internal/jsonrpc2_v2: remove “Box” suffix from channel field names

With the suffixes I end up a little lost in the “box” noise while I'm
reading — the channel ops alone suffice to make the storage mechanism
clear.

(To me, the mechanism of storing a value in a 1-buffered channel is
conceptually similar to storing it in a pointer, atomic.Pointer, or
similar — and we don't generally name those with a suffix either.)

For golang/go#46047.
For golang/go#46520.
For golang/go#49387.

Change-Id: I7f58a9ac532f597fe49ed70606d89bd8cbe33b55
Reviewed-on: https://go-review.googlesource.com/c/tools/+/443355
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Bryan Mills <bcmills@google.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>

internal/jsonrpc2_v2/conn.go

@@ -51,17 +51,17 @@ type Connection struct {
 	closeOnce sync.Once
 	closer    io.Closer
 
-	writerBox   chan Writer
-	outgoingBox chan map[ID]chan<- *Response
-	incomingBox chan map[ID]*incoming
-	async       *async
+	writer   chan Writer
+	outgoing chan map[ID]chan<- *Response
+	incoming chan map[ID]*incoming
+	async    *async
 }
 
 type AsyncCall struct {
-	id        ID
-	response  chan *Response // the channel a response will be delivered on
-	resultBox chan asyncResult
-	endSpan   func() // close the tracing span when all processing for the message is complete
+	id       ID
+	response chan *Response // the channel a response will be delivered on
+	result   chan asyncResult
+	endSpan  func() // close the tracing span when all processing for the message is complete
 }
 
 type asyncResult struct {
@@ -87,11 +87,11 @@ func (o ConnectionOptions) Bind(context.Context, *Connection) (ConnectionOptions
 // This is used by the Dial and Serve functions to build the actual connection.
 func newConnection(ctx context.Context, rwc io.ReadWriteCloser, binder Binder) (*Connection, error) {
 	c := &Connection{
-		closer:      rwc,
-		writerBox:   make(chan Writer, 1),
-		outgoingBox: make(chan map[ID]chan<- *Response, 1),
-		incomingBox: make(chan map[ID]*incoming, 1),
-		async:       newAsync(),
+		closer:   rwc,
+		writer:   make(chan Writer, 1),
+		outgoing: make(chan map[ID]chan<- *Response, 1),
+		incoming: make(chan map[ID]*incoming, 1),
+		async:    newAsync(),
 	}
 
 	options, err := binder.Bind(ctx, c)
@@ -107,8 +107,8 @@ func newConnection(ctx context.Context, rwc io.ReadWriteCloser, binder Binder) (
 	if options.Handler == nil {
 		options.Handler = defaultHandler{}
 	}
-	c.outgoingBox <- make(map[ID]chan<- *Response)
-	c.incomingBox <- make(map[ID]*incoming)
+	c.outgoing <- make(map[ID]chan<- *Response)
+	c.incoming <- make(map[ID]*incoming)
 	// the goroutines started here will continue until the underlying stream is closed
 	reader := options.Framer.Reader(rwc)
 	readToQueue := make(chan *incoming)
@@ -119,7 +119,7 @@ func newConnection(ctx context.Context, rwc io.ReadWriteCloser, binder Binder) (
 
 	// releaseing the writer must be the last thing we do in case any requests
 	// are blocked waiting for the connection to be ready
-	c.writerBox <- options.Framer.Writer(rwc)
+	c.writer <- options.Framer.Writer(rwc)
 	return c, nil
 }
 
@@ -154,14 +154,14 @@ func (c *Connection) Notify(ctx context.Context, method string, params interface
 // If sending the call failed, the response will be ready and have the error in it.
 func (c *Connection) Call(ctx context.Context, method string, params interface{}) *AsyncCall {
 	result := &AsyncCall{
-		id:        Int64ID(atomic.AddInt64(&c.seq, 1)),
-		resultBox: make(chan asyncResult, 1),
+		id:     Int64ID(atomic.AddInt64(&c.seq, 1)),
+		result: make(chan asyncResult, 1),
 	}
 	// generate a new request identifier
 	call, err := NewCall(result.id, method, params)
 	if err != nil {
 		//set the result to failed
-		result.resultBox <- asyncResult{err: fmt.Errorf("marshaling call parameters: %w", err)}
+		result.result <- asyncResult{err: fmt.Errorf("marshaling call parameters: %w", err)}
 		return result
 	}
 	ctx, endSpan := event.Start(ctx, method,
@@ -175,7 +175,7 @@ func (c *Connection) Call(ctx context.Context, method string, params interface{}
 	// are racing the response.
 	// rchan is buffered in case the response arrives without a listener.
 	result.response = make(chan *Response, 1)
-	outgoing, ok := <-c.outgoingBox
+	outgoing, ok := <-c.outgoing
 	if !ok {
 		// If the call failed due to (say) an I/O error or broken pipe, attribute it
 		// as such. (If the error is nil, then the connection must have been shut
@@ -193,7 +193,7 @@ func (c *Connection) Call(ctx context.Context, method string, params interface{}
 		return result
 	}
 	outgoing[result.id] = result.response
-	c.outgoingBox <- outgoing
+	c.outgoing <- outgoing
 	// now we are ready to send
 	if err := c.write(ctx, call); err != nil {
 		// sending failed, we will never get a response, so deliver a fake one
@@ -212,8 +212,8 @@ func (a *AsyncCall) ID() ID { return a.id }
 // returned, or a call that failed to send in the first place.
 func (a *AsyncCall) IsReady() bool {
 	select {
-	case r := <-a.resultBox:
-		a.resultBox <- r
+	case r := <-a.result:
+		a.result <- r
 		return true
 	default:
 		return false
@@ -236,14 +236,14 @@ func (a *AsyncCall) Await(ctx context.Context, result interface{}) error {
 			r.result = response.Result
 			event.Label(ctx, tag.StatusCode.Of("OK"))
 		}
-	case r = <-a.resultBox:
+	case r = <-a.result:
 		// result already available
 	case <-ctx.Done():
 		event.Label(ctx, tag.StatusCode.Of("CANCELLED"))
 		return ctx.Err()
 	}
 	// refill the box for the next caller
-	a.resultBox <- r
+	a.result <- r
 	// and unpack the result
 	if r.err != nil {
 		return r.err
@@ -259,8 +259,8 @@ func (a *AsyncCall) Await(ctx context.Context, result interface{}) error {
 // Respond must be called exactly once for any message for which a handler
 // returns ErrAsyncResponse. It must not be called for any other message.
 func (c *Connection) Respond(id ID, result interface{}, rerr error) error {
-	pending := <-c.incomingBox
-	defer func() { c.incomingBox <- pending }()
+	pending := <-c.incoming
+	defer func() { c.incoming <- pending }()
 	entry, found := pending[id]
 	if !found {
 		return nil
@@ -277,8 +277,8 @@ func (c *Connection) Respond(id ID, result interface{}, rerr error) error {
 // not cause any messages that have not arrived yet with that ID to be
 // cancelled.
 func (c *Connection) Cancel(id ID) {
-	pending := <-c.incomingBox
-	defer func() { c.incomingBox <- pending }()
+	pending := <-c.incoming
+	defer func() { c.incoming <- pending }()
 	if entry, found := pending[id]; found && entry.cancel != nil {
 		entry.cancel()
 		entry.cancel = nil
@@ -310,10 +310,10 @@ func (c *Connection) readIncoming(ctx context.Context, reader Reader, toQueue ch
 	defer func() {
 		// Retire any outgoing requests that were still in flight.
 		// With the Reader no longer being processed, they necessarily cannot receive a response.
-		outgoing := <-c.outgoingBox
-		close(c.outgoingBox) // Prevent new outgoing requests, which would deadlock.
-		for id, responseBox := range outgoing {
-			responseBox <- &Response{ID: id, Error: err}
+		outgoing := <-c.outgoing
+		close(c.outgoing) // Prevent new outgoing requests, which would deadlock.
+		for id, response := range outgoing {
+			response <- &Response{ID: id, Error: err}
 		}
 
 		close(toQueue)
@@ -352,9 +352,9 @@ func (c *Connection) readIncoming(ctx context.Context, reader Reader, toQueue ch
 			// if the request is a call, add it to the incoming map so it can be
 			// cancelled by id
 			if msg.IsCall() {
-				pending := <-c.incomingBox
+				pending := <-c.incoming
 				pending[msg.ID] = entry
-				c.incomingBox <- pending
+				c.incoming <- pending
 			}
 			// send the message to the incoming queue
 			toQueue <- entry
@@ -368,10 +368,10 @@ func (c *Connection) readIncoming(ctx context.Context, reader Reader, toQueue ch
 
 func (c *Connection) incomingResponse(msg *Response) {
 	var response chan<- *Response
-	if outgoing, ok := <-c.outgoingBox; ok {
+	if outgoing, ok := <-c.outgoing; ok {
 		response = outgoing[msg.ID]
 		delete(outgoing, msg.ID)
-		c.outgoingBox <- outgoing
+		c.outgoing <- outgoing
 	}
 	if response != nil {
 		response <- msg
@@ -468,8 +468,8 @@ func (c *Connection) deliverMessages(ctx context.Context, handler Handler, fromQ
 func (c *Connection) reply(entry *incoming, result interface{}, rerr error) {
 	if entry.request.IsCall() {
 		// we have a call finishing, remove it from the incoming map
-		pending := <-c.incomingBox
-		defer func() { c.incomingBox <- pending }()
+		pending := <-c.incoming
+		defer func() { c.incoming <- pending }()
 		delete(pending, entry.request.ID)
 	}
 	if err := c.respond(entry, result, rerr); err != nil {
@@ -527,8 +527,8 @@ func (c *Connection) respond(entry *incoming, result interface{}, rerr error) er
 // write is used by all things that write outgoing messages, including replies.
 // it makes sure that writes are atomic
 func (c *Connection) write(ctx context.Context, msg Message) error {
-	writer := <-c.writerBox
-	defer func() { c.writerBox <- writer }()
+	writer := <-c.writer
+	defer func() { c.writer <- writer }()
 	n, err := writer.Write(ctx, msg)
 	event.Metric(ctx, tag.SentBytes.Of(n))
 	return err

internal/jsonrpc2_v2/jsonrpc2_test.go

@@ -77,7 +77,7 @@ type binder struct {
 type handler struct {
 	conn        *jsonrpc2.Connection
 	accumulator int
-	waitersBox  chan map[string]chan struct{}
+	waiters     chan map[string]chan struct{}
 	calls       map[string]*jsonrpc2.AsyncCall
 }
 
@@ -256,11 +256,11 @@ func verifyResults(t *testing.T, method string, results interface{}, expect inte
 
 func (b binder) Bind(ctx context.Context, conn *jsonrpc2.Connection) (jsonrpc2.ConnectionOptions, error) {
 	h := &handler{
-		conn:       conn,
-		waitersBox: make(chan map[string]chan struct{}, 1),
-		calls:      make(map[string]*jsonrpc2.AsyncCall),
+		conn:    conn,
+		waiters: make(chan map[string]chan struct{}, 1),
+		calls:   make(map[string]*jsonrpc2.AsyncCall),
 	}
-	h.waitersBox <- make(map[string]chan struct{})
+	h.waiters <- make(map[string]chan struct{})
 	if b.runTest != nil {
 		go b.runTest(h)
 	}
@@ -272,8 +272,8 @@ func (b binder) Bind(ctx context.Context, conn *jsonrpc2.Connection) (jsonrpc2.C
 }
 
 func (h *handler) waiter(name string) chan struct{} {
-	waiters := <-h.waitersBox
-	defer func() { h.waitersBox <- waiters }()
+	waiters := <-h.waiters
+	defer func() { h.waiters <- waiters }()
 	waiter, found := waiters[name]
 	if !found {
 		waiter = make(chan struct{})