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khenaidoo5fc5cea2021-08-11 17:39:16 -04001/*
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 tap defines the function handles which are executed on the transport
20// layer of gRPC-Go and related information.
21//
22// Experimental
23//
24// Notice: This API is EXPERIMENTAL and may be changed or removed in a
25// later release.
26package tap
27
28import (
29 "context"
30)
31
32// Info defines the relevant information needed by the handles.
33type Info struct {
34 // FullMethodName is the string of grpc method (in the format of
35 // /package.service/method).
36 FullMethodName string
37 // TODO: More to be added.
38}
39
40// ServerInHandle defines the function which runs before a new stream is
41// created on the server side. If it returns a non-nil error, the stream will
42// not be created and an error will be returned to the client. If the error
43// returned is a status error, that status code and message will be used,
44// otherwise PermissionDenied will be the code and err.Error() will be the
45// message.
46//
47// It's intended to be used in situations where you don't want to waste the
48// resources to accept the new stream (e.g. rate-limiting). For other general
49// usages, please use interceptors.
50//
51// Note that it is executed in the per-connection I/O goroutine(s) instead of
52// per-RPC goroutine. Therefore, users should NOT have any
53// blocking/time-consuming work in this handle. Otherwise all the RPCs would
54// slow down. Also, for the same reason, this handle won't be called
55// concurrently by gRPC.
56type ServerInHandle func(ctx context.Context, info *Info) (context.Context, error)