[feature] scheduled statuses (#4274)

An implementation of [`scheduled_statuses`](https://docs.joinmastodon.org/methods/scheduled_statuses/). Will fix #1006.

this is heavily WIP and I need to reorganize some of the code, working on this made me somehow familiar with the codebase and led to my other recent contributions
i told some fops on fedi i'd work on this so i have no choice but to complete it 🤷‍♀️
btw iirc my avatar presents me working on this branch

Signed-off-by: nicole mikołajczyk <git@mkljczk.pl>
Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4274
Co-authored-by: nicole mikołajczyk <git@mkljczk.pl>
Co-committed-by: nicole mikołajczyk <git@mkljczk.pl>

internal/cache/cache.go

@@ -113,6 +113,7 @@ func (c *Caches) Init() {
 	c.initPollVote()
 	c.initPollVoteIDs()
 	c.initReport()
+	c.initScheduledStatus()
 	c.initSinBinStatus()
 	c.initStatus()
 	c.initStatusBookmark()
@@ -200,6 +201,7 @@ func (c *Caches) Sweep(threshold float64) {
 	c.DB.PollVote.Trim(threshold)
 	c.DB.PollVoteIDs.Trim(threshold)
 	c.DB.Report.Trim(threshold)
+	c.DB.ScheduledStatus.Trim(threshold)
 	c.DB.SinBinStatus.Trim(threshold)
 	c.DB.Status.Trim(threshold)
 	c.DB.StatusBookmark.Trim(threshold)

internal/cache/db.go

@@ -219,6 +219,9 @@ type DBCaches struct {
 	// Report provides access to the gtsmodel Report database cache.
 	Report StructCache[*gtsmodel.Report]
 
+	// ScheduledStatus provides access to the gtsmodel ScheduledStatus database cache.
+	ScheduledStatus StructCache[*gtsmodel.ScheduledStatus]
+
 	// SinBinStatus provides access to the gtsmodel SinBinStatus database cache.
 	SinBinStatus StructCache[*gtsmodel.SinBinStatus]
 
@@ -1287,6 +1290,40 @@ func (c *Caches) initReport() {
 	})
 }
 
+func (c *Caches) initScheduledStatus() {
+	// Calculate maximum cache size.
+	cap := calculateResultCacheMax(
+		sizeofScheduledStatus(), // model in-mem size.
+		config.GetCacheScheduledStatusMemRatio(),
+	)
+
+	log.Infof(nil, "cache size = %d", cap)
+
+	copyF := func(s1 *gtsmodel.ScheduledStatus) *gtsmodel.ScheduledStatus {
+		s2 := new(gtsmodel.ScheduledStatus)
+		*s2 = *s1
+
+		// Don't include ptr fields that
+		// will be populated separately.
+		s2.Account = nil
+		s2.Application = nil
+		s2.MediaAttachments = nil
+
+		return s2
+	}
+
+	c.DB.ScheduledStatus.Init(structr.CacheConfig[*gtsmodel.ScheduledStatus]{
+		Indices: []structr.IndexConfig{
+			{Fields: "ID"},
+			{Fields: "AccountID", Multiple: true},
+		},
+		MaxSize:    cap,
+		IgnoreErr:  ignoreErrors,
+		Copy:       copyF,
+		Invalidate: c.OnInvalidateScheduledStatus,
+	})
+}
+
 func (c *Caches) initSinBinStatus() {
 	// Calculate maximum cache size.
 	cap := calculateResultCacheMax(

internal/cache/invalidate.go

@@ -292,6 +292,11 @@ func (c *Caches) OnInvalidatePollVote(vote *gtsmodel.PollVote) {
 	c.DB.PollVoteIDs.Invalidate(vote.PollID)
 }
 
+func (c *Caches) OnInvalidateScheduledStatus(status *gtsmodel.ScheduledStatus) {
+	// Invalidate cache of related media attachments.
+	c.DB.Media.InvalidateIDs("ID", status.MediaIDs)
+}
+
 func (c *Caches) OnInvalidateStatus(status *gtsmodel.Status) {
 	// Invalidate cached stats objects for this account.
 	c.DB.AccountStats.Invalidate("AccountID", status.AccountID)

internal/cache/size.go

@@ -554,6 +554,25 @@ func sizeofReport() uintptr {
 	}))
 }
 
+func sizeofScheduledStatus() uintptr {
+	return uintptr(size.Of(&gtsmodel.ScheduledStatus{
+		ID:          exampleID,
+		AccountID:   exampleID,
+		ScheduledAt: exampleTime,
+		Text:        exampleText,
+		Poll: gtsmodel.ScheduledStatusPoll{
+			Options:    []string{exampleTextSmall, exampleTextSmall, exampleTextSmall, exampleTextSmall},
+			Multiple:   util.Ptr(false),
+			HideTotals: util.Ptr(false),
+		},
+		MediaIDs:    []string{exampleID, exampleID, exampleID},
+		Sensitive:   util.Ptr(false),
+		SpoilerText: exampleText,
+		Visibility:  gtsmodel.VisibilityPublic,
+		Language:    "en",
+	}))
+}
+
 func sizeofSinBinStatus() uintptr {
 	return uintptr(size.Of(&gtsmodel.SinBinStatus{
 		ID:                  exampleID,