Initial commit

vendor/github.com/emersion/go-smtp/data.go

@@ -0,0 +1,57 @@
+package smtp
+
+import (
+	"io"
+)
+
+type smtpError struct {
+	Code    int
+	Message string
+}
+
+func (err *smtpError) Error() string {
+	return err.Message
+}
+
+var ErrDataTooLarge = &smtpError{
+	Code:    552,
+	Message: "Maximum message size exceeded",
+}
+
+type dataReader struct {
+	r io.Reader
+
+	limited bool
+	n       int64 // Maximum bytes remaining
+}
+
+func newDataReader(c *Conn) io.Reader {
+	dr := &dataReader{
+		r: c.text.DotReader(),
+	}
+
+	if c.server.MaxMessageBytes > 0 {
+		dr.limited = true
+		dr.n = int64(c.server.MaxMessageBytes)
+	}
+
+	return dr
+}
+
+func (r *dataReader) Read(b []byte) (n int, err error) {
+	if r.limited {
+		if r.n <= 0 {
+			return 0, ErrDataTooLarge
+		}
+		if int64(len(b)) > r.n {
+			b = b[0:r.n]
+		}
+	}
+
+	n, err = r.r.Read(b)
+
+	if r.limited {
+		r.n -= int64(n)
+	}
+	return
+}