Refactor GoVPP

Squashed commit of the following:

commit 348930db31575e9f59b3834d9fec07411f011e05
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Wed Aug 15 11:30:13 2018 +0200

    Use debug level for log about different context

commit 9fc963c559cea67a41b85c6cdadc322fb3b1fc7c
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Wed Aug 15 11:22:03 2018 +0200

    Remove annoying logs and add env vars for debugging

commit fdc9fd624d13feadb602e0d03d58f8a44b7a565f
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Wed Aug 15 11:18:47 2018 +0200

    Fix printing unknown VPPApiError

commit 8f968be36a91de4d4a8ea17593ba314f82aa9583
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Tue Aug 14 17:25:10 2018 +0200

    Refactor entire GoVPP

    - fix some cases with inconsistent VPP messages, causing messages
      to be incorrectly identified as event or request
    - simplify API, remove direct access to internal Go channels
    - add module name with message to registration of messages
    - start watching filesystem only when vpe-api file does not exist
    - simplify code in message codec and remove unneeded parts
    - retrieve IDs of all registered messages after connect to VPP
    - define fallback for control ping in core to avoid duplicate registration
    - add SetLogLevel function to set logger level more easily
    - remove lot of unused code

commit 34dd1b7e10ef0324aa8c4e4cc42375bd6021c6cb
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Mon Aug 13 11:29:54 2018 +0200

    Rename VnetError to VPPApiError

commit c6549d6f77847a1367a12ff47fb716e2955e973a
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Mon Aug 13 10:23:43 2018 +0200

    Fix examples and regenerate binapi

commit 4612e36b416779771f5efab4fc654c2766d2cb1c
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Mon Aug 13 09:51:22 2018 +0200

    Add parsing and generation for services

commit ac9c5280c5aa27e325f327609e2364cc66f3723f
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Fri Aug 10 14:30:15 2018 +0200

    Fix exit status on error and add continue-onerror flag

commit 9b3f4ef9fc7c8c62037fa107085eae18a8725314
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 15:20:56 2018 +0200

    Return VnetError when Retval != 0

commit 8fd21a907b5e628ec4d2026215b83d15da96c297
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 14:59:05 2018 +0200

    Add all missing errors from api_errno.h

commit 08450f288d3046ebaecf40203174ae342a07f1eb
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 14:29:27 2018 +0200

    Update README

commit d8dced0728dd62243539be741868fb7d9b8de4cc
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 13:59:59 2018 +0200

    Regenerate vpe in core

commit 254da7592cdbf634cf7aa46ae36ce7bb6d4ee555
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 13:37:00 2018 +0200

    Add VnetError type for Retvals

commit 4475c1087fb53ab4c788e530bc7fef7cfc89d2cd
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 13:36:07 2018 +0200

    Add registration API

commit 892a3ea5a2c703e2f7c29331663f6a6fa706bff5
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 13:30:43 2018 +0200

    Generate registration for messages and check all IDs on connect

commit 389ed03b6e7082260281866c3449d72d72347c99
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 11:32:41 2018 +0200

    Show error for empty adapter (on Darwin/Windows)

commit ef1ea040d656ade64242432dc5f06810ed8dcde6
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 11:31:37 2018 +0200

    Improve logged info

commit d4adae3b14ed54c8d693060dd857fa9ba5ec8e06
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 11:27:48 2018 +0200

    Update examples

commit 63921e1346014701a22639a2611129563bb1eb78
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Thu Aug 9 11:02:56 2018 +0200

    Generate unions and fix some issues

    - add comments between sections
    - define structs on single line if it has no fields
    - generate unions with setters/getters for each field
    - fix detection of message type

commit 6ab3e3fa590b245898306a6ffaf32c7721eab60c
Author: Ondrej Fabry <ofabry@cisco.com>
Date:   Wed Aug 8 15:37:10 2018 +0200

    Refactor binapi-generator

    - split JSON parsing from code generation
    - parse and generate enums
    - parse unions (no generation yet)
    - change output file suffix to '.ba.go'
    - cleanup and simplify code
    - split code into files
    - add flag for debug mode

Change-Id: I58f685e0d4c7a38e9a7b6ea0a1f47792d95d7399
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

1 files changed, 46 insertions, 53 deletions

diff --git a/api/api.go b/api/api.go
index 9c68ab9..39fe60f 100644
--- a/api/api.go
+++ b/api/api.go
@@ -15,10 +15,15 @@
 package api
 
 import (
+	"fmt"
 	"time"
 )
 
 // MessageType represents the type of a VPP message.
+// Note: this is currently derived from the message header (fields),
+// and in many cases it does not represent the actual type of VPP message.
+// This means that some replies can be identified as requests, etc.
+// TODO: use services to identify type of message
 type MessageType int
 
 const (
@@ -26,9 +31,9 @@ const (
 	RequestMessage MessageType = iota
 	// ReplyMessage represents a VPP reply message
 	ReplyMessage
-	// EventMessage represents a VPP notification event message
+	// EventMessage represents a VPP event message
 	EventMessage
-	// OtherMessage represents other VPP message (e.g. counters)
+	// OtherMessage represents other VPP message
 	OtherMessage
 )
 
@@ -37,11 +42,11 @@ type Message interface {
 	// GetMessageName returns the original VPP name of the message, as defined in the VPP API.
 	GetMessageName() string
 
-	// GetMessageType returns the type of the VPP message.
-	GetMessageType() MessageType
-
 	// GetCrcString returns the string with CRC checksum of the message definition (the string represents a hexadecimal number).
 	GetCrcString() string
+
+	// GetMessageType returns the type of the VPP message.
+	GetMessageType() MessageType
 }
 
 // DataType is an interface that is implemented by all VPP Binary API data types by the binapi_generator.
@@ -53,17 +58,6 @@ type DataType interface {
 	GetCrcString() string
 }
 
-// ChannelProvider provides the communication channel with govpp core.
-type ChannelProvider interface {
-	// NewAPIChannel returns a new channel for communication with VPP via govpp core.
-	// It uses default buffer sizes for the request and reply Go channels.
-	NewAPIChannel() (Channel, error)
-
-	// NewAPIChannelBuffered returns a new channel for communication with VPP via govpp core.
-	// It allows to specify custom buffer sizes for the request and reply Go channels.
-	NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (Channel, error)
-}
-
 // MessageDecoder provides functionality for decoding binary data to generated API messages.
 type MessageDecoder interface {
 	// DecodeMsg decodes binary-encoded data of a message into provided Message structure.
@@ -74,43 +68,48 @@ type MessageDecoder interface {
 type MessageIdentifier interface {
 	// GetMessageID returns message identifier of given API message.
 	GetMessageID(msg Message) (uint16, error)
+
 	// LookupByID looks up message name and crc by ID
-	LookupByID(ID uint16) (string, error)
+	LookupByID(msgID uint16) (Message, error)
+}
+
+// ChannelProvider provides the communication channel with govpp core.
+type ChannelProvider interface {
+	// NewAPIChannel returns a new channel for communication with VPP via govpp core.
+	// It uses default buffer sizes for the request and reply Go channels.
+	NewAPIChannel() (Channel, error)
+
+	// NewAPIChannelBuffered returns a new channel for communication with VPP via govpp core.
+	// It allows to specify custom buffer sizes for the request and reply Go channels.
+	NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (Channel, error)
 }
 
 // Channel provides methods for direct communication with VPP channel.
 type Channel interface {
+	// GetID returns channel's ID
+	GetID() uint16
+
 	// 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).
 	SendRequest(msg Message) RequestCtx
+
 	// 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).
 	SendMultiRequest(msg Message) MultiRequestCtx
+
 	// 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.
 	SubscribeNotification(notifChan chan Message, msgFactory func() Message) (*NotifSubscription, error)
+
 	// UnsubscribeNotification unsubscribes from receiving the notifications tied to the provided notification subscription.
 	UnsubscribeNotification(subscription *NotifSubscription) error
-	// CheckMessageCompatibility checks whether provided messages are compatible with the version of VPP
-	// which the library is connected to.
-	CheckMessageCompatibility(messages ...Message) error
+
 	// 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.
 	SetReplyTimeout(timeout time.Duration)
-	// GetRequestChannel returns request go channel of the VPP channel
-	GetRequestChannel() chan<- *VppRequest
-	// GetReplyChannel returns reply go channel of the VPP channel
-	GetReplyChannel() <-chan *VppReply
-	// GetNotificationChannel returns notification go channel of the VPP channel
-	GetNotificationChannel() chan<- *NotifSubscribeRequest
-	// GetNotificationReplyChannel returns notification reply go channel of the VPP channel
-	GetNotificationReplyChannel() <-chan error
-	// GetMessageDecoder returns message decoder instance
-	GetMessageDecoder() MessageDecoder
-	// GetID returns channel's ID
-	GetID() uint16
+
 	// Close closes the API channel and releases all API channel-related resources in the ChannelProvider.
 	Close()
 }
@@ -131,30 +130,24 @@ type MultiRequestCtx interface {
 	ReceiveReply(msg Message) (lastReplyReceived bool, err error)
 }
 
-// VppRequest is a request that will be sent to VPP.
-type VppRequest struct {
-	SeqNum    uint16  // sequence number
-	Message   Message // binary API message to be send to VPP
-	Multipart bool    // true if multipart response is expected, false otherwise
+// NotifSubscription represents a subscription for delivery of specific notification messages.
+type NotifSubscription struct {
+	NotifChan  chan Message   // channel where notification messages will be delivered to
+	MsgFactory func() Message // function that returns a new instance of the specific message that is expected as a notification
+	// TODO: use Message directly here, not a factory, eliminating need to allocation
 }
 
-// VppReply is a reply received from VPP.
-type VppReply struct {
-	MessageID         uint16 // ID of the message
-	SeqNum            uint16 // sequence number
-	Data              []byte // encoded data with the message - MessageDecoder can be used for decoding
-	LastReplyReceived bool   // in case of multipart replies, true if the last reply has been already received and this one should be ignored
-	Error             error  // in case of error, data is nil and this member contains error description
-}
+var registeredMessages = make(map[string]Message)
 
-// NotifSubscribeRequest is a request to subscribe for delivery of specific notification messages.
-type NotifSubscribeRequest struct {
-	Subscription *NotifSubscription // subscription details
-	Subscribe    bool               // true if this is a request to subscribe, false if unsubscribe
+// RegisterMessage is called from generated code to register message.
+func RegisterMessage(x Message, name string) {
+	if _, ok := registeredMessages[name]; ok {
+		panic(fmt.Errorf("govpp: duplicate message registered: %s (%s)", name, x.GetCrcString()))
+	}
+	registeredMessages[name] = x
 }
 
-// NotifSubscription represents a subscription for delivery of specific notification messages.
-type NotifSubscription struct {
-	NotifChan  chan Message   // channel where notification messages will be delivered to
-	MsgFactory func() Message // function that returns a new instance of the specific message that is expected as a notification
+// GetAllMessages returns list of all registered messages.
+func GetAllMessages() map[string]Message {
+	return registeredMessages
 }