Add status service implementation

common/commonspace/statusservice/statusservice.go

@@ -1,10 +1,117 @@
 package statusservice
 
+import (
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/common/app/logger"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/common/nodeconf"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/common/util/slice"
+	"golang.org/x/exp/slices"
+	"sync"
+)
+
+var log = logger.NewNamed("commonspace.statusservice")
+
 type StatusService interface {
 	HeadsChange(treeId string, heads []string)
 	HeadsReceive(senderId, treeId string, heads []string)
-	Watch(treeId string, ch chan struct{})
+	Watch(treeId string, ch chan bool)
 	Unwatch(treeId string)
 	StateCounter() uint64
 	RemoveAllExcept(senderId string, differentRemoteIds []string, stateCounter uint64)
 }
+
+type statusEntry struct {
+	head         string
+	stateCounter uint64
+}
+
+type statusService struct {
+	sync.Mutex
+	spaceId       string
+	treeHeads     map[string]statusEntry
+	watchers      map[string]chan bool
+	configuration nodeconf.Configuration
+	stateCounter  uint64
+}
+
+func NewStatusService(spaceId string, configuration nodeconf.Configuration) StatusService {
+	return &statusService{
+		spaceId:       spaceId,
+		treeHeads:     map[string]statusEntry{},
+		watchers:      map[string]chan bool{},
+		configuration: configuration,
+		stateCounter:  0,
+	}
+}
+
+func (s *statusService) HeadsChange(treeId string, heads []string) {
+	s.Lock()
+	defer s.Unlock()
+	s.treeHeads[treeId] = statusEntry{
+		head:         heads[0],
+		stateCounter: s.stateCounter,
+	}
+	if watcher, ok := s.watchers[treeId]; ok {
+		select {
+		case watcher <- false:
+		default:
+		}
+	}
+	s.stateCounter++
+}
+
+func (s *statusService) HeadsReceive(senderId, treeId string, heads []string) {
+	s.Lock()
+	defer s.Unlock()
+	curHead, ok := s.treeHeads[treeId]
+	if !ok {
+		return
+	}
+	if len(heads) == 0 || !slices.Contains(s.configuration.NodeIds(s.spaceId), senderId) {
+		return
+	}
+	if slice.FindPos(heads, curHead.head) == -1 {
+		return
+	}
+	delete(s.treeHeads, treeId)
+	if watcher, ok := s.watchers[treeId]; ok {
+		select {
+		case watcher <- true:
+		default:
+		}
+	}
+}
+
+func (s *statusService) Watch(treeId string, ch chan bool) {
+	s.Lock()
+	defer s.Unlock()
+	s.watchers[treeId] = ch
+}
+
+func (s *statusService) Unwatch(treeId string) {
+	s.Lock()
+	defer s.Unlock()
+	delete(s.watchers, treeId)
+}
+
+func (s *statusService) StateCounter() uint64 {
+	s.Lock()
+	defer s.Unlock()
+	return s.stateCounter
+}
+
+func (s *statusService) RemoveAllExcept(senderId string, differentRemoteIds []string, stateCounter uint64) {
+	if !slices.Contains(s.configuration.NodeIds(s.spaceId), senderId) {
+		return
+	}
+	s.Lock()
+	defer s.Unlock()
+	slices.Sort(differentRemoteIds)
+	for treeId, entry := range s.treeHeads {
+		if entry.stateCounter > stateCounter {
+			continue
+		}
+		if _, found := slices.BinarySearch(differentRemoteIds, treeId); !found {
+			delete(s.treeHeads, treeId)
+		}
+	}
+}