cmd/blsync, beacon/light: standalone beacon light sync tool

beacon/light/api/api_server.go

@@ -0,0 +1,93 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package api
+
+import (
+	"sync/atomic"
+
+	"github.com/ethereum/go-ethereum/beacon/light/request"
+	"github.com/ethereum/go-ethereum/beacon/light/sync"
+	"github.com/ethereum/go-ethereum/beacon/types"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
+)
+
+type ApiServer struct {
+	api           *BeaconLightApi
+	eventCallback func(event request.Event)
+	unsubscribe   func()
+	lastId        uint64
+}
+
+func NewApiServer(api *BeaconLightApi) *ApiServer {
+	return &ApiServer{api: api}
+}
+
+func (s *ApiServer) Subscribe(eventCallback func(event request.Event)) {
+	s.eventCallback = eventCallback
+	s.unsubscribe = s.api.StartHeadListener(func(slot uint64, blockRoot common.Hash) {
+		eventCallback(request.Event{Type: sync.EvNewHead, Data: types.HeadInfo{Slot: slot, BlockRoot: blockRoot}})
+	}, func(head types.SignedHeader) {
+		eventCallback(request.Event{Type: sync.EvNewSignedHead, Data: head})
+	}, func(err error) {
+		log.Warn("Head event stream error", "err", err)
+	})
+}
+
+func (s *ApiServer) SendRequest(req request.Request) request.ID {
+	id := request.ID(atomic.AddUint64(&s.lastId, 1))
+	go func() {
+		var resp request.Response
+		switch data := req.(type) {
+		case sync.ReqUpdates:
+			if updates, committees, err := s.api.GetBestUpdatesAndCommittees(data.FirstPeriod, data.Count); err == nil {
+				resp = sync.RespUpdates{Updates: updates, Committees: committees}
+			}
+		/*case sync.ReqOptimisticHead:
+		if signedHead, err := s.api.GetOptimisticHeadUpdate(); err == nil {
+			resp = signedHead
+		}*/ //TODO ???
+		case sync.ReqHeader:
+			if header, err := s.api.GetHeader(common.Hash(data)); err == nil {
+				resp = header
+			}
+		case sync.ReqCheckpointData:
+			if bootstrap, err := s.api.GetCheckpointData(common.Hash(data)); err == nil {
+				resp = bootstrap
+			}
+		case sync.ReqBeaconBlock:
+			if block, err := s.api.GetBeaconBlock(common.Hash(data)); err == nil {
+				resp = block
+			}
+		default:
+		}
+		if resp != nil {
+			s.eventCallback(request.Event{Type: request.EvResponse, Data: request.IdAndResponse{ID: id, Response: resp}})
+		} else {
+			s.eventCallback(request.Event{Type: request.EvFail, Data: id})
+		}
+	}()
+	return id
+}
+
+// Note: UnsubscribeHeads should not be called concurrently with SubscribeHeads
+func (s *ApiServer) Unsubscribe() {
+	if s.unsubscribe != nil {
+		s.unsubscribe()
+		s.unsubscribe = nil
+	}
+}