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
 19package grpc
 20
 21import (
 22	"context"
 23)
 24
 25// UnaryInvoker is called by UnaryClientInterceptor to complete RPCs.
 26type 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.
 43type 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.
 46type 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.
 63type 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.
 67type 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.
 81type 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.
 87type 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.
 91type 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.
104type StreamServerInterceptor func(srv any, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error