Deprecate encoded connections (#1674)

Signed-off-by: Piotr Piotrowski <piotr@synadia.com>

README.md

@@ -136,60 +136,6 @@ To find more information on `nats.go` JetStream API, visit
 The service API (`micro`) allows you to [easily build NATS services](micro/README.md) The
 services API is currently in beta release.
 
-## Encoded Connections
-
-```go
-
-nc, _ := nats.Connect(nats.DefaultURL)
-c, _ := nats.NewEncodedConn(nc, nats.JSON_ENCODER)
-defer c.Close()
-
-// Simple Publisher
-c.Publish("foo", "Hello World")
-
-// Simple Async Subscriber
-c.Subscribe("foo", func(s string) {
-    fmt.Printf("Received a message: %s\n", s)
-})
-
-// EncodedConn can Publish any raw Go type using the registered Encoder
-type person struct {
-     Name     string
-     Address  string
-     Age      int
-}
-
-// Go type Subscriber
-c.Subscribe("hello", func(p *person) {
-    fmt.Printf("Received a person: %+v\n", p)
-})
-
-me := &person{Name: "derek", Age: 22, Address: "140 New Montgomery Street, San Francisco, CA"}
-
-// Go type Publisher
-c.Publish("hello", me)
-
-// Unsubscribe
-sub, err := c.Subscribe("foo", nil)
-// ...
-sub.Unsubscribe()
-
-// Requests
-var response string
-err = c.Request("help", "help me", &response, 10*time.Millisecond)
-if err != nil {
-    fmt.Printf("Request failed: %v\n", err)
-}
-
-// Replying
-c.Subscribe("help", func(subj, reply string, msg string) {
-    c.Publish(reply, "I can help!")
-})
-
-// Close connection
-c.Close();
-```
-
 ## New Authentication (Nkeys and User Credentials)
 This requires server with version >= 2.0.0
 
@@ -269,34 +215,6 @@ if err != nil {
 
 ```
 
-## Using Go Channels (netchan)
-
-```go
-nc, _ := nats.Connect(nats.DefaultURL)
-ec, _ := nats.NewEncodedConn(nc, nats.JSON_ENCODER)
-defer ec.Close()
-
-type person struct {
-     Name     string
-     Address  string
-     Age      int
-}
-
-recvCh := make(chan *person)
-ec.BindRecvChan("hello", recvCh)
-
-sendCh := make(chan *person)
-ec.BindSendChan("hello", sendCh)
-
-me := &person{Name: "derek", Age: 22, Address: "140 New Montgomery Street"}
-
-// Send via Go channels
-sendCh <- me
-
-// Receive via Go channels
-who := <- recvCh
-```
-
 ## Wildcard Subscriptions
 
 ```go
@@ -463,19 +381,6 @@ msg, err := nc.RequestWithContext(ctx, "foo", []byte("bar"))
 sub, err := nc.SubscribeSync("foo")
 msg, err := sub.NextMsgWithContext(ctx)
 
-// Encoded Request with context
-c, err := nats.NewEncodedConn(nc, nats.JSON_ENCODER)
-type request struct {
-	Message string `json:"message"`
-}
-type response struct {
-	Code int `json:"code"`
-}
-req := &request{Message: "Hello"}
-resp := &response{}
-err := c.RequestWithContext(ctx, "foo", req, resp)
-```
-
 ## Backwards compatibility
 
 In the development of nats.go, we are committed to maintaining backward compatibility and ensuring a stable and reliable  experience for all users. In general, we follow the standard go compatibility guidelines.

context.go

@@ -217,6 +217,8 @@ func (nc *Conn) FlushWithContext(ctx context.Context) error {
 // RequestWithContext will create an Inbox and perform a Request
 // using the provided cancellation context with the Inbox reply
 // for the data v. A response will be decoded into the vPtr last parameter.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) RequestWithContext(ctx context.Context, subject string, v any, vPtr any) error {
 	if ctx == nil {
 		return ErrInvalidContext

enc.go

@@ -24,7 +24,11 @@ import (
 	"github.com/nats-io/nats.go/encoders/builtin"
 )
 
+//lint:file-ignore SA1019 Ignore deprecation warnings for EncodedConn
+
 // Encoder interface is for all register encoders
+//
+// Deprecated: Encoded connections are no longer supported.
 type Encoder interface {
 	Encode(subject string, v any) ([]byte, error)
 	Decode(subject string, data []byte, vPtr any) error
@@ -51,13 +55,17 @@ func init() {
 // EncodedConn are the preferred way to interface with NATS. They wrap a bare connection to
 // a nats server and have an extendable encoder system that will encode and decode messages
 // from raw Go types.
+//
+// Deprecated: Encoded connections are no longer supported.
 type EncodedConn struct {
 	Conn *Conn
 	Enc  Encoder
 }
 
 // NewEncodedConn will wrap an existing Connection and utilize the appropriate registered
 // encoder.
+//
+// Deprecated: Encoded connections are no longer supported.
 func NewEncodedConn(c *Conn, encType string) (*EncodedConn, error) {
 	if c == nil {
 		return nil, errors.New("nats: Nil Connection")
@@ -73,13 +81,17 @@ func NewEncodedConn(c *Conn, encType string) (*EncodedConn, error) {
 }
 
 // RegisterEncoder will register the encType with the given Encoder. Useful for customization.
+//
+// Deprecated: Encoded connections are no longer supported.
 func RegisterEncoder(encType string, enc Encoder) {
 	encLock.Lock()
 	defer encLock.Unlock()
 	encMap[encType] = enc
 }
 
 // EncoderForType will return the registered Encoder for the encType.
+//
+// Deprecated: Encoded connections are no longer supported.
 func EncoderForType(encType string) Encoder {
 	encLock.Lock()
 	defer encLock.Unlock()
@@ -88,6 +100,8 @@ func EncoderForType(encType string) Encoder {
 
 // Publish publishes the data argument to the given subject. The data argument
 // will be encoded using the associated encoder.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Publish(subject string, v any) error {
 	b, err := c.Enc.Encode(subject, v)
 	if err != nil {
@@ -99,6 +113,8 @@ func (c *EncodedConn) Publish(subject string, v any) error {
 // PublishRequest will perform a Publish() expecting a response on the
 // reply subject. Use Request() for automatically waiting for a response
 // inline.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) PublishRequest(subject, reply string, v any) error {
 	b, err := c.Enc.Encode(subject, v)
 	if err != nil {
@@ -110,6 +126,8 @@ func (c *EncodedConn) PublishRequest(subject, reply string, v any) error {
 // Request will create an Inbox and perform a Request() call
 // with the Inbox reply for the data v. A response will be
 // decoded into the vPtr Response.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Request(subject string, v any, vPtr any, timeout time.Duration) error {
 	b, err := c.Enc.Encode(subject, v)
 	if err != nil {
@@ -150,6 +168,8 @@ func (c *EncodedConn) Request(subject string, v any, vPtr any, timeout time.Dura
 // and demarshal it into the given struct, e.g. person.
 // There are also variants where the callback wants either the subject, or the
 // subject and the reply subject.
+//
+// Deprecated: Encoded connections are no longer supported.
 type Handler any
 
 // Dissect the cb Handler's signature
@@ -170,13 +190,17 @@ var emptyMsgType = reflect.TypeOf(&Msg{})
 // Subscribe will create a subscription on the given subject and process incoming
 // messages using the specified Handler. The Handler should be a func that matches
 // a signature from the description of Handler from above.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Subscribe(subject string, cb Handler) (*Subscription, error) {
 	return c.subscribe(subject, _EMPTY_, cb)
 }
 
 // QueueSubscribe will create a queue subscription on the given subject and process
 // incoming messages using the specified Handler. The Handler should be a func that
 // matches a signature from the description of Handler from above.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) QueueSubscribe(subject, queue string, cb Handler) (*Subscription, error) {
 	return c.subscribe(subject, queue, cb)
 }
@@ -238,18 +262,24 @@ func (c *EncodedConn) subscribe(subject, queue string, cb Handler) (*Subscriptio
 }
 
 // FlushTimeout allows a Flush operation to have an associated timeout.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) FlushTimeout(timeout time.Duration) (err error) {
 	return c.Conn.FlushTimeout(timeout)
 }
 
 // Flush will perform a round trip to the server and return when it
 // receives the internal reply.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Flush() error {
 	return c.Conn.Flush()
 }
 
 // Close will close the connection to the server. This call will release
 // all blocking calls, such as Flush(), etc.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Close() {
 	c.Conn.Close()
 }
@@ -259,11 +289,15 @@ func (c *EncodedConn) Close() {
 // will be drained and can not publish any additional messages. Upon draining
 // of the publishers, the connection will be closed. Use the ClosedCB()
 // option to know when the connection has moved from draining to closed.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) Drain() error {
 	return c.Conn.Drain()
 }
 
 // LastError reports the last error encountered via the Connection.
+//
+// Deprecated: Encoded connections are no longer supported.
 func (c *EncodedConn) LastError() error {
 	return c.Conn.LastError()
 }

encoders/builtin/default_enc.go

@@ -26,6 +26,8 @@ import (
 // turn numbers into appropriate strings that can be decoded. It will also
 // properly encoded and decode bools. If will encode a struct, but if you want
 // to properly handle structures you should use JsonEncoder.
+//
+// Deprecated: Encoded connections are no longer supported.
 type DefaultEncoder struct {
 	// Empty
 }
@@ -35,6 +37,8 @@ var falseB = []byte("false")
 var nilB = []byte("")
 
 // Encode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (je *DefaultEncoder) Encode(subject string, v any) ([]byte, error) {
 	switch arg := v.(type) {
 	case string:
@@ -58,6 +62,8 @@ func (je *DefaultEncoder) Encode(subject string, v any) ([]byte, error) {
 }
 
 // Decode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (je *DefaultEncoder) Decode(subject string, data []byte, vPtr any) error {
 	// Figure out what it's pointing to...
 	sData := *(*string)(unsafe.Pointer(&data))

encoders/builtin/gob_enc.go

@@ -21,13 +21,17 @@ import (
 // GobEncoder is a Go specific GOB Encoder implementation for EncodedConn.
 // This encoder will use the builtin encoding/gob to Marshal
 // and Unmarshal most types, including structs.
+//
+// Deprecated: Encoded connections are no longer supported.
 type GobEncoder struct {
 	// Empty
 }
 
 // FIXME(dlc) - This could probably be more efficient.
 
 // Encode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (ge *GobEncoder) Encode(subject string, v any) ([]byte, error) {
 	b := new(bytes.Buffer)
 	enc := gob.NewEncoder(b)
@@ -38,6 +42,8 @@ func (ge *GobEncoder) Encode(subject string, v any) ([]byte, error) {
 }
 
 // Decode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (ge *GobEncoder) Decode(subject string, data []byte, vPtr any) (err error) {
 	dec := gob.NewDecoder(bytes.NewBuffer(data))
 	err = dec.Decode(vPtr)

encoders/builtin/json_enc.go

@@ -21,11 +21,15 @@ import (
 // JsonEncoder is a JSON Encoder implementation for EncodedConn.
 // This encoder will use the builtin encoding/json to Marshal
 // and Unmarshal most types, including structs.
+//
+// Deprecated: Encoded connections are no longer supported.
 type JsonEncoder struct {
 	// Empty
 }
 
 // Encode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (je *JsonEncoder) Encode(subject string, v any) ([]byte, error) {
 	b, err := json.Marshal(v)
 	if err != nil {
@@ -35,6 +39,8 @@ func (je *JsonEncoder) Encode(subject string, v any) ([]byte, error) {
 }
 
 // Decode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (je *JsonEncoder) Decode(subject string, data []byte, vPtr any) (err error) {
 	switch arg := vPtr.(type) {
 	case *string:

encoders/protobuf/protobuf_enc.go

@@ -20,6 +20,8 @@ import (
 	"google.golang.org/protobuf/proto"
 )
 
+//lint:file-ignore SA1019 Ignore deprecation warnings for EncodedConn
+
 // Additional index for registered Encoders.
 const (
 	PROTOBUF_ENCODER = "protobuf"
@@ -33,6 +35,8 @@ func init() {
 // ProtobufEncoder is a protobuf implementation for EncodedConn
 // This encoder will use the builtin protobuf lib to Marshal
 // and Unmarshal structs.
+//
+// Deprecated: Encoded connections are no longer supported.
 type ProtobufEncoder struct {
 	// Empty
 }
@@ -43,6 +47,8 @@ var (
 )
 
 // Encode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (pb *ProtobufEncoder) Encode(subject string, v any) ([]byte, error) {
 	if v == nil {
 		return nil, nil
@@ -60,6 +66,8 @@ func (pb *ProtobufEncoder) Encode(subject string, v any) ([]byte, error) {
 }
 
 // Decode
+//
+// Deprecated: Encoded connections are no longer supported.
 func (pb *ProtobufEncoder) Decode(subject string, data []byte, vPtr any) error {
 	if _, ok := vPtr.(*any); ok {
 		return nil