MM-56878: Remove unused store method (#26230)

IsUserInChannelUseCache wasn't being used anywhere.

https://mattermost.atlassian.net/browse/MM-56878

```release-note
NONE
```

server/channels/store/opentracinglayer/opentracinglayer.go

@@ -2059,19 +2059,6 @@ func (s *OpenTracingLayerChannelStore) InvalidatePinnedPostCount(channelID strin
 
 }
 
-func (s *OpenTracingLayerChannelStore) IsUserInChannelUseCache(userID string, channelID string) bool {
-	origCtx := s.Root.Store.Context()
-	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.IsUserInChannelUseCache")
-	s.Root.Store.SetContext(newCtx)
-	defer func() {
-		s.Root.Store.SetContext(origCtx)
-	}()
-
-	defer span.Finish()
-	result := s.ChannelStore.IsUserInChannelUseCache(userID, channelID)
-	return result
-}
-
 func (s *OpenTracingLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.MigrateChannelMembers")

server/channels/store/retrylayer/retrylayer.go

@@ -2252,12 +2252,6 @@ func (s *RetryLayerChannelStore) InvalidatePinnedPostCount(channelID string) {
 
 }
 
-func (s *RetryLayerChannelStore) IsUserInChannelUseCache(userID string, channelID string) bool {
-
-	return s.ChannelStore.IsUserInChannelUseCache(userID, channelID)
-
-}
-
 func (s *RetryLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 
 	tries := 0

server/channels/store/sqlstore/channel_store.go

@@ -17,7 +17,6 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost/server/public/model"
-	"github.com/mattermost/mattermost/server/public/shared/mlog"
 	"github.com/mattermost/mattermost/server/public/shared/request"
 	"github.com/mattermost/mattermost/server/v8/channels/store"
 	"github.com/mattermost/mattermost/server/v8/einterfaces"
@@ -2164,35 +2163,6 @@ func (s SqlChannelStore) InvalidateAllChannelMembersForUser(userId string) {
 	}
 }
 
-func (s SqlChannelStore) IsUserInChannelUseCache(userId string, channelId string) bool {
-	var ids map[string]string
-	if err := allChannelMembersForUserCache.Get(userId, &ids); err == nil {
-		if s.metrics != nil {
-			s.metrics.IncrementMemCacheHitCounter("All Channel Members for User")
-		}
-		if _, ok := ids[channelId]; ok {
-			return true
-		}
-		return false
-	}
-
-	if s.metrics != nil {
-		s.metrics.IncrementMemCacheMissCounter("All Channel Members for User")
-	}
-
-	ids, err := s.GetAllChannelMembersForUser(userId, true, false)
-	if err != nil {
-		mlog.Error("Error getting all channel members for user", mlog.Err(err))
-		return false
-	}
-
-	if _, ok := ids[channelId]; ok {
-		return true
-	}
-
-	return false
-}
-
 func (s SqlChannelStore) GetMemberForPost(postId string, userId string, includeArchivedChannels bool) (*model.ChannelMember, error) {
 	var dbMember channelMemberWithSchemeRoles
 	query := `

server/channels/store/store.go

@@ -232,7 +232,6 @@ type ChannelStore interface {
 	GetAllChannelMembersForUser(userID string, allowFromCache bool, includeDeleted bool) (map[string]string, error)
 	GetChannelsMemberCount(channelIDs []string) (map[string]int64, error)
 	InvalidateAllChannelMembersForUser(userID string)
-	IsUserInChannelUseCache(userID string, channelID string) bool
 	GetAllChannelMembersNotifyPropsForChannel(channelID string, allowFromCache bool) (map[string]model.StringMap, error)
 	InvalidateCacheForChannelMembersNotifyProps(channelID string)
 	GetMemberForPost(postID string, userID string, includeArchivedChannels bool) (*model.ChannelMember, error)

server/channels/store/storetest/channel_store.go

@@ -3737,25 +3737,6 @@ func testChannelStoreGetChannels(t *testing.T, rctx request.CTX, ss store.Store)
 	require.Equal(t, o1.Id, list[0].Id, "missing channel")
 	require.Equal(t, o3.Id, list[1].Id, "missing channel")
 
-	require.True(
-		t,
-		ss.Channel().IsUserInChannelUseCache(m1.UserId, o1.Id),
-		"missing channel")
-	require.True(
-		t,
-		ss.Channel().IsUserInChannelUseCache(m1.UserId, o2.Id),
-		"missing channel")
-
-	require.False(
-		t,
-		ss.Channel().IsUserInChannelUseCache(m1.UserId, "blahblah"),
-		"missing channel")
-
-	require.False(
-		t,
-		ss.Channel().IsUserInChannelUseCache("blahblah", "blahblah"),
-		"missing channel")
-
 	ss.Channel().InvalidateAllChannelMembersForUser(m1.UserId)
 }
 

server/channels/store/storetest/mocks/ChannelStore.go

@@ -1903,20 +1903,6 @@ func (_m *ChannelStore) InvalidatePinnedPostCount(channelID string) {
 	_m.Called(channelID)
 }
 
-// IsUserInChannelUseCache provides a mock function with given fields: userID, channelID
-func (_m *ChannelStore) IsUserInChannelUseCache(userID string, channelID string) bool {
-	ret := _m.Called(userID, channelID)
-
-	var r0 bool
-	if rf, ok := ret.Get(0).(func(string, string) bool); ok {
-		r0 = rf(userID, channelID)
-	} else {
-		r0 = ret.Get(0).(bool)
-	}
-
-	return r0
-}
-
 // MigrateChannelMembers provides a mock function with given fields: fromChannelID, fromUserID
 func (_m *ChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	ret := _m.Called(fromChannelID, fromUserID)

server/channels/store/timerlayer/timerlayer.go

@@ -1918,22 +1918,6 @@ func (s *TimerLayerChannelStore) InvalidatePinnedPostCount(channelID string) {
 	}
 }
 
-func (s *TimerLayerChannelStore) IsUserInChannelUseCache(userID string, channelID string) bool {
-	start := time.Now()
-
-	result := s.ChannelStore.IsUserInChannelUseCache(userID, channelID)
-
-	elapsed := float64(time.Since(start)) / float64(time.Second)
-	if s.Root.Metrics != nil {
-		success := "false"
-		if true {
-			success = "true"
-		}
-		s.Root.Metrics.ObserveStoreMethodDuration("ChannelStore.IsUserInChannelUseCache", success, elapsed)
-	}
-	return result
-}
-
 func (s *TimerLayerChannelStore) MigrateChannelMembers(fromChannelID string, fromUserID string) (map[string]string, error) {
 	start := time.Now()