1 // Copyright (c) 2020 Cisco and/or its affiliates.
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at:
7 // http://www.apache.org/licenses/LICENSE-2.0
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
22 // Connection represents the client connection to VPP API.
24 // NOTE: This API is EXPERIMENTAL.
25 type Connection interface {
26 // NewStream creates a new stream for sending and receiving messages.
27 // Context can be used to close the stream using cancel or timeout.
28 NewStream(ctx context.Context, options ...StreamOption) (Stream, error)
30 // Invoke can be used for a simple request-reply RPC.
31 // It creates stream and calls SendMsg with req and RecvMsg with reply.
32 Invoke(ctx context.Context, req Message, reply Message) error
35 // Stream provides low-level access for sending and receiving messages.
36 // Users should handle correct type and ordering of messages.
38 // NOTE: This API is EXPERIMENTAL.
39 type Stream interface {
40 // SendMsg sends a message to the client.
41 // It blocks until message is sent to the transport.
43 // It is safe to have a goroutine calling SendMsg and another goroutine
44 // calling RecvMsg on the same stream at the same time, but it is not safe
45 // to call SendMsg on the same stream in different goroutines.
46 SendMsg(Message) error
48 // RecvMsg blocks until a message is received or error occurs.
50 // It is safe to have a goroutine calling SendMsg and another goroutine
51 // calling RecvMsg on the same stream at the same time, but it is not safe
52 // to call SendMsg on the same stream in different goroutines.
53 RecvMsg() (Message, error)
55 // Close closes the stream. Calling SendMsg and RecvMsg will return error
56 // after closing stream.
60 // StreamOption allows customizing a Stream. Available options are:
64 type StreamOption func(Stream)
66 // ChannelProvider provides the communication channel with govpp core.
67 type ChannelProvider interface {
68 // NewAPIChannel returns a new channel for communication with VPP via govpp core.
69 // It uses default buffer sizes for the request and reply Go channels.
70 NewAPIChannel() (Channel, error)
72 // NewAPIChannelBuffered returns a new channel for communication with VPP via govpp core.
73 // It allows to specify custom buffer sizes for the request and reply Go channels.
74 NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (Channel, error)
77 // Channel provides methods for direct communication with VPP channel.
78 type Channel interface {
79 // SendRequest asynchronously sends a request to VPP. Returns a request context, that can be used to call ReceiveReply.
80 // In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
81 SendRequest(msg Message) RequestCtx
83 // SendMultiRequest asynchronously sends a multipart request (request to which multiple responses are expected) to VPP.
84 // Returns a multipart request context, that can be used to call ReceiveReply.
85 // In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
86 SendMultiRequest(msg Message) MultiRequestCtx
88 // SubscribeNotification subscribes for receiving of the specified notification messages via provided Go channel.
89 // Note that the caller is responsible for creating the Go channel with preferred buffer size. If the channel's
90 // buffer is full, the notifications will not be delivered into it.
91 SubscribeNotification(notifChan chan Message, event Message) (SubscriptionCtx, error)
93 // SetReplyTimeout sets the timeout for replies from VPP. It represents the maximum time the API waits for a reply
94 // from VPP before returning an error.
95 SetReplyTimeout(timeout time.Duration)
97 // CheckCompatibility checks the compatiblity for the given messages.
98 // It will return an error if any of the given messages are not compatible.
99 CheckCompatiblity(msgs ...Message) error
101 // Close closes the API channel and releases all API channel-related resources
102 // in the ChannelProvider.
106 // RequestCtx is helper interface which allows to receive reply on request.
107 type RequestCtx interface {
108 // ReceiveReply receives a reply from VPP (blocks until a reply is delivered
109 // from VPP, or until an error occurs). The reply will be decoded into the msg
110 // argument. Error will be returned if the response cannot be received or decoded.
111 ReceiveReply(msg Message) error
114 // MultiRequestCtx is helper interface which allows to receive reply on multi-request.
115 type MultiRequestCtx interface {
116 // ReceiveReply receives a reply from VPP (blocks until a reply is delivered
117 // from VPP, or until an error occurs).The reply will be decoded into the msg
118 // argument. If the last reply has been already consumed, lastReplyReceived is
119 // set to true. Do not use the message itself if lastReplyReceived is
120 // true - it won't be filled with actual data.Error will be returned if the
121 // response cannot be received or decoded.
122 ReceiveReply(msg Message) (lastReplyReceived bool, err error)
125 // SubscriptionCtx is helper interface which allows to control subscription for
126 // notification events.
127 type SubscriptionCtx interface {
128 // Unsubscribe unsubscribes from receiving the notifications tied to the
129 // subscription context.