add more cache invalidation explanatory comments

internal/cache/db.go

@@ -85,25 +85,52 @@ type DBCaches struct {
 
 	// FollowIDs provides access to the follower / following IDs database cache.
 	// THIS CACHE IS KEYED AS THE FOLLOWING {prefix}{accountID} WHERE PREFIX IS:
-	// - '>'  for following IDs
-	// - 'l>' for local following IDs
-	// - '<'  for follower IDs
-	// - 'l<' for local follower IDs
+	//
+	// - '>{$accountID}'  for following IDs
+	//   e.g. FollowIDs.Load(">" + account.ID, func() {})
+	//   which will load a slice of follows IDs FROM account.
+	//
+	// - 'l>{$accountID}' for local following IDs
+	//   e.g. FollowIDs.Load("l>" + account.ID, func() {})
+	//   which will load a slice of LOCAL follows IDs FROM account.
+	//
+	// - '<{$accountID}' for follower IDs
+	//   e.g. FollowIDs.Load("<" + account.ID, func() {})
+	//   which will load a slice of follows IDs TARGETTING account.
+	//
+	// - 'l<{$accountID}' for local follower IDs
+	//   e.g. FollowIDs.Load("l<" + account.ID, func() {})
+	//   which will load a slice of LOCAL follows IDs TARGETTING account.
+	//
 	FollowIDs SliceCache[string]
 
 	// FollowRequest provides access to the gtsmodel FollowRequest database cache.
 	FollowRequest StructCache[*gtsmodel.FollowRequest]
 
 	// FollowRequestIDs provides access to the follow requester / requesting IDs database
 	// cache. THIS CACHE IS KEYED AS THE FOLLOWING {prefix}{accountID} WHERE PREFIX IS:
-	// - '>'  for following IDs
-	// - '<'  for follower IDs
+	//
+	// - '>{$accountID}'  for follow request IDs
+	//   e.g. FollowRequestIDs.Load(">" + account.ID, func() {})
+	//   which will load a slice of follow request IDs TARGETTING account.
+	//
+	// - '<{$accountID}'  for follow request IDs
+	//   e.g. FollowRequestIDs.Load("<" + account.ID, func() {})
+	//   which will load a slice of follow request IDs FROM account.
+	//
 	FollowRequestIDs SliceCache[string]
 
 	// FollowingTagIDs provides access to account IDs following / tag IDs followed by
 	// account db cache. THIS CACHE IS KEYED AS THE FOLLOWING {prefix}{id} WHERE:
+	//
 	// - '>{$accountID}' for tag IDs followed by account
+	//   e.g. FollowingTagIDs.Load(">" + account.ID, func() {})
+	//   which will load a slice of tag IDs followed by account.
+	//
 	// - '<{$tagIDs}' for account IDs following tag
+	//   e.g. FollowingTagIDs.Load("<" + tag.ID, func() {})
+	//   which will load a slice of account IDs following tag.
+	//
 	FollowingTagIDs SliceCache[string]
 
 	// Instance provides access to the gtsmodel Instance database cache.
@@ -120,14 +147,28 @@ type DBCaches struct {
 
 	// ListIDs provides access to the list IDs owned by account / list IDs follow
 	// contained in db cache. THIS CACHE IS KEYED AS FOLLOWING {prefix}{id} WHERE:
+	//
 	// - 'a{$accountID}' for list IDs owned by account
+	//   e.g. ListIDs.Load("a" + account.ID, func() {})
+	//   which will load a slice of list IDs owned by account.
+	//
 	// - 'f{$followID}' for list IDs follow contained in
+	//   e.g. ListIDs.Load("f" + follow.ID, func() {})
+	//   which will load a slice of list IDs containing follow.
+	//
 	ListIDs SliceCache[string]
 
 	// ListedIDs provides access to the account IDs in list / follow IDs in
 	// list db cache. THIS CACHE IS KEYED AS FOLLOWING {prefix}{id} WHERE:
+	//
 	// - 'a{listID}' for account IDs in list ID
+	//   e.g. ListedIDs.Load("a" + list.ID, func() {})
+	//   which will load a slice of account IDs in list.
+	//
 	// - 'f{listID}' for follow IDs in list ID
+	//   e.g. ListedIDs.Load("f" + list.ID, func() {})
+	//   which will load a slice of follow IDs in list.
+	//
 	ListedIDs SliceCache[string]
 
 	// Marker provides access to the gtsmodel Marker database cache.

internal/cache/invalidate.go

@@ -109,28 +109,28 @@ func (c *Caches) OnInvalidateFollow(follow *gtsmodel.Follow) {
 	c.DB.FollowIDs.Invalidate(
 
 		// Invalidate follow ID lists
-		// FROM the origin account
+		// TARGETTING origin account
 		// (including local-only follows).
 		">"+follow.AccountID,
 		"l>"+follow.AccountID,
 
 		// Invalidate follow ID lists
-		// TARGETTING origin account
+		// FROM the origin account
 		// (including local-only follows).
 		"<"+follow.AccountID,
 		"l<"+follow.AccountID,
 
-		// Invalidate follow ID lists
-		// FROM the target account
-		// (including local-only follows).
-		"<"+follow.TargetAccountID,
-		"l<"+follow.TargetAccountID,
-
 		// Invalidate follow ID lists
 		// TARGETTING the target account
 		// (including local-only follows).
 		">"+follow.TargetAccountID,
 		"l>"+follow.TargetAccountID,
+
+		// Invalidate follow ID lists
+		// FROM the target account
+		// (including local-only follows).
+		"<"+follow.TargetAccountID,
+		"l<"+follow.TargetAccountID,
 	)
 
 	// Invalidate ID slice cache.
@@ -153,13 +153,27 @@ func (c *Caches) OnInvalidateFollowRequest(followReq *gtsmodel.FollowRequest) {
 	// Invalidate follow with this same ID.
 	c.DB.Follow.Invalidate("ID", followReq.ID)
 
-	// Invalidate source account's followreq
-	// lists, and destinations follow req lists.
-	// (see FollowRequestIDs() comment for details).
+	// Invalidate ID slice cache.
 	c.DB.FollowRequestIDs.Invalidate(
+
+		// Invalidate follow request ID
+		// lists TARGETTING origin account
+		// (including local-only follows).
 		">"+followReq.AccountID,
+
+		// Invalidate follow request ID
+		// lists FROM the origin account
+		// (including local-only follows).
 		"<"+followReq.AccountID,
+
+		// Invalidate follow request ID
+		// lists TARGETTING target account
+		// (including local-only follows).
 		">"+followReq.TargetAccountID,
+
+		// Invalidate follow request ID
+		// lists FROM the target account
+		// (including local-only follows).
 		"<"+followReq.TargetAccountID,
 	)
 }