simplify timeline cache loading, fix lo/hi returns, fix timeline invalidation side-effects missing for some federated actions

internal/cache/timeline/status.go

@@ -338,15 +338,10 @@ func (t *StatusTimeline) Load(
 	// to load status models of already cached entries in the timeline.
 	loadIDs func(ids []string) (statuses []*gtsmodel.Status, err error),
 
-	// preFilter can be used to perform filtering of returned
+	// filter can be used to perform filtering of returned
 	// statuses BEFORE insert into cache. i.e. this will effect
 	// what actually gets stored in the timeline cache.
-	preFilter func(each *gtsmodel.Status) (delete bool, err error),
-
-	// postFilter can be used to perform filtering of returned
-	// statuses AFTER insert into cache. i.e. this will not effect
-	// what actually gets stored in the timeline cache.
-	postFilter func(each *gtsmodel.Status) (delete bool, err error),
+	filter func(each *gtsmodel.Status) (delete bool, err error),
 
 	// prepareAPI should prepare internal status model to frontend API model.
 	prepareAPI func(status *gtsmodel.Status) (apiStatus *apimodel.Status, err error),
@@ -392,15 +387,20 @@ func (t *StatusTimeline) Load(
 		dir,
 	)
 
-	if len(metas) > 0 {
-		// We ALWAYS return and work on
-		// statuses in DESC order, but the
-		// timeline cache returns statuses
-		// in the *requested* order.
-		if dir == structr.Asc {
-			slices.Reverse(metas)
-		}
+	// We now reset the lo,hi values to
+	// represent the lowest and highest
+	// index values of loaded statuses.
+	//
+	// We continually update these while
+	// building up statuses to return, for
+	// caller to build next / prev page
+	// response values.
+	lo, hi = "", ""
 
+	// Preallocate a slice of up-to-limit API models.
+	apiStatuses := make([]*apimodel.Status, 0, limit)
+
+	if len(metas) > 0 {
 		// Before we can do any filtering, we need
 		// to load status models for cached entries.
 		err := loadStatuses(metas, loadIDs)
@@ -408,42 +408,38 @@ func (t *StatusTimeline) Load(
 			return nil, "", "", gtserror.Newf("error loading statuses: %w", err)
 		}
 
-		// Update paging values
-		// based on returned data.
-		nextPageParams(nextPg,
-			metas[len(metas)-1].ID,
-			metas[0].ID,
-			order,
+		// Set initial lo, hi values.
+		hi = metas[len(metas)-1].ID
+		lo = metas[0].ID
+
+		// Update paging parameters used for next database query.
+		nextPageParams(nextPg, metas[len(metas)-1].ID, order)
+
+		// Prepare frontend API models for
+		// the cached statuses. For now this
+		// also does its own extra filtering.
+		apiStatuses = prepareStatuses(ctx,
+			metas,
+			prepareAPI,
+			apiStatuses,
+			limit,
 		)
-
-		// Before any further loading,
-		// store current lo, hi values
-		// as possible lo, hi returns.
-		lo = metas[len(metas)-1].ID
-		hi = metas[0].ID
-
-		// Drop all entries we failed to load statuses for.
-		metas = slices.DeleteFunc(metas, (*StatusMeta).isNotLoaded)
-
-		// Perform post-filtering on cached status entries.
-		metas, err = doStatusPostFilter(metas, postFilter)
-		if err != nil {
-			return nil, "", "", gtserror.Newf("error post-filtering statuses: %w", err)
-		}
 	}
 
 	// Track all newly loaded status entries
-	// AFTER 'preFilter', but before 'postFilter',
-	// to later insert into timeline cache.
+	// after filtering for insert into cache.
 	var justLoaded []*StatusMeta
 
 	// Check whether loaded enough from cache.
-	if need := limit - len(metas); need > 0 {
+	if need := limit - len(apiStatuses); need > 0 {
 
-		// Perform a maximum of 5
-		// load attempts fetching
-		// statuses to reach limit.
-		for i := 0; i < 5; i++ {
+		// Load a little more than
+		// limit to reduce db calls.
+		nextPg.Limit += 10
+
+		// Perform maximum of 10 load
+		// attempts fetching statuses.
+		for i := 0; i < 10; i++ {
 
 			// Load next timeline statuses.
 			statuses, err := loadPage(nextPg)
@@ -457,18 +453,19 @@ func (t *StatusTimeline) Load(
 				break
 			}
 
-			// Update paging values
-			// based on returned data.
-			nextPageParams(nextPg,
-				statuses[len(statuses)-1].ID,
-				statuses[0].ID,
-				order,
-			)
+			if lo == "" {
+				// Set min returned paging
+				// value if not already set.
+				lo = statuses[0].ID
+			}
 
-			// Perform any pre-filtering on newly loaded statuses.
-			statuses, err = doStatusPreFilter(statuses, preFilter)
+			// Update nextPg cursor parameter for next database query.
+			nextPageParams(nextPg, statuses[len(statuses)-1].ID, order)
+
+			// Perform any filtering on newly loaded statuses.
+			statuses, err = doStatusFilter(statuses, filter)
 			if err != nil {
-				return nil, "", "", gtserror.Newf("error pre-filtering statuses: %w", err)
+				return nil, "", "", gtserror.Newf("error filtering statuses: %w", err)
 			}
 
 			// After filtering no more
@@ -477,71 +474,46 @@ func (t *StatusTimeline) Load(
 				continue
 			}
 
-			// On each iteration, since statuses
-			// returned will always be in DESC order,
-			// iteratively update the lo paging value
-			// that we return for next / prev pages.
-			lo = statuses[len(statuses)-1].ID
-
 			// Convert to our cache type,
 			// these will get inserted into
 			// the cache in prepare() below.
-			uncached := toStatusMeta(statuses)
+			metas := toStatusMeta(statuses)
 
-			// Before any filtering append to newly loaded.
-			justLoaded = append(justLoaded, uncached...)
+			// Append to newly loaded for later insert.
+			justLoaded = append(justLoaded, metas...)
 
-			// Perform any post-filtering on loaded timeline entries.
-			filtered, err := doStatusPostFilter(uncached, postFilter)
-			if err != nil {
-				return nil, "", "", gtserror.Newf("error post-filtering statuses: %w", err)
-			}
+			// Prepare frontend API models for
+			// the loaded statuses. For now this
+			// also does its own extra filtering.
+			apiStatuses = prepareStatuses(ctx,
+				metas,
+				prepareAPI,
+				apiStatuses,
+				limit,
+			)
 
-			// Append newly filtered meta entries.
-			metas = append(metas, filtered...)
+			// If we have anything, return
+			// here. Even if below limit.
+			if len(apiStatuses) > 0 {
 
-			// Check if we reached
-			// requested page limit.
-			if len(metas) >= limit {
+				// Set returned hi status paging value.
+				hi = apiStatuses[len(apiStatuses)-1].ID
 				break
 			}
 		}
 	}
 
-	// Prepare frontend API models.
-	var apiStatuses []*apimodel.Status
-	if len(metas) > 0 {
-		switch {
-		case len(metas) <= limit:
-			// We have under
-			// expected limit.
-
-		case order.Ascending():
-			// Ascending order was requested
-			// and we have more than limit, so
-			// trim extra metadata from end.
-			metas = metas[:limit]
-
-		default: /* i.e. descending */
-			// Descending order was requested
-			// and we have more than limit, so
-			// trim extra metadata from start.
-			metas = metas[len(metas)-limit:]
-		}
-
-		// Using meta and funcs, prepare frontend API models.
-		apiStatuses = prepareStatuses(ctx, metas, prepareAPI)
+	if order.Ascending() {
+		// The caller always expects the statuses
+		// to be returned in DESC order, but we
+		// build the status slice in paging order.
+		// If paging ASC, we need to reverse the
+		// returned statuses and paging values.
+		slices.Reverse(apiStatuses)
+		lo, hi = hi, lo
 	}
 
 	if len(justLoaded) > 0 {
-		if hi == "" {
-			// Check whether a hi value was set
-			// from an initial load of cached entries,
-			// if not we set the returned hi paging
-			// value from first in loaded statuses.
-			hi = justLoaded[0].ID
-		}
-
 		// Even if we don't return them, insert
 		// the excess (post-filtered) into cache.
 		t.cache.Insert(justLoaded...)
@@ -729,6 +701,8 @@ func prepareStatuses(
 	ctx context.Context,
 	meta []*StatusMeta,
 	prepareAPI func(*gtsmodel.Status) (*apimodel.Status, error),
+	apiStatuses []*apimodel.Status,
+	limit int,
 ) []*apimodel.Status {
 	switch { //nolint:gocritic
 	case prepareAPI == nil:
@@ -737,9 +711,14 @@ func prepareStatuses(
 
 	// Iterate the given StatusMeta objects for pre-prepared
 	// frontend models, otherwise attempting to prepare them.
-	apiStatuses := make([]*apimodel.Status, 0, len(meta))
 	for _, meta := range meta {
 
+		// Check if we have prepared enough
+		// API statuses for caller to return.
+		if len(apiStatuses) >= limit {
+			break
+		}
+
 		if meta.loaded == nil {
 			// We failed loading this
 			// status, skip preparing.
@@ -758,10 +737,6 @@ func prepareStatuses(
 		}
 
 		if meta.prepared != nil {
-			// TODO: we won't need nil check when mutes
-			// / filters are moved to appropriate funcs.
-			//
-			// Add the prepared API model to return slice.
 			apiStatuses = append(apiStatuses, meta.prepared)
 		}
 	}
@@ -823,9 +798,9 @@ func toStatusMeta(statuses []*gtsmodel.Status) []*StatusMeta {
 	})
 }
 
-// doStatusPreFilter performs given filter function on provided statuses,
+// doStatusFilter performs given filter function on provided statuses,
 // returning early if an error is returned. returns filtered statuses.
-func doStatusPreFilter(statuses []*gtsmodel.Status, filter func(*gtsmodel.Status) (bool, error)) ([]*gtsmodel.Status, error) {
+func doStatusFilter(statuses []*gtsmodel.Status, filter func(*gtsmodel.Status) (bool, error)) ([]*gtsmodel.Status, error) {
 
 	// Check for provided
 	// filter function.
@@ -855,37 +830,3 @@ func doStatusPreFilter(statuses []*gtsmodel.Status, filter func(*gtsmodel.Status
 
 	return statuses, nil
 }
-
-// doStatusPostFilter performs given filter function on provided status meta,
-// expecting that embedded status is already loaded, returning filtered status
-// meta, as well as those *filtered out*. returns early if error is returned.
-func doStatusPostFilter(metas []*StatusMeta, filter func(*gtsmodel.Status) (bool, error)) ([]*StatusMeta, error) {
-
-	// Check for provided
-	// filter function.
-	if filter == nil {
-		return metas, nil
-	}
-
-	// Iterate through input metas.
-	for i := 0; i < len(metas); {
-		meta := metas[i]
-
-		// Pass through filter func.
-		ok, err := filter(meta.loaded)
-		if err != nil {
-			return nil, err
-		}
-
-		if ok {
-			// Delete meta entry from input slice.
-			metas = slices.Delete(metas, i, i+1)
-			continue
-		}
-
-		// Iter.
-		i++
-	}
-
-	return metas, nil
-}

internal/cache/timeline/timeline.go

@@ -30,13 +30,13 @@ import (
 // updated while maintaining the boundary value.
 func nextPageParams(
 	page *paging.Page,
-	nextLo, nextHi string,
+	lastIdx string,
 	order paging.Order,
 ) {
 	if order.Ascending() {
-		page.Min.Value = nextLo
+		page.Min.Value = lastIdx
 	} else /* i.e. descending */ { //nolint:revive
-		page.Max.Value = nextHi
+		page.Max.Value = lastIdx
 	}
 }
 

internal/db/bundb/timeline.go

@@ -365,13 +365,6 @@ func loadStatusTimelinePage(
 		return nil, err
 	}
 
-	// The order we return from the database and
-	// timeline caches differs depending on ordering,
-	// but the caller always expects DESCENDING.
-	if order.Ascending() {
-		slices.Reverse(statusIDs)
-	}
-
 	// Fetch statuses from DB / cache with given IDs.
 	return state.DB.GetStatusesByIDs(ctx, statusIDs)
 }

internal/federation/federatingdb/undo.go

@@ -136,10 +136,7 @@ func (f *federatingDB) undoFollow(
 
 	// Convert AS Follow to barebones *gtsmodel.Follow,
 	// retrieving origin + target accts from the db.
-	follow, err := f.converter.ASFollowToFollow(
-		gtscontext.SetBarebones(ctx),
-		asFollow,
-	)
+	follow, err := f.converter.ASFollowToFollow(ctx, asFollow)
 	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		err := gtserror.Newf("error converting AS Follow to follow: %w", err)
 		return err
@@ -152,6 +149,11 @@ func (f *federatingDB) undoFollow(
 		return nil
 	}
 
+	// Lock on the Follow URI
+	// as we may be updating it.
+	unlock := f.state.FedLocks.Lock(follow.URI)
+	defer unlock()
+
 	// Ensure addressee is follow target.
 	if follow.TargetAccountID != receivingAcct.ID {
 		const text = "receivingAcct was not Follow target"
@@ -178,7 +180,16 @@ func (f *federatingDB) undoFollow(
 		return err
 	}
 
-	log.Debug(ctx, "Follow undone")
+	// Send the deleted follow through to
+	// the fedi worker to process side effects.
+	f.state.Workers.Federator.Queue.Push(&messages.FromFediAPI{
+		APObjectType:   ap.ActivityFollow,
+		APActivityType: ap.ActivityUndo,
+		GTSModel:       follow,
+		Receiving:      receivingAcct,
+		Requesting:     requestingAcct,
+	})
+
 	return nil
 }
 
@@ -269,7 +280,16 @@ func (f *federatingDB) undoLike(
 		return err
 	}
 
-	log.Debug(ctx, "Like undone")
+	// Send the deleted block through to
+	// the fedi worker to process side effects.
+	f.state.Workers.Federator.Queue.Push(&messages.FromFediAPI{
+		APObjectType:   ap.ActivityLike,
+		APActivityType: ap.ActivityUndo,
+		GTSModel:       fave,
+		Receiving:      receivingAcct,
+		Requesting:     requestingAcct,
+	})
+
 	return nil
 }
 
@@ -298,10 +318,7 @@ func (f *federatingDB) undoBlock(
 
 	// Convert AS Block to barebones *gtsmodel.Block,
 	// retrieving origin + target accts from the DB.
-	block, err := f.converter.ASBlockToBlock(
-		gtscontext.SetBarebones(ctx),
-		asBlock,
-	)
+	block, err := f.converter.ASBlockToBlock(ctx, asBlock)
 	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		err := gtserror.Newf("error converting AS Block to block: %w", err)
 		return err
@@ -333,7 +350,16 @@ func (f *federatingDB) undoBlock(
 		return err
 	}
 
-	log.Debug(ctx, "Block undone")
+	// Send the deleted block through to
+	// the fedi worker to process side effects.
+	f.state.Workers.Federator.Queue.Push(&messages.FromFediAPI{
+		APObjectType:   ap.ActivityBlock,
+		APActivityType: ap.ActivityUndo,
+		GTSModel:       block,
+		Receiving:      receivingAcct,
+		Requesting:     requestingAcct,
+	})
+
 	return nil
 }
 

internal/processing/timeline/home.go

@@ -38,22 +38,6 @@ func (p *Processor) HomeTimelineGet(
 	*apimodel.PageableResponse,
 	gtserror.WithCode,
 ) {
-	var pageQuery url.Values
-	var postFilter func(*gtsmodel.Status) (bool, error)
-
-	if local {
-		// Set local = true query.
-		pageQuery = localOnlyTrue
-
-		// Remove any non-local statuses if local-only requested.
-		postFilter = func(s *gtsmodel.Status) (bool, error) {
-			return !*s.Local, nil
-		}
-	} else {
-		// Set local = false query.
-		pageQuery = localOnlyFalse
-	}
-
 	return p.getStatusTimeline(ctx,
 
 		// Auth'd
@@ -74,7 +58,19 @@ func (p *Processor) HomeTimelineGet(
 		// page query flag, (this map
 		// later gets copied before
 		// any further usage).
-		pageQuery,
+		func() url.Values {
+			var pageQuery url.Values
+
+			if local {
+				// Set local = true query.
+				pageQuery = localOnlyTrue
+			} else {
+				// Set local = false query.
+				pageQuery = localOnlyFalse
+			}
+
+			return pageQuery
+		}(),
 
 		// Status filter context.
 		statusfilter.FilterContextHome,
@@ -92,9 +88,5 @@ func (p *Processor) HomeTimelineGet(
 			ok, err := p.visFilter.StatusHomeTimelineable(ctx, requester, s)
 			return !ok, err
 		},
-
-		// Post-filtering function,
-		// i.e. filter after caching.
-		postFilter,
 	)
 }

internal/processing/timeline/list.go

@@ -93,7 +93,7 @@ func (p *Processor) ListTimelineGet(
 			return p.state.DB.GetListTimeline(ctx, listID, pg)
 		},
 
-		// Pre-filtering function,
+		// Filtering function,
 		// i.e. filter before caching.
 		func(s *gtsmodel.Status) (bool, error) {
 
@@ -101,9 +101,5 @@ func (p *Processor) ListTimelineGet(
 			ok, err := p.visFilter.StatusHomeTimelineable(ctx, requester, s)
 			return !ok, err
 		},
-
-		// Post-filtering function,
-		// i.e. filter after caching.
-		nil,
 	)
 }

internal/processing/timeline/public.go

@@ -89,10 +89,6 @@ func (p *Processor) publicTimelineGet(
 			ok, err := p.visFilter.StatusPublicTimelineable(ctx, requester, s)
 			return !ok, err
 		},
-
-		// Post-filtering function,
-		// i.e. filter after caching.
-		nil,
 	)
 }
 
@@ -134,7 +130,7 @@ func (p *Processor) localTimelineGet(
 			return p.state.DB.GetLocalTimeline(ctx, pg)
 		},
 
-		// Pre-filtering function,
+		// Filtering function,
 		// i.e. filter before caching.
 		func(s *gtsmodel.Status) (bool, error) {
 
@@ -142,9 +138,5 @@ func (p *Processor) localTimelineGet(
 			ok, err := p.visFilter.StatusPublicTimelineable(ctx, requester, s)
 			return !ok, err
 		},
-
-		// Post-filtering function,
-		// i.e. filter after caching.
-		nil,
 	)
 }

internal/processing/timeline/timeline.go

@@ -70,8 +70,7 @@ func (p *Processor) getStatusTimeline(
 	pageQuery url.Values,
 	filterCtx statusfilter.FilterContext,
 	loadPage func(*paging.Page) (statuses []*gtsmodel.Status, err error),
-	preFilter func(*gtsmodel.Status) (bool, error),
-	postFilter func(*gtsmodel.Status) (bool, error),
+	filter func(*gtsmodel.Status) (bool, error),
 ) (
 	*apimodel.PageableResponse,
 	gtserror.WithCode,
@@ -128,13 +127,9 @@ func (p *Processor) getStatusTimeline(
 			return p.state.DB.GetStatusesByIDs(ctx, ids)
 		},
 
-		// Pre-filtering function,
+		// Filtering function,
 		// i.e. filter before caching.
-		preFilter,
-
-		// Post-filtering function,
-		// i.e. filter after caching.
-		postFilter,
+		filter,
 
 		// Frontend API model preparation function.
 		func(status *gtsmodel.Status) (*apimodel.Status, error) {

internal/processing/workers/fromclientapi.go

@@ -682,8 +682,15 @@ func (p *clientAPI) CreateBlock(ctx context.Context, cMsg *messages.FromClientAP
 		return gtserror.Newf("%T not parseable as *gtsmodel.Block", cMsg.GTSModel)
 	}
 
-	// Perform any necessary timeline invalidation.
-	p.surface.invalidateTimelinesForBlock(ctx, block)
+	if block.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.AccountID)
+	}
+
+	if block.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.TargetAccountID)
+	}
 
 	// TODO: same with notifications?
 	// TODO: same with bookmarks?
@@ -843,6 +850,16 @@ func (p *clientAPI) UndoFollow(ctx context.Context, cMsg *messages.FromClientAPI
 		log.Errorf(ctx, "error updating account stats: %v", err)
 	}
 
+	if follow.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, follow.AccountID)
+	}
+
+	if follow.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, follow.TargetAccountID)
+	}
+
 	if err := p.federate.UndoFollow(ctx, follow); err != nil {
 		log.Errorf(ctx, "error federating follow undo: %v", err)
 	}
@@ -856,6 +873,16 @@ func (p *clientAPI) UndoBlock(ctx context.Context, cMsg *messages.FromClientAPI)
 		return gtserror.Newf("%T not parseable as *gtsmodel.Block", cMsg.GTSModel)
 	}
 
+	if block.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.AccountID)
+	}
+
+	if block.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.TargetAccountID)
+	}
+
 	if err := p.federate.UndoBlock(ctx, block); err != nil {
 		log.Errorf(ctx, "error federating block undo: %v", err)
 	}
@@ -1010,6 +1037,25 @@ func (p *clientAPI) DeleteAccountOrUser(ctx context.Context, cMsg *messages.From
 	p.state.Workers.Federator.Queue.Delete("Receiving.ID", account.ID)
 	p.state.Workers.Federator.Queue.Delete("TargetURI", account.URI)
 
+	// Remove any entries authored by account from timelines.
+	p.surface.removeTimelineEntriesByAccount(account.ID)
+
+	// Remove any of their cached timelines.
+	p.state.Caches.Timelines.Public.Delete(account.ID)
+	p.state.Caches.Timelines.Home.Delete(account.ID)
+	p.state.Caches.Timelines.Local.Delete(account.ID)
+
+	// Get the IDs of all the lists owned by the given account ID.
+	listIDs, err := p.state.DB.GetListIDsByAccountID(ctx, account.ID)
+	if err != nil {
+		log.Errorf(ctx, "error getting lists for account %s: %v", account.ID, err)
+	}
+
+	// Remove list timelines of account.
+	for _, listID := range listIDs {
+		p.state.Caches.Timelines.List.Delete(listID)
+	}
+
 	if err := p.federate.DeleteAccount(ctx, cMsg.Target); err != nil {
 		log.Errorf(ctx, "error federating account delete: %v", err)
 	}

internal/processing/workers/fromfediapi.go

@@ -197,9 +197,22 @@ func (p *Processor) ProcessFromFediAPI(ctx context.Context, fMsg *messages.FromF
 	// UNDO SOMETHING
 	case ap.ActivityUndo:
 
+		switch fMsg.APObjectType {
+		// UNDO FOLLOW
+		case ap.ActivityFollow:
+			return p.fediAPI.UndoFollow(ctx, fMsg)
+
+		// UNDO BLOCK
+		case ap.ActivityBlock:
+			return p.fediAPI.UndoBlock(ctx, fMsg)
+
 		// UNDO ANNOUNCE
-		if fMsg.APObjectType == ap.ActivityAnnounce {
+		case ap.ActivityAnnounce:
 			return p.fediAPI.UndoAnnounce(ctx, fMsg)
+
+		// UNDO LIKE
+		case ap.ActivityLike:
+			return p.fediAPI.UndoFave(ctx, fMsg)
 		}
 	}
 
@@ -701,8 +714,15 @@ func (p *fediAPI) CreateBlock(ctx context.Context, fMsg *messages.FromFediAPI) e
 		return gtserror.Newf("%T not parseable as *gtsmodel.Block", fMsg.GTSModel)
 	}
 
-	// Perform any necessary timeline invalidation.
-	p.surface.invalidateTimelinesForBlock(ctx, block)
+	if block.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.AccountID)
+	}
+
+	if block.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.TargetAccountID)
+	}
 
 	// Remove any follows that existed between blocker + blockee.
 	// (note this handles removing any necessary list entries).
@@ -1054,6 +1074,9 @@ func (p *fediAPI) DeleteAccount(ctx context.Context, fMsg *messages.FromFediAPI)
 	p.state.Workers.Federator.Queue.Delete("Requesting.ID", account.ID)
 	p.state.Workers.Federator.Queue.Delete("TargetURI", account.URI)
 
+	// Remove any entries authored by account from timelines.
+	p.surface.removeTimelineEntriesByAccount(account.ID)
+
 	// First perform the actual account deletion.
 	if err := p.account.Delete(ctx, account, account.ID); err != nil {
 		log.Errorf(ctx, "error deleting account: %v", err)
@@ -1172,6 +1195,44 @@ func (p *fediAPI) RejectAnnounce(ctx context.Context, fMsg *messages.FromFediAPI
 	return nil
 }
 
+func (p *fediAPI) UndoFollow(ctx context.Context, fMsg *messages.FromFediAPI) error {
+	follow, ok := fMsg.GTSModel.(*gtsmodel.Follow)
+	if !ok {
+		return gtserror.Newf("%T not parseable as *gtsmodel.Follow", fMsg.GTSModel)
+	}
+
+	if follow.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, follow.AccountID)
+	}
+
+	if follow.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, follow.TargetAccountID)
+	}
+
+	return nil
+}
+
+func (p *fediAPI) UndoBlock(ctx context.Context, fMsg *messages.FromFediAPI) error {
+	block, ok := fMsg.GTSModel.(*gtsmodel.Block)
+	if !ok {
+		return gtserror.Newf("%T not parseable as *gtsmodel.Block", fMsg.GTSModel)
+	}
+
+	if block.Account.IsLocal() {
+		// Perform timeline invalidation for block origin account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.AccountID)
+	}
+
+	if block.TargetAccount.IsLocal() {
+		// Perform timeline invalidation for block target account.
+		p.surface.invalidateTimelinesForAccount(ctx, block.TargetAccountID)
+	}
+
+	return nil
+}
+
 func (p *fediAPI) UndoAnnounce(
 	ctx context.Context,
 	fMsg *messages.FromFediAPI,
@@ -1200,3 +1261,16 @@ func (p *fediAPI) UndoAnnounce(
 
 	return nil
 }
+
+func (p *fediAPI) UndoFave(ctx context.Context, fMsg *messages.FromFediAPI) error {
+	statusFave, ok := fMsg.GTSModel.(*gtsmodel.StatusFave)
+	if !ok {
+		return gtserror.Newf("%T not parseable as *gtsmodel.StatusFave", fMsg.GTSModel)
+	}
+
+	// Interaction counts changed on the faved status;
+	// uncache the prepared version from all timelines.
+	p.surface.invalidateStatusFromTimelines(statusFave.StatusID)
+
+	return nil
+}

internal/processing/workers/surfacetimeline.go

@@ -524,27 +524,6 @@ func (s *Surface) tagFollowersForStatus(
 	return visibleTagFollowerAccounts, errs.Combine()
 }
 
-// deleteStatusFromTimelines completely removes the given status from all timelines.
-// It will also stream deletion of the status to all open streams.
-func (s *Surface) deleteStatusFromTimelines(ctx context.Context, statusID string) {
-	s.State.Caches.Timelines.Public.RemoveByStatusIDs(statusID)
-	s.State.Caches.Timelines.Local.RemoveByStatusIDs(statusID)
-	s.State.Caches.Timelines.Home.RemoveByStatusIDs(statusID)
-	s.State.Caches.Timelines.List.RemoveByStatusIDs(statusID)
-	s.Stream.Delete(ctx, statusID)
-}
-
-// invalidateStatusFromTimelines does cache invalidation on the given status by
-// unpreparing it from all timelines, forcing it to be prepared again (with updated
-// stats, boost counts, etc) next time it's fetched by the timeline owner. This goes
-// both for the status itself, and for any boosts of the status.
-func (s *Surface) invalidateStatusFromTimelines(statusID string) {
-	s.State.Caches.Timelines.Public.UnprepareByStatusIDs(statusID)
-	s.State.Caches.Timelines.Local.UnprepareByStatusIDs(statusID)
-	s.State.Caches.Timelines.Home.UnprepareByStatusIDs(statusID)
-	s.State.Caches.Timelines.List.UnprepareByStatusIDs(statusID)
-}
-
 // timelineStatusUpdate looks up HOME and LIST timelines of accounts
 // that follow the the status author or tags and pushes edit messages into any
 // active streams.
@@ -822,56 +801,52 @@ func (s *Surface) timelineStatusUpdateForTagFollowers(
 	return errs.Combine()
 }
 
-// invalidateTimelinesForBlock ...
-func (s *Surface) invalidateTimelinesForBlock(ctx context.Context, block *gtsmodel.Block) {
+// deleteStatusFromTimelines completely removes the given status from all timelines.
+// It will also stream deletion of the status to all open streams.
+func (s *Surface) deleteStatusFromTimelines(ctx context.Context, statusID string) {
+	s.State.Caches.Timelines.Public.RemoveByStatusIDs(statusID)
+	s.State.Caches.Timelines.Local.RemoveByStatusIDs(statusID)
+	s.State.Caches.Timelines.Home.RemoveByStatusIDs(statusID)
+	s.State.Caches.Timelines.List.RemoveByStatusIDs(statusID)
+	s.Stream.Delete(ctx, statusID)
+}
 
-	// Check if origin is local account,
-	// i.e. has status timeline caches.
-	if block.Account.IsLocal() {
+// invalidateStatusFromTimelines does cache invalidation on the given status by
+// unpreparing it from all timelines, forcing it to be prepared again (with updated
+// stats, boost counts, etc) next time it's fetched by the timeline owner. This goes
+// both for the status itself, and for any boosts of the status.
+func (s *Surface) invalidateStatusFromTimelines(statusID string) {
+	s.State.Caches.Timelines.Public.UnprepareByStatusIDs(statusID)
+	s.State.Caches.Timelines.Local.UnprepareByStatusIDs(statusID)
+	s.State.Caches.Timelines.Home.UnprepareByStatusIDs(statusID)
+	s.State.Caches.Timelines.List.UnprepareByStatusIDs(statusID)
+}
 
-		// Remove target's statuses
-		// from origin's home timeline.
-		s.State.Caches.Timelines.Home.
-			MustGet(block.AccountID).
-			RemoveByAccountIDs(block.TargetAccountID)
+// removeTimelineEntriesByAccount removes all cached timeline entries authored by account ID.
+func (s *Surface) removeTimelineEntriesByAccount(accountID string) {
+	s.State.Caches.Timelines.Public.RemoveByAccountIDs(accountID)
+	s.State.Caches.Timelines.Home.RemoveByAccountIDs(accountID)
+	s.State.Caches.Timelines.Local.RemoveByAccountIDs(accountID)
+	s.State.Caches.Timelines.List.RemoveByAccountIDs(accountID)
+}
 
-		// Get the IDs of any lists created by origin account.
-		listIDs, err := s.State.DB.GetListIDsByAccountID(ctx, block.AccountID)
-		if err != nil {
-			log.Errorf(ctx, "error getting account's list IDs for %s: %v", block.URI, err)
-		}
+// invalidateTimelinesForAccount invalidates all timeline caches stored for given account ID.
+func (s *Surface) invalidateTimelinesForAccount(ctx context.Context, accountID string) {
 
-		// Remove target's statuses from
-		// any of origin's list timelines.
-		for _, listID := range listIDs {
-			s.State.Caches.Timelines.List.
-				MustGet(listID).
-				RemoveByAccountIDs(block.TargetAccountID)
-		}
+	// There's a lot of visibility changes to caclculate for any
+	// relationship change, so just clear all account's timelines.
+	s.State.Caches.Timelines.Public.Clear(accountID)
+	s.State.Caches.Timelines.Home.Clear(accountID)
+	s.State.Caches.Timelines.Local.Clear(accountID)
+
+	// Get the IDs of all the lists owned by the given account ID.
+	listIDs, err := s.State.DB.GetListIDsByAccountID(ctx, accountID)
+	if err != nil {
+		log.Errorf(ctx, "error getting lists for account %s: %v", accountID, err)
 	}
 
-	// Check if target is local account,
-	// i.e. has status timeline caches.
-	if block.TargetAccount.IsLocal() {
-
-		// Remove origin's statuses
-		// from target's home timeline.
-		s.State.Caches.Timelines.Home.
-			MustGet(block.TargetAccountID).
-			RemoveByAccountIDs(block.AccountID)
-
-		// Get the IDs of any lists created by target account.
-		listIDs, err := s.State.DB.GetListIDsByAccountID(ctx, block.TargetAccountID)
-		if err != nil {
-			log.Errorf(ctx, "error getting target account's list IDs for %s: %v", block.URI, err)
-		}
-
-		// Remove origin's statuses from
-		// any of target's list timelines.
-		for _, listID := range listIDs {
-			s.State.Caches.Timelines.List.
-				MustGet(listID).
-				RemoveByAccountIDs(block.AccountID)
-		}
+	// Clear list timelines of account.
+	for _, listID := range listIDs {
+		s.State.Caches.Timelines.List.Clear(listID)
 	}
 }

internal/typeutils/astointernal.go

@@ -512,7 +512,9 @@ func (c *Converter) ASFollowToFollow(ctx context.Context, followable ap.Followab
 
 	follow := &gtsmodel.Follow{
 		URI:             uri,
+		Account:         origin,
 		AccountID:       origin.ID,
+		TargetAccount:   target,
 		TargetAccountID: target.ID,
 	}