fix #2424

Add a ChanServ setting to suppress storage of non-message events
(JOIN/PART/QUIT can be especially spammy)

CHANGELOG.md

@@ -7,7 +7,7 @@ We're pleased to be publishing the release candidate for v2.19.0 (the official r
 
 This release includes changes to the config file format, one of which is not backwards-compatible (see below to determine whether you are affected). It includes no changes to the database file format.
 
-Many thanks to [@andymandias](https://github.com/andymandias), [@emersion](https://github.com/emersion), [@englut](https://github.com/englut), [@Jokler](https://github.com/Jokler), [@jwheare](https://github.com/jwheare), [@KlaasT](https://github.com/KlaasT), [@SAY-5](https://github.com/SAY-5), [@skizzerz](https://github.com/skizzerz), [@ValwareIRC](https://github.com/ValwareIRC), and [@whitequark](https://github.com/whitequark) for helpful discussions, contributing patches, reporting issues, and helping test.
+Many thanks to [@andymandias](https://github.com/andymandias), [@emersion](https://github.com/emersion), [@englut](https://github.com/englut), [@Jokler](https://github.com/Jokler), [@jwheare](https://github.com/jwheare), [@KlaasT](https://github.com/KlaasT), [@luxaritas](https://github.com/luxaritas), [@SAY-5](https://github.com/SAY-5), [@skizzerz](https://github.com/skizzerz), [@ValwareIRC](https://github.com/ValwareIRC), and [@whitequark](https://github.com/whitequark) for helpful discussions, contributing patches, reporting issues, and helping test.
 
 ### Compatibility breaks
 * The `extjwt` configuration block now takes `algorithm` (`hmac`, `rsa`, or `eddsa`) and either `key` or `key-file` to configure the signing key (see `default.yaml` for examples). If you are using `extjwt`, the suggested upgrade path is to add the new keys before upgrading (duplicating the legacy keys `secret` and/or `rsa-private-key-file`), upgrade Ergo, then once the new version is confirmed stable, delete the legacy keys. (#2385)
@@ -29,6 +29,7 @@ Many thanks to [@andymandias](https://github.com/andymandias), [@emersion](https
 * Added support for [draft/whoami](https://github.com/ircv3/ircv3-specifications/pull/603), a proposed IRCv3 extension allowing clients to track their message source ("NUH") (#2417)
 * HTTP cookies are harvested from the initial websocket handshake; if a websocket client sends `SASL EXTERNAL`, they can be passed to an `auth-script` for validation (future versions of Ergo may implement some form of native HTTP cookie authentication) (#2185, thanks [@emersion](https://github.com/emersion)!)
 * Added new API endpoints: `/v1/whois` (analogue of the `WHOIS` command to get information about an active nickname), `/v1/ns/saget` (retrieves user account settings), and `/v1/ns/saset` (modifies user account settings) (#2387, #2421, thanks [@KlaasT](https://github.com/KlaasT)!)
+* Added a new ChanServ setting `store-events` to optionally suppress history storage of events like `JOIN` and `QUIT` (#2424, thanks [@luxaritas](https://github.com/luxaritas)!)
 
 ### Fixed
 * Fixed a race condition where an always-on client's channel join might not be persisted (#2398)

irc/channel.go

@@ -28,6 +28,7 @@ import (
 type ChannelSettings struct {
 	History     HistoryStatus
 	QueryCutoff HistoryCutoff
+	StoreEvents StoreEvents
 }
 
 // Channel represents a channel that clients can join.
@@ -101,7 +102,7 @@ func (channel *Channel) initializeLists() {
 }
 
 func (channel *Channel) resizeHistory(config *Config) {
-	status, _, _ := channel.historyStatus(config)
+	status, _, _, _ := channel.historyStatus(config)
 	if status == HistoryEphemeral {
 		channel.history.Resize(config.History.ChannelLength, time.Duration(config.History.AutoresizeWindow))
 	} else {
@@ -674,9 +675,9 @@ func (channel *Channel) IsEmpty() bool {
 
 // figure out where history is being stored: persistent, ephemeral, or neither
 // target is only needed if we're doing persistent history
-func (channel *Channel) historyStatus(config *Config) (status HistoryStatus, target string, restrictions HistoryCutoff) {
+func (channel *Channel) historyStatus(config *Config) (status HistoryStatus, storeEvents StoreEvents, target string, restrictions HistoryCutoff) {
 	if !config.History.Enabled {
-		return HistoryDisabled, "", HistoryCutoffNone
+		return HistoryDisabled, StoreEventsAll, "", HistoryCutoffNone
 	}
 
 	channel.stateMutex.RLock()
@@ -690,7 +691,7 @@ func (channel *Channel) historyStatus(config *Config) (status HistoryStatus, tar
 		restrictions = config.History.Restrictions.queryCutoff
 	}
 
-	return channelHistoryStatus(config, registered, settings.History), target, restrictions
+	return channelHistoryStatus(config, registered, settings.History), settings.StoreEvents, target, restrictions
 }
 
 func (channel *Channel) joinTimeCutoff(client *Client) (present bool, cutoff time.Time) {
@@ -726,12 +727,28 @@ func channelHistoryStatus(config *Config, registered bool, storedStatus HistoryS
 	}
 }
 
+func channelEventIsStorable(itemType history.ItemType, storeEvents StoreEvents) bool {
+	switch storeEvents {
+	case StoreEventsAll:
+		return true
+	case StoreEventsNoJoins:
+		return !(itemType == history.Join || itemType == history.Part || itemType == history.Quit)
+	case StoreEventsNone:
+		return itemType == history.Privmsg || itemType == history.Notice || itemType == history.Tagmsg
+	default:
+		return true
+	}
+}
+
 func (channel *Channel) AddHistoryItem(item history.Item, account string) (err error) {
 	if !itemIsStorable(&item, channel.server.Config()) {
 		return
 	}
 
-	status, target, _ := channel.historyStatus(channel.server.Config())
+	status, storeEvents, target, _ := channel.historyStatus(channel.server.Config())
+	if !channelEventIsStorable(item.Type, storeEvents) {
+		return
+	}
 	if status == HistoryPersistent {
 		err = channel.server.historyDB.AddChannelItem(target, item, account)
 		if err != nil {

irc/chanserv.go

@@ -183,6 +183,12 @@ by unprivileged users. Your options are:
                          channel; note that history will be effectively
                          unavailable to clients that are not always-on]
 4. 'default'            [use the server default]`,
+				`$bSTORE-EVENTS$b
+'store-events' lets you control whether non-message events (like JOIN or
+QUIT) are stored in your channel's history. Your options are:
+1. 'all'         [store all events, the default]
+2. 'no-joins'    [don't store JOIN/PART/QUIT]
+3. 'none'        [don't store any events, including TOPIC/KICK]`,
 			},
 			enabled:   chanregEnabled,
 			minParams: 3,
@@ -813,6 +819,8 @@ func displayChannelSetting(service *ircService, settingName string, settings Cha
 		}
 		service.Notice(rb, fmt.Sprintf(client.t("The stored channel history query cutoff setting is: %s"), historyCutoffToString(settings.QueryCutoff)))
 		service.Notice(rb, fmt.Sprintf(client.t("Given current server settings, the channel history query cutoff setting is: %s"), historyCutoffToString(effectiveValue)))
+	case "store-events":
+		service.Notice(rb, fmt.Sprintf(client.t("The stored channel setting for store-events is: %s"), storeEventsToString(settings.StoreEvents)))
 	default:
 		service.Notice(rb, client.t("Invalid params"))
 	}
@@ -863,6 +871,13 @@ func csSetHandler(service *ircService, server *Server, client *Client, command s
 			break
 		}
 		channel.SetSettings(settings)
+	case "store-events":
+		settings.StoreEvents, err = storeEventsFromString(value)
+		if err != nil {
+			err = errInvalidParams
+			break
+		}
+		channel.SetSettings(settings)
 	}
 
 	switch err {

irc/config.go

@@ -242,6 +242,40 @@ func historyStatusToString(status HistoryStatus) string {
 	}
 }
 
+type StoreEvents uint
+
+const (
+	StoreEventsAll     StoreEvents = iota // default, store all events
+	StoreEventsNoJoins                    // don't store JOIN/QUIT/PART, do store TOPIC and NICK
+	StoreEventsNone                       // don't store any events, only HISTORY/PRIVMSG/TAGMSG
+)
+
+func storeEventsFromString(str string) (status StoreEvents, err error) {
+	switch strings.ToLower(str) {
+	case "all", "default", "on", "true", "yes":
+		return StoreEventsAll, nil
+	case "no-joins":
+		return StoreEventsNoJoins, nil
+	case "none":
+		return StoreEventsNone, nil
+	default:
+		return StoreEventsAll, errInvalidParams
+	}
+}
+
+func storeEventsToString(storeEvents StoreEvents) string {
+	switch storeEvents {
+	case StoreEventsAll:
+		return "all"
+	case StoreEventsNoJoins:
+		return "no-joins"
+	case StoreEventsNone:
+		return "none"
+	default:
+		return "unknown"
+	}
+}
+
 // XXX you must have already checked History.Enabled before calling this
 func historyEnabled(serverSetting PersistentStatus, localSetting HistoryStatus) (result HistoryStatus) {
 	switch serverSetting {

irc/handlers.go

@@ -3721,7 +3721,7 @@ func renameHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 	}
 
 	config := server.Config()
-	status, _, _ := channel.historyStatus(config)
+	status, _, _, _ := channel.historyStatus(config)
 	if status == HistoryPersistent {
 		rb.Add(nil, server.name, "FAIL", "RENAME", "CANNOT_RENAME", oldName, utils.SafeErrorParam(newName), client.t("Channels with persistent history cannot be renamed"))
 		return false

irc/server.go

@@ -1177,7 +1177,7 @@ func (server *Server) GetHistorySequence(providedChannel *Channel, client *Clien
 			err = errInsufficientPrivs
 			return
 		}
-		status, target, restriction = channel.historyStatus(config)
+		status, _, target, restriction = channel.historyStatus(config)
 		switch status {
 		case HistoryEphemeral:
 			hist = &channel.history
@@ -1279,7 +1279,7 @@ func (server *Server) DeleteMessage(target, msgid, accountName string) (err erro
 		if target[0] == '#' {
 			channel := server.channels.Get(target)
 			if channel != nil {
-				if status, _, _ := channel.historyStatus(config); status == HistoryEphemeral {
+				if status, _, _, _ := channel.historyStatus(config); status == HistoryEphemeral {
 					hist = &channel.history
 				}
 			}