diff --git a/vendor/github.com/Shopify/sarama/real_decoder.go b/vendor/github.com/Shopify/sarama/real_decoder.go
new file mode 100644
index 0000000..085cbb3
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/real_decoder.go
@@ -0,0 +1,332 @@
+package sarama
+
+import (
+	"encoding/binary"
+	"math"
+)
+
+var errInvalidArrayLength = PacketDecodingError{"invalid array length"}
+var errInvalidByteSliceLength = PacketDecodingError{"invalid byteslice length"}
+var errInvalidByteSliceLengthType = PacketDecodingError{"invalid byteslice length type"}
+var errInvalidStringLength = PacketDecodingError{"invalid string length"}
+var errInvalidSubsetSize = PacketDecodingError{"invalid subset size"}
+var errVarintOverflow = PacketDecodingError{"varint overflow"}
+var errInvalidBool = PacketDecodingError{"invalid bool"}
+
+type realDecoder struct {
+	raw   []byte
+	off   int
+	stack []pushDecoder
+}
+
+// primitives
+
+func (rd *realDecoder) getInt8() (int8, error) {
+	if rd.remaining() < 1 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int8(rd.raw[rd.off])
+	rd.off++
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt16() (int16, error) {
+	if rd.remaining() < 2 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int16(binary.BigEndian.Uint16(rd.raw[rd.off:]))
+	rd.off += 2
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt32() (int32, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int32(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+	return tmp, nil
+}
+
+func (rd *realDecoder) getInt64() (int64, error) {
+	if rd.remaining() < 8 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int64(binary.BigEndian.Uint64(rd.raw[rd.off:]))
+	rd.off += 8
+	return tmp, nil
+}
+
+func (rd *realDecoder) getVarint() (int64, error) {
+	tmp, n := binary.Varint(rd.raw[rd.off:])
+	if n == 0 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	if n < 0 {
+		rd.off -= n
+		return -1, errVarintOverflow
+	}
+	rd.off += n
+	return tmp, nil
+}
+
+func (rd *realDecoder) getArrayLength() (int, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	}
+	tmp := int(int32(binary.BigEndian.Uint32(rd.raw[rd.off:])))
+	rd.off += 4
+	if tmp > rd.remaining() {
+		rd.off = len(rd.raw)
+		return -1, ErrInsufficientData
+	} else if tmp > 2*math.MaxUint16 {
+		return -1, errInvalidArrayLength
+	}
+	return tmp, nil
+}
+
+func (rd *realDecoder) getBool() (bool, error) {
+	b, err := rd.getInt8()
+	if err != nil || b == 0 {
+		return false, err
+	}
+	if b != 1 {
+		return false, errInvalidBool
+	}
+	return true, nil
+}
+
+// collections
+
+func (rd *realDecoder) getBytes() ([]byte, error) {
+	tmp, err := rd.getInt32()
+	if err != nil {
+		return nil, err
+	}
+	if tmp == -1 {
+		return nil, nil
+	}
+
+	return rd.getRawBytes(int(tmp))
+}
+
+func (rd *realDecoder) getVarintBytes() ([]byte, error) {
+	tmp, err := rd.getVarint()
+	if err != nil {
+		return nil, err
+	}
+	if tmp == -1 {
+		return nil, nil
+	}
+
+	return rd.getRawBytes(int(tmp))
+}
+
+func (rd *realDecoder) getStringLength() (int, error) {
+	length, err := rd.getInt16()
+	if err != nil {
+		return 0, err
+	}
+
+	n := int(length)
+
+	switch {
+	case n < -1:
+		return 0, errInvalidStringLength
+	case n > rd.remaining():
+		rd.off = len(rd.raw)
+		return 0, ErrInsufficientData
+	}
+
+	return n, nil
+}
+
+func (rd *realDecoder) getString() (string, error) {
+	n, err := rd.getStringLength()
+	if err != nil || n == -1 {
+		return "", err
+	}
+
+	tmpStr := string(rd.raw[rd.off : rd.off+n])
+	rd.off += n
+	return tmpStr, nil
+}
+
+func (rd *realDecoder) getNullableString() (*string, error) {
+	n, err := rd.getStringLength()
+	if err != nil || n == -1 {
+		return nil, err
+	}
+
+	tmpStr := string(rd.raw[rd.off : rd.off+n])
+	rd.off += n
+	return &tmpStr, err
+}
+
+func (rd *realDecoder) getInt32Array() ([]int32, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if rd.remaining() < 4*n {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]int32, n)
+	for i := range ret {
+		ret[i] = int32(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+		rd.off += 4
+	}
+	return ret, nil
+}
+
+func (rd *realDecoder) getInt64Array() ([]int64, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if rd.remaining() < 8*n {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]int64, n)
+	for i := range ret {
+		ret[i] = int64(binary.BigEndian.Uint64(rd.raw[rd.off:]))
+		rd.off += 8
+	}
+	return ret, nil
+}
+
+func (rd *realDecoder) getStringArray() ([]string, error) {
+	if rd.remaining() < 4 {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+	n := int(binary.BigEndian.Uint32(rd.raw[rd.off:]))
+	rd.off += 4
+
+	if n == 0 {
+		return nil, nil
+	}
+
+	if n < 0 {
+		return nil, errInvalidArrayLength
+	}
+
+	ret := make([]string, n)
+	for i := range ret {
+		str, err := rd.getString()
+		if err != nil {
+			return nil, err
+		}
+
+		ret[i] = str
+	}
+	return ret, nil
+}
+
+// subsets
+
+func (rd *realDecoder) remaining() int {
+	return len(rd.raw) - rd.off
+}
+
+func (rd *realDecoder) getSubset(length int) (packetDecoder, error) {
+	buf, err := rd.getRawBytes(length)
+	if err != nil {
+		return nil, err
+	}
+	return &realDecoder{raw: buf}, nil
+}
+
+func (rd *realDecoder) getRawBytes(length int) ([]byte, error) {
+	if length < 0 {
+		return nil, errInvalidByteSliceLength
+	} else if length > rd.remaining() {
+		rd.off = len(rd.raw)
+		return nil, ErrInsufficientData
+	}
+
+	start := rd.off
+	rd.off += length
+	return rd.raw[start:rd.off], nil
+}
+
+func (rd *realDecoder) peek(offset, length int) (packetDecoder, error) {
+	if rd.remaining() < offset+length {
+		return nil, ErrInsufficientData
+	}
+	off := rd.off + offset
+	return &realDecoder{raw: rd.raw[off : off+length]}, nil
+}
+
+func (rd *realDecoder) peekInt8(offset int) (int8, error) {
+	const byteLen = 1
+	if rd.remaining() < offset+byteLen {
+		return -1, ErrInsufficientData
+	}
+	return int8(rd.raw[rd.off+offset]), nil
+}
+
+// stacks
+
+func (rd *realDecoder) push(in pushDecoder) error {
+	in.saveOffset(rd.off)
+
+	var reserve int
+	if dpd, ok := in.(dynamicPushDecoder); ok {
+		if err := dpd.decode(rd); err != nil {
+			return err
+		}
+	} else {
+		reserve = in.reserveLength()
+		if rd.remaining() < reserve {
+			rd.off = len(rd.raw)
+			return ErrInsufficientData
+		}
+	}
+
+	rd.stack = append(rd.stack, in)
+
+	rd.off += reserve
+
+	return nil
+}
+
+func (rd *realDecoder) pop() error {
+	// this is go's ugly pop pattern (the inverse of append)
+	in := rd.stack[len(rd.stack)-1]
+	rd.stack = rd.stack[:len(rd.stack)-1]
+
+	return in.check(rd.off, rd.raw)
+}