make TAGMSG storage configurable

conventional.yaml

@@ -847,3 +847,18 @@ history:
         # allowing deletion of JSON export of an account's messages. this
         # may be needed for compliance with data privacy regulations.
         enable-account-indexing: false
+
+    # options to control storage of TAGMSG
+    tagmsg-storage:
+        # by default, should TAGMSG be stored?
+        default: false
+
+        # if `default` is false, store TAGMSG containing any of these tags:
+        whitelist:
+            - "+draft/react"
+            - "react"
+
+        # if `default` is true, don't store TAGMSG containing any of these tags:
+        #blacklist:
+        #    - "+draft/typing"
+        #    - "typing"

default.yaml

@@ -873,3 +873,18 @@ history:
         # allowing deletion of JSON export of an account's messages. this
         # may be needed for compliance with data privacy regulations.
         enable-account-indexing: false
+
+    # options to control storage of TAGMSG
+    tagmsg-storage:
+        # by default, should TAGMSG be stored?
+        default: false
+
+        # if `default` is false, store TAGMSG containing any of these tags:
+        whitelist:
+            - "+draft/react"
+            - "react"
+
+        # if `default` is true, don't store TAGMSG containing any of these tags:
+        #blacklist:
+        #    - "+draft/typing"
+        #    - "typing"

irc/channel.go

@@ -646,7 +646,7 @@ func channelHistoryStatus(config *Config, registered bool, storedStatus HistoryS
 }
 
 func (channel *Channel) AddHistoryItem(item history.Item, account string) (err error) {
-	if !item.IsStorable() {
+	if !itemIsStorable(&item, channel.server.Config()) {
 		return
 	}
 

irc/config.go

@@ -612,6 +612,11 @@ type Config struct {
 			AllowIndividualDelete bool `yaml:"allow-individual-delete"`
 			EnableAccountIndexing bool `yaml:"enable-account-indexing"`
 		}
+		TagmsgStorage struct {
+			Default   bool
+			Whitelist []string
+			Blacklist []string
+		} `yaml:"tagmsg-storage"`
 	}
 
 	Filename string
@@ -1283,6 +1288,16 @@ func (config *Config) Diff(oldConfig *Config) (addedCaps, removedCaps *caps.Set)
 	return
 }
 
+// determine whether we need to resize / create / destroy
+// the in-memory history buffers:
+func (config *Config) historyChangedFrom(oldConfig *Config) bool {
+	return config.History.Enabled != oldConfig.History.Enabled ||
+		config.History.ChannelLength != oldConfig.History.ChannelLength ||
+		config.History.ClientLength != oldConfig.History.ClientLength ||
+		config.History.AutoresizeWindow != oldConfig.History.AutoresizeWindow ||
+		config.History.Persistent != oldConfig.History.Persistent
+}
+
 func compileGuestRegexp(guestFormat string, casemapping Casemapping) (standard, folded *regexp.Regexp, err error) {
 	if strings.Count(guestFormat, "?") != 0 || strings.Count(guestFormat, "*") != 1 {
 		err = errors.New("guest format must contain 1 '*' and no '?'s")

irc/handlers.go

@@ -2113,7 +2113,7 @@ func dispatchMessageToTarget(client *Client, tags map[string]string, histType hi
 			AccountName: accountName,
 			Tags:        tags,
 		}
-		if !item.IsStorable() || !allowedPlusR {
+		if !itemIsStorable(&item, config) || !allowedPlusR {
 			return
 		}
 		targetedItem := item
@@ -2136,6 +2136,32 @@ func dispatchMessageToTarget(client *Client, tags map[string]string, histType hi
 	}
 }
 
+func itemIsStorable(item *history.Item, config *Config) bool {
+	switch item.Type {
+	case history.Tagmsg:
+		if config.History.TagmsgStorage.Default {
+			for _, blacklistedTag := range config.History.TagmsgStorage.Blacklist {
+				if _, ok := item.Tags[blacklistedTag]; ok {
+					return false
+				}
+			}
+			return true
+		} else {
+			for _, whitelistedTag := range config.History.TagmsgStorage.Whitelist {
+				if _, ok := item.Tags[whitelistedTag]; ok {
+					return true
+				}
+			}
+			return false
+		}
+	case history.Privmsg, history.Notice:
+		// don't store CTCP other than ACTION
+		return !item.Message.IsRestrictedCTCPMessage()
+	default:
+		return true
+	}
+}
+
 // NPC <target> <sourcenick> <message>
 func npcHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
 	target := msg.Params[0]

irc/history/history.go

@@ -29,12 +29,6 @@ const (
 	initialAutoSize = 32
 )
 
-// a Tagmsg that consists entirely of transient tags is not stored
-var transientTags = map[string]bool{
-	"+draft/typing": true,
-	"+typing":       true, // future-proofing
-}
-
 // Item represents an event (e.g., a PRIVMSG or a JOIN) and its associated data
 type Item struct {
 	Type ItemType
@@ -57,23 +51,6 @@ func (item *Item) HasMsgid(msgid string) bool {
 	return item.Message.Msgid == msgid
 }
 
-func (item *Item) IsStorable() bool {
-	switch item.Type {
-	case Tagmsg:
-		for name := range item.Tags {
-			if !transientTags[name] {
-				return true
-			}
-		}
-		return false // all tags were blacklisted
-	case Privmsg, Notice:
-		// don't store CTCP other than ACTION
-		return !item.Message.IsRestrictedCTCPMessage()
-	default:
-		return true
-	}
-}
-
 type Predicate func(item *Item) (matches bool)
 
 func Reverse(results []Item) {

irc/server.go

@@ -546,7 +546,7 @@ func (server *Server) applyConfig(config *Config) (err error) {
 			server.channels.loadRegisteredChannels(config)
 		}
 		// resize history buffers as needed
-		if oldConfig.History != config.History {
+		if config.historyChangedFrom(oldConfig) {
 			for _, channel := range server.channels.Channels() {
 				channel.resizeHistory(config)
 			}