diff --git a/vendor/github.com/Shopify/sarama/length_field.go b/vendor/github.com/Shopify/sarama/length_field.go
new file mode 100644
index 0000000..7d864f6
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/length_field.go
@@ -0,0 +1,99 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"sync"
+)
+
+// LengthField implements the PushEncoder and PushDecoder interfaces for calculating 4-byte lengths.
+type lengthField struct {
+	startOffset int
+	length      int32
+}
+
+var lengthFieldPool = sync.Pool{}
+
+func acquireLengthField() *lengthField {
+	val := lengthFieldPool.Get()
+	if val != nil {
+		return val.(*lengthField)
+	}
+	return &lengthField{}
+}
+
+func releaseLengthField(m *lengthField) {
+	lengthFieldPool.Put(m)
+}
+
+func (l *lengthField) decode(pd packetDecoder) error {
+	var err error
+	l.length, err = pd.getInt32()
+	if err != nil {
+		return err
+	}
+	if l.length > int32(pd.remaining()) {
+		return ErrInsufficientData
+	}
+	return nil
+}
+
+func (l *lengthField) saveOffset(in int) {
+	l.startOffset = in
+}
+
+func (l *lengthField) reserveLength() int {
+	return 4
+}
+
+func (l *lengthField) run(curOffset int, buf []byte) error {
+	binary.BigEndian.PutUint32(buf[l.startOffset:], uint32(curOffset-l.startOffset-4))
+	return nil
+}
+
+func (l *lengthField) check(curOffset int, buf []byte) error {
+	if int32(curOffset-l.startOffset-4) != l.length {
+		return PacketDecodingError{"length field invalid"}
+	}
+
+	return nil
+}
+
+type varintLengthField struct {
+	startOffset int
+	length      int64
+}
+
+func (l *varintLengthField) decode(pd packetDecoder) error {
+	var err error
+	l.length, err = pd.getVarint()
+	return err
+}
+
+func (l *varintLengthField) saveOffset(in int) {
+	l.startOffset = in
+}
+
+func (l *varintLengthField) adjustLength(currOffset int) int {
+	oldFieldSize := l.reserveLength()
+	l.length = int64(currOffset - l.startOffset - oldFieldSize)
+
+	return l.reserveLength() - oldFieldSize
+}
+
+func (l *varintLengthField) reserveLength() int {
+	var tmp [binary.MaxVarintLen64]byte
+	return binary.PutVarint(tmp[:], l.length)
+}
+
+func (l *varintLengthField) run(curOffset int, buf []byte) error {
+	binary.PutVarint(buf[l.startOffset:], l.length)
+	return nil
+}
+
+func (l *varintLengthField) check(curOffset int, buf []byte) error {
+	if int64(curOffset-l.startOffset-l.reserveLength()) != l.length {
+		return PacketDecodingError{"length field invalid"}
+	}
+
+	return nil
+}