Move away from the "andForget" style of function (#3046)

This is the second and last part of the refactoring.
First part is documented here:
https://github.com/mattermost/platform/pull/3043

api/channel.go

@@ -5,14 +5,15 @@ package api
 
 import (
 	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
 	l4g "github.com/alecthomas/log4go"
 	"github.com/gorilla/mux"
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/store"
 	"github.com/mattermost/platform/utils"
-	"net/http"
-	"strconv"
-	"strings"
 )
 
 const (
@@ -154,7 +155,7 @@ func CreateDirectChannel(userId string, otherUserId string) (*model.Channel, *mo
 	} else {
 		message := model.NewMessage("", channel.Id, userId, model.ACTION_DIRECT_ADDED)
 		message.Add("teammate_id", otherUserId)
-		PublishAndForget(message)
+		go Publish(message)
 
 		return result.Data.(*model.Channel), nil
 	}
@@ -291,15 +292,14 @@ func updateChannelHeader(c *Context, w http.ResponseWriter, r *http.Request) {
 			c.Err = ucresult.Err
 			return
 		} else {
-			PostUpdateChannelHeaderMessageAndForget(c, channel.Id, oldChannelHeader, channelHeader)
+			go PostUpdateChannelHeaderMessage(c, channel.Id, oldChannelHeader, channelHeader)
 			c.LogAudit("name=" + channel.Name)
 			w.Write([]byte(channel.ToJson()))
 		}
 	}
 }
 
-func PostUpdateChannelHeaderMessageAndForget(c *Context, channelId string, oldChannelHeader, newChannelHeader string) {
+func PostUpdateChannelHeaderMessage(c *Context, channelId string, oldChannelHeader, newChannelHeader string) {
-	go func() {
 	uc := Srv.Store.User().Get(c.Session.UserId)
 
 	if uresult := <-uc; uresult.Err != nil {
@@ -326,7 +326,6 @@ func PostUpdateChannelHeaderMessageAndForget(c *Context, channelId string, oldCh
 			l4g.Error(utils.T("api.channel.post_update_channel_header_message_and_forget.join_leave.error"), err)
 		}
 	}
-	}()
 }
 
 func updateChannelPurpose(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -490,7 +489,7 @@ func joinChannel(c *Context, channelChannel store.StoreChannel, userChannel stor
 			if _, err := AddUserToChannel(user, channel); err != nil {
 				return err, nil
 			}
-			PostUserAddRemoveMessageAndForget(c, channel.Id, fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username))
+			go PostUserAddRemoveMessage(c, channel.Id, fmt.Sprintf(utils.T("api.channel.join_channel.post_and_forget"), user.Username))
 		} else {
 			return model.NewLocAppError("join", "api.channel.join_channel.permissions.app_error", nil, ""), nil
 		}
@@ -498,8 +497,7 @@ func joinChannel(c *Context, channelChannel store.StoreChannel, userChannel stor
 	}
 }
 
-func PostUserAddRemoveMessageAndForget(c *Context, channelId string, message string) {
+func PostUserAddRemoveMessage(c *Context, channelId string, message string) {
-	go func() {
 	post := &model.Post{
 		ChannelId: channelId,
 		Message:   message,
@@ -508,7 +506,6 @@ func PostUserAddRemoveMessageAndForget(c *Context, channelId string, message str
 	if _, err := CreatePost(c, post, false); err != nil {
 		l4g.Error(utils.T("api.channel.post_user_add_remove_message_and_forget.error"), err)
 	}
-	}()
 }
 
 func AddUserToChannel(user *model.User, channel *model.Channel) (*model.ChannelMember, *model.AppError) {
@@ -539,7 +536,7 @@ func AddUserToChannel(user *model.User, channel *model.Channel) (*model.ChannelM
 		InvalidateCacheForUser(user.Id)
 
 		message := model.NewMessage(channel.TeamId, channel.Id, user.Id, model.ACTION_USER_ADDED)
-		PublishAndForget(message)
+		go Publish(message)
 	}()
 
 	return newMember, nil
@@ -627,7 +624,7 @@ func leave(c *Context, w http.ResponseWriter, r *http.Request) {
 
 		RemoveUserFromChannel(c.Session.UserId, c.Session.UserId, channel)
 
-		PostUserAddRemoveMessageAndForget(c, channel.Id, fmt.Sprintf(utils.T("api.channel.leave.left"), user.Username))
+		go PostUserAddRemoveMessage(c, channel.Id, fmt.Sprintf(utils.T("api.channel.leave.left"), user.Username))
 
 		result := make(map[string]string)
 		result["id"] = channel.Id
@@ -722,7 +719,7 @@ func deleteChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 		go func() {
 			InvalidateCacheForChannel(channel.Id)
 			message := model.NewMessage(c.TeamId, channel.Id, c.Session.UserId, model.ACTION_CHANNEL_DELETED)
-			PublishAndForget(message)
+			go Publish(message)
 
 			post := &model.Post{
 				ChannelId: channel.Id,
@@ -758,7 +755,7 @@ func updateLastViewedAt(c *Context, w http.ResponseWriter, r *http.Request) {
 	message := model.NewMessage(c.TeamId, id, c.Session.UserId, model.ACTION_CHANNEL_VIEWED)
 	message.Add("channel_id", id)
 
-	PublishAndForget(message)
+	go Publish(message)
 
 	result := make(map[string]string)
 	result["id"] = id
@@ -907,7 +904,7 @@ func addMember(c *Context, w http.ResponseWriter, r *http.Request) {
 
 			c.LogAudit("name=" + channel.Name + " user_id=" + userId)
 
-			PostUserAddRemoveMessageAndForget(c, channel.Id, fmt.Sprintf(utils.T("api.channel.add_member.added"), nUser.Username, oUser.Username))
+			go PostUserAddRemoveMessage(c, channel.Id, fmt.Sprintf(utils.T("api.channel.add_member.added"), nUser.Username, oUser.Username))
 
 			<-Srv.Store.Channel().UpdateLastViewedAt(id, oUser.Id)
 			w.Write([]byte(cm.ToJson()))
@@ -978,7 +975,7 @@ func RemoveUserFromChannel(userIdToRemove string, removerUserId string, channel
 
 	message := model.NewMessage(channel.TeamId, channel.Id, userIdToRemove, model.ACTION_USER_REMOVED)
 	message.Add("remover_id", removerUserId)
-	PublishAndForget(message)
+	go Publish(message)
 
 	return nil
 }

api/file.go

@@ -6,16 +6,6 @@ package api
 import (
 	"bytes"
 	"fmt"
-	l4g "github.com/alecthomas/log4go"
-	"github.com/disintegration/imaging"
-	"github.com/goamz/goamz/aws"
-	"github.com/goamz/goamz/s3"
-	"github.com/gorilla/mux"
-	"github.com/mattermost/platform/model"
-	"github.com/mattermost/platform/utils"
-	"github.com/mssola/user_agent"
-	"github.com/rwcarlsen/goexif/exif"
-	_ "golang.org/x/image/bmp"
 	"image"
 	"image/color"
 	"image/draw"
@@ -30,6 +20,17 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	l4g "github.com/alecthomas/log4go"
+	"github.com/disintegration/imaging"
+	"github.com/goamz/goamz/aws"
+	"github.com/goamz/goamz/s3"
+	"github.com/gorilla/mux"
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+	"github.com/mssola/user_agent"
+	"github.com/rwcarlsen/goexif/exif"
+	_ "golang.org/x/image/bmp"
 )
 
 const (
@@ -165,14 +166,12 @@ func uploadFile(c *Context, w http.ResponseWriter, r *http.Request) {
 		resStruct.ClientIds = append(resStruct.ClientIds, clientId)
 	}
 
-	handleImagesAndForget(imageNameList, imageDataList, c.TeamId, channelId, c.Session.UserId)
+	go handleImages(imageNameList, imageDataList, c.TeamId, channelId, c.Session.UserId)
 
 	w.Write([]byte(resStruct.ToJson()))
 }
 
-func handleImagesAndForget(filenames []string, fileData [][]byte, teamId, channelId, userId string) {
+func handleImages(filenames []string, fileData [][]byte, teamId, channelId, userId string) {
-
-	go func() {
 	dest := "teams/" + teamId + "/channels/" + channelId + "/users/" + userId + "/"
 
 	for i, filename := range filenames {
@@ -268,7 +267,6 @@ func handleImagesAndForget(filenames []string, fileData [][]byte, teamId, channe
 			}()
 		}()
 	}
-	}()
 }
 
 func getImageOrientation(imageData []byte) (int, error) {
@@ -329,7 +327,7 @@ func getFileInfo(c *Context, w http.ResponseWriter, r *http.Request) {
 		info = cached.(*model.FileInfo)
 	} else {
 		fileData := make(chan []byte)
-		getFileAndForget(path, fileData)
+		go readFile(path, fileData)
 
 		newInfo, err := model.GetInfoForBytes(filename, <-fileData)
 		if err != nil {
@@ -435,7 +433,7 @@ func getFileData(teamId string, channelId string, userId string, filename string
 	path := "teams/" + teamId + "/channels/" + channelId + "/users/" + userId + "/" + filename
 
 	fileChan := make(chan []byte)
-	getFileAndForget(path, fileChan)
+	go readFile(path, fileChan)
 
 	if bytes := <-fileChan; bytes == nil {
 		err := model.NewLocAppError("writeFileResponse", "api.file.get_file.not_found.app_error", nil, "path="+path)
@@ -472,8 +470,7 @@ func writeFileResponse(filename string, bytes []byte, w http.ResponseWriter, r *
 	return nil
 }
 
-func getFileAndForget(path string, fileData chan []byte) {
+func readFile(path string, fileData chan []byte) {
-	go func() {
 	data, getErr := ReadFile(path)
 	if getErr != nil {
 		l4g.Error(getErr)
@@ -481,7 +478,6 @@ func getFileAndForget(path string, fileData chan []byte) {
 	} else {
 		fileData <- data
 	}
-	}()
 }
 
 func getPublicLink(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -588,7 +584,7 @@ func WriteFile(f []byte, path string) *model.AppError {
 func MoveFile(oldPath, newPath string) *model.AppError {
 	if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_S3 {
 		fileData := make(chan []byte)
-		getFileAndForget(oldPath, fileData)
+		go readFile(oldPath, fileData)
 		fileBytes := <-fileData
 
 		if fileBytes == nil {

api/post.go

@@ -6,11 +6,6 @@ package api
 import (
 	"crypto/tls"
 	"fmt"
-	l4g "github.com/alecthomas/log4go"
-	"github.com/gorilla/mux"
-	"github.com/mattermost/platform/model"
-	"github.com/mattermost/platform/store"
-	"github.com/mattermost/platform/utils"
 	"html/template"
 	"net/http"
 	"net/url"
@@ -20,6 +15,12 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	l4g "github.com/alecthomas/log4go"
+	"github.com/gorilla/mux"
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/store"
+	"github.com/mattermost/platform/utils"
 )
 
 func InitPost() {
@@ -147,8 +148,7 @@ func CreatePost(c *Context, post *model.Post, triggerWebhooks bool) (*model.Post
 	} else {
 		rpost = result.Data.(*model.Post)
 
-		handlePostEventsAndForget(c, rpost, triggerWebhooks)
+		go handlePostEvents(c, rpost, triggerWebhooks)
-
 	}
 
 	return rpost, nil
@@ -227,8 +227,7 @@ func CreateWebhookPost(c *Context, channelId, text, overrideUsername, overrideIc
 	return post, nil
 }
 
-func handlePostEventsAndForget(c *Context, post *model.Post, triggerWebhooks bool) {
+func handlePostEvents(c *Context, post *model.Post, triggerWebhooks bool) {
-	go func() {
 	tchan := Srv.Store.Team().Get(c.TeamId)
 	cchan := Srv.Store.Channel().Get(post.ChannelId)
 	uchan := Srv.Store.User().Get(post.UserId)
@@ -290,13 +289,12 @@ func handlePostEventsAndForget(c *Context, post *model.Post, triggerWebhooks boo
 	}
 
 	if triggerWebhooks {
-			handleWebhookEventsAndForget(c, post, team, channel, user)
+		go handleWebhookEvents(c, post, team, channel, user)
 	}
 
 	if channel.Type == model.CHANNEL_DIRECT {
 		go makeDirectChannelVisible(c.TeamId, post.ChannelId)
 	}
-	}()
 }
 
 func makeDirectChannelVisible(teamId string, channelId string) {
@@ -332,7 +330,7 @@ func makeDirectChannelVisible(teamId string, channelId string) {
 				message := model.NewMessage(teamId, channelId, member.UserId, model.ACTION_PREFERENCE_CHANGED)
 				message.Add("preference", preference.ToJson())
 
-				PublishAndForget(message)
+				go Publish(message)
 			}
 		} else {
 			preference := result.Data.(model.Preference)
@@ -347,15 +345,14 @@ func makeDirectChannelVisible(teamId string, channelId string) {
 					message := model.NewMessage(teamId, channelId, member.UserId, model.ACTION_PREFERENCE_CHANGED)
 					message.Add("preference", preference.ToJson())
 
-					PublishAndForget(message)
+					go Publish(message)
 				}
 			}
 		}
 	}
 }
 
-func handleWebhookEventsAndForget(c *Context, post *model.Post, team *model.Team, channel *model.Channel, user *model.User) {
+func handleWebhookEvents(c *Context, post *model.Post, team *model.Team, channel *model.Channel, user *model.User) {
-	go func() {
 	if !utils.Cfg.ServiceSettings.EnableOutgoingWebhooks {
 		return
 	}
@@ -465,9 +462,6 @@ func handleWebhookEventsAndForget(c *Context, post *model.Post, team *model.Team
 
 		}(hook)
 	}
-
-	}()
-
 }
 
 func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *model.Channel, profileMap map[string]*model.User, members []model.ChannelMember) {
@@ -595,7 +589,7 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 		}
 
 		for id := range toEmailMap {
-			updateMentionCountAndForget(post.ChannelId, id)
+			go updateMentionCount(post.ChannelId, id)
 		}
 	}
 
@@ -779,15 +773,13 @@ func sendNotifications(c *Context, post *model.Post, team *model.Team, channel *
 		message.Add("mentions", model.ArrayToJson(mentionedUsers))
 	}
 
-	PublishAndForget(message)
+	go Publish(message)
 }
 
-func updateMentionCountAndForget(channelId, userId string) {
+func updateMentionCount(channelId, userId string) {
-	go func() {
 	if result := <-Srv.Store.Channel().IncrementMentionCount(channelId, userId); result.Err != nil {
 		l4g.Error(utils.T("api.post.update_mention_count_and_forget.update_error"), userId, channelId, result.Err)
 	}
-	}()
 }
 
 func checkForOutOfChannelMentions(c *Context, post *model.Post, channel *model.Channel, allProfiles map[string]*model.User, members []model.ChannelMember) {
@@ -876,7 +868,7 @@ func SendEphemeralPost(teamId, userId string, post *model.Post) {
 	message := model.NewMessage(teamId, post.ChannelId, userId, model.ACTION_EPHEMERAL_MESSAGE)
 	message.Add("post", post.ToJson())
 
-	PublishAndForget(message)
+	go Publish(message)
 }
 
 func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -938,7 +930,7 @@ func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
 		message := model.NewMessage(c.TeamId, rpost.ChannelId, c.Session.UserId, model.ACTION_POST_EDITED)
 		message.Add("post", rpost.ToJson())
 
-		PublishAndForget(message)
+		go Publish(message)
 
 		w.Write([]byte(rpost.ToJson()))
 	}
@@ -1202,8 +1194,8 @@ func deletePost(c *Context, w http.ResponseWriter, r *http.Request) {
 		message := model.NewMessage(c.TeamId, post.ChannelId, c.Session.UserId, model.ACTION_POST_DELETED)
 		message.Add("post", post.ToJson())
 
-		PublishAndForget(message)
+		go Publish(message)
-		DeletePostFilesAndForget(c.TeamId, post)
+		go DeletePostFiles(c.TeamId, post)
 
 		result := make(map[string]string)
 		result["id"] = postId
@@ -1211,8 +1203,7 @@ func deletePost(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func DeletePostFilesAndForget(teamId string, post *model.Post) {
+func DeletePostFiles(teamId string, post *model.Post) {
-	go func() {
 	if len(post.Filenames) == 0 {
 		return
 	}
@@ -1224,8 +1215,6 @@ func DeletePostFilesAndForget(teamId string, post *model.Post) {
 		newPath := prefix + splitUrl[len(splitUrl)-2] + "/deleted_" + splitUrl[len(splitUrl)-1]
 		MoveFile(oldPath, newPath)
 	}
-
-	}()
 }
 
 func getPostsBefore(c *Context, w http.ResponseWriter, r *http.Request) {

api/team.go

@@ -274,7 +274,7 @@ func JoinUserToTeam(team *model.Team, user *model.User) *model.AppError {
 	InvalidateCacheForUser(user.Id)
 
 	// This message goes to every channel, so the channelId is irrelevant
-	PublishAndForget(model.NewMessage("", "", user.Id, model.ACTION_NEW_USER))
+	go Publish(model.NewMessage("", "", user.Id, model.ACTION_NEW_USER))
 
 	return nil
 }

api/user.go

@@ -260,7 +260,7 @@ func CreateUser(user *model.User) (*model.User, *model.AppError) {
 		ruser.Sanitize(map[string]bool{})
 
 		// This message goes to every channel, so the channelId is irrelevant
-		PublishAndForget(model.NewMessage("", "", ruser.Id, model.ACTION_NEW_USER))
+		go Publish(model.NewMessage("", "", ruser.Id, model.ACTION_NEW_USER))
 
 		return ruser, nil
 	}

api/web_conn.go

@@ -4,11 +4,12 @@
 package api
 
 import (
+	"time"
+
 	l4g "github.com/alecthomas/log4go"
 	"github.com/gorilla/websocket"
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/utils"
-	"time"
 )
 
 const (
@@ -77,7 +78,7 @@ func (c *WebConn) readPump() {
 			return
 		} else {
 			msg.UserId = c.UserId
-			PublishAndForget(&msg)
+			go Publish(&msg)
 		}
 	}
 }

api/web_hub.go

@@ -29,10 +29,8 @@ var hub = &Hub{
 	invalidateChannel: make(chan string),
 }
 
-func PublishAndForget(message *model.Message) {
+func Publish(message *model.Message) {
-	go func() {
 	hub.Broadcast(message)
-	}()
 }
 
 func InvalidateCacheForUser(userId string) {

mattermost.go

@@ -121,7 +121,7 @@ func main() {
 		}
 
 		setDiagnosticId()
-		runSecurityAndDiagnosticsJobAndForget()
+		go runSecurityAndDiagnosticsJob()
 
 		if einterfaces.GetComplianceInterface() != nil {
 			einterfaces.GetComplianceInterface().StartComplianceDailyJob()
@@ -152,8 +152,7 @@ func setDiagnosticId() {
 	}
 }
 
-func runSecurityAndDiagnosticsJobAndForget() {
+func runSecurityAndDiagnosticsJob() {
-	go func() {
 	for {
 		if *utils.Cfg.ServiceSettings.EnableSecurityFixAlert {
 			if result := <-api.Srv.Store.System().Get(); result.Err == nil {
@@ -241,7 +240,6 @@ func runSecurityAndDiagnosticsJobAndForget() {
 
 		time.Sleep(time.Hour * 4)
 	}
-	}()
 }
 
 func parseCmds() {