From 5e076ea36fdfc77de8247dabebffdb4da668d8de Mon Sep 17 00:00:00 2001
From: Martin Kraft <martinkraft@gmail.com>
Date: Fri, 26 Mar 2021 14:09:32 -0400
Subject: [PATCH] =?UTF-8?q?MM-33402:=20Invalidated=20the=20LRU=20cache=20f?=
 =?UTF-8?q?or=20channel=20members=20after=20moderat=E2=80=A6=20(#17171)?=
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* MM-33402: Invalidated the LRU cache for channel members after moderation changes.

* MM-33402: Handles cache invalidation error.

* Revert "MM-33402: Handles cache invalidation error."

This reverts commit 2d30d24658321bbaa32ebfc181dbdade685fd23d.

* MM-33402: Un-exports method.

* MM-33402: Removes log warning from previous code use.

* MM-33402: Handles possible (store.ChannelStore).GetMembers error.

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
---
 app/channel.go      | 36 ++++++++++++++++++++++++++++--------
 app/channel_test.go | 31 +++++++++++++++++++++++++++++++
 i18n/en.json        |  4 ++++
 3 files changed, 63 insertions(+), 8 deletions(-)

diff --git a/app/channel.go b/app/channel.go
index 93b55e2641..dd2397c843 100644
--- a/app/channel.go
+++ b/app/channel.go
@@ -1029,6 +1029,14 @@ func (a *App) PatchChannelModerationsForChannel(channel *model.Channel, channelM
 		}
 	}
 
+	cErr := a.forEachChannelMember(channel.Id, func(channelMember model.ChannelMember) error {
+		a.Srv().Store.Channel().InvalidateAllChannelMembersForUser(channelMember.UserId)
+		return nil
+	})
+	if cErr != nil {
+		return nil, model.NewAppError("PatchChannelModerationsForChannel", "api.channel.patch_channel_moderations.cache_invalidation.error", nil, cErr.Error(), http.StatusInternalServerError)
+	}
+
 	return buildChannelModerations(channel.Type, memberRole, guestRole, higherScopedMemberRole, higherScopedGuestRole), nil
 }
 
@@ -2981,23 +2989,20 @@ func (a *App) FillInChannelsProps(channelList *model.ChannelList) *model.AppErro
 	return nil
 }
 
-func (a *App) ClearChannelMembersCache(channelID string) {
+func (a *App) forEachChannelMember(channelID string, f func(model.ChannelMember) error) error {
 	perPage := 100
 	page := 0
 
 	for {
 		channelMembers, err := a.Srv().Store.Channel().GetMembers(channelID, page*perPage, perPage)
 		if err != nil {
-			a.Log().Warn("error clearing cache for channel members", mlog.String("channel_id", channelID))
-			break
+			return err
 		}
 
 		for _, channelMember := range *channelMembers {
-			a.ClearSessionCacheForUser(channelMember.UserId)
-
-			message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_CHANNEL_MEMBER_UPDATED, "", "", channelMember.UserId, nil)
-			message.Add("channelMember", channelMember.ToJson())
-			a.Publish(message)
+			if err = f(channelMember); err != nil {
+				return err
+			}
 		}
 
 		length := len(*(channelMembers))
@@ -3007,6 +3012,21 @@ func (a *App) ClearChannelMembersCache(channelID string) {
 
 		page++
 	}
+
+	return nil
+}
+
+func (a *App) ClearChannelMembersCache(channelID string) {
+	clearSessionCache := func(channelMember model.ChannelMember) error {
+		a.ClearSessionCacheForUser(channelMember.UserId)
+		message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_CHANNEL_MEMBER_UPDATED, "", "", channelMember.UserId, nil)
+		message.Add("channelMember", channelMember.ToJson())
+		a.Publish(message)
+		return nil
+	}
+	if err := a.forEachChannelMember(channelID, clearSessionCache); err != nil {
+		a.Log().Warn("error clearing cache for channel members", mlog.String("channel_id", channelID))
+	}
 }
 
 func (a *App) GetMemberCountsByGroup(channelID string, includeTimezones bool) ([]*model.ChannelMemberCountByGroup, *model.AppError) {
diff --git a/app/channel_test.go b/app/channel_test.go
index f1a5828835..2f60630bec 100644
--- a/app/channel_test.go
+++ b/app/channel_test.go
@@ -1517,6 +1517,9 @@ func TestPatchChannelModerationsForChannel(t *testing.T) {
 	th.App.SetPhase2PermissionsMigrationStatus(true)
 	channel := th.BasicChannel
 
+	user := th.BasicUser
+	th.AddUserToChannel(user, channel)
+
 	createPosts := model.ChannelModeratedPermissions[0]
 	createReactions := model.ChannelModeratedPermissions[1]
 	manageMembers := model.ChannelModeratedPermissions[2]
@@ -1901,6 +1904,34 @@ func TestPatchChannelModerationsForChannel(t *testing.T) {
 		assert.Contains(t, higherScopedGuestRole.Permissions, createPosts)
 	})
 
+	t.Run("Updates the authorization to create post", func(t *testing.T) {
+		addCreatePosts := []*model.ChannelModerationPatch{
+			{
+				Name: &createPosts,
+				Roles: &model.ChannelModeratedRolesPatch{
+					Members: model.NewBool(true),
+				},
+			},
+		}
+		removeCreatePosts := []*model.ChannelModerationPatch{
+			{
+				Name: &createPosts,
+				Roles: &model.ChannelModeratedRolesPatch{
+					Members: model.NewBool(false),
+				},
+			},
+		}
+
+		mockSession := model.Session{UserId: user.Id}
+
+		_, err := th.App.PatchChannelModerationsForChannel(channel.DeepCopy(), addCreatePosts)
+		require.Nil(t, err)
+		require.True(t, th.App.SessionHasPermissionToChannel(mockSession, channel.Id, model.PERMISSION_CREATE_POST))
+
+		_, err = th.App.PatchChannelModerationsForChannel(channel.DeepCopy(), removeCreatePosts)
+		require.Nil(t, err)
+		require.False(t, th.App.SessionHasPermissionToChannel(mockSession, channel.Id, model.PERMISSION_CREATE_POST))
+	})
 }
 
 // TestMarkChannelsAsViewedPanic verifies that returning an error from a.GetUser
diff --git a/i18n/en.json b/i18n/en.json
index 66232c579f..a681f198f8 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -343,6 +343,10 @@
     "id": "api.channel.move_channel.type.invalid",
     "translation": "Unable to move direct or group message channels"
   },
+  {
+    "id": "api.channel.patch_channel_moderations.cache_invalidation.error",
+    "translation": "Error invalidating cache"
+  },
   {
     "id": "api.channel.patch_channel_moderations.license.error",
     "translation": "Your license does not support channel moderation"