Files
crockery/vendor/github.com/emersion/go-message/multipart.go
2018-06-28 01:09:56 +01:00

111 lines
1.9 KiB
Go

package message
import (
"io"
"mime/multipart"
)
// MultipartReader is an iterator over parts in a MIME multipart body.
type MultipartReader interface {
io.Closer
// NextPart returns the next part in the multipart or an error. When there are
// no more parts, the error io.EOF is returned.
//
// Entity.Body must be read completely before the next call to NextPart,
// otherwise it will be discarded.
NextPart() (*Entity, error)
}
type multipartReader struct {
r *multipart.Reader
}
// NextPart implements MultipartReader.
func (r *multipartReader) NextPart() (*Entity, error) {
p, err := r.r.NextPart()
if err != nil {
return nil, err
}
return New(Header(p.Header), p)
}
// Close implements io.Closer.
func (r *multipartReader) Close() error {
return nil
}
type multipartBody struct {
header Header
parts []*Entity
r *io.PipeReader
w *Writer
i int
}
// Read implements io.Reader.
func (m *multipartBody) Read(p []byte) (n int, err error) {
if m.r == nil {
r, w := io.Pipe()
m.r = r
m.w = newWriter(w, m.header)
// Prevent calls to NextPart to succeed
m.i = len(m.parts)
go func() {
if err := m.writeBodyTo(m.w); err != nil {
w.CloseWithError(err)
return
}
if err := m.w.Close(); err != nil {
w.CloseWithError(err)
return
}
w.Close()
}()
}
return m.r.Read(p)
}
// Close implements io.Closer.
func (m *multipartBody) Close() error {
if m.r != nil {
m.r.Close()
}
return nil
}
// NextPart implements MultipartReader.
func (m *multipartBody) NextPart() (*Entity, error) {
if m.i >= len(m.parts) {
return nil, io.EOF
}
part := m.parts[m.i]
m.i++
return part, nil
}
func (m *multipartBody) writeBodyTo(w *Writer) error {
for _, p := range m.parts {
pw, err := w.CreatePart(p.Header)
if err != nil {
return err
}
if err := p.writeBodyTo(pw); err != nil {
return err
}
if err := pw.Close(); err != nil {
return err
}
}
return nil
}