1 // Copyright (c) 2017 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.
21 // MessageType represents the type of a VPP message.
25 // RequestMessage represents a VPP request message
26 RequestMessage MessageType = iota
27 // ReplyMessage represents a VPP reply message
29 // EventMessage represents a VPP notification event message
31 // OtherMessage represents other VPP message (e.g. counters)
35 // Message is an interface that is implemented by all VPP Binary API messages generated by the binapigenerator.
36 type Message interface {
37 // GetMessageName returns the original VPP name of the message, as defined in the VPP API.
38 GetMessageName() string
40 // GetMessageType returns the type of the VPP message.
41 GetMessageType() MessageType
43 // GetCrcString returns the string with CRC checksum of the message definition (the string represents a hexadecimal number).
47 // DataType is an interface that is implemented by all VPP Binary API data types by the binapi_generator.
48 type DataType interface {
49 // GetTypeName returns the original VPP name of the data type, as defined in the VPP API.
52 // GetCrcString returns the string with CRC checksum of the data type definition (the string represents a hexadecimal number).
56 // ChannelProvider provides the communication channel with govpp core.
57 type ChannelProvider interface {
58 // NewAPIChannel returns a new channel for communication with VPP via govpp core.
59 // It uses default buffer sizes for the request and reply Go channels.
60 NewAPIChannel() (Channel, error)
62 // NewAPIChannelBuffered returns a new channel for communication with VPP via govpp core.
63 // It allows to specify custom buffer sizes for the request and reply Go channels.
64 NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (Channel, error)
67 // MessageDecoder provides functionality for decoding binary data to generated API messages.
68 type MessageDecoder interface {
69 // DecodeMsg decodes binary-encoded data of a message into provided Message structure.
70 DecodeMsg(data []byte, msg Message) error
73 // MessageIdentifier provides identification of generated API messages.
74 type MessageIdentifier interface {
75 // GetMessageID returns message identifier of given API message.
76 GetMessageID(msg Message) (uint16, error)
77 // LookupByID looks up message name and crc by ID
78 LookupByID(ID uint16) (string, error)
81 // Channel provides methods for direct communication with VPP channel.
82 type Channel interface {
83 // SendRequest asynchronously sends a request to VPP. Returns a request context, that can be used to call ReceiveReply.
84 // In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
85 SendRequest(msg Message) RequestCtx
86 // SendMultiRequest asynchronously sends a multipart request (request to which multiple responses are expected) to VPP.
87 // Returns a multipart request context, that can be used to call ReceiveReply.
88 // In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
89 SendMultiRequest(msg Message) MultiRequestCtx
90 // SubscribeNotification subscribes for receiving of the specified notification messages via provided Go channel.
91 // Note that the caller is responsible for creating the Go channel with preferred buffer size. If the channel's
92 // buffer is full, the notifications will not be delivered into it.
93 SubscribeNotification(notifChan chan Message, msgFactory func() Message) (*NotifSubscription, error)
94 // UnsubscribeNotification unsubscribes from receiving the notifications tied to the provided notification subscription.
95 UnsubscribeNotification(subscription *NotifSubscription) error
96 // CheckMessageCompatibility checks whether provided messages are compatible with the version of VPP
97 // which the library is connected to.
98 CheckMessageCompatibility(messages ...Message) error
99 // SetReplyTimeout sets the timeout for replies from VPP. It represents the maximum time the API waits for a reply
100 // from VPP before returning an error.
101 SetReplyTimeout(timeout time.Duration)
102 // GetRequestChannel returns request go channel of the VPP channel
103 GetRequestChannel() chan<- *VppRequest
104 // GetReplyChannel returns reply go channel of the VPP channel
105 GetReplyChannel() <-chan *VppReply
106 // GetNotificationChannel returns notification go channel of the VPP channel
107 GetNotificationChannel() chan<- *NotifSubscribeRequest
108 // GetNotificationReplyChannel returns notification reply go channel of the VPP channel
109 GetNotificationReplyChannel() <-chan error
110 // GetMessageDecoder returns message decoder instance
111 GetMessageDecoder() MessageDecoder
112 // GetID returns channel's ID
114 // Close closes the API channel and releases all API channel-related resources in the ChannelProvider.
118 // RequestCtx is helper interface which allows to receive reply on request context data
119 type RequestCtx interface {
120 // ReceiveReply receives a reply from VPP (blocks until a reply is delivered from VPP, or until an error occurs).
121 // The reply will be decoded into the msg argument. Error will be returned if the response cannot be received or decoded.
122 ReceiveReply(msg Message) error
125 // MultiRequestCtx is helper interface which allows to receive reply on multi-request context data
126 type MultiRequestCtx interface {
127 // ReceiveReply receives a reply from VPP (blocks until a reply is delivered from VPP, or until an error occurs).
128 // The reply will be decoded into the msg argument. If the last reply has been already consumed, lastReplyReceived is
129 // set to true. Do not use the message itself if lastReplyReceived is true - it won't be filled with actual data.
130 // Error will be returned if the response cannot be received or decoded.
131 ReceiveReply(msg Message) (lastReplyReceived bool, err error)
134 // VppRequest is a request that will be sent to VPP.
135 type VppRequest struct {
136 SeqNum uint16 // sequence number
137 Message Message // binary API message to be send to VPP
138 Multipart bool // true if multipart response is expected, false otherwise
141 // VppReply is a reply received from VPP.
142 type VppReply struct {
143 MessageID uint16 // ID of the message
144 SeqNum uint16 // sequence number
145 Data []byte // encoded data with the message - MessageDecoder can be used for decoding
146 LastReplyReceived bool // in case of multipart replies, true if the last reply has been already received and this one should be ignored
147 Error error // in case of error, data is nil and this member contains error description
150 // NotifSubscribeRequest is a request to subscribe for delivery of specific notification messages.
151 type NotifSubscribeRequest struct {
152 Subscription *NotifSubscription // subscription details
153 Subscribe bool // true if this is a request to subscribe, false if unsubscribe
156 // NotifSubscription represents a subscription for delivery of specific notification messages.
157 type NotifSubscription struct {
158 NotifChan chan Message // channel where notification messages will be delivered to
159 MsgFactory func() Message // function that returns a new instance of the specific message that is expected as a notification