peridot/vendor/github.com/aws/aws-sdk-go/private/protocol/eventstream/header.go

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2022-07-07 20:11:50 +00:00
package eventstream
import (
"encoding/binary"
"fmt"
"io"
)
// Headers are a collection of EventStream header values.
type Headers []Header
// Header is a single EventStream Key Value header pair.
type Header struct {
Name string
Value Value
}
// Set associates the name with a value. If the header name already exists in
// the Headers the value will be replaced with the new one.
func (hs *Headers) Set(name string, value Value) {
var i int
for ; i < len(*hs); i++ {
if (*hs)[i].Name == name {
(*hs)[i].Value = value
return
}
}
*hs = append(*hs, Header{
Name: name, Value: value,
})
}
// Get returns the Value associated with the header. Nil is returned if the
// value does not exist.
func (hs Headers) Get(name string) Value {
for i := 0; i < len(hs); i++ {
if h := hs[i]; h.Name == name {
return h.Value
}
}
return nil
}
// Del deletes the value in the Headers if it exists.
func (hs *Headers) Del(name string) {
for i := 0; i < len(*hs); i++ {
if (*hs)[i].Name == name {
copy((*hs)[i:], (*hs)[i+1:])
(*hs) = (*hs)[:len(*hs)-1]
}
}
}
// Clone returns a deep copy of the headers
func (hs Headers) Clone() Headers {
o := make(Headers, 0, len(hs))
for _, h := range hs {
o.Set(h.Name, h.Value)
}
return o
}
func decodeHeaders(r io.Reader) (Headers, error) {
hs := Headers{}
for {
name, err := decodeHeaderName(r)
if err != nil {
if err == io.EOF {
// EOF while getting header name means no more headers
break
}
return nil, err
}
value, err := decodeHeaderValue(r)
if err != nil {
return nil, err
}
hs.Set(name, value)
}
return hs, nil
}
func decodeHeaderName(r io.Reader) (string, error) {
var n headerName
var err error
n.Len, err = decodeUint8(r)
if err != nil {
return "", err
}
name := n.Name[:n.Len]
if _, err := io.ReadFull(r, name); err != nil {
return "", err
}
return string(name), nil
}
func decodeHeaderValue(r io.Reader) (Value, error) {
var raw rawValue
typ, err := decodeUint8(r)
if err != nil {
return nil, err
}
raw.Type = valueType(typ)
var v Value
switch raw.Type {
case trueValueType:
v = BoolValue(true)
case falseValueType:
v = BoolValue(false)
case int8ValueType:
var tv Int8Value
err = tv.decode(r)
v = tv
case int16ValueType:
var tv Int16Value
err = tv.decode(r)
v = tv
case int32ValueType:
var tv Int32Value
err = tv.decode(r)
v = tv
case int64ValueType:
var tv Int64Value
err = tv.decode(r)
v = tv
case bytesValueType:
var tv BytesValue
err = tv.decode(r)
v = tv
case stringValueType:
var tv StringValue
err = tv.decode(r)
v = tv
case timestampValueType:
var tv TimestampValue
err = tv.decode(r)
v = tv
case uuidValueType:
var tv UUIDValue
err = tv.decode(r)
v = tv
default:
panic(fmt.Sprintf("unknown value type %d", raw.Type))
}
// Error could be EOF, let caller deal with it
return v, err
}
const maxHeaderNameLen = 255
type headerName struct {
Len uint8
Name [maxHeaderNameLen]byte
}
func (v headerName) encode(w io.Writer) error {
if err := binary.Write(w, binary.BigEndian, v.Len); err != nil {
return err
}
_, err := w.Write(v.Name[:v.Len])
return err
}