pkg: hide it by moving to _pkg.dev

The idea here is to preserve the history of `dev` branch development and its
code when merging with the `master`. Later this code could be moved into the
masters code where appropriate.

_pkg.dev/wire/payload/mheaders.go

@@ -0,0 +1,82 @@
+package payload
+
+import (
+	"errors"
+	"io"
+
+	"github.com/CityOfZion/neo-go/pkg/wire/command"
+	"github.com/CityOfZion/neo-go/pkg/wire/util"
+)
+
+// HeadersMessage represents a Header(s) Message on the neo-network
+type HeadersMessage struct {
+	Headers []*BlockBase
+
+	// Padding that is fixed to 0
+	_ uint8
+}
+
+// Users can at most request 2k header
+const (
+	maxHeadersAllowed = 2000
+)
+
+var (
+	errMaxHeaders = errors.New("Maximum amount of headers allowed is 2000")
+)
+
+//NewHeadersMessage returns a HeadersMessage Object
+func NewHeadersMessage() (*HeadersMessage, error) {
+
+	headers := &HeadersMessage{nil, 0}
+	return headers, nil
+}
+
+// AddHeader adds a header into the list of Headers.
+// Since a header is just blockbase with padding, we use BlockBase
+func (h *HeadersMessage) AddHeader(head *BlockBase) error {
+	if len(h.Headers)+1 > maxHeadersAllowed {
+		return errMaxHeaders
+	}
+	h.Headers = append(h.Headers, head)
+
+	return nil
+}
+
+// DecodePayload Implements Messager interface
+func (h *HeadersMessage) DecodePayload(r io.Reader) error {
+
+	br := &util.BinReader{R: r}
+
+	lenHeaders := br.VarUint()
+	h.Headers = make([]*BlockBase, lenHeaders)
+
+	for i := 0; i < int(lenHeaders); i++ {
+		header := &BlockBase{}
+		header.DecodePayload(br)
+		var padding uint8
+		br.Read(&padding)
+		if padding != 0 {
+			return errPadding
+		}
+		h.Headers[i] = header
+	}
+
+	return br.Err
+}
+
+// EncodePayload Implements messager interface
+func (h *HeadersMessage) EncodePayload(w io.Writer) error {
+	bw := &util.BinWriter{W: w}
+	bw.VarUint(uint64(len(h.Headers)))
+	for _, header := range h.Headers {
+		header.EncodePayload(bw)
+		bw.Write(uint8(0))
+	}
+	return bw.Err
+}
+
+// Command Implements messager interface
+func (h *HeadersMessage) Command() command.Type {
+	return command.Headers
+}