add options

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

xml.go

@@ -2,7 +2,9 @@
 package xml // import "go.unistack.org/micro-codec-xml/v3"
 
 import (
+	"bytes"
 	"encoding/xml"
+	"io"
 
 	pb "go.unistack.org/micro-proto/v3/codec"
 	"go.unistack.org/micro/v3/codec"
@@ -19,6 +21,18 @@ const (
 	flattenTag = "flatten"
 )
 
+type unmarshalStrictKey struct{}
+
+func UnmarshalStrict(b bool) codec.Option {
+	return codec.SetOption(unmarshalStrictKey{}, b)
+}
+
+type unmarshalXML11Key struct{}
+
+func UnmarshalXML11(b bool) codec.Option {
+	return codec.SetOption(unmarshalXML11Key{}, b)
+}
+
 func (c *xmlCodec) Marshal(v interface{}, opts ...codec.Option) ([]byte, error) {
 	if v == nil {
 		return nil, nil
@@ -80,7 +94,66 @@ func (c *xmlCodec) Unmarshal(b []byte, v interface{}, opts ...codec.Option) erro
 		return nil
 	}
 
-	return xml.Unmarshal(b, v)
+	var unmarshalStrict bool
+	var unmarshalXML11 bool
+	if options.Context != nil {
+		if v, ok := options.Context.Value(unmarshalStrictKey{}).(bool); ok {
+			unmarshalStrict = v
+		}
+		if v, ok := options.Context.Value(unmarshalXML11Key{}).(bool); ok {
+			unmarshalXML11 = v
+		}
+	}
+
+	var r io.Reader
+
+	if unmarshalXML11 {
+		r = newReader(b)
+	} else {
+		r = bytes.NewReader(b)
+	}
+
+	d := xml.NewDecoder(r)
+
+	if unmarshalStrict {
+		d.Strict = true
+	}
+
+	return d.Decode(v)
+}
+
+type reader struct {
+	s        []byte
+	i        int64 // current reading index
+	prevRune int   // index of previous rune; or < 0
+	skip     bool
+}
+
+func newReader(b []byte) io.Reader {
+	return &reader{b, 0, -1, false}
+}
+
+var (
+	srcP = []byte(`version="1.1"`)
+	srcL = len(srcP)
+	dstP = []byte(`version="1.0"`)
+)
+
+func (r *reader) Read(b []byte) (n int, err error) {
+	if r.i >= int64(len(r.s)) {
+		return 0, io.EOF
+	}
+	r.prevRune = -1
+	n = copy(b, r.s[r.i:])
+	if !r.skip {
+		if idx := bytes.Index(b, srcP); idx > 0 {
+			copy(b[idx:idx+srcL], dstP)
+			r.skip = true
+		}
+	}
+
+	r.i += int64(n)
+	return
 }
 
 func (c *xmlCodec) String() string {