[performance] cache more database calls, reduce required database calls overall (#3290)

* improvements to caching for lists and relationship to accounts / follows

* fix nil panic in AddToList()

* ensure list related caches are correctly invalidated

* ensure returned ID lists are ordered correctly

* bump go-structr to v0.8.9 (returns early if zero uncached keys to be loaded)

* remove zero checks in uncached key load functions (go-structr now handles this)

* fix issues after rebase on upstream/main

* update the expected return order of CSV exports (since list entries are now down by entry creation date)

* rename some funcs, allow deleting list entries for multiple follow IDs at a time, fix up more tests

* use returning statements on delete to get cache invalidation info

* fixes to recent database delete changes

* fix broken list entries delete sql

* remove unused db function

* update remainder of delete functions to behave in similar way, some other small tweaks

* fix delete user sql, allow returning on err no entries

* uncomment + fix list database tests

* update remaining list tests

* update envparsing test

* add comments to each specific key being invalidated

* add more cache invalidation explanatory comments

* whoops; actually delete poll votes from database in the DeletePollByID() func

* remove added but-commented-out field

* improved comment regarding paging being disabled

* make cache invalidation comments match what's actually happening

* fix up delete query comments to match what is happening

* rename function to read a bit better

* don't use ErrNoEntries on delete when not needed (it's only needed for a RETURNING call)

* update function name in test

* move list exclusivity check to AFTER eligibility check. use log.Panic() instead of panic()

* use the poll_id column in poll_votes for selecting votes in poll ID

* fix function name

1 files changed, 89 insertions, 62 deletions

diff --git a/internal/cache/db.go b/internal/cache/db.go
index 7f54ee8c5..fe9085613 100644
--- a/internal/cache/db.go
+++ b/internal/cache/db.go
@@ -29,9 +29,6 @@ type DBCaches struct {
 	// Account provides access to the gtsmodel Account database cache.
 	Account StructCache[*gtsmodel.Account]
 
-	// AccountIDsFollowingTag caches account IDs following a given tag ID.
-	AccountIDsFollowingTag SliceCache[string]
-
 	// AccountNote provides access to the gtsmodel Note database cache.
 	AccountNote StructCache[*gtsmodel.AccountNote]
 
@@ -88,10 +85,23 @@ 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.
@@ -99,10 +109,30 @@ type DBCaches struct {
 
 	// 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.
 	Instance StructCache[*gtsmodel.Instance]
 
@@ -115,8 +145,31 @@ type DBCaches struct {
 	// List provides access to the gtsmodel List database cache.
 	List StructCache[*gtsmodel.List]
 
-	// ListEntry provides access to the gtsmodel ListEntry database cache.
-	ListEntry StructCache[*gtsmodel.ListEntry]
+	// 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.
 	Marker StructCache[*gtsmodel.Marker]
@@ -151,10 +204,10 @@ type DBCaches struct {
 	// Status provides access to the gtsmodel Status database cache.
 	Status StructCache[*gtsmodel.Status]
 
-	// StatusBookmark ...
+	// StatusBookmark provides access to the gtsmodel StatusBookmark database cache.
 	StatusBookmark StructCache[*gtsmodel.StatusBookmark]
 
-	// StatusBookmarkIDs ...
+	// StatusBookmarkIDs provides access to the status bookmark IDs list database cache.
 	StatusBookmarkIDs SliceCache[string]
 
 	// StatusFave provides access to the gtsmodel StatusFave database cache.
@@ -166,9 +219,6 @@ type DBCaches struct {
 	// Tag provides access to the gtsmodel Tag database cache.
 	Tag StructCache[*gtsmodel.Tag]
 
-	// TagIDsFollowedByAccount caches tag IDs followed by a given account ID.
-	TagIDsFollowedByAccount SliceCache[string]
-
 	// ThreadMute provides access to the gtsmodel ThreadMute database cache.
 	ThreadMute StructCache[*gtsmodel.ThreadMute]
 
@@ -243,17 +293,6 @@ func (c *Caches) initAccount() {
 	})
 }
 
-func (c *Caches) initAccountIDsFollowingTag() {
-	// Calculate maximum cache size.
-	cap := calculateSliceCacheMax(
-		config.GetCacheAccountIDsFollowingTagMemRatio(),
-	)
-
-	log.Infof(nil, "cache size = %d", cap)
-
-	c.DB.AccountIDsFollowingTag.Init(0, cap)
-}
-
 func (c *Caches) initAccountNote() {
 	// Calculate maximum cache size.
 	cap := calculateResultCacheMax(
@@ -761,6 +800,17 @@ func (c *Caches) initFollowRequestIDs() {
 	c.DB.FollowRequestIDs.Init(0, cap)
 }
 
+func (c *Caches) initFollowingTagIDs() {
+	// Calculate maximum cache size.
+	cap := calculateSliceCacheMax(
+		config.GetCacheFollowingTagIDsMemRatio(),
+	)
+
+	log.Infof(nil, "cache size = %d", cap)
+
+	c.DB.FollowingTagIDs.Init(0, cap)
+}
+
 func (c *Caches) initInReplyToIDs() {
 	// Calculate maximum cache size.
 	cap := calculateSliceCacheMax(
@@ -860,7 +910,6 @@ func (c *Caches) initList() {
 		// will be populated separately.
 		// See internal/db/bundb/list.go.
 		l2.Account = nil
-		l2.ListEntries = nil
 
 		return l2
 	}
@@ -876,37 +925,26 @@ func (c *Caches) initList() {
 	})
 }
 
-func (c *Caches) initListEntry() {
+func (c *Caches) initListIDs() {
 	// Calculate maximum cache size.
-	cap := calculateResultCacheMax(
-		sizeofListEntry(), // model in-mem size.
-		config.GetCacheListEntryMemRatio(),
+	cap := calculateSliceCacheMax(
+		config.GetCacheListIDsMemRatio(),
 	)
 
 	log.Infof(nil, "cache size = %d", cap)
 
-	copyF := func(l1 *gtsmodel.ListEntry) *gtsmodel.ListEntry {
-		l2 := new(gtsmodel.ListEntry)
-		*l2 = *l1
+	c.DB.ListIDs.Init(0, cap)
+}
 
-		// Don't include ptr fields that
-		// will be populated separately.
-		// See internal/db/bundb/list.go.
-		l2.Follow = nil
+func (c *Caches) initListedIDs() {
+	// Calculate maximum cache size.
+	cap := calculateSliceCacheMax(
+		config.GetCacheListedIDsMemRatio(),
+	)
 
-		return l2
-	}
+	log.Infof(nil, "cache size = %d", cap)
 
-	c.DB.ListEntry.Init(structr.CacheConfig[*gtsmodel.ListEntry]{
-		Indices: []structr.IndexConfig{
-			{Fields: "ID"},
-			{Fields: "ListID", Multiple: true},
-			{Fields: "FollowID", Multiple: true},
-		},
-		MaxSize:   cap,
-		IgnoreErr: ignoreErrors,
-		Copy:      copyF,
-	})
+	c.DB.ListedIDs.Init(0, cap)
 }
 
 func (c *Caches) initMarker() {
@@ -1368,17 +1406,6 @@ func (c *Caches) initTag() {
 	})
 }
 
-func (c *Caches) initTagIDsFollowedByAccount() {
-	// Calculate maximum cache size.
-	cap := calculateSliceCacheMax(
-		config.GetCacheTagIDsFollowedByAccountMemRatio(),
-	)
-
-	log.Infof(nil, "cache size = %d", cap)
-
-	c.DB.TagIDsFollowedByAccount.Init(0, cap)
-}
-
 func (c *Caches) initThreadMute() {
 	cap := calculateResultCacheMax(
 		sizeofThreadMute(), // model in-mem size.