[#205] object: Initial EC implementation

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

object/erasure_code.go

@@ -0,0 +1,121 @@
+package object
+
+import (
+	"errors"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/object"
+	refs "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/refs"
+	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
+)
+
+// ECHeader represents erasure coding header.
+type ECHeader struct {
+	parent       oid.ID
+	index        uint32
+	total        uint32
+	header       []byte
+	headerLength uint32
+}
+
+// NewECHeader constructs new erasure coding header.
+func NewECHeader(parent oid.ID, index, total uint32, header []byte, headerLength uint32) *ECHeader {
+	return &ECHeader{
+		parent:       parent,
+		index:        index,
+		total:        total,
+		header:       header,
+		headerLength: headerLength,
+	}
+}
+
+// WriteToV2 converts SDK structure to v2-api one.
+func (e *ECHeader) WriteToV2(h *object.ECHeader) {
+	var parent refs.ObjectID
+	e.parent.WriteToV2(&parent)
+	h.Parent = &parent
+	h.Index = e.index
+	h.Total = e.total
+	h.Header = e.header
+	h.HeaderLength = e.headerLength
+}
+
+// ReadFromV2 converts v2-api structure to SDK one.
+func (e *ECHeader) ReadFromV2(h *object.ECHeader) error {
+	if h == nil {
+		return nil
+	}
+	if h.Parent == nil {
+		return errors.New("empty parent")
+	}
+
+	_ = e.parent.ReadFromV2(*h.Parent)
+	e.index = h.Index
+	e.total = h.Total
+	e.header = h.Header
+	e.headerLength = h.HeaderLength
+	return nil
+}
+
+func (o *Object) ECHeader() *ECHeader {
+	ec := (*object.Object)(o).GetHeader().GetEC()
+	if ec == nil {
+		return nil
+	}
+
+	h := new(ECHeader)
+	_ = h.ReadFromV2(ec)
+	return h
+}
+
+func (o *Object) SetECHeader(ec *ECHeader) {
+	o.setHeaderField(func(h *object.Header) {
+		if ec == nil {
+			h.SetEC(nil)
+			return
+		}
+
+		v2 := new(object.ECHeader)
+		ec.WriteToV2(v2)
+		h.SetEC(v2)
+	})
+}
+
+func (e *ECHeader) Parent() oid.ID {
+	return e.parent
+}
+
+func (e *ECHeader) SetParent(id oid.ID) {
+	e.parent = id
+}
+
+func (e *ECHeader) Index() uint32 {
+	return e.index
+}
+
+func (e *ECHeader) SetIndex(i uint32) {
+	e.index = i
+}
+
+func (e *ECHeader) Total() uint32 {
+	return e.total
+}
+
+func (e *ECHeader) SetTotal(i uint32) {
+	e.total = i
+}
+
+func (e *ECHeader) Header() []byte {
+	return e.header
+}
+
+func (e *ECHeader) SetHeader(header []byte) {
+	e.header = header
+}
+
+func (e *ECHeader) HeaderLength() uint32 {
+	return e.headerLength
+}
+
+func (e *ECHeader) SetHeaderLength(l uint32) {
+	e.headerLength = l
+}