. XMLName field in underlying struct;
+ // 2. field name/tag in the struct field; and
+ // 3. type name
+ var xmlns, name string
+ if tinfo.xmlname != nil {
+ xmlname := tinfo.xmlname
+ if xmlname.name != "" {
+ xmlns, name = xmlname.xmlns, xmlname.name
+ } else if v, ok := val.FieldByIndex(xmlname.idx).Interface().(Name); ok && v.Local != "" {
+ xmlns, name = v.Space, v.Local
+ }
+ }
+ if name == "" && finfo != nil {
+ xmlns, name = finfo.xmlns, finfo.name
+ }
+ if name == "" {
+ name = typ.Name()
+ if name == "" {
+ return &UnsupportedTypeError{typ}
+ }
+ }
+
+ p.WriteByte('<')
+ p.WriteString(name)
+
+ if xmlns != "" {
+ p.WriteString(` xmlns="`)
+ // TODO: EscapeString, to avoid the allocation.
+ Escape(p, []byte(xmlns))
+ p.WriteByte('"')
+ }
+
+ // Attributes
+ for i := range tinfo.fields {
+ finfo := &tinfo.fields[i]
+ if finfo.flags&fAttr == 0 {
+ continue
+ }
+ fv := val.FieldByIndex(finfo.idx)
+ switch fv.Kind() {
+ case reflect.String, reflect.Array, reflect.Slice:
+ // TODO: Should we really do this once ,omitempty is in?
+ if fv.Len() == 0 {
+ continue
+ }
+ }
+ p.WriteByte(' ')
+ p.WriteString(finfo.name)
+ p.WriteString(`="`)
+ if err := p.marshalSimple(fv.Type(), fv); err != nil {
+ return err
+ }
+ p.WriteByte('"')
+ }
+ p.WriteByte('>')
+
+ if val.Kind() == reflect.Struct {
+ err = p.marshalStruct(tinfo, val)
+ } else {
+ err = p.marshalSimple(typ, val)
+ }
+ if err != nil {
+ return err
+ }
+
+ p.WriteByte('<')
+ p.WriteByte('/')
+ p.WriteString(name)
+ p.WriteByte('>')
+
+ return nil
+}
+
+func (p *printer) marshalSimple(typ reflect.Type, val reflect.Value) error {
+ switch val.Kind() {
+ case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+ p.WriteString(strconv.FormatInt(val.Int(), 10))
+ case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+ p.WriteString(strconv.FormatUint(val.Uint(), 10))
+ case reflect.Float32, reflect.Float64:
+ p.WriteString(strconv.FormatFloat(val.Float(), 'g', -1, 64))
+ case reflect.String:
+ // TODO: Add EscapeString.
+ Escape(p, []byte(val.String()))
+ case reflect.Bool:
+ p.WriteString(strconv.FormatBool(val.Bool()))
+ case reflect.Array:
+ // will be [...]byte
+ bytes := make([]byte, val.Len())
+ for i := range bytes {
+ bytes[i] = val.Index(i).Interface().(byte)
+ }
+ Escape(p, bytes)
+ case reflect.Slice:
+ // will be []byte
+ Escape(p, val.Bytes())
+ default:
+ return &UnsupportedTypeError{typ}
+ }
+ return nil
+}
+
+var ddBytes = []byte("--")
+
+func (p *printer) marshalStruct(tinfo *typeInfo, val reflect.Value) error {
+ s := parentStack{printer: p}
+ for i := range tinfo.fields {
+ finfo := &tinfo.fields[i]
+ if finfo.flags&(fAttr|fAny) != 0 {
+ continue
+ }
+ vf := val.FieldByIndex(finfo.idx)
+ switch finfo.flags & fMode {
+ case fCharData:
+ switch vf.Kind() {
+ case reflect.String:
+ Escape(p, []byte(vf.String()))
+ case reflect.Slice:
+ if elem, ok := vf.Interface().([]byte); ok {
+ Escape(p, elem)
+ }
+ }
+ continue
+
+ case fComment:
+ k := vf.Kind()
+ if !(k == reflect.String || k == reflect.Slice && vf.Type().Elem().Kind() == reflect.Uint8) {
+ return fmt.Errorf("xml: bad type for comment field of %s", val.Type())
+ }
+ if vf.Len() == 0 {
+ continue
+ }
+ p.WriteString("<!--")
+ dashDash := false
+ dashLast := false
+ switch k {
+ case reflect.String:
+ s := vf.String()
+ dashDash = strings.Index(s, "--") >= 0
+ dashLast = s[len(s)-1] == '-'
+ if !dashDash {
+ p.WriteString(s)
+ }
+ case reflect.Slice:
+ b := vf.Bytes()
+ dashDash = bytes.Index(b, ddBytes) >= 0
+ dashLast = b[len(b)-1] == '-'
+ if !dashDash {
+ p.Write(b)
+ }
+ default:
+ panic("can't happen")
+ }
+ if dashDash {
+ return fmt.Errorf(`xml: comments must not contain "--"`)
+ }
+ if dashLast {
+ // "--->" is invalid grammar. Make it "- -->"
+ p.WriteByte(' ')
+ }
+ p.WriteString("-->")
+ continue
+
+ case fInnerXml:
+ iface := vf.Interface()
+ switch raw := iface.(type) {
+ case []byte:
+ p.Write(raw)
+ continue
+ case string:
+ p.WriteString(raw)
+ continue
+ }
+
+ case fElement:
+ s.trim(finfo.parents)
+ if len(finfo.parents) > len(s.stack) {
+ if vf.Kind() != reflect.Ptr && vf.Kind() != reflect.Interface || !vf.IsNil() {
+ s.push(finfo.parents[len(s.stack):])
+ }
+ }
+ }
+ if err := p.marshalValue(vf, finfo); err != nil {
+ return err
+ }
+ }
+ s.trim(nil)
+ return nil
+}
+
+type parentStack struct {
+ *printer
+ stack []string
+}
+
+// trim updates the XML context to match the longest common prefix of the stack
+// and the given parents. A closing tag will be written for every parent
+// popped. Passing a zero slice or nil will close all the elements.
+func (s *parentStack) trim(parents []string) {
+ split := 0
+ for ; split < len(parents) && split < len(s.stack); split++ {
+ if parents[split] != s.stack[split] {
+ break
+ }
+ }
+
+ for i := len(s.stack) - 1; i >= split; i-- {
+ s.WriteString("</")
+ s.WriteString(s.stack[i])
+ s.WriteByte('>')
+ }
+
+ s.stack = parents[:split]
+}
+
+// push adds parent elements to the stack and writes open tags.
+func (s *parentStack) push(parents []string) {
+ for i := 0; i < len(parents); i++ {
+ s.WriteString("<")
+ s.WriteString(parents[i])
+ s.WriteByte('>')
+ }
+ s.stack = append(s.stack, parents...)
+}
+
+// A MarshalXMLError is returned when Marshal encounters a type
+// that cannot be converted into XML.
+type UnsupportedTypeError struct {
+ Type reflect.Type
+}
+
+func (e *UnsupportedTypeError) Error() string {
+ return "xml: unsupported type: " + e.Type.String()
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-21 19:51:20 +0000