Snap for 9757917 from 09c5a32afc5b66f28f166a68afe1fc71afbf9b73 to build-tools-releasebuild-tools-release

Change-Id: If48e809642d94de846f47e34b88e446095e21aa5

1 files changed, 148 insertions, 0 deletions

diff --git a/gopls/internal/lsp/lsprpc/binder.go b/gopls/internal/lsp/lsprpc/binder.go
new file mode 100644
index 000000000..01e59f7bb
--- /dev/null
+++ b/gopls/internal/lsp/lsprpc/binder.go
@@ -0,0 +1,148 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package lsprpc
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+
+	"golang.org/x/tools/gopls/internal/lsp/protocol"
+	"golang.org/x/tools/internal/event"
+	jsonrpc2_v2 "golang.org/x/tools/internal/jsonrpc2_v2"
+	"golang.org/x/tools/internal/xcontext"
+)
+
+// The BinderFunc type adapts a bind function to implement the jsonrpc2.Binder
+// interface.
+type BinderFunc func(ctx context.Context, conn *jsonrpc2_v2.Connection) jsonrpc2_v2.ConnectionOptions
+
+func (f BinderFunc) Bind(ctx context.Context, conn *jsonrpc2_v2.Connection) jsonrpc2_v2.ConnectionOptions {
+	return f(ctx, conn)
+}
+
+// Middleware defines a transformation of jsonrpc2 Binders, that may be
+// composed to build jsonrpc2 servers.
+type Middleware func(jsonrpc2_v2.Binder) jsonrpc2_v2.Binder
+
+// A ServerFunc is used to construct an LSP server for a given client.
+type ServerFunc func(context.Context, protocol.ClientCloser) protocol.Server
+
+// ServerBinder binds incoming connections to a new server.
+type ServerBinder struct {
+	newServer ServerFunc
+}
+
+func NewServerBinder(newServer ServerFunc) *ServerBinder {
+	return &ServerBinder{newServer: newServer}
+}
+
+func (b *ServerBinder) Bind(ctx context.Context, conn *jsonrpc2_v2.Connection) jsonrpc2_v2.ConnectionOptions {
+	client := protocol.ClientDispatcherV2(conn)
+	server := b.newServer(ctx, client)
+	serverHandler := protocol.ServerHandlerV2(server)
+	// Wrap the server handler to inject the client into each request context, so
+	// that log events are reflected back to the client.
+	wrapped := jsonrpc2_v2.HandlerFunc(func(ctx context.Context, req *jsonrpc2_v2.Request) (interface{}, error) {
+		ctx = protocol.WithClient(ctx, client)
+		return serverHandler.Handle(ctx, req)
+	})
+	preempter := &canceler{
+		conn: conn,
+	}
+	return jsonrpc2_v2.ConnectionOptions{
+		Handler:   wrapped,
+		Preempter: preempter,
+	}
+}
+
+type canceler struct {
+	conn *jsonrpc2_v2.Connection
+}
+
+func (c *canceler) Preempt(ctx context.Context, req *jsonrpc2_v2.Request) (interface{}, error) {
+	if req.Method != "$/cancelRequest" {
+		return nil, jsonrpc2_v2.ErrNotHandled
+	}
+	var params protocol.CancelParams
+	if err := json.Unmarshal(req.Params, &params); err != nil {
+		return nil, fmt.Errorf("%w: %v", jsonrpc2_v2.ErrParse, err)
+	}
+	var id jsonrpc2_v2.ID
+	switch raw := params.ID.(type) {
+	case float64:
+		id = jsonrpc2_v2.Int64ID(int64(raw))
+	case string:
+		id = jsonrpc2_v2.StringID(raw)
+	default:
+		return nil, fmt.Errorf("%w: invalid ID type %T", jsonrpc2_v2.ErrParse, params.ID)
+	}
+	c.conn.Cancel(id)
+	return nil, nil
+}
+
+type ForwardBinder struct {
+	dialer jsonrpc2_v2.Dialer
+	onBind func(*jsonrpc2_v2.Connection)
+}
+
+func NewForwardBinder(dialer jsonrpc2_v2.Dialer) *ForwardBinder {
+	return &ForwardBinder{
+		dialer: dialer,
+	}
+}
+
+func (b *ForwardBinder) Bind(ctx context.Context, conn *jsonrpc2_v2.Connection) (opts jsonrpc2_v2.ConnectionOptions) {
+	client := protocol.ClientDispatcherV2(conn)
+	clientBinder := NewClientBinder(func(context.Context, protocol.Server) protocol.Client { return client })
+
+	serverConn, err := jsonrpc2_v2.Dial(context.Background(), b.dialer, clientBinder)
+	if err != nil {
+		return jsonrpc2_v2.ConnectionOptions{
+			Handler: jsonrpc2_v2.HandlerFunc(func(context.Context, *jsonrpc2_v2.Request) (interface{}, error) {
+				return nil, fmt.Errorf("%w: %v", jsonrpc2_v2.ErrInternal, err)
+			}),
+		}
+	}
+
+	if b.onBind != nil {
+		b.onBind(serverConn)
+	}
+	server := protocol.ServerDispatcherV2(serverConn)
+	preempter := &canceler{
+		conn: conn,
+	}
+	detached := xcontext.Detach(ctx)
+	go func() {
+		conn.Wait()
+		if err := serverConn.Close(); err != nil {
+			event.Log(detached, fmt.Sprintf("closing remote connection: %v", err))
+		}
+	}()
+	return jsonrpc2_v2.ConnectionOptions{
+		Handler:   protocol.ServerHandlerV2(server),
+		Preempter: preempter,
+	}
+}
+
+// A ClientFunc is used to construct an LSP client for a given server.
+type ClientFunc func(context.Context, protocol.Server) protocol.Client
+
+// ClientBinder binds an LSP client to an incoming connection.
+type ClientBinder struct {
+	newClient ClientFunc
+}
+
+func NewClientBinder(newClient ClientFunc) *ClientBinder {
+	return &ClientBinder{newClient}
+}
+
+func (b *ClientBinder) Bind(ctx context.Context, conn *jsonrpc2_v2.Connection) jsonrpc2_v2.ConnectionOptions {
+	server := protocol.ServerDispatcherV2(conn)
+	client := b.newClient(ctx, server)
+	return jsonrpc2_v2.ConnectionOptions{
+		Handler: protocol.ClientHandlerV2(client),
+	}
+}