beacon/light/sync: add unit tests

beacon/light/sync/head_sync.go

@@ -67,11 +67,15 @@ func (s *HeadSync) Process(tracker request.Tracker, requestEvents []request.Requ
 	for _, event := range serverEvents {
 		switch event.Type {
 		case EvNewHead:
-			trigger = trigger || s.setServerHead(event.Server, event.Data.(types.HeadInfo))
+			if s.setServerHead(event.Server, event.Data.(types.HeadInfo)) {
+				trigger = true
+			}
 		case EvNewSignedHead:
 			s.newSignedHead(event.Server, event.Data.(types.SignedHeader))
 		case request.EvUnregistered:
-			trigger = trigger || s.setServerHead(event.Server, types.HeadInfo{})
+			if s.setServerHead(event.Server, types.HeadInfo{}) {
+				trigger = true
+			}
 			delete(s.serverHeads, event.Server)
 			delete(s.queuedHeads, event.Server)
 		}
@@ -81,6 +85,7 @@ func (s *HeadSync) Process(tracker request.Tracker, requestEvents []request.Requ
 
 func (s *HeadSync) newSignedHead(server any, signedHead types.SignedHeader) {
 	if signedHead.Header.SyncPeriod() > s.nextSyncPeriod {
+		//TODO avoid excessively long queues
 		s.queuedHeads[server] = append(s.queuedHeads[server], signedHead)
 		return
 	}
@@ -129,6 +134,9 @@ func (s *HeadSync) setServerHead(server any, head types.HeadInfo) bool {
 		}
 		h.serverCount++
 		s.headServerCount[head] = h
+		s.serverHeads[server] = head
+	} else {
+		delete(s.serverHeads, server)
 	}
 	var (
 		bestHead     types.HeadInfo

beacon/light/sync/head_sync_test.go

@@ -0,0 +1,118 @@
+// 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 sync
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/beacon/light/request"
+	"github.com/ethereum/go-ethereum/beacon/types"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+var (
+	testServer1 = 1
+	testServer2 = 2
+	testServer3 = 3
+	testServer4 = 4
+
+	testHead0 = types.HeadInfo{}
+	testHead1 = types.HeadInfo{Slot: 123, BlockRoot: common.Hash{1}}
+	testHead2 = types.HeadInfo{Slot: 124, BlockRoot: common.Hash{2}}
+	testHead3 = types.HeadInfo{Slot: 124, BlockRoot: common.Hash{3}}
+	testHead4 = types.HeadInfo{Slot: 125, BlockRoot: common.Hash{4}}
+)
+
+/*func TestValidatedHead(t *testing.T) {
+	tracker := &testTracker{}
+	chain := &testCommitteeChain{}
+	headTracker := &testHeadTracker{
+		cc:     chain,
+		accept: true,
+	}
+	headSync := NewHeadSync(headTracker, chain)
+	var index int
+	expHead := func(exp types.HeadInfo) {
+		index++
+		if headTracker.vhead != exp {
+			t.Errorf("Wrong validated head #%d (expected {slot %d blockRoot %x}, got {slot %d blockRoot %x})", index, exp.Slot, exp.BlockRoot, headTracker.phead.Slot, headTracker.phead.BlockRoot)
+		}
+	}
+}*/
+
+func TestPrefetchHead(t *testing.T) {
+	tracker := &testTracker{}
+	chain := &testCommitteeChain{}
+	headTracker := &testHeadTracker{
+		cc:     chain,
+		accept: true,
+	}
+	headSync := NewHeadSync(headTracker, chain)
+	var index int
+	expHead := func(exp types.HeadInfo) {
+		index++
+		if headTracker.phead != exp {
+			t.Errorf("Wrong prefetch head #%d (expected {slot %d blockRoot %x}, got {slot %d blockRoot %x})", index, exp.Slot, exp.BlockRoot, headTracker.phead.Slot, headTracker.phead.BlockRoot)
+		}
+	}
+
+	expHead(testHead0) // no servers registered
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer1, Type: request.EvRegistered},
+		{Server: testServer1, Type: EvNewHead, Data: testHead1},
+	})
+	expHead(testHead1) // s1: h1
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer2, Type: request.EvRegistered},
+		{Server: testServer2, Type: EvNewHead, Data: testHead2},
+	})
+	expHead(testHead2) // s1: h1, s2: h2
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer1, Type: EvNewHead, Data: testHead2},
+	})
+	expHead(testHead2) // s1: h2, s2: h2
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer3, Type: request.EvRegistered},
+		{Server: testServer3, Type: EvNewHead, Data: testHead3},
+	})
+	expHead(testHead2) // s1: h2, s2: h2, s3: h3
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer4, Type: request.EvRegistered},
+		{Server: testServer4, Type: EvNewHead, Data: testHead4},
+	})
+	expHead(testHead2) // s1: h2, s2: h2, s3: h3, s4: h4
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer2, Type: EvNewHead, Data: testHead3},
+	})
+	expHead(testHead3) // s1: h2, s2: h3, s3: h3, s4: h4
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer3, Type: request.EvUnregistered},
+	})
+	expHead(testHead4) // s1: h2, s2: h3, s4: h4
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer1, Type: request.EvUnregistered},
+	})
+	expHead(testHead4) // s2: h3, s4: h4
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer4, Type: request.EvUnregistered},
+	})
+	expHead(testHead3) // s2: h3
+	headSync.Process(tracker, nil, []request.ServerEvent{
+		{Server: testServer2, Type: request.EvUnregistered},
+	})
+	expHead(testHead0) // no servers registered
+}

beacon/light/sync/test_helpers.go

@@ -0,0 +1,71 @@
+// 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 sync
+
+import (
+	"errors"
+
+	"github.com/ethereum/go-ethereum/beacon/light/request"
+	"github.com/ethereum/go-ethereum/beacon/types"
+)
+
+type testTracker struct{}
+
+func (t *testTracker) TryRequest(requestFn func(server any) (request.Request, float32)) (request.ServerAndId, request.Request) {
+	return request.ServerAndId{}, nil
+}
+
+func (t *testTracker) InvalidResponse(id request.ServerAndId, desc string) {
+	return
+}
+
+type testCommitteeChain struct {
+	nsp  uint64
+	init bool
+}
+
+func (t *testCommitteeChain) CheckpointInit(bootstrap types.BootstrapData) error {
+	return nil
+}
+
+func (t *testCommitteeChain) InsertUpdate(update *types.LightClientUpdate, nextCommittee *types.SerializedSyncCommittee) error {
+	return nil
+}
+
+func (t *testCommitteeChain) NextSyncPeriod() (uint64, bool) {
+	return t.nsp, t.init
+}
+
+type testHeadTracker struct {
+	cc     *testCommitteeChain
+	phead  types.HeadInfo
+	accept bool
+}
+
+func (t *testHeadTracker) Validate(head types.SignedHeader) (bool, error) {
+	if !t.cc.init || types.SyncPeriod(head.SignatureSlot) > t.cc.nsp {
+		return false, errors.New("committee unknown")
+	}
+	if t.accept {
+		return true, nil
+	}
+	return false, errors.New("invalid signature")
+}
+
+func (t *testHeadTracker) SetPrefetchHead(head types.HeadInfo) {
+	t.phead = head
+}