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