status-go/vendor/go.lsp.dev/protocol/handler.go

89 lines
2.6 KiB
Go

// SPDX-FileCopyrightText: 2021 The Go Language Server Authors
// SPDX-License-Identifier: BSD-3-Clause
package protocol
import (
"context"
"fmt"
"github.com/segmentio/encoding/json"
"go.lsp.dev/jsonrpc2"
"go.lsp.dev/pkg/xcontext"
)
// CancelHandler handler of cancelling.
func CancelHandler(handler jsonrpc2.Handler) jsonrpc2.Handler {
handler, canceller := jsonrpc2.CancelHandler(handler)
h := func(ctx context.Context, reply jsonrpc2.Replier, req jsonrpc2.Request) error {
if req.Method() != MethodCancelRequest {
// TODO(iancottrell): See if we can generate a reply for the request to be cancelled
// at the point of cancellation rather than waiting for gopls to naturally reply.
// To do that, we need to keep track of whether a reply has been sent already and
// be careful about racing between the two paths.
// TODO(iancottrell): Add a test that watches the stream and verifies the response
// for the cancelled request flows.
reply := func(ctx context.Context, resp interface{}, err error) error {
// https://microsoft.github.io/language-server-protocol/specifications/specification-current/#cancelRequest
if ctx.Err() != nil && err == nil {
err = ErrRequestCancelled
}
ctx = xcontext.Detach(ctx)
return reply(ctx, resp, err)
}
return handler(ctx, reply, req)
}
var params CancelParams
if err := json.Unmarshal(req.Params(), &params); err != nil {
return replyParseError(ctx, reply, err)
}
switch id := params.ID.(type) {
case int32:
canceller(jsonrpc2.NewNumberID(id))
case string:
canceller(jsonrpc2.NewStringID(id))
default:
return replyParseError(ctx, reply, fmt.Errorf("request ID %v malformed", id))
}
return reply(ctx, nil, nil)
}
return h
}
// Handlers default jsonrpc2.Handler.
func Handlers(handler jsonrpc2.Handler) jsonrpc2.Handler {
return CancelHandler(
jsonrpc2.AsyncHandler(
jsonrpc2.ReplyHandler(handler),
),
)
}
// Call calls method to params and result.
func Call(ctx context.Context, conn jsonrpc2.Conn, method string, params, result interface{}) error {
id, err := conn.Call(ctx, method, params, result)
if ctx.Err() != nil {
notifyCancel(ctx, conn, id)
}
return err
}
func notifyCancel(ctx context.Context, conn jsonrpc2.Conn, id jsonrpc2.ID) {
ctx = xcontext.Detach(ctx)
// Note that only *jsonrpc2.ID implements json.Marshaler.
conn.Notify(ctx, MethodCancelRequest, &CancelParams{ID: &id})
}
func replyParseError(ctx context.Context, reply jsonrpc2.Replier, err error) error {
return reply(ctx, nil, fmt.Errorf("%s: %w", jsonrpc2.ErrParse, err))
}