-
-// RequestCtx is a context of a ongoing request (simple one - only one response is expected).
-type RequestCtx struct {
- ch *Channel
-}
-
-// MultiRequestCtx is a context of a ongoing multipart request (multiple responses are expected).
-type MultiRequestCtx struct {
- ch *Channel
-}
-
-const defaultReplyTimeout = time.Second * 1 // default timeout for replies from VPP, can be changed with SetReplyTimeout
-
-// NewChannelInternal returns a new channel structure with metadata field filled in with the provided argument.
-// Note that this is just a raw channel not yet connected to VPP, it is not intended to be used directly.
-// Use ChannelProvider to get an API channel ready for communication with VPP.
-func NewChannelInternal(metadata interface{}) *Channel {
- return &Channel{
- replyTimeout: defaultReplyTimeout,
- metadata: metadata,
- }
-}
-
-// Metadata returns the metadata stored within the channel structure by the NewChannelInternal call.
-func (ch *Channel) Metadata() interface{} {
- return ch.metadata
-}
-
-// SetReplyTimeout sets the timeout for replies from VPP. It represents the maximum time the API waits for a reply
-// from VPP before returning an error.
-func (ch *Channel) SetReplyTimeout(timeout time.Duration) {
- ch.replyTimeout = timeout
-}
-
-// Close closes the API channel and releases all API channel-related resources in the ChannelProvider.
-func (ch *Channel) Close() {
- if ch.ReqChan != nil {
- close(ch.ReqChan)
- }
-}
-
-// SendRequest asynchronously sends a request to VPP. Returns a request context, that can be used to call ReceiveReply.
-// In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
-func (ch *Channel) SendRequest(msg Message) *RequestCtx {
- ch.ReqChan <- &VppRequest{
- Message: msg,
- }
- return &RequestCtx{ch: ch}
-}
-
-// ReceiveReply receives a reply from VPP (blocks until a reply is delivered from VPP, or until an error occurs).
-// The reply will be decoded into the msg argument. Error will be returned if the response cannot be received or decoded.
-func (req *RequestCtx) ReceiveReply(msg Message) error {
- if req == nil || req.ch == nil {
- return errors.New("invalid request context")
- }
-
- lastReplyReceived, err := req.ch.receiveReplyInternal(msg)
-
- if lastReplyReceived {
- err = errors.New("multipart reply recieved while a simple reply expected")
- }
- return err
-}
-
-// SendMultiRequest asynchronously sends a multipart request (request to which multiple responses are expected) to VPP.
-// Returns a multipart request context, that can be used to call ReceiveReply.
-// In case of any errors by sending, the error will be delivered to ReplyChan (and returned by ReceiveReply).
-func (ch *Channel) SendMultiRequest(msg Message) *MultiRequestCtx {
- ch.ReqChan <- &VppRequest{
- Message: msg,
- Multipart: true,
- }
- return &MultiRequestCtx{ch: ch}
-}
-
-// ReceiveReply receives a reply from VPP (blocks until a reply is delivered from VPP, or until an error occurs).
-// The reply will be decoded into the msg argument. If the last reply has been already consumed, LastReplyReceived is
-// set to true. Do not use the message itself if LastReplyReceived is true - it won't be filled with actual data.
-// Error will be returned if the response cannot be received or decoded.
-func (req *MultiRequestCtx) ReceiveReply(msg Message) (LastReplyReceived bool, err error) {
- if req == nil || req.ch == nil {
- return false, errors.New("invalid request context")
- }
-
- return req.ch.receiveReplyInternal(msg)
-}
-
-// receiveReplyInternal receives a reply from the reply channel into the provided msg structure.
-func (ch *Channel) receiveReplyInternal(msg Message) (LastReplyReceived bool, err error) {
- if msg == nil {
- return false, errors.New("nil message passed in")
- }
- select {
- // blocks until a reply comes to ReplyChan or until timeout expires
- case vppReply := <-ch.ReplyChan:
- if vppReply.Error != nil {
- err = vppReply.Error
- return
- }
- if vppReply.LastReplyReceived {
- LastReplyReceived = true
- return
- }
- // message checks
- expMsgID, err := ch.MsgIdentifier.GetMessageID(msg)
- if err != nil {
- err = fmt.Errorf("message %s with CRC %s is not compatible with the VPP we are connected to",
- msg.GetMessageName(), msg.GetCrcString())
- return false, err
- }
- if vppReply.MessageID != expMsgID {
- err = fmt.Errorf("invalid message ID %d, expected %d", vppReply.MessageID, expMsgID)
- return false, err
- }
- // decode the message
- err = ch.MsgDecoder.DecodeMsg(vppReply.Data, msg)
-
- case <-time.After(ch.replyTimeout):
- err = fmt.Errorf("no reply received within the timeout period %ds", ch.replyTimeout/time.Second)
- }
- return
-}
-
-// SubscribeNotification subscribes for receiving of the specified notification messages via provided Go channel.
-// Note that the caller is responsible for creating the Go channel with preferred buffer size. If the channel's
-// buffer is full, the notifications will not be delivered into it.
-func (ch *Channel) SubscribeNotification(notifChan chan Message, msgFactory func() Message) (*NotifSubscription, error) {
- subscription := &NotifSubscription{
- NotifChan: notifChan,
- MsgFactory: msgFactory,
- }
- ch.NotifSubsChan <- &NotifSubscribeRequest{
- Subscription: subscription,
- Subscribe: true,
- }
- return subscription, <-ch.NotifSubsReplyChan
-}
-
-// UnsubscribeNotification unsubscribes from receiving the notifications tied to the provided notification subscription.
-func (ch *Channel) UnsubscribeNotification(subscription *NotifSubscription) error {
- ch.NotifSubsChan <- &NotifSubscribeRequest{
- Subscription: subscription,
- Subscribe: false,
- }
- return <-ch.NotifSubsReplyChan
-}
-
-// CheckMessageCompatibility checks whether provided messages are compatible with the version of VPP
-// which the library is connected to.
-func (ch *Channel) CheckMessageCompatibility(messages ...Message) error {
- for _, msg := range messages {
- _, err := ch.MsgIdentifier.GetMessageID(msg)
- if err != nil {
- return fmt.Errorf("message %s with CRC %s is not compatible with the VPP we are connected to",
- msg.GetMessageName(), msg.GetCrcString())
- }
- }
- return nil
-}