vendor.github.com.aws.smithy-go.encoding.xml.value.go Maven / Gradle / Ivy
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package xml
import (
"encoding/base64"
"fmt"
"math/big"
"strconv"
"github.com/aws/smithy-go/encoding"
)
// Value represents an XML Value type
// XML Value types: Object, Array, Map, String, Number, Boolean.
type Value struct {
w writer
scratch *[]byte
// xml start element is the associated start element for the Value
startElement StartElement
// indicates if the Value represents a flattened shape
isFlattened bool
}
// newFlattenedValue returns a Value encoder. newFlattenedValue does NOT write the start element tag
func newFlattenedValue(w writer, scratch *[]byte, startElement StartElement) Value {
return Value{
w: w,
scratch: scratch,
startElement: startElement,
}
}
// newValue writes the start element xml tag and returns a Value
func newValue(w writer, scratch *[]byte, startElement StartElement) Value {
writeStartElement(w, startElement)
return Value{w: w, scratch: scratch, startElement: startElement}
}
// writeStartElement takes in a start element and writes it.
// It handles namespace, attributes in start element.
func writeStartElement(w writer, el StartElement) error {
if el.isZero() {
return fmt.Errorf("xml start element cannot be nil")
}
w.WriteRune(leftAngleBracket)
if len(el.Name.Space) != 0 {
escapeString(w, el.Name.Space)
w.WriteRune(colon)
}
escapeString(w, el.Name.Local)
for _, attr := range el.Attr {
w.WriteRune(' ')
writeAttribute(w, &attr)
}
w.WriteRune(rightAngleBracket)
return nil
}
// writeAttribute writes an attribute from a provided Attribute
// For a namespace attribute, the attr.Name.Space must be defined as "xmlns".
// https://www.w3.org/TR/REC-xml-names/#NT-DefaultAttName
func writeAttribute(w writer, attr *Attr) {
// if local, space both are not empty
if len(attr.Name.Space) != 0 && len(attr.Name.Local) != 0 {
escapeString(w, attr.Name.Space)
w.WriteRune(colon)
}
// if prefix is empty, the default `xmlns` space should be used as prefix.
if len(attr.Name.Local) == 0 {
attr.Name.Local = attr.Name.Space
}
escapeString(w, attr.Name.Local)
w.WriteRune(equals)
w.WriteRune(quote)
escapeString(w, attr.Value)
w.WriteRune(quote)
}
// writeEndElement takes in a end element and writes it.
func writeEndElement(w writer, el EndElement) error {
if el.isZero() {
return fmt.Errorf("xml end element cannot be nil")
}
w.WriteRune(leftAngleBracket)
w.WriteRune(forwardSlash)
if len(el.Name.Space) != 0 {
escapeString(w, el.Name.Space)
w.WriteRune(colon)
}
escapeString(w, el.Name.Local)
w.WriteRune(rightAngleBracket)
return nil
}
// String encodes v as a XML string.
// It will auto close the parent xml element tag.
func (xv Value) String(v string) {
escapeString(xv.w, v)
xv.Close()
}
// Byte encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Byte(v int8) {
xv.Long(int64(v))
}
// Short encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Short(v int16) {
xv.Long(int64(v))
}
// Integer encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Integer(v int32) {
xv.Long(int64(v))
}
// Long encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Long(v int64) {
*xv.scratch = strconv.AppendInt((*xv.scratch)[:0], v, 10)
xv.w.Write(*xv.scratch)
xv.Close()
}
// Float encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Float(v float32) {
xv.float(float64(v), 32)
xv.Close()
}
// Double encodes v as a XML number.
// It will auto close the parent xml element tag.
func (xv Value) Double(v float64) {
xv.float(v, 64)
xv.Close()
}
func (xv Value) float(v float64, bits int) {
*xv.scratch = encoding.EncodeFloat((*xv.scratch)[:0], v, bits)
xv.w.Write(*xv.scratch)
}
// Boolean encodes v as a XML boolean.
// It will auto close the parent xml element tag.
func (xv Value) Boolean(v bool) {
*xv.scratch = strconv.AppendBool((*xv.scratch)[:0], v)
xv.w.Write(*xv.scratch)
xv.Close()
}
// Base64EncodeBytes writes v as a base64 value in XML string.
// It will auto close the parent xml element tag.
func (xv Value) Base64EncodeBytes(v []byte) {
encodeByteSlice(xv.w, (*xv.scratch)[:0], v)
xv.Close()
}
// BigInteger encodes v big.Int as XML value.
// It will auto close the parent xml element tag.
func (xv Value) BigInteger(v *big.Int) {
xv.w.Write([]byte(v.Text(10)))
xv.Close()
}
// BigDecimal encodes v big.Float as XML value.
// It will auto close the parent xml element tag.
func (xv Value) BigDecimal(v *big.Float) {
if i, accuracy := v.Int64(); accuracy == big.Exact {
xv.Long(i)
return
}
xv.w.Write([]byte(v.Text('e', -1)))
xv.Close()
}
// Write writes v directly to the xml document
// if escapeXMLText is set to true, write will escape text.
// It will auto close the parent xml element tag.
func (xv Value) Write(v []byte, escapeXMLText bool) {
// escape and write xml text
if escapeXMLText {
escapeText(xv.w, v)
} else {
// write xml directly
xv.w.Write(v)
}
xv.Close()
}
// MemberElement does member element encoding. It returns a Value.
// Member Element method should be used for all shapes except flattened shapes.
//
// A call to MemberElement will write nested element tags directly using the
// provided start element. The value returned by MemberElement should be closed.
func (xv Value) MemberElement(element StartElement) Value {
return newValue(xv.w, xv.scratch, element)
}
// FlattenedElement returns flattened element encoding. It returns a Value.
// This method should be used for flattened shapes.
//
// Unlike MemberElement, flattened element will NOT write element tags
// directly for the associated start element.
//
// The value returned by the FlattenedElement does not need to be closed.
func (xv Value) FlattenedElement(element StartElement) Value {
v := newFlattenedValue(xv.w, xv.scratch, element)
v.isFlattened = true
return v
}
// Array returns an array encoder. By default, the members of array are
// wrapped with `` element tag.
// If value is marked as flattened, the start element is used to wrap the members instead of
// the `` element.
func (xv Value) Array() *Array {
return newArray(xv.w, xv.scratch, arrayMemberWrapper, xv.startElement, xv.isFlattened)
}
/*
ArrayWithCustomName returns an array encoder.
It takes named start element as an argument, the named start element will used to wrap xml array entries.
for eg, `entry1 ` element tag.
If value is marked as flattened, the start element is used to wrap the entry instead of
the `` element.
*/
func (xv Value) Map() *Map {
// flattened map
if xv.isFlattened {
return newFlattenedMap(xv.w, xv.scratch, xv.startElement)
}
// un-flattened map
return newMap(xv.w, xv.scratch)
}
// encodeByteSlice is modified copy of json encoder's encodeByteSlice.
// It is used to base64 encode a byte slice.
func encodeByteSlice(w writer, scratch []byte, v []byte) {
if v == nil {
return
}
encodedLen := base64.StdEncoding.EncodedLen(len(v))
if encodedLen <= len(scratch) {
// If the encoded bytes fit in e.scratch, avoid an extra
// allocation and use the cheaper Encoding.Encode.
dst := scratch[:encodedLen]
base64.StdEncoding.Encode(dst, v)
w.Write(dst)
} else if encodedLen <= 1024 {
// The encoded bytes are short enough to allocate for, and
// Encoding.Encode is still cheaper.
dst := make([]byte, encodedLen)
base64.StdEncoding.Encode(dst, v)
w.Write(dst)
} else {
// The encoded bytes are too long to cheaply allocate, and
// Encoding.Encode is no longer noticeably cheaper.
enc := base64.NewEncoder(base64.StdEncoding, w)
enc.Write(v)
enc.Close()
}
}
// IsFlattened returns true if value is for flattened shape.
func (xv Value) IsFlattened() bool {
return xv.isFlattened
}
// Close closes the value.
func (xv Value) Close() {
writeEndElement(xv.w, xv.startElement.End())
}