vendor/google.golang.org/grpc/interceptor.go

   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 interface{}, cc *ClientConn, opts ...CallOption) error
  27
  28 // UnaryClientInterceptor intercepts the execution of a unary RPC on the client. invoker is the handler to complete the RPC
  29 // and it is the responsibility of the interceptor to call it.
  30 // This is an EXPERIMENTAL API.
  31 type UnaryClientInterceptor func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error
  32
  33 // Streamer is called by StreamClientInterceptor to create a ClientStream.
  34 type Streamer func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)
  35
  36 // StreamClientInterceptor intercepts the creation of ClientStream. It may return a custom ClientStream to intercept all I/O
  37 // operations. streamer is the handler to create a ClientStream and it is the responsibility of the interceptor to call it.
  38 // This is an EXPERIMENTAL API.
  39 type StreamClientInterceptor func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error)
  40
  41 // UnaryServerInfo consists of various information about a unary RPC on
  42 // server side. All per-rpc information may be mutated by the interceptor.
  43 type UnaryServerInfo struct {
  44         // Server is the service implementation the user provides. This is read-only.
  45         Server interface{}
  46         // FullMethod is the full RPC method string, i.e., /package.service/method.
  47         FullMethod string
  48 }
  49
  50 // UnaryHandler defines the handler invoked by UnaryServerInterceptor to complete the normal
  51 // execution of a unary RPC. If a UnaryHandler returns an error, it should be produced by the
  52 // status package, or else gRPC will use codes.Unknown as the status code and err.Error() as
  53 // the status message of the RPC.
  54 type UnaryHandler func(ctx context.Context, req interface{}) (interface{}, error)
  55
  56 // UnaryServerInterceptor provides a hook to intercept the execution of a unary RPC on the server. info
  57 // contains all the information of this RPC the interceptor can operate on. And handler is the wrapper
  58 // of the service method implementation. It is the responsibility of the interceptor to invoke handler
  59 // to complete the RPC.
  60 type UnaryServerInterceptor func(ctx context.Context, req interface{}, info *UnaryServerInfo, handler UnaryHandler) (resp interface{}, err error)
  61
  62 // StreamServerInfo consists of various information about a streaming RPC on
  63 // server side. All per-rpc information may be mutated by the interceptor.
  64 type StreamServerInfo struct {
  65         // FullMethod is the full RPC method string, i.e., /package.service/method.
  66         FullMethod string
  67         // IsClientStream indicates whether the RPC is a client streaming RPC.
  68         IsClientStream bool
  69         // IsServerStream indicates whether the RPC is a server streaming RPC.
  70         IsServerStream bool
  71 }
  72
  73 // StreamServerInterceptor provides a hook to intercept the execution of a streaming RPC on the server.
  74 // info contains all the information of this RPC the interceptor can operate on. And handler is the
  75 // service method implementation. It is the responsibility of the interceptor to invoke handler to
  76 // complete the RPC.
  77 type StreamServerInterceptor func(srv interface{}, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error