Fix GCS

Signed-off-by: Olivier Gambier <olivier@docker.com>

vendor/google.golang.org/grpc/rpc_util.go

@@ -35,9 +35,12 @@ package grpc
 
 import (
 	"bytes"
+	"compress/gzip"
 	"encoding/binary"
 	"fmt"
 	"io"
+	"io/ioutil"
+	"math"
 	"math/rand"
 	"os"
 	"time"
@@ -75,6 +78,71 @@ func (protoCodec) String() string {
 	return "proto"
 }
 
+// Compressor defines the interface gRPC uses to compress a message.
+type Compressor interface {
+	// Do compresses p into w.
+	Do(w io.Writer, p []byte) error
+	// Type returns the compression algorithm the Compressor uses.
+	Type() string
+}
+
+// NewGZIPCompressor creates a Compressor based on GZIP.
+func NewGZIPCompressor() Compressor {
+	return &gzipCompressor{}
+}
+
+type gzipCompressor struct {
+}
+
+func (c *gzipCompressor) Do(w io.Writer, p []byte) error {
+	z := gzip.NewWriter(w)
+	if _, err := z.Write(p); err != nil {
+		return err
+	}
+	return z.Close()
+}
+
+func (c *gzipCompressor) Type() string {
+	return "gzip"
+}
+
+// Decompressor defines the interface gRPC uses to decompress a message.
+type Decompressor interface {
+	// Do reads the data from r and uncompress them.
+	Do(r io.Reader) ([]byte, error)
+	// Type returns the compression algorithm the Decompressor uses.
+	Type() string
+}
+
+type gzipDecompressor struct {
+}
+
+// NewGZIPDecompressor creates a Decompressor based on GZIP.
+func NewGZIPDecompressor() Decompressor {
+	return &gzipDecompressor{}
+}
+
+func (d *gzipDecompressor) Do(r io.Reader) ([]byte, error) {
+	z, err := gzip.NewReader(r)
+	if err != nil {
+		return nil, err
+	}
+	defer z.Close()
+	return ioutil.ReadAll(z)
+}
+
+func (d *gzipDecompressor) Type() string {
+	return "gzip"
+}
+
+// callInfo contains all related configuration and information about an RPC.
+type callInfo struct {
+	failFast  bool
+	headerMD  metadata.MD
+	trailerMD metadata.MD
+	traceInfo traceInfo // in trace.go
+}
+
 // CallOption configures a Call before it starts or extracts information from
 // a Call after it completes.
 type CallOption interface {
@@ -118,51 +186,62 @@ type payloadFormat uint8
 
 const (
 	compressionNone payloadFormat = iota // no compression
-	compressionFlate
-	// More formats
+	compressionMade
 )
 
 // parser reads complelete gRPC messages from the underlying reader.
 type parser struct {
-	s io.Reader
+	// r is the underlying reader.
+	// See the comment on recvMsg for the permissible
+	// error types.
+	r io.Reader
+
+	// The header of a gRPC message. Find more detail
+	// at http://www.grpc.io/docs/guides/wire.html.
+	header [5]byte
 }
 
-// msgFixedHeader defines the header of a gRPC message (go/grpc-wirefmt).
-type msgFixedHeader struct {
-	T      payloadFormat
-	Length uint32
-}
-
-// recvMsg is to read a complete gRPC message from the stream. It is blocking if
-// the message has not been complete yet. It returns the message and its type,
-// EOF is returned with nil msg and 0 pf if the entire stream is done. Other
-// non-nil error is returned if something is wrong on reading.
+// recvMsg reads a complete gRPC message from the stream.
+//
+// It returns the message and its payload (compression/encoding)
+// format. The caller owns the returned msg memory.
+//
+// If there is an error, possible values are:
+//   * io.EOF, when no messages remain
+//   * io.ErrUnexpectedEOF
+//   * of type transport.ConnectionError
+//   * of type transport.StreamError
+// No other error values or types must be returned, which also means
+// that the underlying io.Reader must not return an incompatible
+// error.
 func (p *parser) recvMsg() (pf payloadFormat, msg []byte, err error) {
-	var hdr msgFixedHeader
-	if err := binary.Read(p.s, binary.BigEndian, &hdr); err != nil {
+	if _, err := io.ReadFull(p.r, p.header[:]); err != nil {
 		return 0, nil, err
 	}
-	if hdr.Length == 0 {
-		return hdr.T, nil, nil
+
+	pf = payloadFormat(p.header[0])
+	length := binary.BigEndian.Uint32(p.header[1:])
+
+	if length == 0 {
+		return pf, nil, nil
 	}
-	msg = make([]byte, int(hdr.Length))
-	if _, err := io.ReadFull(p.s, msg); err != nil {
+	// TODO(bradfitz,zhaoq): garbage. reuse buffer after proto decoding instead
+	// of making it for each message:
+	msg = make([]byte, int(length))
+	if _, err := io.ReadFull(p.r, msg); err != nil {
 		if err == io.EOF {
 			err = io.ErrUnexpectedEOF
 		}
 		return 0, nil, err
 	}
-	return hdr.T, msg, nil
+	return pf, msg, nil
 }
 
 // encode serializes msg and prepends the message header. If msg is nil, it
 // generates the message header of 0 message length.
-func encode(c Codec, msg interface{}, pf payloadFormat) ([]byte, error) {
-	var buf bytes.Buffer
-	// Write message fixed header.
-	buf.WriteByte(uint8(pf))
+func encode(c Codec, msg interface{}, cp Compressor, cbuf *bytes.Buffer) ([]byte, error) {
 	var b []byte
-	var length uint32
+	var length uint
 	if msg != nil {
 		var err error
 		// TODO(zhaoq): optimize to reduce memory alloc and copying.
@@ -170,27 +249,71 @@ func encode(c Codec, msg interface{}, pf payloadFormat) ([]byte, error) {
 		if err != nil {
 			return nil, err
 		}
-		length = uint32(len(b))
+		if cp != nil {
+			if err := cp.Do(cbuf, b); err != nil {
+				return nil, err
+			}
+			b = cbuf.Bytes()
+		}
+		length = uint(len(b))
 	}
-	var szHdr [4]byte
-	binary.BigEndian.PutUint32(szHdr[:], length)
-	buf.Write(szHdr[:])
-	buf.Write(b)
-	return buf.Bytes(), nil
+	if length > math.MaxUint32 {
+		return nil, Errorf(codes.InvalidArgument, "grpc: message too large (%d bytes)", length)
+	}
+
+	const (
+		payloadLen = 1
+		sizeLen    = 4
+	)
+
+	var buf = make([]byte, payloadLen+sizeLen+len(b))
+
+	// Write payload format
+	if cp == nil {
+		buf[0] = byte(compressionNone)
+	} else {
+		buf[0] = byte(compressionMade)
+	}
+	// Write length of b into buf
+	binary.BigEndian.PutUint32(buf[1:], uint32(length))
+	// Copy encoded msg to buf
+	copy(buf[5:], b)
+
+	return buf, nil
 }
 
-func recv(p *parser, c Codec, m interface{}) error {
+func checkRecvPayload(pf payloadFormat, recvCompress string, dc Decompressor) error {
+	switch pf {
+	case compressionNone:
+	case compressionMade:
+		if recvCompress == "" {
+			return transport.StreamErrorf(codes.InvalidArgument, "grpc: invalid grpc-encoding %q with compression enabled", recvCompress)
+		}
+		if dc == nil || recvCompress != dc.Type() {
+			return transport.StreamErrorf(codes.InvalidArgument, "grpc: Decompressor is not installed for grpc-encoding %q", recvCompress)
+		}
+	default:
+		return transport.StreamErrorf(codes.InvalidArgument, "grpc: received unexpected payload format %d", pf)
+	}
+	return nil
+}
+
+func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}) error {
 	pf, d, err := p.recvMsg()
 	if err != nil {
 		return err
 	}
-	switch pf {
-	case compressionNone:
-		if err := c.Unmarshal(d, m); err != nil {
-			return Errorf(codes.Internal, "grpc: %v", err)
+	if err := checkRecvPayload(pf, s.RecvCompress(), dc); err != nil {
+		return err
+	}
+	if pf == compressionMade {
+		d, err = dc.Do(bytes.NewReader(d))
+		if err != nil {
+			return transport.StreamErrorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
 		}
-	default:
-		return Errorf(codes.Internal, "gprc: compression is not supported yet.")
+	}
+	if err := c.Unmarshal(d, m); err != nil {
+		return transport.StreamErrorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
 	}
 	return nil
 }
@@ -217,6 +340,18 @@ func Code(err error) codes.Code {
 	return codes.Unknown
 }
 
+// ErrorDesc returns the error description of err if it was produced by the rpc system.
+// Otherwise, it returns err.Error() or empty string when err is nil.
+func ErrorDesc(err error) string {
+	if err == nil {
+		return ""
+	}
+	if e, ok := err.(rpcError); ok {
+		return e.desc
+	}
+	return err.Error()
+}
+
 // Errorf returns an error containing an error code and a description;
 // Errorf returns nil if c is OK.
 func Errorf(c codes.Code, format string, a ...interface{}) error {
@@ -232,6 +367,8 @@ func Errorf(c codes.Code, format string, a ...interface{}) error {
 // toRPCErr converts an error into a rpcError.
 func toRPCErr(err error) error {
 	switch e := err.(type) {
+	case rpcError:
+		return err
 	case transport.StreamError:
 		return rpcError{
 			code: e.Code,
@@ -277,30 +414,39 @@ func convertCode(err error) codes.Code {
 const (
 	// how long to wait after the first failure before retrying
 	baseDelay = 1.0 * time.Second
-	// upper bound on backoff delay
-	maxDelay      = 120 * time.Second
-	backoffFactor = 2.0 // backoff increases by this factor on each retry
-	backoffRange  = 0.4 // backoff is randomized downwards by this factor
+	// upper bound of backoff delay
+	maxDelay = 120 * time.Second
+	// backoff increases by this factor on each retry
+	backoffFactor = 1.6
+	// backoff is randomized downwards by this factor
+	backoffJitter = 0.2
 )
 
-// backoff returns a value in [0, maxDelay] that increases exponentially with
-// retries, starting from baseDelay.
-func backoff(retries int) time.Duration {
+func backoff(retries int) (t time.Duration) {
+	if retries == 0 {
+		return baseDelay
+	}
 	backoff, max := float64(baseDelay), float64(maxDelay)
 	for backoff < max && retries > 0 {
-		backoff = backoff * backoffFactor
+		backoff *= backoffFactor
 		retries--
 	}
 	if backoff > max {
 		backoff = max
 	}
-
 	// Randomize backoff delays so that if a cluster of requests start at
-	// the same time, they won't operate in lockstep.  We just subtract up
-	// to 40% so that we obey maxDelay.
-	backoff -= backoff * backoffRange * rand.Float64()
+	// the same time, they won't operate in lockstep.
+	backoff *= 1 + backoffJitter*(rand.Float64()*2-1)
 	if backoff < 0 {
 		return 0
 	}
 	return time.Duration(backoff)
 }
+
+// SupportPackageIsVersion1 is referenced from generated protocol buffer files
+// to assert that that code is compatible with this version of the grpc package.
+//
+// This constant may be renamed in the future if a change in the generated code
+// requires a synchronised update of grpc-go and protoc-gen-go. This constant
+// should not be referenced from any other code.
+const SupportPackageIsVersion1 = true