3 * Copyright 2014 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
35 "google.golang.org/grpc/codes"
36 "google.golang.org/grpc/credentials"
37 "google.golang.org/grpc/encoding"
38 "google.golang.org/grpc/encoding/proto"
39 "google.golang.org/grpc/internal/transport"
40 "google.golang.org/grpc/metadata"
41 "google.golang.org/grpc/peer"
42 "google.golang.org/grpc/stats"
43 "google.golang.org/grpc/status"
46 // Compressor defines the interface gRPC uses to compress a message.
48 // Deprecated: use package encoding.
49 type Compressor interface {
50 // Do compresses p into w.
51 Do(w io.Writer, p []byte) error
52 // Type returns the compression algorithm the Compressor uses.
56 type gzipCompressor struct {
60 // NewGZIPCompressor creates a Compressor based on GZIP.
62 // Deprecated: use package encoding/gzip.
63 func NewGZIPCompressor() Compressor {
64 c, _ := NewGZIPCompressorWithLevel(gzip.DefaultCompression)
68 // NewGZIPCompressorWithLevel is like NewGZIPCompressor but specifies the gzip compression level instead
69 // of assuming DefaultCompression.
71 // The error returned will be nil if the level is valid.
73 // Deprecated: use package encoding/gzip.
74 func NewGZIPCompressorWithLevel(level int) (Compressor, error) {
75 if level < gzip.DefaultCompression || level > gzip.BestCompression {
76 return nil, fmt.Errorf("grpc: invalid compression level: %d", level)
78 return &gzipCompressor{
80 New: func() interface{} {
81 w, err := gzip.NewWriterLevel(ioutil.Discard, level)
91 func (c *gzipCompressor) Do(w io.Writer, p []byte) error {
92 z := c.pool.Get().(*gzip.Writer)
95 if _, err := z.Write(p); err != nil {
101 func (c *gzipCompressor) Type() string {
105 // Decompressor defines the interface gRPC uses to decompress a message.
107 // Deprecated: use package encoding.
108 type Decompressor interface {
109 // Do reads the data from r and uncompress them.
110 Do(r io.Reader) ([]byte, error)
111 // Type returns the compression algorithm the Decompressor uses.
115 type gzipDecompressor struct {
119 // NewGZIPDecompressor creates a Decompressor based on GZIP.
121 // Deprecated: use package encoding/gzip.
122 func NewGZIPDecompressor() Decompressor {
123 return &gzipDecompressor{}
126 func (d *gzipDecompressor) Do(r io.Reader) ([]byte, error) {
128 switch maybeZ := d.pool.Get().(type) {
130 newZ, err := gzip.NewReader(r)
137 if err := z.Reset(r); err != nil {
147 return ioutil.ReadAll(z)
150 func (d *gzipDecompressor) Type() string {
154 // callInfo contains all related configuration and information about an RPC.
155 type callInfo struct {
156 compressorType string
159 maxReceiveMessageSize *int
160 maxSendMessageSize *int
161 creds credentials.PerRPCCredentials
162 contentSubtype string
164 maxRetryRPCBufferSize int
167 func defaultCallInfo() *callInfo {
170 maxRetryRPCBufferSize: 256 * 1024, // 256KB
174 // CallOption configures a Call before it starts or extracts information from
175 // a Call after it completes.
176 type CallOption interface {
177 // before is called before the call is sent to any server. If before
178 // returns a non-nil error, the RPC fails with that error.
179 before(*callInfo) error
181 // after is called after the call has completed. after cannot return an
182 // error, so any failures should be reported via output parameters.
186 // EmptyCallOption does not alter the Call configuration.
187 // It can be embedded in another structure to carry satellite data for use
189 type EmptyCallOption struct{}
191 func (EmptyCallOption) before(*callInfo) error { return nil }
192 func (EmptyCallOption) after(*callInfo) {}
194 // Header returns a CallOptions that retrieves the header metadata
196 func Header(md *metadata.MD) CallOption {
197 return HeaderCallOption{HeaderAddr: md}
200 // HeaderCallOption is a CallOption for collecting response header metadata.
201 // The metadata field will be populated *after* the RPC completes.
202 // This is an EXPERIMENTAL API.
203 type HeaderCallOption struct {
204 HeaderAddr *metadata.MD
207 func (o HeaderCallOption) before(c *callInfo) error { return nil }
208 func (o HeaderCallOption) after(c *callInfo) {
210 *o.HeaderAddr, _ = c.stream.Header()
214 // Trailer returns a CallOptions that retrieves the trailer metadata
216 func Trailer(md *metadata.MD) CallOption {
217 return TrailerCallOption{TrailerAddr: md}
220 // TrailerCallOption is a CallOption for collecting response trailer metadata.
221 // The metadata field will be populated *after* the RPC completes.
222 // This is an EXPERIMENTAL API.
223 type TrailerCallOption struct {
224 TrailerAddr *metadata.MD
227 func (o TrailerCallOption) before(c *callInfo) error { return nil }
228 func (o TrailerCallOption) after(c *callInfo) {
230 *o.TrailerAddr = c.stream.Trailer()
234 // Peer returns a CallOption that retrieves peer information for a unary RPC.
235 // The peer field will be populated *after* the RPC completes.
236 func Peer(p *peer.Peer) CallOption {
237 return PeerCallOption{PeerAddr: p}
240 // PeerCallOption is a CallOption for collecting the identity of the remote
241 // peer. The peer field will be populated *after* the RPC completes.
242 // This is an EXPERIMENTAL API.
243 type PeerCallOption struct {
247 func (o PeerCallOption) before(c *callInfo) error { return nil }
248 func (o PeerCallOption) after(c *callInfo) {
250 if x, ok := peer.FromContext(c.stream.Context()); ok {
256 // WaitForReady configures the action to take when an RPC is attempted on broken
257 // connections or unreachable servers. If waitForReady is false, the RPC will fail
258 // immediately. Otherwise, the RPC client will block the call until a
259 // connection is available (or the call is canceled or times out) and will
260 // retry the call if it fails due to a transient error. gRPC will not retry if
261 // data was written to the wire unless the server indicates it did not process
262 // the data. Please refer to
263 // https://github.com/grpc/grpc/blob/master/doc/wait-for-ready.md.
265 // By default, RPCs don't "wait for ready".
266 func WaitForReady(waitForReady bool) CallOption {
267 return FailFastCallOption{FailFast: !waitForReady}
270 // FailFast is the opposite of WaitForReady.
272 // Deprecated: use WaitForReady.
273 func FailFast(failFast bool) CallOption {
274 return FailFastCallOption{FailFast: failFast}
277 // FailFastCallOption is a CallOption for indicating whether an RPC should fail
279 // This is an EXPERIMENTAL API.
280 type FailFastCallOption struct {
284 func (o FailFastCallOption) before(c *callInfo) error {
285 c.failFast = o.FailFast
288 func (o FailFastCallOption) after(c *callInfo) {}
290 // MaxCallRecvMsgSize returns a CallOption which sets the maximum message size the client can receive.
291 func MaxCallRecvMsgSize(s int) CallOption {
292 return MaxRecvMsgSizeCallOption{MaxRecvMsgSize: s}
295 // MaxRecvMsgSizeCallOption is a CallOption that indicates the maximum message
296 // size the client can receive.
297 // This is an EXPERIMENTAL API.
298 type MaxRecvMsgSizeCallOption struct {
302 func (o MaxRecvMsgSizeCallOption) before(c *callInfo) error {
303 c.maxReceiveMessageSize = &o.MaxRecvMsgSize
306 func (o MaxRecvMsgSizeCallOption) after(c *callInfo) {}
308 // MaxCallSendMsgSize returns a CallOption which sets the maximum message size the client can send.
309 func MaxCallSendMsgSize(s int) CallOption {
310 return MaxSendMsgSizeCallOption{MaxSendMsgSize: s}
313 // MaxSendMsgSizeCallOption is a CallOption that indicates the maximum message
314 // size the client can send.
315 // This is an EXPERIMENTAL API.
316 type MaxSendMsgSizeCallOption struct {
320 func (o MaxSendMsgSizeCallOption) before(c *callInfo) error {
321 c.maxSendMessageSize = &o.MaxSendMsgSize
324 func (o MaxSendMsgSizeCallOption) after(c *callInfo) {}
326 // PerRPCCredentials returns a CallOption that sets credentials.PerRPCCredentials
328 func PerRPCCredentials(creds credentials.PerRPCCredentials) CallOption {
329 return PerRPCCredsCallOption{Creds: creds}
332 // PerRPCCredsCallOption is a CallOption that indicates the per-RPC
333 // credentials to use for the call.
334 // This is an EXPERIMENTAL API.
335 type PerRPCCredsCallOption struct {
336 Creds credentials.PerRPCCredentials
339 func (o PerRPCCredsCallOption) before(c *callInfo) error {
343 func (o PerRPCCredsCallOption) after(c *callInfo) {}
345 // UseCompressor returns a CallOption which sets the compressor used when
346 // sending the request. If WithCompressor is also set, UseCompressor has
349 // This API is EXPERIMENTAL.
350 func UseCompressor(name string) CallOption {
351 return CompressorCallOption{CompressorType: name}
354 // CompressorCallOption is a CallOption that indicates the compressor to use.
355 // This is an EXPERIMENTAL API.
356 type CompressorCallOption struct {
357 CompressorType string
360 func (o CompressorCallOption) before(c *callInfo) error {
361 c.compressorType = o.CompressorType
364 func (o CompressorCallOption) after(c *callInfo) {}
366 // CallContentSubtype returns a CallOption that will set the content-subtype
367 // for a call. For example, if content-subtype is "json", the Content-Type over
368 // the wire will be "application/grpc+json". The content-subtype is converted
369 // to lowercase before being included in Content-Type. See Content-Type on
370 // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
373 // If ForceCodec is not also used, the content-subtype will be used to look up
374 // the Codec to use in the registry controlled by RegisterCodec. See the
375 // documentation on RegisterCodec for details on registration. The lookup of
376 // content-subtype is case-insensitive. If no such Codec is found, the call
377 // will result in an error with code codes.Internal.
379 // If ForceCodec is also used, that Codec will be used for all request and
380 // response messages, with the content-subtype set to the given contentSubtype
381 // here for requests.
382 func CallContentSubtype(contentSubtype string) CallOption {
383 return ContentSubtypeCallOption{ContentSubtype: strings.ToLower(contentSubtype)}
386 // ContentSubtypeCallOption is a CallOption that indicates the content-subtype
387 // used for marshaling messages.
388 // This is an EXPERIMENTAL API.
389 type ContentSubtypeCallOption struct {
390 ContentSubtype string
393 func (o ContentSubtypeCallOption) before(c *callInfo) error {
394 c.contentSubtype = o.ContentSubtype
397 func (o ContentSubtypeCallOption) after(c *callInfo) {}
399 // ForceCodec returns a CallOption that will set the given Codec to be
400 // used for all request and response messages for a call. The result of calling
401 // String() will be used as the content-subtype in a case-insensitive manner.
403 // See Content-Type on
404 // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
405 // more details. Also see the documentation on RegisterCodec and
406 // CallContentSubtype for more details on the interaction between Codec and
409 // This function is provided for advanced users; prefer to use only
410 // CallContentSubtype to select a registered codec instead.
412 // This is an EXPERIMENTAL API.
413 func ForceCodec(codec encoding.Codec) CallOption {
414 return ForceCodecCallOption{Codec: codec}
417 // ForceCodecCallOption is a CallOption that indicates the codec used for
418 // marshaling messages.
420 // This is an EXPERIMENTAL API.
421 type ForceCodecCallOption struct {
425 func (o ForceCodecCallOption) before(c *callInfo) error {
429 func (o ForceCodecCallOption) after(c *callInfo) {}
431 // CallCustomCodec behaves like ForceCodec, but accepts a grpc.Codec instead of
432 // an encoding.Codec.
434 // Deprecated: use ForceCodec instead.
435 func CallCustomCodec(codec Codec) CallOption {
436 return CustomCodecCallOption{Codec: codec}
439 // CustomCodecCallOption is a CallOption that indicates the codec used for
440 // marshaling messages.
442 // This is an EXPERIMENTAL API.
443 type CustomCodecCallOption struct {
447 func (o CustomCodecCallOption) before(c *callInfo) error {
451 func (o CustomCodecCallOption) after(c *callInfo) {}
453 // MaxRetryRPCBufferSize returns a CallOption that limits the amount of memory
454 // used for buffering this RPC's requests for retry purposes.
456 // This API is EXPERIMENTAL.
457 func MaxRetryRPCBufferSize(bytes int) CallOption {
458 return MaxRetryRPCBufferSizeCallOption{bytes}
461 // MaxRetryRPCBufferSizeCallOption is a CallOption indicating the amount of
462 // memory to be used for caching this RPC for retry purposes.
463 // This is an EXPERIMENTAL API.
464 type MaxRetryRPCBufferSizeCallOption struct {
465 MaxRetryRPCBufferSize int
468 func (o MaxRetryRPCBufferSizeCallOption) before(c *callInfo) error {
469 c.maxRetryRPCBufferSize = o.MaxRetryRPCBufferSize
472 func (o MaxRetryRPCBufferSizeCallOption) after(c *callInfo) {}
474 // The format of the payload: compressed or not?
475 type payloadFormat uint8
478 compressionNone payloadFormat = 0 // no compression
479 compressionMade payloadFormat = 1 // compressed
482 // parser reads complete gRPC messages from the underlying reader.
484 // r is the underlying reader.
485 // See the comment on recvMsg for the permissible
489 // The header of a gRPC message. Find more detail at
490 // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
494 // recvMsg reads a complete gRPC message from the stream.
496 // It returns the message and its payload (compression/encoding)
497 // format. The caller owns the returned msg memory.
499 // If there is an error, possible values are:
500 // * io.EOF, when no messages remain
501 // * io.ErrUnexpectedEOF
502 // * of type transport.ConnectionError
503 // * an error from the status package
504 // No other error values or types must be returned, which also means
505 // that the underlying io.Reader must not return an incompatible
507 func (p *parser) recvMsg(maxReceiveMessageSize int) (pf payloadFormat, msg []byte, err error) {
508 if _, err := p.r.Read(p.header[:]); err != nil {
512 pf = payloadFormat(p.header[0])
513 length := binary.BigEndian.Uint32(p.header[1:])
518 if int64(length) > int64(maxInt) {
519 return 0, nil, status.Errorf(codes.ResourceExhausted, "grpc: received message larger than max length allowed on current machine (%d vs. %d)", length, maxInt)
521 if int(length) > maxReceiveMessageSize {
522 return 0, nil, status.Errorf(codes.ResourceExhausted, "grpc: received message larger than max (%d vs. %d)", length, maxReceiveMessageSize)
524 // TODO(bradfitz,zhaoq): garbage. reuse buffer after proto decoding instead
525 // of making it for each message:
526 msg = make([]byte, int(length))
527 if _, err := p.r.Read(msg); err != nil {
529 err = io.ErrUnexpectedEOF
536 // encode serializes msg and returns a buffer containing the message, or an
537 // error if it is too large to be transmitted by grpc. If msg is nil, it
538 // generates an empty message.
539 func encode(c baseCodec, msg interface{}) ([]byte, error) {
540 if msg == nil { // NOTE: typed nils will not be caught by this check
543 b, err := c.Marshal(msg)
545 return nil, status.Errorf(codes.Internal, "grpc: error while marshaling: %v", err.Error())
547 if uint(len(b)) > math.MaxUint32 {
548 return nil, status.Errorf(codes.ResourceExhausted, "grpc: message too large (%d bytes)", len(b))
553 // compress returns the input bytes compressed by compressor or cp. If both
554 // compressors are nil, returns nil.
556 // TODO(dfawley): eliminate cp parameter by wrapping Compressor in an encoding.Compressor.
557 func compress(in []byte, cp Compressor, compressor encoding.Compressor) ([]byte, error) {
558 if compressor == nil && cp == nil {
561 wrapErr := func(err error) error {
562 return status.Errorf(codes.Internal, "grpc: error while compressing: %v", err.Error())
564 cbuf := &bytes.Buffer{}
565 if compressor != nil {
566 z, err := compressor.Compress(cbuf)
568 return nil, wrapErr(err)
570 if _, err := z.Write(in); err != nil {
571 return nil, wrapErr(err)
573 if err := z.Close(); err != nil {
574 return nil, wrapErr(err)
577 if err := cp.Do(cbuf, in); err != nil {
578 return nil, wrapErr(err)
581 return cbuf.Bytes(), nil
587 headerLen = payloadLen + sizeLen
590 // msgHeader returns a 5-byte header for the message being transmitted and the
591 // payload, which is compData if non-nil or data otherwise.
592 func msgHeader(data, compData []byte) (hdr []byte, payload []byte) {
593 hdr = make([]byte, headerLen)
595 hdr[0] = byte(compressionMade)
598 hdr[0] = byte(compressionNone)
601 // Write length of payload into buf
602 binary.BigEndian.PutUint32(hdr[payloadLen:], uint32(len(data)))
606 func outPayload(client bool, msg interface{}, data, payload []byte, t time.Time) *stats.OutPayload {
607 return &stats.OutPayload{
612 WireLength: len(payload) + headerLen,
617 func checkRecvPayload(pf payloadFormat, recvCompress string, haveCompressor bool) *status.Status {
619 case compressionNone:
620 case compressionMade:
621 if recvCompress == "" || recvCompress == encoding.Identity {
622 return status.New(codes.Internal, "grpc: compressed flag set with identity or empty encoding")
625 return status.Newf(codes.Unimplemented, "grpc: Decompressor is not installed for grpc-encoding %q", recvCompress)
628 return status.Newf(codes.Internal, "grpc: received unexpected payload format %d", pf)
633 type payloadInfo struct {
634 wireLength int // The compressed length got from wire.
635 uncompressedBytes []byte
638 func recvAndDecompress(p *parser, s *transport.Stream, dc Decompressor, maxReceiveMessageSize int, payInfo *payloadInfo, compressor encoding.Compressor) ([]byte, error) {
639 pf, d, err := p.recvMsg(maxReceiveMessageSize)
644 payInfo.wireLength = len(d)
647 if st := checkRecvPayload(pf, s.RecvCompress(), compressor != nil || dc != nil); st != nil {
651 if pf == compressionMade {
652 // To match legacy behavior, if the decompressor is set by WithDecompressor or RPCDecompressor,
653 // use this decompressor as the default.
655 d, err = dc.Do(bytes.NewReader(d))
657 return nil, status.Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
660 dcReader, err := compressor.Decompress(bytes.NewReader(d))
662 return nil, status.Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
664 // Read from LimitReader with limit max+1. So if the underlying
665 // reader is over limit, the result will be bigger than max.
666 d, err = ioutil.ReadAll(io.LimitReader(dcReader, int64(maxReceiveMessageSize)+1))
668 return nil, status.Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
672 if len(d) > maxReceiveMessageSize {
673 // TODO: Revisit the error code. Currently keep it consistent with java
675 return nil, status.Errorf(codes.ResourceExhausted, "grpc: received message larger than max (%d vs. %d)", len(d), maxReceiveMessageSize)
680 // For the two compressor parameters, both should not be set, but if they are,
681 // dc takes precedence over compressor.
682 // TODO(dfawley): wrap the old compressor/decompressor using the new API?
683 func recv(p *parser, c baseCodec, s *transport.Stream, dc Decompressor, m interface{}, maxReceiveMessageSize int, payInfo *payloadInfo, compressor encoding.Compressor) error {
684 d, err := recvAndDecompress(p, s, dc, maxReceiveMessageSize, payInfo, compressor)
688 if err := c.Unmarshal(d, m); err != nil {
689 return status.Errorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
692 payInfo.uncompressedBytes = d
697 type rpcInfo struct {
701 type rpcInfoContextKey struct{}
703 func newContextWithRPCInfo(ctx context.Context, failfast bool) context.Context {
704 return context.WithValue(ctx, rpcInfoContextKey{}, &rpcInfo{failfast: failfast})
707 func rpcInfoFromContext(ctx context.Context) (s *rpcInfo, ok bool) {
708 s, ok = ctx.Value(rpcInfoContextKey{}).(*rpcInfo)
712 // Code returns the error code for err if it was produced by the rpc system.
713 // Otherwise, it returns codes.Unknown.
715 // Deprecated: use status.Code instead.
716 func Code(err error) codes.Code {
717 return status.Code(err)
720 // ErrorDesc returns the error description of err if it was produced by the rpc system.
721 // Otherwise, it returns err.Error() or empty string when err is nil.
723 // Deprecated: use status.Convert and Message method instead.
724 func ErrorDesc(err error) string {
725 return status.Convert(err).Message()
728 // Errorf returns an error containing an error code and a description;
729 // Errorf returns nil if c is OK.
731 // Deprecated: use status.Errorf instead.
732 func Errorf(c codes.Code, format string, a ...interface{}) error {
733 return status.Errorf(c, format, a...)
736 // toRPCErr converts an error into an error from the status package.
737 func toRPCErr(err error) error {
738 if err == nil || err == io.EOF {
741 if err == io.ErrUnexpectedEOF {
742 return status.Error(codes.Internal, err.Error())
744 if _, ok := status.FromError(err); ok {
747 switch e := err.(type) {
748 case transport.ConnectionError:
749 return status.Error(codes.Unavailable, e.Desc)
752 case context.DeadlineExceeded:
753 return status.Error(codes.DeadlineExceeded, err.Error())
754 case context.Canceled:
755 return status.Error(codes.Canceled, err.Error())
758 return status.Error(codes.Unknown, err.Error())
761 // setCallInfoCodec should only be called after CallOptions have been applied.
762 func setCallInfoCodec(c *callInfo) error {
764 // codec was already set by a CallOption; use it.
768 if c.contentSubtype == "" {
769 // No codec specified in CallOptions; use proto by default.
770 c.codec = encoding.GetCodec(proto.Name)
774 // c.contentSubtype is already lowercased in CallContentSubtype
775 c.codec = encoding.GetCodec(c.contentSubtype)
777 return status.Errorf(codes.Internal, "no codec registered for content-subtype %s", c.contentSubtype)
782 // parseDialTarget returns the network and address to pass to dialer
783 func parseDialTarget(target string) (net string, addr string) {
786 m1 := strings.Index(target, ":")
787 m2 := strings.Index(target, ":/")
789 // handle unix:addr which will fail with url.Parse
790 if m1 >= 0 && m2 < 0 {
791 if n := target[0:m1]; n == "unix" {
798 t, err := url.Parse(target)
804 if scheme == "unix" {
816 // channelzData is used to store channelz related data for ClientConn, addrConn and Server.
817 // These fields cannot be embedded in the original structs (e.g. ClientConn), since to do atomic
818 // operation on int64 variable on 32-bit machine, user is responsible to enforce memory alignment.
819 // Here, by grouping those int64 fields inside a struct, we are enforcing the alignment.
820 type channelzData struct {
824 // lastCallStartedTime stores the timestamp that last call starts. It is of int64 type instead of
825 // time.Time since it's more costly to atomically update time.Time variable than int64 variable.
826 lastCallStartedTime int64
829 // The SupportPackageIsVersion variables are referenced from generated protocol
830 // buffer files to ensure compatibility with the gRPC version used. The latest
831 // support package version is 5.
833 // Older versions are kept for compatibility. They may be removed if
834 // compatibility cannot be maintained.
836 // These constants should not be referenced from any other code.
838 SupportPackageIsVersion3 = true
839 SupportPackageIsVersion4 = true
840 SupportPackageIsVersion5 = true
843 const grpcUA = "grpc-go/" + Version