add dep management

vendor/github.com/segmentio/kafka-go/protocol.go

@@ -0,0 +1,84 @@
+package kafka
+
+import (
+	"bufio"
+	"encoding/binary"
+	"fmt"
+)
+
+type apiKey int16
+
+const (
+	produceRequest          apiKey = 0
+	fetchRequest            apiKey = 1
+	listOffsetRequest       apiKey = 2
+	metadataRequest         apiKey = 3
+	offsetCommitRequest     apiKey = 8
+	offsetFetchRequest      apiKey = 9
+	groupCoordinatorRequest apiKey = 10
+	joinGroupRequest        apiKey = 11
+	heartbeatRequest        apiKey = 12
+	leaveGroupRequest       apiKey = 13
+	syncGroupRequest        apiKey = 14
+	describeGroupsRequest   apiKey = 15
+	listGroupsRequest       apiKey = 16
+	createTopicsRequest     apiKey = 19
+	deleteTopicsRequest     apiKey = 20
+)
+
+type apiVersion int16
+
+const (
+	v0 apiVersion = 0
+	v1 apiVersion = 1
+	v2 apiVersion = 2
+	v3 apiVersion = 3
+)
+
+type requestHeader struct {
+	Size          int32
+	ApiKey        int16
+	ApiVersion    int16
+	CorrelationID int32
+	ClientID      string
+}
+
+func (h requestHeader) size() int32 {
+	return 4 + 2 + 2 + 4 + sizeofString(h.ClientID)
+}
+
+func (h requestHeader) writeTo(w *bufio.Writer) {
+	writeInt32(w, h.Size)
+	writeInt16(w, h.ApiKey)
+	writeInt16(w, h.ApiVersion)
+	writeInt32(w, h.CorrelationID)
+	writeString(w, h.ClientID)
+}
+
+type request interface {
+	size() int32
+	writeTo(*bufio.Writer)
+}
+
+func makeInt8(b []byte) int8 {
+	return int8(b[0])
+}
+
+func makeInt16(b []byte) int16 {
+	return int16(binary.BigEndian.Uint16(b))
+}
+
+func makeInt32(b []byte) int32 {
+	return int32(binary.BigEndian.Uint32(b))
+}
+
+func makeInt64(b []byte) int64 {
+	return int64(binary.BigEndian.Uint64(b))
+}
+
+func expectZeroSize(sz int, err error) error {
+	if err == nil && sz != 0 {
+		err = fmt.Errorf("reading a response left %d unread bytes", sz)
+	}
+	return err
+}