forked from jhump/protoreflect
-
Notifications
You must be signed in to change notification settings - Fork 0
/
stub.go
303 lines (270 loc) · 10.8 KB
/
stub.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
// Package grpcdynamic provides a dynamic RPC stub. It can be used to invoke RPC
// method where only method descriptors are known. The actual request and response
// messages may be dynamic messages.
package grpcdynamic
import (
"fmt"
"io"
"github.com/golang/protobuf/proto"
"golang.org/x/net/context"
"google.golang.org/grpc"
"google.golang.org/grpc/metadata"
"github.com/xiaoshude/protoreflect/desc"
"github.com/xiaoshude/protoreflect/dynamic"
)
// Stub is an RPC client stub, used for dynamically dispatching RPCs to a server.
type Stub struct {
channel Channel
mf *dynamic.MessageFactory
}
// Channel represents the operations necessary to issue RPCs via gRPC. The
// *grpc.ClientConn type provides this interface and will typically the concrete
// type used to construct Stubs. But the use of this interface allows
// construction of stubs that use alternate concrete types as the transport for
// RPC operations.
type Channel interface {
Invoke(ctx context.Context, method string, args, reply interface{}, opts ...grpc.CallOption) error
NewStream(ctx context.Context, desc *grpc.StreamDesc, method string, opts ...grpc.CallOption) (grpc.ClientStream, error)
}
var _ Channel = (*grpc.ClientConn)(nil)
// NewStub creates a new RPC stub that uses the given channel for dispatching RPCs.
func NewStub(channel Channel) Stub {
return NewStubWithMessageFactory(channel, nil)
}
// NewStubWithMessageFactory creates a new RPC stub that uses the given channel for
// dispatching RPCs and the given MessageFactory for creating response messages.
func NewStubWithMessageFactory(channel Channel, mf *dynamic.MessageFactory) Stub {
return Stub{channel: channel, mf: mf}
}
func requestMethod(md *desc.MethodDescriptor) string {
return fmt.Sprintf("/%s/%s", md.GetService().GetFullyQualifiedName(), md.GetName())
}
// InvokeRpc sends a unary RPC and returns the response. Use this for unary methods.
func (s Stub) InvokeRpc(ctx context.Context, method *desc.MethodDescriptor, request proto.Message, opts ...grpc.CallOption) (proto.Message, error) {
if method.IsClientStreaming() || method.IsServerStreaming() {
return nil, fmt.Errorf("InvokeRpc is for unary methods; %q is %s", method.GetFullyQualifiedName(), methodType(method))
}
if err := checkMessageType(method.GetInputType(), request); err != nil {
return nil, err
}
resp := s.mf.NewMessage(method.GetOutputType())
if err := s.channel.Invoke(ctx, requestMethod(method), request, resp, opts...); err != nil {
return nil, err
}
return resp, nil
}
// InvokeRpcServerStream sends a unary RPC and returns the response stream. Use this for server-streaming methods.
func (s Stub) InvokeRpcServerStream(ctx context.Context, method *desc.MethodDescriptor, request proto.Message, opts ...grpc.CallOption) (*ServerStream, error) {
if method.IsClientStreaming() || !method.IsServerStreaming() {
return nil, fmt.Errorf("InvokeRpcServerStream is for server-streaming methods; %q is %s", method.GetFullyQualifiedName(), methodType(method))
}
if err := checkMessageType(method.GetInputType(), request); err != nil {
return nil, err
}
ctx, cancel := context.WithCancel(ctx)
sd := grpc.StreamDesc{
StreamName: method.GetName(),
ServerStreams: method.IsServerStreaming(),
ClientStreams: method.IsClientStreaming(),
}
if cs, err := s.channel.NewStream(ctx, &sd, requestMethod(method), opts...); err != nil {
return nil, err
} else {
err = cs.SendMsg(request)
if err != nil {
cancel()
return nil, err
}
err = cs.CloseSend()
if err != nil {
cancel()
return nil, err
}
return &ServerStream{cs, method.GetOutputType(), s.mf}, nil
}
}
// InvokeRpcClientStream creates a new stream that is used to send request messages and, at the end,
// receive the response message. Use this for client-streaming methods.
func (s Stub) InvokeRpcClientStream(ctx context.Context, method *desc.MethodDescriptor, opts ...grpc.CallOption) (*ClientStream, error) {
if !method.IsClientStreaming() || method.IsServerStreaming() {
return nil, fmt.Errorf("InvokeRpcClientStream is for client-streaming methods; %q is %s", method.GetFullyQualifiedName(), methodType(method))
}
ctx, cancel := context.WithCancel(ctx)
sd := grpc.StreamDesc{
StreamName: method.GetName(),
ServerStreams: method.IsServerStreaming(),
ClientStreams: method.IsClientStreaming(),
}
if cs, err := s.channel.NewStream(ctx, &sd, requestMethod(method), opts...); err != nil {
return nil, err
} else {
return &ClientStream{cs, method, s.mf, cancel}, nil
}
}
// InvokeRpcBidiStream creates a new stream that is used to both send request messages and receive response
// messages. Use this for bidi-streaming methods.
func (s Stub) InvokeRpcBidiStream(ctx context.Context, method *desc.MethodDescriptor, opts ...grpc.CallOption) (*BidiStream, error) {
if !method.IsClientStreaming() || !method.IsServerStreaming() {
return nil, fmt.Errorf("InvokeRpcBidiStream is for bidi-streaming methods; %q is %s", method.GetFullyQualifiedName(), methodType(method))
}
sd := grpc.StreamDesc{
StreamName: method.GetName(),
ServerStreams: method.IsServerStreaming(),
ClientStreams: method.IsClientStreaming(),
}
if cs, err := s.channel.NewStream(ctx, &sd, requestMethod(method), opts...); err != nil {
return nil, err
} else {
return &BidiStream{cs, method.GetInputType(), method.GetOutputType(), s.mf}, nil
}
}
func methodType(md *desc.MethodDescriptor) string {
if md.IsClientStreaming() && md.IsServerStreaming() {
return "bidi-streaming"
} else if md.IsClientStreaming() {
return "client-streaming"
} else if md.IsServerStreaming() {
return "server-streaming"
} else {
return "unary"
}
}
func checkMessageType(md *desc.MessageDescriptor, msg proto.Message) error {
var typeName string
if dm, ok := msg.(*dynamic.Message); ok {
typeName = dm.GetMessageDescriptor().GetFullyQualifiedName()
} else {
typeName = proto.MessageName(msg)
}
if typeName != md.GetFullyQualifiedName() {
return fmt.Errorf("expecting message of type %s; got %s", md.GetFullyQualifiedName(), typeName)
}
return nil
}
// ServerStream represents a response stream from a server. Messages in the stream can be queried
// as can header and trailer metadata sent by the server.
type ServerStream struct {
stream grpc.ClientStream
respType *desc.MessageDescriptor
mf *dynamic.MessageFactory
}
// Header returns any header metadata sent by the server (blocks if necessary until headers are
// received).
func (s *ServerStream) Header() (metadata.MD, error) {
return s.stream.Header()
}
// Trailer returns the trailer metadata sent by the server. It must only be called after
// RecvMsg returns a non-nil error (which may be EOF for normal completion of stream).
func (s *ServerStream) Trailer() metadata.MD {
return s.stream.Trailer()
}
// Context returns the context associated with this streaming operation.
func (s *ServerStream) Context() context.Context {
return s.stream.Context()
}
// RecvMsg returns the next message in the response stream or an error. If the stream
// has completed normally, the error is io.EOF. Otherwise, the error indicates the
// nature of the abnormal termination of the stream.
func (s *ServerStream) RecvMsg() (proto.Message, error) {
resp := s.mf.NewMessage(s.respType)
if err := s.stream.RecvMsg(resp); err != nil {
return nil, err
} else {
return resp, nil
}
}
// ClientStream represents a response stream from a client. Messages in the stream can be sent
// and, when done, the unary server message and header and trailer metadata can be queried.
type ClientStream struct {
stream grpc.ClientStream
method *desc.MethodDescriptor
mf *dynamic.MessageFactory
cancel context.CancelFunc
}
// Header returns any header metadata sent by the server (blocks if necessary until headers are
// received).
func (s *ClientStream) Header() (metadata.MD, error) {
return s.stream.Header()
}
// Trailer returns the trailer metadata sent by the server. It must only be called after
// RecvMsg returns a non-nil error (which may be EOF for normal completion of stream).
func (s *ClientStream) Trailer() metadata.MD {
return s.stream.Trailer()
}
// Context returns the context associated with this streaming operation.
func (s *ClientStream) Context() context.Context {
return s.stream.Context()
}
// SendMsg sends a request message to the server.
func (s *ClientStream) SendMsg(m proto.Message) error {
if err := checkMessageType(s.method.GetInputType(), m); err != nil {
return err
}
return s.stream.SendMsg(m)
}
// CloseAndReceive closes the outgoing request stream and then blocks for the server's response.
func (s *ClientStream) CloseAndReceive() (proto.Message, error) {
if err := s.stream.CloseSend(); err != nil {
return nil, err
}
resp := s.mf.NewMessage(s.method.GetOutputType())
if err := s.stream.RecvMsg(resp); err != nil {
return nil, err
}
// make sure we get EOF for a second message
if err := s.stream.RecvMsg(resp); err != io.EOF {
if err == nil {
s.cancel()
return nil, fmt.Errorf("client-streaming method %q returned more than one response message", s.method.GetFullyQualifiedName())
} else {
return nil, err
}
}
return resp, nil
}
// BidiStream represents a bi-directional stream for sending messages to and receiving
// messages from a server. The header and trailer metadata sent by the server can also be
// queried.
type BidiStream struct {
stream grpc.ClientStream
reqType *desc.MessageDescriptor
respType *desc.MessageDescriptor
mf *dynamic.MessageFactory
}
// Header returns any header metadata sent by the server (blocks if necessary until headers are
// received).
func (s *BidiStream) Header() (metadata.MD, error) {
return s.stream.Header()
}
// Trailer returns the trailer metadata sent by the server. It must only be called after
// RecvMsg returns a non-nil error (which may be EOF for normal completion of stream).
func (s *BidiStream) Trailer() metadata.MD {
return s.stream.Trailer()
}
// Context returns the context associated with this streaming operation.
func (s *BidiStream) Context() context.Context {
return s.stream.Context()
}
// SendMsg sends a request message to the server.
func (s *BidiStream) SendMsg(m proto.Message) error {
if err := checkMessageType(s.reqType, m); err != nil {
return err
}
return s.stream.SendMsg(m)
}
// CloseSend indicates the request stream has ended. Invoke this after all request messages
// are sent (even if there are zero such messages).
func (s *BidiStream) CloseSend() error {
return s.stream.CloseSend()
}
// RecvMsg returns the next message in the response stream or an error. If the stream
// has completed normally, the error is io.EOF. Otherwise, the error indicates the
// nature of the abnormal termination of the stream.
func (s *BidiStream) RecvMsg() (proto.Message, error) {
resp := s.mf.NewMessage(s.respType)
if err := s.stream.RecvMsg(resp); err != nil {
return nil, err
} else {
return resp, nil
}
}