Precompute values for userIDSet in sync notifier (#2348)

* Precompute values for `userIDSet` in sync notifier

* Mutexes

* Fixes

* Sensible initial value

* Update syncapi/notifier/notifier.go

Co-authored-by: Till <2353100+S7evinK@users.noreply.github.com>

* Placate the almighty linter

Co-authored-by: Till <2353100+S7evinK@users.noreply.github.com>
This commit is contained in:
Neil Alexander 2022-04-13 12:35:30 +01:00 committed by GitHub
parent 29f2168789
commit 1140f39993
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@ -36,7 +36,7 @@ import (
type Notifier struct {
lock *sync.RWMutex
// A map of RoomID => Set<UserID> : Must only be accessed by the OnNewEvent goroutine
roomIDToJoinedUsers map[string]userIDSet
roomIDToJoinedUsers map[string]*userIDSet
// A map of RoomID => Set<UserID> : Must only be accessed by the OnNewEvent goroutine
roomIDToPeekingDevices map[string]peekingDeviceSet
// The latest sync position
@ -54,7 +54,7 @@ type Notifier struct {
// the joined users within each of them by calling Notifier.Load(*storage.SyncServerDatabase).
func NewNotifier() *Notifier {
return &Notifier{
roomIDToJoinedUsers: make(map[string]userIDSet),
roomIDToJoinedUsers: make(map[string]*userIDSet),
roomIDToPeekingDevices: make(map[string]peekingDeviceSet),
userDeviceStreams: make(map[string]map[string]*UserDeviceStream),
lock: &sync.RWMutex{},
@ -262,7 +262,7 @@ func (n *Notifier) SharedUsers(userID string) []string {
func (n *Notifier) _sharedUsers(userID string) []string {
n._sharedUserMap[userID] = struct{}{}
for roomID, users := range n.roomIDToJoinedUsers {
if _, ok := users[userID]; !ok {
if ok := users.isIn(userID); !ok {
continue
}
for _, userID := range n._joinedUsers(roomID) {
@ -282,8 +282,11 @@ func (n *Notifier) IsSharedUser(userA, userB string) bool {
defer n.lock.RUnlock()
var okA, okB bool
for _, users := range n.roomIDToJoinedUsers {
_, okA = users[userA]
_, okB = users[userB]
okA = users.isIn(userA)
if !okA {
continue
}
okB = users.isIn(userB)
if okA && okB {
return true
}
@ -345,11 +348,12 @@ func (n *Notifier) setUsersJoinedToRooms(roomIDToUserIDs map[string][]string) {
// This is just the bulk form of addJoinedUser
for roomID, userIDs := range roomIDToUserIDs {
if _, ok := n.roomIDToJoinedUsers[roomID]; !ok {
n.roomIDToJoinedUsers[roomID] = make(userIDSet, len(userIDs))
n.roomIDToJoinedUsers[roomID] = newUserIDSet(len(userIDs))
}
for _, userID := range userIDs {
n.roomIDToJoinedUsers[roomID].add(userID)
}
n.roomIDToJoinedUsers[roomID].precompute()
}
}
@ -440,16 +444,18 @@ func (n *Notifier) _fetchUserStreams(userID string) []*UserDeviceStream {
func (n *Notifier) _addJoinedUser(roomID, userID string) {
if _, ok := n.roomIDToJoinedUsers[roomID]; !ok {
n.roomIDToJoinedUsers[roomID] = make(userIDSet)
n.roomIDToJoinedUsers[roomID] = newUserIDSet(8)
}
n.roomIDToJoinedUsers[roomID].add(userID)
n.roomIDToJoinedUsers[roomID].precompute()
}
func (n *Notifier) _removeJoinedUser(roomID, userID string) {
if _, ok := n.roomIDToJoinedUsers[roomID]; !ok {
n.roomIDToJoinedUsers[roomID] = make(userIDSet)
n.roomIDToJoinedUsers[roomID] = newUserIDSet(8)
}
n.roomIDToJoinedUsers[roomID].remove(userID)
n.roomIDToJoinedUsers[roomID].precompute()
}
func (n *Notifier) JoinedUsers(roomID string) (userIDs []string) {
@ -521,19 +527,52 @@ func (n *Notifier) _removeEmptyUserStreams() {
}
// A string set, mainly existing for improving clarity of structs in this file.
type userIDSet map[string]struct{}
func (s userIDSet) add(str string) {
s[str] = struct{}{}
type userIDSet struct {
sync.Mutex
set map[string]struct{}
precomputed []string
}
func (s userIDSet) remove(str string) {
delete(s, str)
func newUserIDSet(cap int) *userIDSet {
return &userIDSet{
set: make(map[string]struct{}, cap),
precomputed: nil,
}
}
func (s userIDSet) values() (vals []string) {
vals = make([]string, 0, len(s))
for str := range s {
func (s *userIDSet) add(str string) {
s.Lock()
defer s.Unlock()
s.set[str] = struct{}{}
s.precomputed = s.precomputed[:0] // invalidate cache
}
func (s *userIDSet) remove(str string) {
s.Lock()
defer s.Unlock()
delete(s.set, str)
s.precomputed = s.precomputed[:0] // invalidate cache
}
func (s *userIDSet) precompute() {
s.Lock()
defer s.Unlock()
s.precomputed = s.values()
}
func (s *userIDSet) isIn(str string) bool {
s.Lock()
defer s.Unlock()
_, ok := s.set[str]
return ok
}
func (s *userIDSet) values() (vals []string) {
if len(s.precomputed) > 0 {
return s.precomputed // only return if not invalidated
}
vals = make([]string, 0, len(s.set))
for str := range s.set {
vals = append(vals, str)
}
return