1 /*
2 *
3 * Copyright 2016 gRPC authors.
4 *
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
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
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.
16 *
17 */
18 19 package grpc
20 21 import (
22 "context"
23 )
24 25 // UnaryInvoker is called by UnaryClientInterceptor to complete RPCs.
26 type UnaryInvoker func(ctx context.Context, method string, req, reply any, cc *ClientConn, opts ...CallOption) error
27 28 // UnaryClientInterceptor intercepts the execution of a unary RPC on the client.
29 // Unary interceptors can be specified as a DialOption, using
30 // WithUnaryInterceptor() or WithChainUnaryInterceptor(), when creating a
31 // ClientConn. When a unary interceptor(s) is set on a ClientConn, gRPC
32 // delegates all unary RPC invocations to the interceptor, and it is the
33 // responsibility of the interceptor to call invoker to complete the processing
34 // of the RPC.
35 //
36 // method is the RPC name. req and reply are the corresponding request and
37 // response messages. cc is the ClientConn on which the RPC was invoked. invoker
38 // is the handler to complete the RPC and it is the responsibility of the
39 // interceptor to call it. opts contain all applicable call options, including
40 // defaults from the ClientConn as well as per-call options.
41 //
42 // The returned error must be compatible with the status package.
43 type UnaryClientInterceptor func(ctx context.Context, method string, req, reply any, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error
44 45 // Streamer is called by StreamClientInterceptor to create a ClientStream.
46 type Streamer func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)
47 48 // StreamClientInterceptor intercepts the creation of a ClientStream. Stream
49 // interceptors can be specified as a DialOption, using WithStreamInterceptor()
50 // or WithChainStreamInterceptor(), when creating a ClientConn. When a stream
51 // interceptor(s) is set on the ClientConn, gRPC delegates all stream creations
52 // to the interceptor, and it is the responsibility of the interceptor to call
53 // streamer.
54 //
55 // desc contains a description of the stream. cc is the ClientConn on which the
56 // RPC was invoked. streamer is the handler to create a ClientStream and it is
57 // the responsibility of the interceptor to call it. opts contain all applicable
58 // call options, including defaults from the ClientConn as well as per-call
59 // options.
60 //
61 // StreamClientInterceptor may return a custom ClientStream to intercept all I/O
62 // operations. The returned error must be compatible with the status package.
63 type StreamClientInterceptor func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error)
64 65 // UnaryServerInfo consists of various information about a unary RPC on
66 // server side. All per-rpc information may be mutated by the interceptor.
67 type UnaryServerInfo struct {
68 // Server is the service implementation the user provides. This is read-only.
69 Server any
70 // FullMethod is the full RPC method string, i.e., /package.service/method.
71 FullMethod string
72 }
73 74 // UnaryHandler defines the handler invoked by UnaryServerInterceptor to complete the normal
75 // execution of a unary RPC.
76 //
77 // If a UnaryHandler returns an error, it should either be produced by the
78 // status package, or be one of the context errors. Otherwise, gRPC will use
79 // codes.Unknown as the status code and err.Error() as the status message of the
80 // RPC.
81 type UnaryHandler func(ctx context.Context, req any) (any, error)
82 83 // UnaryServerInterceptor provides a hook to intercept the execution of a unary RPC on the server. info
84 // contains all the information of this RPC the interceptor can operate on. And handler is the wrapper
85 // of the service method implementation. It is the responsibility of the interceptor to invoke handler
86 // to complete the RPC.
87 type UnaryServerInterceptor func(ctx context.Context, req any, info *UnaryServerInfo, handler UnaryHandler) (resp any, err error)
88 89 // StreamServerInfo consists of various information about a streaming RPC on
90 // server side. All per-rpc information may be mutated by the interceptor.
91 type StreamServerInfo struct {
92 // FullMethod is the full RPC method string, i.e., /package.service/method.
93 FullMethod string
94 // IsClientStream indicates whether the RPC is a client streaming RPC.
95 IsClientStream bool
96 // IsServerStream indicates whether the RPC is a server streaming RPC.
97 IsServerStream bool
98 }
99 100 // StreamServerInterceptor provides a hook to intercept the execution of a streaming RPC on the server.
101 // info contains all the information of this RPC the interceptor can operate on. And handler is the
102 // service method implementation. It is the responsibility of the interceptor to invoke handler to
103 // complete the RPC.
104 type StreamServerInterceptor func(srv any, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error
105