/*
*
* Copyright 2014, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
package grpc
import (
"bytes"
"compress/gzip"
"encoding/binary"
"io"
"io/ioutil"
"math"
"os"
"time"
"golang.org/x/net/context"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/peer"
"google.golang.org/grpc/stats"
"google.golang.org/grpc/status"
"google.golang.org/grpc/transport"
)
// 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
peer *peer.Peer
traceInfo traceInfo // in trace.go
}
var defaultCallInfo = callInfo{failFast: true}
// CallOption configures a Call before it starts or extracts information from
// a Call after it completes.
type CallOption interface {
// before is called before the call is sent to any server. If before
// returns a non-nil error, the RPC fails with that error.
before(*callInfo) error
// after is called after the call has completed. after cannot return an
// error, so any failures should be reported via output parameters.
after(*callInfo)
}
type beforeCall func(c *callInfo) error
func (o beforeCall) before(c *callInfo) error { return o(c) }
func (o beforeCall) after(c *callInfo) {}
type afterCall func(c *callInfo)
func (o afterCall) before(c *callInfo) error { return nil }
func (o afterCall) after(c *callInfo) { o(c) }
// Header returns a CallOptions that retrieves the header metadata
// for a unary RPC.
func Header(md *metadata.MD) CallOption {
return afterCall(func(c *callInfo) {
*md = c.headerMD
})
}
// Trailer returns a CallOptions that retrieves the trailer metadata
// for a unary RPC.
func Trailer(md *metadata.MD) CallOption {
return afterCall(func(c *callInfo) {
*md = c.trailerMD
})
}
// Peer returns a CallOption that retrieves peer information for a
// unary RPC.
func Peer(peer *peer.Peer) CallOption {
return afterCall(func(c *callInfo) {
if c.peer != nil {
*peer = *c.peer
}
})
}
// FailFast configures the action to take when an RPC is attempted on broken
// connections or unreachable servers. If failfast is true, the RPC will fail
// immediately. Otherwise, the RPC client will block the call until a
// connection is available (or the call is canceled or times out) and will retry
// the call if it fails due to a transient error. Please refer to
// https://github.com/grpc/grpc/blob/master/doc/fail_fast.md. Note: failFast is default to true.
func FailFast(failFast bool) CallOption {
return beforeCall(func(c *callInfo) error {
c.failFast = failFast
return nil
})
}
// The format of the payload: compressed or not?
type payloadFormat uint8
const (
compressionNone payloadFormat = iota // no compression
compressionMade
)
// parser reads complete gRPC messages from the underlying reader.
type parser struct {
// 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
}
// 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(maxMsgSize int) (pf payloadFormat, msg []byte, err error) {
if _, err := io.ReadFull(p.r, p.header[:]); err != nil {
return 0, nil, err
}
pf = payloadFormat(p.header[0])
length := binary.BigEndian.Uint32(p.header[1:])
if length == 0 {
return pf, nil, nil
}
if length > uint32(maxMsgSize) {
return 0, nil, Errorf(codes.Internal, "grpc: received message length %d exceeding the max size %d", length, maxMsgSize)
}
// 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 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{}, cp Compressor, cbuf *bytes.Buffer, outPayload *stats.OutPayload) ([]byte, error) {
var (
b []byte
length uint
)
if msg != nil {
var err error
// TODO(zhaoq): optimize to reduce memory alloc and copying.
b, err = c.Marshal(msg)
if err != nil {
return nil, err
}
if outPayload != nil {
outPayload.Payload = msg
// TODO truncate large payload.
outPayload.Data = b
outPayload.Length = len(b)
}
if cp != nil {
if err := cp.Do(cbuf, b); err != nil {
return nil, err
}
b = cbuf.Bytes()
}
length = uint(len(b))
}
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)
if outPayload != nil {
outPayload.WireLength = len(buf)
}
return buf, nil
}
func checkRecvPayload(pf payloadFormat, recvCompress string, dc Decompressor) error {
switch pf {
case compressionNone:
case compressionMade:
if dc == nil || recvCompress != dc.Type() {
return Errorf(codes.Unimplemented, "grpc: Decompressor is not installed for grpc-encoding %q", recvCompress)
}
default:
return Errorf(codes.Internal, "grpc: received unexpected payload format %d", pf)
}
return nil
}
func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}, maxMsgSize int, inPayload *stats.InPayload) error {
pf, d, err := p.recvMsg(maxMsgSize)
if err != nil {
return err
}
if inPayload != nil {
inPayload.WireLength = len(d)
}
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 Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
}
}
if len(d) > maxMsgSize {
// TODO: Revisit the error code. Currently keep it consistent with java
// implementation.
return Errorf(codes.Internal, "grpc: received a message of %d bytes exceeding %d limit", len(d), maxMsgSize)
}
if err := c.Unmarshal(d, m); err != nil {
return Errorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
}
if inPayload != nil {
inPayload.RecvTime = time.Now()
inPayload.Payload = m
// TODO truncate large payload.
inPayload.Data = d
inPayload.Length = len(d)
}
return nil
}
type rpcInfo struct {
bytesSent bool
bytesReceived bool
}
type rpcInfoContextKey struct{}
func newContextWithRPCInfo(ctx context.Context) context.Context {
return context.WithValue(ctx, rpcInfoContextKey{}, &rpcInfo{})
}
func rpcInfoFromContext(ctx context.Context) (s *rpcInfo, ok bool) {
s, ok = ctx.Value(rpcInfoContextKey{}).(*rpcInfo)
return
}
func updateRPCInfoInContext(ctx context.Context, s rpcInfo) {
if ss, ok := rpcInfoFromContext(ctx); ok {
*ss = s
}
return
}
// Code returns the error code for err if it was produced by the rpc system.
// Otherwise, it returns codes.Unknown.
//
// Deprecated; use status.FromError and Code method instead.
func Code(err error) codes.Code {
if s, ok := status.FromError(err); ok {
return s.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.
//
// Deprecated; use status.FromError and Message method instead.
func ErrorDesc(err error) string {
if s, ok := status.FromError(err); ok {
return s.Message()
}
return err.Error()
}
// Errorf returns an error containing an error code and a description;
// Errorf returns nil if c is OK.
//
// Deprecated; use status.Errorf instead.
func Errorf(c codes.Code, format string, a ...interface{}) error {
return status.Errorf(c, format, a...)
}
// toRPCErr converts an error into an error from the status package.
func toRPCErr(err error) error {
if _, ok := status.FromError(err); ok {
return err
}
switch e := err.(type) {
case transport.StreamError:
return status.Error(e.Code, e.Desc)
case transport.ConnectionError:
return status.Error(codes.Internal, e.Desc)
default:
switch err {
case context.DeadlineExceeded:
return status.Error(codes.DeadlineExceeded, err.Error())
case context.Canceled:
return status.Error(codes.Canceled, err.Error())
case ErrClientConnClosing:
return status.Error(codes.FailedPrecondition, err.Error())
}
}
return status.Error(codes.Unknown, err.Error())
}
// convertCode converts a standard Go error into its canonical code. Note that
// this is only used to translate the error returned by the server applications.
func convertCode(err error) codes.Code {
switch err {
case nil:
return codes.OK
case io.EOF:
return codes.OutOfRange
case io.ErrClosedPipe, io.ErrNoProgress, io.ErrShortBuffer, io.ErrShortWrite, io.ErrUnexpectedEOF:
return codes.FailedPrecondition
case os.ErrInvalid:
return codes.InvalidArgument
case context.Canceled:
return codes.Canceled
case context.DeadlineExceeded:
return codes.DeadlineExceeded
}
switch {
case os.IsExist(err):
return codes.AlreadyExists
case os.IsNotExist(err):
return codes.NotFound
case os.IsPermission(err):
return codes.PermissionDenied
}
return codes.Unknown
}
// MethodConfig defines the configuration recommended by the service providers for a
// particular method.
// This is EXPERIMENTAL and subject to change.
type MethodConfig struct {
// WaitForReady indicates whether RPCs sent to this method should wait until
// the connection is ready by default (!failfast). The value specified via the
// gRPC client API will override the value set here.
WaitForReady bool
// Timeout is the default timeout for RPCs sent to this method. The actual
// deadline used will be the minimum of the value specified here and the value
// set by the application via the gRPC client API. If either one is not set,
// then the other will be used. If neither is set, then the RPC has no deadline.
Timeout time.Duration
// MaxReqSize is the maximum allowed payload size for an individual request in a
// stream (client->server) in bytes. The size which is measured is the serialized
// payload after per-message compression (but before stream compression) in bytes.
// The actual value used is the minumum of the value specified here and the value set
// by the application via the gRPC client API. If either one is not set, then the other
// will be used. If neither is set, then the built-in default is used.
// TODO: support this.
MaxReqSize uint32
// MaxRespSize is the maximum allowed payload size for an individual response in a
// stream (server->client) in bytes.
// TODO: support this.
MaxRespSize uint32
}
// ServiceConfig is provided by the service provider and contains parameters for how
// clients that connect to the service should behave.
// This is EXPERIMENTAL and subject to change.
type ServiceConfig struct {
// LB is the load balancer the service providers recommends. The balancer specified
// via grpc.WithBalancer will override this.
LB Balancer
// Methods contains a map for the methods in this service.
Methods map[string]MethodConfig
}
// SupportPackageIsVersion4 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 SupportPackageIsVersion4 = true
// Version is the current grpc version.
const Version = "1.3.0"
const grpcUA = "grpc-go/" + Version