[feature] Rework timeline code to make it useful for more than just statuses (#373)

* add preparable and timelineable interfaces

* initialize timeline manager within the processor

* generic renaming

* move status-specific timeline logic into the processor

* refactor timeline to make it useful for more than statuses

cmd/gotosocial/action/server/server.go

@@ -65,7 +65,6 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/oidc"
 	"github.com/superseriousbusiness/gotosocial/internal/processing"
 	"github.com/superseriousbusiness/gotosocial/internal/router"
-	timelineprocessing "github.com/superseriousbusiness/gotosocial/internal/timeline"
 	"github.com/superseriousbusiness/gotosocial/internal/transport"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
 	"github.com/superseriousbusiness/gotosocial/internal/web"
@@ -95,7 +94,6 @@ var Start action.GTSAction = func(ctx context.Context) error {
 
 	// build converters and util
 	typeConverter := typeutils.NewConverter(dbService)
-	timelineManager := timelineprocessing.NewManager(dbService, typeConverter)
 
 	// Open the storage backend
 	storageBasePath := viper.GetString(config.Keys.StorageLocalBasePath)
@@ -128,7 +126,7 @@ var Start action.GTSAction = func(ctx context.Context) error {
 	}
 
 	// create and start the message processor using the other services we've created so far
-	processor := processing.NewProcessor(typeConverter, federator, oauthServer, mediaHandler, storage, timelineManager, dbService, emailSender)
+	processor := processing.NewProcessor(typeConverter, federator, oauthServer, mediaHandler, storage, dbService, emailSender)
 	if err := processor.Start(ctx); err != nil {
 		return fmt.Errorf("error starting processor: %s", err)
 	}

internal/api/model/status.go

@@ -96,6 +96,36 @@ type Status struct {
 	Text string `json:"text"`
 }
 
+/*
+** The below functions are added onto the API model status so that it satisfies
+** the Preparable interface in internal/timeline.
+ */
+
+func (s *Status) GetID() string {
+	return s.ID
+}
+
+func (s *Status) GetAccountID() string {
+	if s.Account != nil {
+		return s.Account.ID
+	}
+	return ""
+}
+
+func (s *Status) GetBoostOfID() string {
+	if s.Reblog != nil {
+		return s.Reblog.ID
+	}
+	return ""
+}
+
+func (s *Status) GetBoostOfAccountID() string {
+	if s.Reblog != nil && s.Reblog.Account != nil {
+		return s.Reblog.Account.ID
+	}
+	return ""
+}
+
 // StatusReblogged represents a reblogged status.
 //
 // swagger:model statusReblogged

internal/api/s2s/webfinger/webfingerget_test.go

@@ -69,7 +69,7 @@ func (suite *WebfingerGetTestSuite) TestFingerUser() {
 func (suite *WebfingerGetTestSuite) TestFingerUserWithDifferentAccountDomainByHost() {
 	viper.Set(config.Keys.Host, "gts.example.org")
 	viper.Set(config.Keys.AccountDomain, "example.org")
-	suite.processor = processing.NewProcessor(suite.tc, suite.federator, testrig.NewTestOauthServer(suite.db), testrig.NewTestMediaHandler(suite.db, suite.storage), suite.storage, testrig.NewTestTimelineManager(suite.db), suite.db, suite.emailSender)
+	suite.processor = processing.NewProcessor(suite.tc, suite.federator, testrig.NewTestOauthServer(suite.db), testrig.NewTestMediaHandler(suite.db, suite.storage), suite.storage, suite.db, suite.emailSender)
 	suite.webfingerModule = webfinger.New(suite.processor).(*webfinger.Module)
 
 	targetAccount := accountDomainAccount()
@@ -103,7 +103,7 @@ func (suite *WebfingerGetTestSuite) TestFingerUserWithDifferentAccountDomainByHo
 func (suite *WebfingerGetTestSuite) TestFingerUserWithDifferentAccountDomainByAccountDomain() {
 	viper.Set(config.Keys.Host, "gts.example.org")
 	viper.Set(config.Keys.AccountDomain, "example.org")
-	suite.processor = processing.NewProcessor(suite.tc, suite.federator, testrig.NewTestOauthServer(suite.db), testrig.NewTestMediaHandler(suite.db, suite.storage), suite.storage, testrig.NewTestTimelineManager(suite.db), suite.db, suite.emailSender)
+	suite.processor = processing.NewProcessor(suite.tc, suite.federator, testrig.NewTestOauthServer(suite.db), testrig.NewTestMediaHandler(suite.db, suite.storage), suite.storage, suite.db, suite.emailSender)
 	suite.webfingerModule = webfinger.New(suite.processor).(*webfinger.Module)
 
 	targetAccount := accountDomainAccount()

internal/gtsmodel/status.go

@@ -66,6 +66,27 @@ type Status struct {
 	Likeable                 bool               `validate:"-" bun:",notnull"`                                                                          // This status can be liked/faved
 }
 
+/*
+	The below functions are added onto the gtsmodel status so that it satisfies
+	the Timelineable interface in internal/timeline.
+*/
+
+func (s *Status) GetID() string {
+	return s.ID
+}
+
+func (s *Status) GetAccountID() string {
+	return s.AccountID
+}
+
+func (s *Status) GetBoostOfID() string {
+	return s.BoostOfID
+}
+
+func (s *Status) GetBoostOfAccountID() string {
+	return s.BoostOfAccountID
+}
+
 // StatusToTag is an intermediate struct to facilitate the many2many relationship between a status and one or more tags.
 type StatusToTag struct {
 	StatusID string  `validate:"ulid,required" bun:"type:CHAR(26),unique:statustag,nullzero,notnull"`

internal/processing/fromclientapi.go

@@ -192,10 +192,10 @@ func (p *processor) processCreateBlockFromClientAPI(ctx context.Context, clientM
 	}
 
 	// remove any of the blocking account's statuses from the blocked account's timeline, and vice versa
-	if err := p.timelineManager.WipeStatusesFromAccountID(ctx, block.AccountID, block.TargetAccountID); err != nil {
+	if err := p.statusTimelines.WipeItemsFromAccountID(ctx, block.AccountID, block.TargetAccountID); err != nil {
 		return err
 	}
-	if err := p.timelineManager.WipeStatusesFromAccountID(ctx, block.TargetAccountID, block.AccountID); err != nil {
+	if err := p.statusTimelines.WipeItemsFromAccountID(ctx, block.TargetAccountID, block.AccountID); err != nil {
 		return err
 	}
 

internal/processing/fromcommon.go

@@ -413,7 +413,7 @@ func (p *processor) timelineStatusForAccount(ctx context.Context, status *gtsmod
 	}
 
 	// stick the status in the timeline for the account and then immediately prepare it so they can see it right away
-	inserted, err := p.timelineManager.IngestAndPrepare(ctx, status, timelineAccount.ID)
+	inserted, err := p.statusTimelines.IngestAndPrepare(ctx, status, timelineAccount.ID)
 	if err != nil {
 		errors <- fmt.Errorf("timelineStatusForAccount: error ingesting status %s: %s", status.ID, err)
 		return
@@ -436,7 +436,7 @@ func (p *processor) timelineStatusForAccount(ctx context.Context, status *gtsmod
 // deleteStatusFromTimelines completely removes the given status from all timelines.
 // It will also stream deletion of the status to all open streams.
 func (p *processor) deleteStatusFromTimelines(ctx context.Context, status *gtsmodel.Status) error {
-	if err := p.timelineManager.WipeStatusFromAllTimelines(ctx, status.ID); err != nil {
+	if err := p.statusTimelines.WipeItemFromAllTimelines(ctx, status.ID); err != nil {
 		return err
 	}
 

internal/processing/fromfederator.go

@@ -213,10 +213,10 @@ func (p *processor) processCreateBlockFromFederator(ctx context.Context, federat
 	}
 
 	// remove any of the blocking account's statuses from the blocked account's timeline, and vice versa
-	if err := p.timelineManager.WipeStatusesFromAccountID(ctx, block.AccountID, block.TargetAccountID); err != nil {
+	if err := p.statusTimelines.WipeItemsFromAccountID(ctx, block.AccountID, block.TargetAccountID); err != nil {
 		return err
 	}
-	if err := p.timelineManager.WipeStatusesFromAccountID(ctx, block.TargetAccountID, block.AccountID); err != nil {
+	if err := p.statusTimelines.WipeItemsFromAccountID(ctx, block.TargetAccountID, block.AccountID); err != nil {
 		return err
 	}
 	// TODO: same with notifications

internal/processing/processor.go

@@ -237,7 +237,7 @@ type processor struct {
 	oauthServer     oauth.Server
 	mediaHandler    media.Handler
 	storage         *kv.KVStore
-	timelineManager timeline.Manager
+	statusTimelines timeline.Manager
 	db              db.DB
 	filter          visibility.Filter
 
@@ -261,7 +261,6 @@ func NewProcessor(
 	oauthServer oauth.Server,
 	mediaHandler media.Handler,
 	storage *kv.KVStore,
-	timelineManager timeline.Manager,
 	db db.DB,
 	emailSender email.Sender) Processor {
 	fromClientAPI := make(chan messages.FromClientAPI, 1000)
@@ -274,6 +273,7 @@ func NewProcessor(
 	mediaProcessor := mediaProcessor.New(db, tc, mediaHandler, storage)
 	userProcessor := user.New(db, emailSender)
 	federationProcessor := federationProcessor.New(db, tc, federator, fromFederator)
+	filter := visibility.NewFilter(db)
 
 	return &processor{
 		fromClientAPI:   fromClientAPI,
@@ -284,7 +284,7 @@ func NewProcessor(
 		oauthServer:     oauthServer,
 		mediaHandler:    mediaHandler,
 		storage:         storage,
-		timelineManager: timelineManager,
+		statusTimelines: timeline.NewManager(StatusGrabFunction(db), StatusFilterFunction(db, filter), StatusPrepareFunction(db, tc), StatusSkipInsertFunction()),
 		db:              db,
 		filter:          visibility.NewFilter(db),
 

internal/processing/processor_test.go

@@ -219,10 +219,9 @@ func (suite *ProcessingStandardTestSuite) SetupTest() {
 	suite.federator = testrig.NewTestFederator(suite.db, suite.transportController, suite.storage)
 	suite.oauthServer = testrig.NewTestOauthServer(suite.db)
 	suite.mediaHandler = testrig.NewTestMediaHandler(suite.db, suite.storage)
-	suite.timelineManager = testrig.NewTestTimelineManager(suite.db)
 	suite.emailSender = testrig.NewEmailSender("../../web/template/", nil)
 
-	suite.processor = processing.NewProcessor(suite.typeconverter, suite.federator, suite.oauthServer, suite.mediaHandler, suite.storage, suite.timelineManager, suite.db, suite.emailSender)
+	suite.processor = processing.NewProcessor(suite.typeconverter, suite.federator, suite.oauthServer, suite.mediaHandler, suite.storage, suite.db, suite.emailSender)
 
 	testrig.StandardDBSetup(suite.db, suite.testAccounts)
 	testrig.StandardStorageSetup(suite.storage, "../../testrig/media")

internal/processing/statustimeline.go

@@ -20,6 +20,7 @@ package processing
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/url"
 
@@ -32,8 +33,113 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/oauth"
+	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 )
 
+const boostReinsertionDepth = 50
+
+// StatusGrabFunction returns a function that satisfies the GrabFunction interface in internal/timeline.
+func StatusGrabFunction(database db.DB) timeline.GrabFunction {
+	return func(ctx context.Context, timelineAccountID string, maxID string, sinceID string, minID string, limit int) ([]timeline.Timelineable, bool, error) {
+		statuses, err := database.GetHomeTimeline(ctx, timelineAccountID, maxID, sinceID, minID, limit, false)
+		if err != nil {
+			if err == db.ErrNoEntries {
+				return nil, true, nil // we just don't have enough statuses left in the db so return stop = true
+			}
+			return nil, false, fmt.Errorf("statusGrabFunction: error getting statuses from db: %s", err)
+		}
+
+		items := []timeline.Timelineable{}
+		for _, s := range statuses {
+			items = append(items, s)
+		}
+
+		return items, false, nil
+	}
+}
+
+// StatusFilterFunction returns a function that satisfies the FilterFunction interface in internal/timeline.
+func StatusFilterFunction(database db.DB, filter visibility.Filter) timeline.FilterFunction {
+	return func(ctx context.Context, timelineAccountID string, item timeline.Timelineable) (shouldIndex bool, err error) {
+		status, ok := item.(*gtsmodel.Status)
+		if !ok {
+			return false, errors.New("statusFilterFunction: could not convert item to *gtsmodel.Status")
+		}
+
+		requestingAccount, err := database.GetAccountByID(ctx, timelineAccountID)
+		if err != nil {
+			return false, fmt.Errorf("statusFilterFunction: error getting account with id %s", timelineAccountID)
+		}
+
+		timelineable, err := filter.StatusHometimelineable(ctx, status, requestingAccount)
+		if err != nil {
+			logrus.Warnf("error checking hometimelineability of status %s for account %s: %s", status.ID, timelineAccountID, err)
+		}
+
+		return timelineable, nil // we don't return the error here because we want to just skip this item if something goes wrong
+	}
+}
+
+// StatusPrepareFunction returns a function that satisfies the PrepareFunction interface in internal/timeline.
+func StatusPrepareFunction(database db.DB, tc typeutils.TypeConverter) timeline.PrepareFunction {
+	return func(ctx context.Context, timelineAccountID string, itemID string) (timeline.Preparable, error) {
+		status, err := database.GetStatusByID(ctx, itemID)
+		if err != nil {
+			return nil, fmt.Errorf("statusPrepareFunction: error getting status with id %s", itemID)
+		}
+
+		requestingAccount, err := database.GetAccountByID(ctx, timelineAccountID)
+		if err != nil {
+			return nil, fmt.Errorf("statusPrepareFunction: error getting account with id %s", timelineAccountID)
+		}
+
+		return tc.StatusToAPIStatus(ctx, status, requestingAccount)
+	}
+}
+
+// StatusSkipInsertFunction returns a function that satisifes the SkipInsertFunction interface in internal/timeline.
+func StatusSkipInsertFunction() timeline.SkipInsertFunction {
+	return func(
+		ctx context.Context,
+		newItemID string,
+		newItemAccountID string,
+		newItemBoostOfID string,
+		newItemBoostOfAccountID string,
+		nextItemID string,
+		nextItemAccountID string,
+		nextItemBoostOfID string,
+		nextItemBoostOfAccountID string,
+		depth int) (bool, error) {
+
+		// make sure we don't insert a duplicate
+		if newItemID == nextItemID {
+			return true, nil
+		}
+
+		// check if it's a boost
+		if newItemBoostOfID != "" {
+			// skip if we've recently put another boost of this status in the timeline
+			if newItemBoostOfID == nextItemBoostOfID {
+				if depth < boostReinsertionDepth {
+					return true, nil
+				}
+			}
+
+			// skip if we've recently put the original status in the timeline
+			if newItemBoostOfID == nextItemID {
+				if depth < boostReinsertionDepth {
+					return true, nil
+				}
+			}
+		}
+
+		// insert the item
+		return false, nil
+	}
+}
+
 func (p *processor) packageStatusResponse(statuses []*apimodel.Status, path string, nextMaxID string, prevMinID string, limit int) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
 	resp := &apimodel.StatusTimelineResponse{
 		Statuses: []*apimodel.Status{},
@@ -67,18 +173,27 @@ func (p *processor) packageStatusResponse(statuses []*apimodel.Status, path stri
 }
 
 func (p *processor) HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
-	statuses, err := p.timelineManager.HomeTimeline(ctx, authed.Account.ID, maxID, sinceID, minID, limit, local)
+	preparedItems, err := p.statusTimelines.GetTimeline(ctx, authed.Account.ID, maxID, sinceID, minID, limit, local)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	if len(statuses) == 0 {
+	if len(preparedItems) == 0 {
 		return &apimodel.StatusTimelineResponse{
 			Statuses: []*apimodel.Status{},
 		}, nil
 	}
 
-	return p.packageStatusResponse(statuses, "api/v1/timelines/home", statuses[len(statuses)-1].ID, statuses[0].ID, limit)
+	statuses := []*apimodel.Status{}
+	for _, i := range preparedItems {
+		status, ok := i.(*apimodel.Status)
+		if !ok {
+			return nil, gtserror.NewErrorInternalError(errors.New("error converting prepared timeline entry to api status"))
+		}
+		statuses = append(statuses, status)
+	}
+
+	return p.packageStatusResponse(statuses, "api/v1/timelines/home", statuses[len(preparedItems)-1].ID, statuses[0].ID, limit)
 }
 
 func (p *processor) PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {

internal/timeline/get.go

@@ -25,12 +25,11 @@ import (
 	"fmt"
 
 	"github.com/sirupsen/logrus"
-	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 )
 
 const retries = 5
 
-func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID string, minID string, prepareNext bool) ([]*apimodel.Status, error) {
+func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID string, minID string, prepareNext bool) ([]Preparable, error) {
 	l := logrus.WithFields(logrus.Fields{
 		"func":      "Get",
 		"accountID": t.accountID,
@@ -41,16 +40,16 @@ func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID st
 	})
 	l.Debug("entering get")
 
-	var statuses []*apimodel.Status
+	var items []Preparable
 	var err error
 
 	// no params are defined to just fetch from the top
-	// this is equivalent to a user asking for the top x posts from their timeline
+	// this is equivalent to a user asking for the top x items from their timeline
 	if maxID == "" && sinceID == "" && minID == "" {
-		statuses, err = t.GetXFromTop(ctx, amount)
+		items, err = t.GetXFromTop(ctx, amount)
 		// aysnchronously prepare the next predicted query so it's ready when the user asks for it
-		if len(statuses) != 0 {
-			nextMaxID := statuses[len(statuses)-1].ID
+		if len(items) != 0 {
+			nextMaxID := items[len(items)-1].GetID()
 			if prepareNext {
 				// already cache the next query to speed up scrolling
 				go func() {
@@ -64,13 +63,13 @@ func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID st
 	}
 
 	// maxID is defined but sinceID isn't so take from behind
-	// this is equivalent to a user asking for the next x posts from their timeline, starting from maxID
+	// this is equivalent to a user asking for the next x items from their timeline, starting from maxID
 	if maxID != "" && sinceID == "" {
 		attempts := 0
-		statuses, err = t.GetXBehindID(ctx, amount, maxID, &attempts)
+		items, err = t.GetXBehindID(ctx, amount, maxID, &attempts)
 		// aysnchronously prepare the next predicted query so it's ready when the user asks for it
-		if len(statuses) != 0 {
-			nextMaxID := statuses[len(statuses)-1].ID
+		if len(items) != 0 {
+			nextMaxID := items[len(items)-1].GetID()
 			if prepareNext {
 				// already cache the next query to speed up scrolling
 				go func() {
@@ -84,59 +83,59 @@ func (t *timeline) Get(ctx context.Context, amount int, maxID string, sinceID st
 	}
 
 	// maxID is defined and sinceID || minID are as well, so take a slice between them
-	// this is equivalent to a user asking for posts older than x but newer than y
+	// this is equivalent to a user asking for items older than x but newer than y
 	if maxID != "" && sinceID != "" {
-		statuses, err = t.GetXBetweenID(ctx, amount, maxID, minID)
+		items, err = t.GetXBetweenID(ctx, amount, maxID, minID)
 	}
 	if maxID != "" && minID != "" {
-		statuses, err = t.GetXBetweenID(ctx, amount, maxID, minID)
+		items, err = t.GetXBetweenID(ctx, amount, maxID, minID)
 	}
 
 	// maxID isn't defined, but sinceID || minID are, so take x before
-	// this is equivalent to a user asking for posts newer than x (eg., refreshing the top of their timeline)
+	// this is equivalent to a user asking for items newer than x (eg., refreshing the top of their timeline)
 	if maxID == "" && sinceID != "" {
-		statuses, err = t.GetXBeforeID(ctx, amount, sinceID, true)
+		items, err = t.GetXBeforeID(ctx, amount, sinceID, true)
 	}
 	if maxID == "" && minID != "" {
-		statuses, err = t.GetXBeforeID(ctx, amount, minID, true)
+		items, err = t.GetXBeforeID(ctx, amount, minID, true)
 	}
 
-	return statuses, err
+	return items, err
 }
 
-func (t *timeline) GetXFromTop(ctx context.Context, amount int) ([]*apimodel.Status, error) {
-	// make a slice of statuses with the length we need to return
-	statuses := make([]*apimodel.Status, 0, amount)
+func (t *timeline) GetXFromTop(ctx context.Context, amount int) ([]Preparable, error) {
+	// make a slice of preparedItems with the length we need to return
+	preparedItems := make([]Preparable, 0, amount)
 
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
 	}
 
-	// make sure we have enough posts prepared to return
-	if t.preparedPosts.data.Len() < amount {
+	// make sure we have enough items prepared to return
+	if t.preparedItems.data.Len() < amount {
 		if err := t.PrepareFromTop(ctx, amount); err != nil {
 			return nil, err
 		}
 	}
 
-	// work through the prepared posts from the top and return
+	// work through the prepared items from the top and return
 	var served int
-	for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*preparedPostsEntry)
+	for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
-			return nil, errors.New("GetXFromTop: could not parse e as a preparedPostsEntry")
+			return nil, errors.New("GetXFromTop: could not parse e as a preparedItemsEntry")
 		}
-		statuses = append(statuses, entry.prepared)
+		preparedItems = append(preparedItems, entry.prepared)
 		served++
 		if served >= amount {
 			break
 		}
 	}
 
-	return statuses, nil
+	return preparedItems, nil
 }
 
-func (t *timeline) GetXBehindID(ctx context.Context, amount int, behindID string, attempts *int) ([]*apimodel.Status, error) {
+func (t *timeline) GetXBehindID(ctx context.Context, amount int, behindID string, attempts *int) ([]Preparable, error) {
 	l := logrus.WithFields(logrus.Fields{
 		"func":     "GetXBehindID",
 		"amount":   amount,
@@ -148,11 +147,11 @@ func (t *timeline) GetXBehindID(ctx context.Context, amount int, behindID string
 	newAttempts++
 	attempts = &newAttempts
 
-	// make a slice of statuses with the length we need to return
-	statuses := make([]*apimodel.Status, 0, amount)
+	// make a slice of items with the length we need to return
+	items := make([]Preparable, 0, amount)
 
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
 	}
 
 	// iterate through the modified list until we hit the mark we're looking for
@@ -160,14 +159,14 @@ func (t *timeline) GetXBehindID(ctx context.Context, amount int, behindID string
 	var behindIDMark *list.Element
 
 findMarkLoop:
-	for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
+	for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
 		position++
-		entry, ok := e.Value.(*preparedPostsEntry)
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return nil, errors.New("GetXBehindID: could not parse e as a preparedPostsEntry")
 		}
 
-		if entry.statusID <= behindID {
+		if entry.itemID <= behindID {
 			l.Trace("found behindID mark")
 			behindIDMark = e
 			break findMarkLoop
@@ -175,33 +174,33 @@ findMarkLoop:
 	}
 
 	// we didn't find it, so we need to make sure it's indexed and prepared and then try again
-	// this can happen when a user asks for really old posts
+	// this can happen when a user asks for really old items
 	if behindIDMark == nil {
 		if err := t.PrepareBehind(ctx, behindID, amount); err != nil {
 			return nil, fmt.Errorf("GetXBehindID: error preparing behind and including ID %s", behindID)
 		}
-		oldestID, err := t.OldestPreparedPostID(ctx)
+		oldestID, err := t.OldestPreparedItemID(ctx)
 		if err != nil {
 			return nil, err
 		}
 		if oldestID == "" {
 			l.Tracef("oldestID is empty so we can't return behindID %s", behindID)
-			return statuses, nil
+			return items, nil
 		}
 		if oldestID == behindID {
 			l.Tracef("given behindID %s is the same as oldestID %s so there's nothing to return behind it", behindID, oldestID)
-			return statuses, nil
+			return items, nil
 		}
 		if *attempts > retries {
 			l.Tracef("exceeded retries looking for behindID %s", behindID)
-			return statuses, nil
+			return items, nil
 		}
 		l.Trace("trying GetXBehindID again")
 		return t.GetXBehindID(ctx, amount, behindID, attempts)
 	}
 
-	// make sure we have enough posts prepared behind it to return what we're being asked for
-	if t.preparedPosts.data.Len() < amount+position {
+	// make sure we have enough items prepared behind it to return what we're being asked for
+	if t.preparedItems.data.Len() < amount+position {
 		if err := t.PrepareBehind(ctx, behindID, amount); err != nil {
 			return nil, err
 		}
@@ -211,40 +210,40 @@ findMarkLoop:
 	var served int
 serveloop:
 	for e := behindIDMark.Next(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*preparedPostsEntry)
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return nil, errors.New("GetXBehindID: could not parse e as a preparedPostsEntry")
 		}
 
 		// serve up to the amount requested
-		statuses = append(statuses, entry.prepared)
+		items = append(items, entry.prepared)
 		served++
 		if served >= amount {
 			break serveloop
 		}
 	}
 
-	return statuses, nil
+	return items, nil
 }
 
-func (t *timeline) GetXBeforeID(ctx context.Context, amount int, beforeID string, startFromTop bool) ([]*apimodel.Status, error) {
-	// make a slice of statuses with the length we need to return
-	statuses := make([]*apimodel.Status, 0, amount)
+func (t *timeline) GetXBeforeID(ctx context.Context, amount int, beforeID string, startFromTop bool) ([]Preparable, error) {
+	// make a slice of items with the length we need to return
+	items := make([]Preparable, 0, amount)
 
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
 	}
 
 	// iterate through the modified list until we hit the mark we're looking for, or as close as possible to it
 	var beforeIDMark *list.Element
 findMarkLoop:
-	for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*preparedPostsEntry)
+	for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return nil, errors.New("GetXBeforeID: could not parse e as a preparedPostsEntry")
 		}
 
-		if entry.statusID >= beforeID {
+		if entry.itemID >= beforeID {
 			beforeIDMark = e
 		} else {
 			break findMarkLoop
@@ -252,26 +251,26 @@ findMarkLoop:
 	}
 
 	if beforeIDMark == nil {
-		return statuses, nil
+		return items, nil
 	}
 
 	var served int
 
 	if startFromTop {
-		// start serving from the front/top and keep going until we hit mark or get x amount statuses
+		// start serving from the front/top and keep going until we hit mark or get x amount items
 	serveloopFromTop:
-		for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
-			entry, ok := e.Value.(*preparedPostsEntry)
+		for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
+			entry, ok := e.Value.(*preparedItemsEntry)
 			if !ok {
 				return nil, errors.New("GetXBeforeID: could not parse e as a preparedPostsEntry")
 			}
 
-			if entry.statusID == beforeID {
+			if entry.itemID == beforeID {
 				break serveloopFromTop
 			}
 
 			// serve up to the amount requested
-			statuses = append(statuses, entry.prepared)
+			items = append(items, entry.prepared)
 			served++
 			if served >= amount {
 				break serveloopFromTop
@@ -281,13 +280,13 @@ findMarkLoop:
 		// start serving from the entry right before the mark
 	serveloopFromBottom:
 		for e := beforeIDMark.Prev(); e != nil; e = e.Prev() {
-			entry, ok := e.Value.(*preparedPostsEntry)
+			entry, ok := e.Value.(*preparedItemsEntry)
 			if !ok {
 				return nil, errors.New("GetXBeforeID: could not parse e as a preparedPostsEntry")
 			}
 
 			// serve up to the amount requested
-			statuses = append(statuses, entry.prepared)
+			items = append(items, entry.prepared)
 			served++
 			if served >= amount {
 				break serveloopFromBottom
@@ -295,29 +294,29 @@ findMarkLoop:
 		}
 	}
 
-	return statuses, nil
+	return items, nil
 }
 
-func (t *timeline) GetXBetweenID(ctx context.Context, amount int, behindID string, beforeID string) ([]*apimodel.Status, error) {
-	// make a slice of statuses with the length we need to return
-	statuses := make([]*apimodel.Status, 0, amount)
+func (t *timeline) GetXBetweenID(ctx context.Context, amount int, behindID string, beforeID string) ([]Preparable, error) {
+	// make a slice of items with the length we need to return
+	items := make([]Preparable, 0, amount)
 
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
 	}
 
 	// iterate through the modified list until we hit the mark we're looking for
 	var position int
 	var behindIDMark *list.Element
 findMarkLoop:
-	for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
+	for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
 		position++
-		entry, ok := e.Value.(*preparedPostsEntry)
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return nil, errors.New("GetXBetweenID: could not parse e as a preparedPostsEntry")
 		}
 
-		if entry.statusID == behindID {
+		if entry.itemID == behindID {
 			behindIDMark = e
 			break findMarkLoop
 		}
@@ -325,11 +324,11 @@ findMarkLoop:
 
 	// we didn't find it
 	if behindIDMark == nil {
-		return nil, fmt.Errorf("GetXBetweenID: couldn't find status with ID %s", behindID)
+		return nil, fmt.Errorf("GetXBetweenID: couldn't find item with ID %s", behindID)
 	}
 
-	// make sure we have enough posts prepared behind it to return what we're being asked for
-	if t.preparedPosts.data.Len() < amount+position {
+	// make sure we have enough items prepared behind it to return what we're being asked for
+	if t.preparedItems.data.Len() < amount+position {
 		if err := t.PrepareBehind(ctx, behindID, amount); err != nil {
 			return nil, err
 		}
@@ -339,22 +338,22 @@ findMarkLoop:
 	var served int
 serveloop:
 	for e := behindIDMark.Next(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*preparedPostsEntry)
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return nil, errors.New("GetXBetweenID: could not parse e as a preparedPostsEntry")
 		}
 
-		if entry.statusID == beforeID {
+		if entry.itemID == beforeID {
 			break serveloop
 		}
 
 		// serve up to the amount requested
-		statuses = append(statuses, entry.prepared)
+		items = append(items, entry.prepared)
 		served++
 		if served >= amount {
 			break serveloop
 		}
 	}
 
-	return statuses, nil
+	return items, nil
 }

internal/timeline/get_test.go

@@ -24,7 +24,9 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/processing"
 	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 	"github.com/superseriousbusiness/gotosocial/testrig"
 )
 
@@ -43,18 +45,26 @@ func (suite *GetTestSuite) SetupTest() {
 
 	suite.db = testrig.NewTestDB()
 	suite.tc = testrig.NewTestTypeConverter(suite.db)
+	suite.filter = visibility.NewFilter(suite.db)
 
 	testrig.StandardDBSetup(suite.db, nil)
 
 	// let's take local_account_1 as the timeline owner
-	tl, err := timeline.NewTimeline(context.Background(), suite.testAccounts["local_account_1"].ID, suite.db, suite.tc)
+	tl, err := timeline.NewTimeline(
+		context.Background(),
+		suite.testAccounts["local_account_1"].ID,
+		processing.StatusGrabFunction(suite.db),
+		processing.StatusFilterFunction(suite.db, suite.filter),
+		processing.StatusPrepareFunction(suite.db, suite.tc),
+		processing.StatusSkipInsertFunction(),
+	)
 	if err != nil {
 		suite.FailNow(err.Error())
 	}
 
 	// prepare the timeline by just shoving all test statuses in it -- let's not be fussy about who sees what
 	for _, s := range suite.testStatuses {
-		_, err := tl.IndexAndPrepareOne(context.Background(), s.CreatedAt, s.ID, s.BoostOfID, s.AccountID, s.BoostOfAccountID)
+		_, err := tl.IndexAndPrepareOne(context.Background(), s.GetID(), s.BoostOfID, s.AccountID, s.BoostOfAccountID)
 		if err != nil {
 			suite.FailNow(err.Error())
 		}
@@ -81,10 +91,10 @@ func (suite *GetTestSuite) TestGetDefault() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -102,10 +112,10 @@ func (suite *GetTestSuite) TestGetDefaultPrepareNext() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 
@@ -127,10 +137,10 @@ func (suite *GetTestSuite) TestGetMaxID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -149,10 +159,10 @@ func (suite *GetTestSuite) TestGetMaxIDPrepareNext() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 
@@ -174,10 +184,10 @@ func (suite *GetTestSuite) TestGetMinID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -196,10 +206,10 @@ func (suite *GetTestSuite) TestGetSinceID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -218,10 +228,10 @@ func (suite *GetTestSuite) TestGetSinceIDPrepareNext() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 
@@ -243,10 +253,10 @@ func (suite *GetTestSuite) TestGetBetweenID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -265,10 +275,10 @@ func (suite *GetTestSuite) TestGetBetweenIDPrepareNext() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 
@@ -289,10 +299,10 @@ func (suite *GetTestSuite) TestGetXFromTop() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
 	}
 }
@@ -314,12 +324,12 @@ func (suite *GetTestSuite) TestGetXBehindID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
-		suite.Less(s.ID, "01F8MHBQCBTDKN6X5VHGMMN4MA")
+		suite.Less(s.GetID(), "01F8MHBQCBTDKN6X5VHGMMN4MA")
 	}
 }
 
@@ -353,12 +363,12 @@ func (suite *GetTestSuite) TestGetXBehindNonexistentReasonableID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
-		suite.Less(s.ID, "01F8MHBCN8120SYH7D5S050MGK")
+		suite.Less(s.GetID(), "01F8MHBCN8120SYH7D5S050MGK")
 	}
 }
 
@@ -380,12 +390,12 @@ func (suite *GetTestSuite) TestGetXBehindVeryHighID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
-		suite.Less(s.ID, "9998MHBQCBTDKN6X5VHGMMN4MA")
+		suite.Less(s.GetID(), "9998MHBQCBTDKN6X5VHGMMN4MA")
 	}
 }
 
@@ -403,12 +413,12 @@ func (suite *GetTestSuite) TestGetXBeforeID() {
 	var highest string
 	for i, s := range statuses {
 		if i == 0 {
-			highest = s.ID
+			highest = s.GetID()
 		} else {
-			suite.Less(s.ID, highest)
-			highest = s.ID
+			suite.Less(s.GetID(), highest)
+			highest = s.GetID()
 		}
-		suite.Greater(s.ID, "01F8MHBQCBTDKN6X5VHGMMN4MA")
+		suite.Greater(s.GetID(), "01F8MHBQCBTDKN6X5VHGMMN4MA")
 	}
 }
 
@@ -426,12 +436,12 @@ func (suite *GetTestSuite) TestGetXBeforeIDNoStartFromTop() {
 	var lowest string
 	for i, s := range statuses {
 		if i == 0 {
-			lowest = s.ID
+			lowest = s.GetID()
 		} else {
-			suite.Greater(s.ID, lowest)
-			lowest = s.ID
+			suite.Greater(s.GetID(), lowest)
+			lowest = s.GetID()
 		}
-		suite.Greater(s.ID, "01F8MHBQCBTDKN6X5VHGMMN4MA")
+		suite.Greater(s.GetID(), "01F8MHBQCBTDKN6X5VHGMMN4MA")
 	}
 }
 

internal/timeline/index.go

@@ -23,173 +23,166 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"time"
 
 	"github.com/sirupsen/logrus"
-	"github.com/superseriousbusiness/gotosocial/internal/db"
-	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 )
 
-func (t *timeline) IndexBefore(ctx context.Context, statusID string, include bool, amount int) error {
+func (t *timeline) IndexBefore(ctx context.Context, itemID string, amount int) error {
+	l := logrus.WithFields(logrus.Fields{
+		"func":   "IndexBefore",
+		"amount": amount,
+	})
+
 	// lazily initialize index if it hasn't been done already
-	if t.postIndex.data == nil {
-		t.postIndex.data = &list.List{}
-		t.postIndex.data.Init()
+	if t.itemIndex.data == nil {
+		t.itemIndex.data = &list.List{}
+		t.itemIndex.data.Init()
 	}
 
-	filtered := []*gtsmodel.Status{}
-	offsetStatus := statusID
+	toIndex := []Timelineable{}
+	offsetID := itemID
 
-	if include {
-		// if we have the status with given statusID in the database, include it in the results set as well
-		s := &gtsmodel.Status{}
-		if err := t.db.GetByID(ctx, statusID, s); err == nil {
-			filtered = append(filtered, s)
-		}
-	}
-
-	i := 0
+	l.Trace("entering grabloop")
 grabloop:
-	for ; len(filtered) < amount && i < 5; i++ { // try the grabloop 5 times only
-		statuses, err := t.db.GetHomeTimeline(ctx, t.accountID, "", "", offsetStatus, amount, false)
+	for i := 0; len(toIndex) < amount && i < 5; i++ { // try the grabloop 5 times only
+		// first grab items using the caller-provided grab function
+		l.Trace("grabbing...")
+		items, stop, err := t.grabFunction(ctx, t.accountID, "", "", offsetID, amount)
 		if err != nil {
-			if err == db.ErrNoEntries {
-				break grabloop // we just don't have enough statuses left in the db so index what we've got and then bail
+			return err
 		}
-			return fmt.Errorf("IndexBefore: error getting statuses from db: %s", err)
+		if stop {
+			break grabloop
 		}
 
-		for _, s := range statuses {
-			timelineable, err := t.filter.StatusHometimelineable(ctx, s, t.account)
+		l.Trace("filtering...")
+		// now filter each item using the caller-provided filter function
+		for _, item := range items {
+			shouldIndex, err := t.filterFunction(ctx, t.accountID, item)
 			if err != nil {
-				continue
+				return err
 			}
-			if timelineable {
-				filtered = append(filtered, s)
+			if shouldIndex {
+				toIndex = append(toIndex, item)
 			}
-			offsetStatus = s.ID
+			offsetID = item.GetID()
 		}
 	}
+	l.Trace("left grabloop")
 
-	for _, s := range filtered {
-		if _, err := t.IndexOne(ctx, s.CreatedAt, s.ID, s.BoostOfID, s.AccountID, s.BoostOfAccountID); err != nil {
-			return fmt.Errorf("IndexBefore: error indexing status with id %s: %s", s.ID, err)
+	// index the items we got
+	for _, s := range toIndex {
+		if _, err := t.IndexOne(ctx, s.GetID(), s.GetBoostOfID(), s.GetAccountID(), s.GetBoostOfAccountID()); err != nil {
+			return fmt.Errorf("IndexBehind: error indexing item with id %s: %s", s.GetID(), err)
 		}
 	}
 
 	return nil
 }
 
-func (t *timeline) IndexBehind(ctx context.Context, statusID string, include bool, amount int) error {
+func (t *timeline) IndexBehind(ctx context.Context, itemID string, amount int) error {
 	l := logrus.WithFields(logrus.Fields{
 		"func":   "IndexBehind",
-		"include": include,
 		"amount": amount,
 	})
 
 	// lazily initialize index if it hasn't been done already
-	if t.postIndex.data == nil {
-		t.postIndex.data = &list.List{}
-		t.postIndex.data.Init()
+	if t.itemIndex.data == nil {
+		t.itemIndex.data = &list.List{}
+		t.itemIndex.data.Init()
 	}
 
-	// If we're already indexedBehind given statusID by the required amount, we can return nil.
-	// First find position of statusID (or as near as possible).
+	// If we're already indexedBehind given itemID by the required amount, we can return nil.
+	// First find position of itemID (or as near as possible).
 	var position int
 positionLoop:
-	for e := t.postIndex.data.Front(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*postIndexEntry)
+	for e := t.itemIndex.data.Front(); e != nil; e = e.Next() {
+		entry, ok := e.Value.(*itemIndexEntry)
 		if !ok {
-			return errors.New("IndexBehind: could not parse e as a postIndexEntry")
+			return errors.New("IndexBehind: could not parse e as an itemIndexEntry")
 		}
 
-		if entry.statusID <= statusID {
+		if entry.itemID <= itemID {
 			// we've found it
 			break positionLoop
 		}
 		position++
 	}
-	// now check if the length of indexed posts exceeds the amount of posts required (position of statusID, plus amount of posts requested after that)
-	if t.postIndex.data.Len() > position+amount {
+
+	// now check if the length of indexed items exceeds the amount of items required (position of itemID, plus amount of posts requested after that)
+	if t.itemIndex.data.Len() > position+amount {
 		// we have enough indexed behind already to satisfy amount, so don't need to make db calls
-		l.Trace("returning nil since we already have enough posts indexed")
+		l.Trace("returning nil since we already have enough items indexed")
 		return nil
 	}
 
-	filtered := []*gtsmodel.Status{}
-	offsetStatus := statusID
+	toIndex := []Timelineable{}
+	offsetID := itemID
 
-	if include {
-		// if we have the status with given statusID in the database, include it in the results set as well
-		s := &gtsmodel.Status{}
-		if err := t.db.GetByID(ctx, statusID, s); err == nil {
-			filtered = append(filtered, s)
-		}
-	}
-
-	i := 0
+	l.Trace("entering grabloop")
 grabloop:
-	for ; len(filtered) < amount && i < 5; i++ { // try the grabloop 5 times only
-		l.Tracef("entering grabloop; i is %d; len(filtered) is %d", i, len(filtered))
-		statuses, err := t.db.GetHomeTimeline(ctx, t.accountID, offsetStatus, "", "", amount, false)
+	for i := 0; len(toIndex) < amount && i < 5; i++ { // try the grabloop 5 times only
+		// first grab items using the caller-provided grab function
+		l.Trace("grabbing...")
+		items, stop, err := t.grabFunction(ctx, t.accountID, offsetID, "", "", amount)
 		if err != nil {
-			if err == db.ErrNoEntries {
-				break grabloop // we just don't have enough statuses left in the db so index what we've got and then bail
+			return err
 		}
-			return fmt.Errorf("IndexBehind: error getting statuses from db: %s", err)
+		if stop {
+			break grabloop
 		}
-		l.Tracef("got %d statuses", len(statuses))
 
-		for _, s := range statuses {
-			timelineable, err := t.filter.StatusHometimelineable(ctx, s, t.account)
+		l.Trace("filtering...")
+		// now filter each item using the caller-provided filter function
+		for _, item := range items {
+			shouldIndex, err := t.filterFunction(ctx, t.accountID, item)
 			if err != nil {
-				l.Tracef("status was not hometimelineable: %s", err)
-				continue
+				return err
 			}
-			if timelineable {
-				filtered = append(filtered, s)
+			if shouldIndex {
+				toIndex = append(toIndex, item)
 			}
-			offsetStatus = s.ID
+			offsetID = item.GetID()
 		}
 	}
 	l.Trace("left grabloop")
 
-	for _, s := range filtered {
-		if _, err := t.IndexOne(ctx, s.CreatedAt, s.ID, s.BoostOfID, s.AccountID, s.BoostOfAccountID); err != nil {
-			return fmt.Errorf("IndexBehind: error indexing status with id %s: %s", s.ID, err)
+	// index the items we got
+	for _, s := range toIndex {
+		if _, err := t.IndexOne(ctx, s.GetID(), s.GetBoostOfID(), s.GetAccountID(), s.GetBoostOfAccountID()); err != nil {
+			return fmt.Errorf("IndexBehind: error indexing item with id %s: %s", s.GetID(), err)
 		}
 	}
 
-	l.Trace("exiting function")
 	return nil
 }
 
-func (t *timeline) IndexOne(ctx context.Context, statusCreatedAt time.Time, statusID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error) {
+func (t *timeline) IndexOne(ctx context.Context, itemID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error) {
 	t.Lock()
 	defer t.Unlock()
 
-	postIndexEntry := &postIndexEntry{
-		statusID:         statusID,
+	postIndexEntry := &itemIndexEntry{
+		itemID:           itemID,
 		boostOfID:        boostOfID,
 		accountID:        accountID,
 		boostOfAccountID: boostOfAccountID,
 	}
 
-	return t.postIndex.insertIndexed(postIndexEntry)
+	return t.itemIndex.insertIndexed(ctx, postIndexEntry)
 }
 
-func (t *timeline) IndexAndPrepareOne(ctx context.Context, statusCreatedAt time.Time, statusID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error) {
+func (t *timeline) IndexAndPrepareOne(ctx context.Context, statusID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error) {
 	t.Lock()
 	defer t.Unlock()
 
-	postIndexEntry := &postIndexEntry{
-		statusID:         statusID,
+	postIndexEntry := &itemIndexEntry{
+		itemID:           statusID,
 		boostOfID:        boostOfID,
 		accountID:        accountID,
 		boostOfAccountID: boostOfAccountID,
 	}
 
-	inserted, err := t.postIndex.insertIndexed(postIndexEntry)
+	inserted, err := t.itemIndex.insertIndexed(ctx, postIndexEntry)
 	if err != nil {
 		return inserted, fmt.Errorf("IndexAndPrepareOne: error inserting indexed: %s", err)
 	}
@@ -203,32 +196,32 @@ func (t *timeline) IndexAndPrepareOne(ctx context.Context, statusCreatedAt time.
 	return inserted, nil
 }
 
-func (t *timeline) OldestIndexedPostID(ctx context.Context) (string, error) {
+func (t *timeline) OldestIndexedItemID(ctx context.Context) (string, error) {
 	var id string
-	if t.postIndex == nil || t.postIndex.data == nil || t.postIndex.data.Back() == nil {
+	if t.itemIndex == nil || t.itemIndex.data == nil || t.itemIndex.data.Back() == nil {
 		// return an empty string if postindex hasn't been initialized yet
 		return id, nil
 	}
 
-	e := t.postIndex.data.Back()
-	entry, ok := e.Value.(*postIndexEntry)
+	e := t.itemIndex.data.Back()
+	entry, ok := e.Value.(*itemIndexEntry)
 	if !ok {
-		return id, errors.New("OldestIndexedPostID: could not parse e as a postIndexEntry")
+		return id, errors.New("OldestIndexedItemID: could not parse e as itemIndexEntry")
 	}
-	return entry.statusID, nil
+	return entry.itemID, nil
 }
 
-func (t *timeline) NewestIndexedPostID(ctx context.Context) (string, error) {
+func (t *timeline) NewestIndexedItemID(ctx context.Context) (string, error) {
 	var id string
-	if t.postIndex == nil || t.postIndex.data == nil || t.postIndex.data.Front() == nil {
+	if t.itemIndex == nil || t.itemIndex.data == nil || t.itemIndex.data.Front() == nil {
 		// return an empty string if postindex hasn't been initialized yet
 		return id, nil
 	}
 
-	e := t.postIndex.data.Front()
-	entry, ok := e.Value.(*postIndexEntry)
+	e := t.itemIndex.data.Front()
+	entry, ok := e.Value.(*itemIndexEntry)
 	if !ok {
-		return id, errors.New("NewestIndexedPostID: could not parse e as a postIndexEntry")
+		return id, errors.New("NewestIndexedItemID: could not parse e as itemIndexEntry")
 	}
-	return entry.statusID, nil
+	return entry.itemID, nil
 }

internal/timeline/index_test.go

@@ -25,7 +25,9 @@ import (
 
 	"github.com/stretchr/testify/suite"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/processing"
 	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 	"github.com/superseriousbusiness/gotosocial/testrig"
 )
 
@@ -44,11 +46,19 @@ func (suite *IndexTestSuite) SetupTest() {
 
 	suite.db = testrig.NewTestDB()
 	suite.tc = testrig.NewTestTypeConverter(suite.db)
+	suite.filter = visibility.NewFilter(suite.db)
 
 	testrig.StandardDBSetup(suite.db, nil)
 
 	// let's take local_account_1 as the timeline owner, and start with an empty timeline
-	tl, err := timeline.NewTimeline(context.Background(), suite.testAccounts["local_account_1"].ID, suite.db, suite.tc)
+	tl, err := timeline.NewTimeline(
+		context.Background(),
+		suite.testAccounts["local_account_1"].ID,
+		processing.StatusGrabFunction(suite.db),
+		processing.StatusFilterFunction(suite.db, suite.filter),
+		processing.StatusPrepareFunction(suite.db, suite.tc),
+		processing.StatusSkipInsertFunction(),
+	)
 	if err != nil {
 		suite.FailNow(err.Error())
 	}
@@ -61,82 +71,82 @@ func (suite *IndexTestSuite) TearDownTest() {
 
 func (suite *IndexTestSuite) TestIndexBeforeLowID() {
 	// index 10 before the lowest status ID possible
-	err := suite.timeline.IndexBefore(context.Background(), "00000000000000000000000000", true, 10)
+	err := suite.timeline.IndexBefore(context.Background(), "00000000000000000000000000", 10)
 	suite.NoError(err)
 
 	// the oldest indexed post should be the lowest one we have in our testrig
-	postID, err := suite.timeline.OldestIndexedPostID(context.Background())
+	postID, err := suite.timeline.OldestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Equal("01F8MHAYFKS4KMXF8K5Y1C0KRN", postID)
 
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(10, indexLength)
 }
 
 func (suite *IndexTestSuite) TestIndexBeforeHighID() {
 	// index 10 before the highest status ID possible
-	err := suite.timeline.IndexBefore(context.Background(), "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", true, 10)
+	err := suite.timeline.IndexBefore(context.Background(), "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", 10)
 	suite.NoError(err)
 
 	// the oldest indexed post should be empty
-	postID, err := suite.timeline.OldestIndexedPostID(context.Background())
+	postID, err := suite.timeline.OldestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Empty(postID)
 
 	// indexLength should be 0
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(0, indexLength)
 }
 
 func (suite *IndexTestSuite) TestIndexBehindHighID() {
 	// index 10 behind the highest status ID possible
-	err := suite.timeline.IndexBehind(context.Background(), "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", true, 10)
+	err := suite.timeline.IndexBehind(context.Background(), "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", 10)
 	suite.NoError(err)
 
 	// the newest indexed post should be the highest one we have in our testrig
-	postID, err := suite.timeline.NewestIndexedPostID(context.Background())
+	postID, err := suite.timeline.NewestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Equal("01FN3VJGFH10KR7S2PB0GFJZYG", postID)
 
 	// indexLength should be 10 because that's all this user has hometimelineable
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(10, indexLength)
 }
 
 func (suite *IndexTestSuite) TestIndexBehindLowID() {
 	// index 10 behind the lowest status ID possible
-	err := suite.timeline.IndexBehind(context.Background(), "00000000000000000000000000", true, 10)
+	err := suite.timeline.IndexBehind(context.Background(), "00000000000000000000000000", 10)
 	suite.NoError(err)
 
 	// the newest indexed post should be empty
-	postID, err := suite.timeline.NewestIndexedPostID(context.Background())
+	postID, err := suite.timeline.NewestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Empty(postID)
 
 	// indexLength should be 0
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(0, indexLength)
 }
 
-func (suite *IndexTestSuite) TestOldestIndexedPostIDEmpty() {
+func (suite *IndexTestSuite) TestOldestIndexedItemIDEmpty() {
 	// the oldest indexed post should be an empty string since there's nothing indexed yet
-	postID, err := suite.timeline.OldestIndexedPostID(context.Background())
+	postID, err := suite.timeline.OldestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Empty(postID)
 
 	// indexLength should be 0
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(0, indexLength)
 }
 
-func (suite *IndexTestSuite) TestNewestIndexedPostIDEmpty() {
+func (suite *IndexTestSuite) TestNewestIndexedItemIDEmpty() {
 	// the newest indexed post should be an empty string since there's nothing indexed yet
-	postID, err := suite.timeline.NewestIndexedPostID(context.Background())
+	postID, err := suite.timeline.NewestIndexedItemID(context.Background())
 	suite.NoError(err)
 	suite.Empty(postID)
 
 	// indexLength should be 0
-	indexLength := suite.timeline.PostIndexLength(context.Background())
+	indexLength := suite.timeline.ItemIndexLength(context.Background())
 	suite.Equal(0, indexLength)
 }
 
@@ -144,12 +154,12 @@ func (suite *IndexTestSuite) TestIndexAlreadyIndexed() {
 	testStatus := suite.testStatuses["local_account_1_status_1"]
 
 	// index one post -- it should be indexed
-	indexed, err := suite.timeline.IndexOne(context.Background(), testStatus.CreatedAt, testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
+	indexed, err := suite.timeline.IndexOne(context.Background(), testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.True(indexed)
 
 	// try to index the same post again -- it should not be indexed
-	indexed, err = suite.timeline.IndexOne(context.Background(), testStatus.CreatedAt, testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
+	indexed, err = suite.timeline.IndexOne(context.Background(), testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.False(indexed)
 }
@@ -158,12 +168,12 @@ func (suite *IndexTestSuite) TestIndexAndPrepareAlreadyIndexedAndPrepared() {
 	testStatus := suite.testStatuses["local_account_1_status_1"]
 
 	// index and prepare one post -- it should be indexed
-	indexed, err := suite.timeline.IndexAndPrepareOne(context.Background(), testStatus.CreatedAt, testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
+	indexed, err := suite.timeline.IndexAndPrepareOne(context.Background(), testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.True(indexed)
 
 	// try to index and prepare the same post again -- it should not be indexed
-	indexed, err = suite.timeline.IndexAndPrepareOne(context.Background(), testStatus.CreatedAt, testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
+	indexed, err = suite.timeline.IndexAndPrepareOne(context.Background(), testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.False(indexed)
 }
@@ -179,12 +189,12 @@ func (suite *IndexTestSuite) TestIndexBoostOfAlreadyIndexed() {
 	}
 
 	// index one post -- it should be indexed
-	indexed, err := suite.timeline.IndexOne(context.Background(), testStatus.CreatedAt, testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
+	indexed, err := suite.timeline.IndexOne(context.Background(), testStatus.ID, testStatus.BoostOfID, testStatus.AccountID, testStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.True(indexed)
 
 	// try to index the a boost of that post -- it should not be indexed
-	indexed, err = suite.timeline.IndexOne(context.Background(), boostOfTestStatus.CreatedAt, boostOfTestStatus.ID, boostOfTestStatus.BoostOfID, boostOfTestStatus.AccountID, boostOfTestStatus.BoostOfAccountID)
+	indexed, err = suite.timeline.IndexOne(context.Background(), boostOfTestStatus.ID, boostOfTestStatus.BoostOfID, boostOfTestStatus.AccountID, boostOfTestStatus.BoostOfAccountID)
 	suite.NoError(err)
 	suite.False(indexed)
 }

internal/timeline/itemindex.go

@@ -20,21 +20,23 @@ package timeline
 
 import (
 	"container/list"
+	"context"
 	"errors"
 )
 
-type postIndex struct {
+type itemIndex struct {
 	data       *list.List
+	skipInsert SkipInsertFunction
 }
 
-type postIndexEntry struct {
-	statusID         string
+type itemIndexEntry struct {
+	itemID           string
 	boostOfID        string
 	accountID        string
 	boostOfAccountID string
 }
 
-func (p *postIndex) insertIndexed(i *postIndexEntry) (bool, error) {
+func (p *itemIndex) insertIndexed(ctx context.Context, i *itemIndexEntry) (bool, error) {
 	if p.data == nil {
 		p.data = &list.List{}
 	}
@@ -47,36 +49,30 @@ func (p *postIndex) insertIndexed(i *postIndexEntry) (bool, error) {
 
 	var insertMark *list.Element
 	var position int
-	// We need to iterate through the index to make sure we put this post in the appropriate place according to when it was created.
-	// We also need to make sure we're not inserting a duplicate post -- this can happen sometimes and it's not nice UX (*shudder*).
+	// We need to iterate through the index to make sure we put this item in the appropriate place according to when it was created.
+	// We also need to make sure we're not inserting a duplicate item -- this can happen sometimes and it's not nice UX (*shudder*).
 	for e := p.data.Front(); e != nil; e = e.Next() {
 		position++
 
-		entry, ok := e.Value.(*postIndexEntry)
+		entry, ok := e.Value.(*itemIndexEntry)
 		if !ok {
-			return false, errors.New("index: could not parse e as a postIndexEntry")
+			return false, errors.New("index: could not parse e as an itemIndexEntry")
 		}
 
-		// don't insert this if it's a boost of a status we've seen recently
-		if i.boostOfID != "" {
-			if i.boostOfID == entry.boostOfID || i.boostOfID == entry.statusID {
-				if position < boostReinsertionDepth {
+		skip, err := p.skipInsert(ctx, i.itemID, i.accountID, i.boostOfID, i.boostOfAccountID, entry.itemID, entry.accountID, entry.boostOfID, entry.boostOfAccountID, position)
+		if err != nil {
+			return false, err
+		}
+		if skip {
 			return false, nil
 		}
-			}
-		}
 
-		// if the post to index is newer than e, insert it before e in the list
+		// if the item to index is newer than e, insert it before e in the list
 		if insertMark == nil {
-			if i.statusID > entry.statusID {
+			if i.itemID > entry.itemID {
 				insertMark = e
 			}
 		}
-
-		// make sure we don't insert a duplicate
-		if entry.statusID == i.statusID {
-			return false, nil
-		}
 	}
 
 	if insertMark != nil {
@@ -84,7 +80,7 @@ func (p *postIndex) insertIndexed(i *postIndexEntry) (bool, error) {
 		return true, nil
 	}
 
-	// if we reach this point it's the oldest post we've seen so put it at the back
+	// if we reach this point it's the oldest item we've seen so put it at the back
 	p.data.PushBack(i)
 	return true, nil
 }

internal/timeline/manager.go

@@ -25,10 +25,6 @@ import (
 	"sync"
 
 	"github.com/sirupsen/logrus"
-	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
-	"github.com/superseriousbusiness/gotosocial/internal/db"
-	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
-	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
 )
 
 const (
@@ -37,71 +33,75 @@ const (
 
 // Manager abstracts functions for creating timelines for multiple accounts, and adding, removing, and fetching entries from those timelines.
 //
-// By the time a status hits the manager interface, it should already have been filtered and it should be established that the status indeed
-// belongs in the home timeline of the given account ID.
+// By the time a timelineable hits the manager interface, it should already have been filtered and it should be established that the item indeed
+// belongs in the timeline of the given account ID.
 //
-// The manager makes a distinction between *indexed* posts and *prepared* posts.
+// The manager makes a distinction between *indexed* items and *prepared* items.
 //
-// Indexed posts consist of just that post's ID (in the database) and the time it was created. An indexed post takes up very little memory, so
-// it's not a huge priority to keep trimming the indexed posts list.
+// Indexed items consist of just that item's ID (in the database) and the time it was created. An indexed item takes up very little memory, so
+// it's not a huge priority to keep trimming the indexed items list.
 //
-// Prepared posts consist of the post's database ID, the time it was created, AND the apimodel representation of that post, for quick serialization.
-// Prepared posts of course take up more memory than indexed posts, so they should be regularly pruned if they're not being actively served.
+// Prepared items consist of the item's database ID, the time it was created, AND the apimodel representation of that item, for quick serialization.
+// Prepared items of course take up more memory than indexed items, so they should be regularly pruned if they're not being actively served.
 type Manager interface {
-	// Ingest takes one status and indexes it into the timeline for the given account ID.
+	// Ingest takes one item and indexes it into the timeline for the given account ID.
 	//
-	// It should already be established before calling this function that the status/post actually belongs in the timeline!
+	// It should already be established before calling this function that the item actually belongs in the timeline!
 	//
-	// The returned bool indicates whether the status was actually put in the timeline. This could be false in cases where
-	// the status is a boost, but a boost of the original post or the post itself already exists recently in the timeline.
-	Ingest(ctx context.Context, status *gtsmodel.Status, timelineAccountID string) (bool, error)
-	// IngestAndPrepare takes one status and indexes it into the timeline for the given account ID, and then immediately prepares it for serving.
-	// This is useful in cases where we know the status will need to be shown at the top of a user's timeline immediately (eg., a new status is created).
+	// The returned bool indicates whether the item was actually put in the timeline. This could be false in cases where
+	// the item is a boosted status, but a boost of the original status or the status itself already exists recently in the timeline.
+	Ingest(ctx context.Context, item Timelineable, timelineAccountID string) (bool, error)
+	// IngestAndPrepare takes one timelineable and indexes it into the timeline for the given account ID, and then immediately prepares it for serving.
+	// This is useful in cases where we know the item will need to be shown at the top of a user's timeline immediately (eg., a new status is created).
 	//
-	// It should already be established before calling this function that the status/post actually belongs in the timeline!
+	// It should already be established before calling this function that the item actually belongs in the timeline!
 	//
-	// The returned bool indicates whether the status was actually put in the timeline. This could be false in cases where
-	// the status is a boost, but a boost of the original post or the post itself already exists recently in the timeline.
-	IngestAndPrepare(ctx context.Context, status *gtsmodel.Status, timelineAccountID string) (bool, error)
-	// HomeTimeline returns limit n amount of entries from the home timeline of the given account ID, in descending chronological order.
-	// If maxID is provided, it will return entries from that maxID onwards, inclusive.
-	HomeTimeline(ctx context.Context, accountID string, maxID string, sinceID string, minID string, limit int, local bool) ([]*apimodel.Status, error)
-	// GetIndexedLength returns the amount of posts/statuses that have been *indexed* for the given account ID.
+	// The returned bool indicates whether the item was actually put in the timeline. This could be false in cases where
+	// a status is a boost, but a boost of the original status or the status itself already exists recently in the timeline.
+	IngestAndPrepare(ctx context.Context, item Timelineable, timelineAccountID string) (bool, error)
+	// GetTimeline returns limit n amount of prepared entries from the timeline of the given account ID, in descending chronological order.
+	// If maxID is provided, it will return prepared entries from that maxID onwards, inclusive.
+	GetTimeline(ctx context.Context, accountID string, maxID string, sinceID string, minID string, limit int, local bool) ([]Preparable, error)
+	// GetIndexedLength returns the amount of items that have been *indexed* for the given account ID.
 	GetIndexedLength(ctx context.Context, timelineAccountID string) int
-	// GetDesiredIndexLength returns the amount of posts that we, ideally, index for each user.
+	// GetDesiredIndexLength returns the amount of items that we, ideally, index for each user.
 	GetDesiredIndexLength(ctx context.Context) int
-	// GetOldestIndexedID returns the status ID for the oldest post that we have indexed for the given account.
+	// GetOldestIndexedID returns the id ID for the oldest item that we have indexed for the given account.
 	GetOldestIndexedID(ctx context.Context, timelineAccountID string) (string, error)
-	// PrepareXFromTop prepares limit n amount of posts, based on their indexed representations, from the top of the index.
+	// PrepareXFromTop prepares limit n amount of items, based on their indexed representations, from the top of the index.
 	PrepareXFromTop(ctx context.Context, timelineAccountID string, limit int) error
-	// Remove removes one status from the timeline of the given timelineAccountID
-	Remove(ctx context.Context, timelineAccountID string, statusID string) (int, error)
-	// WipeStatusFromAllTimelines removes one status from the index and prepared posts of all timelines
-	WipeStatusFromAllTimelines(ctx context.Context, statusID string) error
-	// WipeStatusesFromAccountID removes all statuses by the given accountID from the timelineAccountID's timelines.
-	WipeStatusesFromAccountID(ctx context.Context, timelineAccountID string, accountID string) error
+	// Remove removes one item from the timeline of the given timelineAccountID
+	Remove(ctx context.Context, timelineAccountID string, itemID string) (int, error)
+	// WipeItemFromAllTimelines removes one item from the index and prepared items of all timelines
+	WipeItemFromAllTimelines(ctx context.Context, itemID string) error
+	// WipeStatusesFromAccountID removes all items by the given accountID from the timelineAccountID's timelines.
+	WipeItemsFromAccountID(ctx context.Context, timelineAccountID string, accountID string) error
 }
 
-// NewManager returns a new timeline manager with the given database, typeconverter, config, and log.
-func NewManager(db db.DB, tc typeutils.TypeConverter) Manager {
+// NewManager returns a new timeline manager.
+func NewManager(grabFunction GrabFunction, filterFunction FilterFunction, prepareFunction PrepareFunction, skipInsertFunction SkipInsertFunction) Manager {
 	return &manager{
 		accountTimelines:   sync.Map{},
-		db:               db,
-		tc:               tc,
+		grabFunction:       grabFunction,
+		filterFunction:     filterFunction,
+		prepareFunction:    prepareFunction,
+		skipInsertFunction: skipInsertFunction,
 	}
 }
 
 type manager struct {
 	accountTimelines   sync.Map
-	db               db.DB
-	tc               typeutils.TypeConverter
+	grabFunction       GrabFunction
+	filterFunction     FilterFunction
+	prepareFunction    PrepareFunction
+	skipInsertFunction SkipInsertFunction
 }
 
-func (m *manager) Ingest(ctx context.Context, status *gtsmodel.Status, timelineAccountID string) (bool, error) {
+func (m *manager) Ingest(ctx context.Context, item Timelineable, timelineAccountID string) (bool, error) {
 	l := logrus.WithFields(logrus.Fields{
 		"func":              "Ingest",
 		"timelineAccountID": timelineAccountID,
-		"statusID":          status.ID,
+		"itemID":            item.GetID(),
 	})
 
 	t, err := m.getOrCreateTimeline(ctx, timelineAccountID)
@@ -109,15 +109,15 @@ func (m *manager) Ingest(ctx context.Context, status *gtsmodel.Status, timelineA
 		return false, err
 	}
 
-	l.Trace("ingesting status")
-	return t.IndexOne(ctx, status.CreatedAt, status.ID, status.BoostOfID, status.AccountID, status.BoostOfAccountID)
+	l.Trace("ingesting item")
+	return t.IndexOne(ctx, item.GetID(), item.GetBoostOfID(), item.GetAccountID(), item.GetBoostOfAccountID())
 }
 
-func (m *manager) IngestAndPrepare(ctx context.Context, status *gtsmodel.Status, timelineAccountID string) (bool, error) {
+func (m *manager) IngestAndPrepare(ctx context.Context, item Timelineable, timelineAccountID string) (bool, error) {
 	l := logrus.WithFields(logrus.Fields{
 		"func":              "IngestAndPrepare",
 		"timelineAccountID": timelineAccountID,
-		"statusID":          status.ID,
+		"itemID":            item.GetID(),
 	})
 
 	t, err := m.getOrCreateTimeline(ctx, timelineAccountID)
@@ -125,15 +125,15 @@ func (m *manager) IngestAndPrepare(ctx context.Context, status *gtsmodel.Status,
 		return false, err
 	}
 
-	l.Trace("ingesting status")
-	return t.IndexAndPrepareOne(ctx, status.CreatedAt, status.ID, status.BoostOfID, status.AccountID, status.BoostOfAccountID)
+	l.Trace("ingesting item")
+	return t.IndexAndPrepareOne(ctx, item.GetID(), item.GetBoostOfID(), item.GetAccountID(), item.GetBoostOfAccountID())
 }
 
-func (m *manager) Remove(ctx context.Context, timelineAccountID string, statusID string) (int, error) {
+func (m *manager) Remove(ctx context.Context, timelineAccountID string, itemID string) (int, error) {
 	l := logrus.WithFields(logrus.Fields{
 		"func":              "Remove",
 		"timelineAccountID": timelineAccountID,
-		"statusID":          statusID,
+		"itemID":            itemID,
 	})
 
 	t, err := m.getOrCreateTimeline(ctx, timelineAccountID)
@@ -141,13 +141,13 @@ func (m *manager) Remove(ctx context.Context, timelineAccountID string, statusID
 		return 0, err
 	}
 
-	l.Trace("removing status")
-	return t.Remove(ctx, statusID)
+	l.Trace("removing item")
+	return t.Remove(ctx, itemID)
 }
 
-func (m *manager) HomeTimeline(ctx context.Context, timelineAccountID string, maxID string, sinceID string, minID string, limit int, local bool) ([]*apimodel.Status, error) {
+func (m *manager) GetTimeline(ctx context.Context, timelineAccountID string, maxID string, sinceID string, minID string, limit int, local bool) ([]Preparable, error) {
 	l := logrus.WithFields(logrus.Fields{
-		"func":              "HomeTimelineGet",
+		"func":              "GetTimeline",
 		"timelineAccountID": timelineAccountID,
 	})
 
@@ -156,11 +156,11 @@ func (m *manager) HomeTimeline(ctx context.Context, timelineAccountID string, ma
 		return nil, err
 	}
 
-	statuses, err := t.Get(ctx, limit, maxID, sinceID, minID, true)
+	items, err := t.Get(ctx, limit, maxID, sinceID, minID, true)
 	if err != nil {
 		l.Errorf("error getting statuses: %s", err)
 	}
-	return statuses, nil
+	return items, nil
 }
 
 func (m *manager) GetIndexedLength(ctx context.Context, timelineAccountID string) int {
@@ -169,7 +169,7 @@ func (m *manager) GetIndexedLength(ctx context.Context, timelineAccountID string
 		return 0
 	}
 
-	return t.PostIndexLength(ctx)
+	return t.ItemIndexLength(ctx)
 }
 
 func (m *manager) GetDesiredIndexLength(ctx context.Context) int {
@@ -182,7 +182,7 @@ func (m *manager) GetOldestIndexedID(ctx context.Context, timelineAccountID stri
 		return "", err
 	}
 
-	return t.OldestIndexedPostID(ctx)
+	return t.OldestIndexedItemID(ctx)
 }
 
 func (m *manager) PrepareXFromTop(ctx context.Context, timelineAccountID string, limit int) error {
@@ -194,7 +194,7 @@ func (m *manager) PrepareXFromTop(ctx context.Context, timelineAccountID string,
 	return t.PrepareFromTop(ctx, limit)
 }
 
-func (m *manager) WipeStatusFromAllTimelines(ctx context.Context, statusID string) error {
+func (m *manager) WipeItemFromAllTimelines(ctx context.Context, statusID string) error {
 	errors := []string{}
 	m.accountTimelines.Range(func(k interface{}, i interface{}) bool {
 		t, ok := i.(Timeline)
@@ -217,7 +217,7 @@ func (m *manager) WipeStatusFromAllTimelines(ctx context.Context, statusID strin
 	return err
 }
 
-func (m *manager) WipeStatusesFromAccountID(ctx context.Context, timelineAccountID string, accountID string) error {
+func (m *manager) WipeItemsFromAccountID(ctx context.Context, timelineAccountID string, accountID string) error {
 	t, err := m.getOrCreateTimeline(ctx, timelineAccountID)
 	if err != nil {
 		return err
@@ -232,7 +232,7 @@ func (m *manager) getOrCreateTimeline(ctx context.Context, timelineAccountID str
 	i, ok := m.accountTimelines.Load(timelineAccountID)
 	if !ok {
 		var err error
-		t, err = NewTimeline(ctx, timelineAccountID, m.db, m.tc)
+		t, err = NewTimeline(ctx, timelineAccountID, m.grabFunction, m.filterFunction, m.prepareFunction, m.skipInsertFunction)
 		if err != nil {
 			return nil, err
 		}

internal/timeline/manager_test.go

@@ -23,6 +23,9 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/processing"
+	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 	"github.com/superseriousbusiness/gotosocial/testrig"
 )
 
@@ -41,10 +44,16 @@ func (suite *ManagerTestSuite) SetupTest() {
 
 	suite.db = testrig.NewTestDB()
 	suite.tc = testrig.NewTestTypeConverter(suite.db)
+	suite.filter = visibility.NewFilter(suite.db)
 
 	testrig.StandardDBSetup(suite.db, nil)
 
-	manager := testrig.NewTestTimelineManager(suite.db)
+	manager := timeline.NewManager(
+		processing.StatusGrabFunction(suite.db),
+		processing.StatusFilterFunction(suite.db, suite.filter),
+		processing.StatusPrepareFunction(suite.db, suite.tc),
+		processing.StatusSkipInsertFunction(),
+	)
 	suite.manager = manager
 }
 
@@ -78,12 +87,12 @@ func (suite *ManagerTestSuite) TestManagerIntegration() {
 	suite.Equal("01F8MH75CBF9JFX4ZAD54N0W0R", oldestIndexed)
 
 	// get hometimeline
-	statuses, err := suite.manager.HomeTimeline(context.Background(), testAccount.ID, "", "", "", 20, false)
+	statuses, err := suite.manager.GetTimeline(context.Background(), testAccount.ID, "", "", "", 20, false)
 	suite.NoError(err)
 	suite.Len(statuses, 14)
 
 	// now wipe the last status from all timelines, as though it had been deleted by the owner
-	err = suite.manager.WipeStatusFromAllTimelines(context.Background(), "01F8MH75CBF9JFX4ZAD54N0W0R")
+	err = suite.manager.WipeItemFromAllTimelines(context.Background(), "01F8MH75CBF9JFX4ZAD54N0W0R")
 	suite.NoError(err)
 
 	// timeline should be shorter
@@ -110,7 +119,7 @@ func (suite *ManagerTestSuite) TestManagerIntegration() {
 	suite.Equal("01F8MHAAY43M6RJ473VQFCVH37", oldestIndexed)
 
 	// now remove all entries by local_account_2 from the timeline
-	err = suite.manager.WipeStatusesFromAccountID(context.Background(), testAccount.ID, suite.testAccounts["local_account_2"].ID)
+	err = suite.manager.WipeItemsFromAccountID(context.Background(), testAccount.ID, suite.testAccounts["local_account_2"].ID)
 	suite.NoError(err)
 
 	// timeline should be shorter

internal/timeline/preparable.go

@@ -0,0 +1,26 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package timeline
+
+type Preparable interface {
+	GetID() string
+	GetAccountID() string
+	GetBoostOfID() string
+	GetBoostOfAccountID() string
+}

internal/timeline/prepare.go

@@ -26,7 +26,6 @@ import (
 
 	"github.com/sirupsen/logrus"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
-	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 )
 
 func (t *timeline) prepareNextQuery(ctx context.Context, amount int, maxID string, sinceID string, minID string) error {
@@ -59,19 +58,19 @@ func (t *timeline) prepareNextQuery(ctx context.Context, amount int, maxID strin
 	return err
 }
 
-func (t *timeline) PrepareBehind(ctx context.Context, statusID string, amount int) error {
-	// lazily initialize prepared posts if it hasn't been done already
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
-		t.preparedPosts.data.Init()
+func (t *timeline) PrepareBehind(ctx context.Context, itemID string, amount int) error {
+	// lazily initialize prepared items if it hasn't been done already
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
+		t.preparedItems.data.Init()
 	}
 
-	if err := t.IndexBehind(ctx, statusID, true, amount); err != nil {
-		return fmt.Errorf("PrepareBehind: error indexing behind id %s: %s", statusID, err)
+	if err := t.IndexBehind(ctx, itemID, amount); err != nil {
+		return fmt.Errorf("PrepareBehind: error indexing behind id %s: %s", itemID, err)
 	}
 
-	// if the postindex is nil, nothing has been indexed yet so there's nothing to prepare
-	if t.postIndex.data == nil {
+	// if the itemindex is nil, nothing has been indexed yet so there's nothing to prepare
+	if t.itemIndex.data == nil {
 		return nil
 	}
 
@@ -80,25 +79,25 @@ func (t *timeline) PrepareBehind(ctx context.Context, statusID string, amount in
 	t.Lock()
 	defer t.Unlock()
 prepareloop:
-	for e := t.postIndex.data.Front(); e != nil; e = e.Next() {
-		entry, ok := e.Value.(*postIndexEntry)
+	for e := t.itemIndex.data.Front(); e != nil; e = e.Next() {
+		entry, ok := e.Value.(*itemIndexEntry)
 		if !ok {
-			return errors.New("PrepareBehind: could not parse e as a postIndexEntry")
+			return errors.New("PrepareBehind: could not parse e as itemIndexEntry")
 		}
 
 		if !preparing {
 			// we haven't hit the position we need to prepare from yet
-			if entry.statusID == statusID {
+			if entry.itemID == itemID {
 				preparing = true
 			}
 		}
 
 		if preparing {
-			if err := t.prepare(ctx, entry.statusID); err != nil {
+			if err := t.prepare(ctx, entry.itemID); err != nil {
 				// there's been an error
 				if err != db.ErrNoEntries {
 					// it's a real error
-					return fmt.Errorf("PrepareBehind: error preparing status with id %s: %s", entry.statusID, err)
+					return fmt.Errorf("PrepareBehind: error preparing item with id %s: %s", entry.itemID, err)
 				}
 				// the status just doesn't exist (anymore) so continue to the next one
 				continue
@@ -119,28 +118,28 @@ func (t *timeline) PrepareBefore(ctx context.Context, statusID string, include b
 	defer t.Unlock()
 
 	// lazily initialize prepared posts if it hasn't been done already
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
-		t.preparedPosts.data.Init()
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
+		t.preparedItems.data.Init()
 	}
 
 	// if the postindex is nil, nothing has been indexed yet so there's nothing to prepare
-	if t.postIndex.data == nil {
+	if t.itemIndex.data == nil {
 		return nil
 	}
 
 	var prepared int
 	var preparing bool
 prepareloop:
-	for e := t.postIndex.data.Back(); e != nil; e = e.Prev() {
-		entry, ok := e.Value.(*postIndexEntry)
+	for e := t.itemIndex.data.Back(); e != nil; e = e.Prev() {
+		entry, ok := e.Value.(*itemIndexEntry)
 		if !ok {
 			return errors.New("PrepareBefore: could not parse e as a postIndexEntry")
 		}
 
 		if !preparing {
 			// we haven't hit the position we need to prepare from yet
-			if entry.statusID == statusID {
+			if entry.itemID == statusID {
 				preparing = true
 				if !include {
 					continue
@@ -149,11 +148,11 @@ prepareloop:
 		}
 
 		if preparing {
-			if err := t.prepare(ctx, entry.statusID); err != nil {
+			if err := t.prepare(ctx, entry.itemID); err != nil {
 				// there's been an error
 				if err != db.ErrNoEntries {
 					// it's a real error
-					return fmt.Errorf("PrepareBefore: error preparing status with id %s: %s", entry.statusID, err)
+					return fmt.Errorf("PrepareBefore: error preparing status with id %s: %s", entry.itemID, err)
 				}
 				// the status just doesn't exist (anymore) so continue to the next one
 				continue
@@ -176,15 +175,15 @@ func (t *timeline) PrepareFromTop(ctx context.Context, amount int) error {
 	})
 
 	// lazily initialize prepared posts if it hasn't been done already
-	if t.preparedPosts.data == nil {
-		t.preparedPosts.data = &list.List{}
-		t.preparedPosts.data.Init()
+	if t.preparedItems.data == nil {
+		t.preparedItems.data = &list.List{}
+		t.preparedItems.data.Init()
 	}
 
 	// if the postindex is nil, nothing has been indexed yet so index from the highest ID possible
-	if t.postIndex.data == nil {
+	if t.itemIndex.data == nil {
 		l.Debug("postindex.data was nil, indexing behind highest possible ID")
-		if err := t.IndexBehind(ctx, "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", false, amount); err != nil {
+		if err := t.IndexBehind(ctx, "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", amount); err != nil {
 			return fmt.Errorf("PrepareFromTop: error indexing behind id %s: %s", "ZZZZZZZZZZZZZZZZZZZZZZZZZZ", err)
 		}
 	}
@@ -194,21 +193,21 @@ func (t *timeline) PrepareFromTop(ctx context.Context, amount int) error {
 	defer t.Unlock()
 	var prepared int
 prepareloop:
-	for e := t.postIndex.data.Front(); e != nil; e = e.Next() {
+	for e := t.itemIndex.data.Front(); e != nil; e = e.Next() {
 		if e == nil {
 			continue
 		}
 
-		entry, ok := e.Value.(*postIndexEntry)
+		entry, ok := e.Value.(*itemIndexEntry)
 		if !ok {
 			return errors.New("PrepareFromTop: could not parse e as a postIndexEntry")
 		}
 
-		if err := t.prepare(ctx, entry.statusID); err != nil {
+		if err := t.prepare(ctx, entry.itemID); err != nil {
 			// there's been an error
 			if err != db.ErrNoEntries {
 				// it's a real error
-				return fmt.Errorf("PrepareFromTop: error preparing status with id %s: %s", entry.statusID, err)
+				return fmt.Errorf("PrepareFromTop: error preparing status with id %s: %s", entry.itemID, err)
 			}
 			// the status just doesn't exist (anymore) so continue to the next one
 			continue
@@ -226,57 +225,42 @@ prepareloop:
 	return nil
 }
 
-func (t *timeline) prepare(ctx context.Context, statusID string) error {
-
-	// start by getting the status out of the database according to its indexed ID
-	gtsStatus := &gtsmodel.Status{}
-	if err := t.db.GetByID(ctx, statusID, gtsStatus); err != nil {
-		return err
-	}
-
-	// if the account pointer hasn't been set on this timeline already, set it lazily here
-	if t.account == nil {
-		timelineOwnerAccount := &gtsmodel.Account{}
-		if err := t.db.GetByID(ctx, t.accountID, timelineOwnerAccount); err != nil {
-			return err
-		}
-		t.account = timelineOwnerAccount
-	}
-
-	// serialize the status (or, at least, convert it to a form that's ready to be serialized)
-	apiModelStatus, err := t.tc.StatusToAPIStatus(ctx, gtsStatus, t.account)
+func (t *timeline) prepare(ctx context.Context, itemID string) error {
+	// trigger the caller-provided prepare function
+	prepared, err := t.prepareFunction(ctx, t.accountID, itemID)
 	if err != nil {
 		return err
 	}
 
-	// shove it in prepared posts as a prepared posts entry
-	preparedPostsEntry := &preparedPostsEntry{
-		statusID:         gtsStatus.ID,
-		boostOfID:        gtsStatus.BoostOfID,
-		accountID:        gtsStatus.AccountID,
-		boostOfAccountID: gtsStatus.BoostOfAccountID,
-		prepared:         apiModelStatus,
+	// shove it in prepared items as a prepared items entry
+	preparedItemsEntry := &preparedItemsEntry{
+		itemID:           prepared.GetID(),
+		boostOfID:        prepared.GetBoostOfID(),
+		accountID:        prepared.GetAccountID(),
+		boostOfAccountID: prepared.GetBoostOfAccountID(),
+		prepared:         prepared,
 	}
 
-	return t.preparedPosts.insertPrepared(preparedPostsEntry)
+	return t.preparedItems.insertPrepared(ctx, preparedItemsEntry)
 }
 
-func (t *timeline) OldestPreparedPostID(ctx context.Context) (string, error) {
+func (t *timeline) OldestPreparedItemID(ctx context.Context) (string, error) {
 	var id string
-	if t.preparedPosts == nil || t.preparedPosts.data == nil {
-		// return an empty string if prepared posts hasn't been initialized yet
+	if t.preparedItems == nil || t.preparedItems.data == nil {
+		// return an empty string if prepared items hasn't been initialized yet
 		return id, nil
 	}
 
-	e := t.preparedPosts.data.Back()
+	e := t.preparedItems.data.Back()
 	if e == nil {
 		// return an empty string if there's no back entry (ie., the index list hasn't been initialized yet)
 		return id, nil
 	}
 
-	entry, ok := e.Value.(*preparedPostsEntry)
+	entry, ok := e.Value.(*preparedItemsEntry)
 	if !ok {
-		return id, errors.New("OldestPreparedPostID: could not parse e as a preparedPostsEntry")
+		return id, errors.New("OldestPreparedItemID: could not parse e as a preparedItemsEntry")
 	}
-	return entry.statusID, nil
+
+	return entry.itemID, nil
 }

internal/timeline/prepareditems.go

@@ -20,24 +20,24 @@ package timeline
 
 import (
 	"container/list"
+	"context"
 	"errors"
-
-	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 )
 
-type preparedPosts struct {
+type preparedItems struct {
 	data       *list.List
+	skipInsert SkipInsertFunction
 }
 
-type preparedPostsEntry struct {
-	statusID         string
+type preparedItemsEntry struct {
+	itemID           string
 	boostOfID        string
 	accountID        string
 	boostOfAccountID string
-	prepared         *apimodel.Status
+	prepared         Preparable
 }
 
-func (p *preparedPosts) insertPrepared(i *preparedPostsEntry) error {
+func (p *preparedItems) insertPrepared(ctx context.Context, i *preparedItemsEntry) error {
 	if p.data == nil {
 		p.data = &list.List{}
 	}
@@ -55,35 +55,28 @@ func (p *preparedPosts) insertPrepared(i *preparedPostsEntry) error {
 	for e := p.data.Front(); e != nil; e = e.Next() {
 		position++
 
-		entry, ok := e.Value.(*preparedPostsEntry)
+		entry, ok := e.Value.(*preparedItemsEntry)
 		if !ok {
 			return errors.New("index: could not parse e as a preparedPostsEntry")
 		}
 
-		// don't insert this if it's a boost of a status we've seen recently
-		if i.prepared.Reblog != nil {
-			if entry.prepared.Reblog != nil && i.prepared.Reblog.ID == entry.prepared.Reblog.ID {
-				if position < boostReinsertionDepth {
+		skip, err := p.skipInsert(ctx, i.itemID, i.accountID, i.boostOfID, i.boostOfAccountID, entry.itemID, entry.accountID, entry.boostOfID, entry.boostOfAccountID, position)
+		if err != nil {
+			return err
+		}
+		if skip {
 			return nil
 		}
-			}
-
-			if i.prepared.Reblog.ID == entry.statusID {
-				if position < boostReinsertionDepth {
-					return nil
-				}
-			}
-		}
 
 		// if the post to index is newer than e, insert it before e in the list
 		if insertMark == nil {
-			if i.statusID > entry.statusID {
+			if i.itemID > entry.itemID {
 				insertMark = e
 			}
 		}
 
 		// make sure we don't insert a duplicate
-		if entry.statusID == i.statusID {
+		if entry.itemID == i.itemID {
 			return nil
 		}
 	}

internal/timeline/remove.go

@@ -38,39 +38,39 @@ func (t *timeline) Remove(ctx context.Context, statusID string) (int, error) {
 
 	// remove entr(ies) from the post index
 	removeIndexes := []*list.Element{}
-	if t.postIndex != nil && t.postIndex.data != nil {
-		for e := t.postIndex.data.Front(); e != nil; e = e.Next() {
-			entry, ok := e.Value.(*postIndexEntry)
+	if t.itemIndex != nil && t.itemIndex.data != nil {
+		for e := t.itemIndex.data.Front(); e != nil; e = e.Next() {
+			entry, ok := e.Value.(*itemIndexEntry)
 			if !ok {
 				return removed, errors.New("Remove: could not parse e as a postIndexEntry")
 			}
-			if entry.statusID == statusID {
+			if entry.itemID == statusID {
 				l.Debug("found status in postIndex")
 				removeIndexes = append(removeIndexes, e)
 			}
 		}
 	}
 	for _, e := range removeIndexes {
-		t.postIndex.data.Remove(e)
+		t.itemIndex.data.Remove(e)
 		removed++
 	}
 
 	// remove entr(ies) from prepared posts
 	removePrepared := []*list.Element{}
-	if t.preparedPosts != nil && t.preparedPosts.data != nil {
-		for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
-			entry, ok := e.Value.(*preparedPostsEntry)
+	if t.preparedItems != nil && t.preparedItems.data != nil {
+		for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
+			entry, ok := e.Value.(*preparedItemsEntry)
 			if !ok {
 				return removed, errors.New("Remove: could not parse e as a preparedPostsEntry")
 			}
-			if entry.statusID == statusID {
+			if entry.itemID == statusID {
 				l.Debug("found status in preparedPosts")
 				removePrepared = append(removePrepared, e)
 			}
 		}
 	}
 	for _, e := range removePrepared {
-		t.preparedPosts.data.Remove(e)
+		t.preparedItems.data.Remove(e)
 		removed++
 	}
 
@@ -90,9 +90,9 @@ func (t *timeline) RemoveAllBy(ctx context.Context, accountID string) (int, erro
 
 	// remove entr(ies) from the post index
 	removeIndexes := []*list.Element{}
-	if t.postIndex != nil && t.postIndex.data != nil {
-		for e := t.postIndex.data.Front(); e != nil; e = e.Next() {
-			entry, ok := e.Value.(*postIndexEntry)
+	if t.itemIndex != nil && t.itemIndex.data != nil {
+		for e := t.itemIndex.data.Front(); e != nil; e = e.Next() {
+			entry, ok := e.Value.(*itemIndexEntry)
 			if !ok {
 				return removed, errors.New("Remove: could not parse e as a postIndexEntry")
 			}
@@ -103,15 +103,15 @@ func (t *timeline) RemoveAllBy(ctx context.Context, accountID string) (int, erro
 		}
 	}
 	for _, e := range removeIndexes {
-		t.postIndex.data.Remove(e)
+		t.itemIndex.data.Remove(e)
 		removed++
 	}
 
 	// remove entr(ies) from prepared posts
 	removePrepared := []*list.Element{}
-	if t.preparedPosts != nil && t.preparedPosts.data != nil {
-		for e := t.preparedPosts.data.Front(); e != nil; e = e.Next() {
-			entry, ok := e.Value.(*preparedPostsEntry)
+	if t.preparedItems != nil && t.preparedItems.data != nil {
+		for e := t.preparedItems.data.Front(); e != nil; e = e.Next() {
+			entry, ok := e.Value.(*preparedItemsEntry)
 			if !ok {
 				return removed, errors.New("Remove: could not parse e as a preparedPostsEntry")
 			}
@@ -122,7 +122,7 @@ func (t *timeline) RemoveAllBy(ctx context.Context, accountID string) (int, erro
 		}
 	}
 	for _, e := range removePrepared {
-		t.preparedPosts.data.Remove(e)
+		t.preparedItems.data.Remove(e)
 		removed++
 	}
 

internal/timeline/timeline.go

@@ -21,104 +21,135 @@ package timeline
 import (
 	"context"
 	"sync"
-	"time"
-
-	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
-	"github.com/superseriousbusiness/gotosocial/internal/db"
-	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
-	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
-	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 )
 
-const boostReinsertionDepth = 50
+// GrabFunction is used by a Timeline to grab more items to index.
+//
+// It should be provided to NewTimeline when the caller is creating a timeline
+// (of statuses, notifications, etc).
+//
+//  timelineAccountID: the owner of the timeline
+//  maxID: the maximum item ID desired.
+//  sinceID: the minimum item ID desired.
+//  minID: see sinceID
+//  limit: the maximum amount of items to be returned
+//
+// If an error is returned, the timeline will stop processing whatever request called GrabFunction,
+// and return the error. If no error is returned, but stop = true, this indicates to the caller of GrabFunction
+// that there are no more items to return, and processing should continue with the items already grabbed.
+type GrabFunction func(ctx context.Context, timelineAccountID string, maxID string, sinceID string, minID string, limit int) (items []Timelineable, stop bool, err error)
 
-// Timeline represents a timeline for one account, and contains indexed and prepared posts.
+// FilterFunction is used by a Timeline to filter whether or not a grabbed item should be indexed.
+type FilterFunction func(ctx context.Context, timelineAccountID string, item Timelineable) (shouldIndex bool, err error)
+
+// PrepareFunction converts a Timelineable into a Preparable.
+//
+// For example, this might result in the converstion of a *gtsmodel.Status with the given itemID into a serializable *apimodel.Status.
+type PrepareFunction func(ctx context.Context, timelineAccountID string, itemID string) (Preparable, error)
+
+// SkipInsertFunction indicates whether a new item about to be inserted in the prepared list should be skipped,
+// based on the item itself, the next item in the timeline, and the depth at which nextItem has been found in the list.
+//
+// This will be called for every item found while iterating through a timeline, so callers should be very careful
+// not to do anything expensive here.
+type SkipInsertFunction func(ctx context.Context,
+	newItemID string,
+	newItemAccountID string,
+	newItemBoostOfID string,
+	newItemBoostOfAccountID string,
+	nextItemID string,
+	nextItemAccountID string,
+	nextItemBoostOfID string,
+	nextItemBoostOfAccountID string,
+	depth int) (bool, error)
+
+// Timeline represents a timeline for one account, and contains indexed and prepared items.
 type Timeline interface {
 	/*
 		RETRIEVAL FUNCTIONS
 	*/
 
-	// Get returns an amount of statuses with the given parameters.
+	// Get returns an amount of prepared items with the given parameters.
 	// If prepareNext is true, then the next predicted query will be prepared already in a goroutine,
 	// to make the next call to Get faster.
-	Get(ctx context.Context, amount int, maxID string, sinceID string, minID string, prepareNext bool) ([]*apimodel.Status, error)
-	// GetXFromTop returns x amount of posts from the top of the timeline, from newest to oldest.
-	GetXFromTop(ctx context.Context, amount int) ([]*apimodel.Status, error)
-	// GetXBehindID returns x amount of posts from the given id onwards, from newest to oldest.
-	// This will NOT include the status with the given ID.
+	Get(ctx context.Context, amount int, maxID string, sinceID string, minID string, prepareNext bool) ([]Preparable, error)
+	// GetXFromTop returns x amount of items from the top of the timeline, from newest to oldest.
+	GetXFromTop(ctx context.Context, amount int) ([]Preparable, error)
+	// GetXBehindID returns x amount of items from the given id onwards, from newest to oldest.
+	// This will NOT include the item with the given ID.
 	//
 	// This corresponds to an api call to /timelines/home?max_id=WHATEVER
-	GetXBehindID(ctx context.Context, amount int, fromID string, attempts *int) ([]*apimodel.Status, error)
-	// GetXBeforeID returns x amount of posts up to the given id, from newest to oldest.
-	// This will NOT include the status with the given ID.
+	GetXBehindID(ctx context.Context, amount int, fromID string, attempts *int) ([]Preparable, error)
+	// GetXBeforeID returns x amount of items up to the given id, from newest to oldest.
+	// This will NOT include the item with the given ID.
 	//
 	// This corresponds to an api call to /timelines/home?since_id=WHATEVER
-	GetXBeforeID(ctx context.Context, amount int, sinceID string, startFromTop bool) ([]*apimodel.Status, error)
-	// GetXBetweenID returns x amount of posts from the given maxID, up to the given id, from newest to oldest.
-	// This will NOT include the status with the given IDs.
+	GetXBeforeID(ctx context.Context, amount int, sinceID string, startFromTop bool) ([]Preparable, error)
+	// GetXBetweenID returns x amount of items from the given maxID, up to the given id, from newest to oldest.
+	// This will NOT include the item with the given IDs.
 	//
 	// This corresponds to an api call to /timelines/home?since_id=WHATEVER&max_id=WHATEVER_ELSE
-	GetXBetweenID(ctx context.Context, amount int, maxID string, sinceID string) ([]*apimodel.Status, error)
+	GetXBetweenID(ctx context.Context, amount int, maxID string, sinceID string) ([]Preparable, error)
 
 	/*
 		INDEXING FUNCTIONS
 	*/
 
-	// IndexOne puts a status into the timeline at the appropriate place according to its 'createdAt' property.
+	// IndexOne puts a item into the timeline at the appropriate place according to its 'createdAt' property.
 	//
-	// The returned bool indicates whether or not the status was actually inserted into the timeline. This will be false
-	// if the status is a boost and the original post or another boost of it already exists < boostReinsertionDepth back in the timeline.
-	IndexOne(ctx context.Context, statusCreatedAt time.Time, statusID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error)
+	// The returned bool indicates whether or not the item was actually inserted into the timeline. This will be false
+	// if the item is a boost and the original item or another boost of it already exists < boostReinsertionDepth back in the timeline.
+	IndexOne(ctx context.Context, itemID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error)
 
-	// OldestIndexedPostID returns the id of the rearmost (ie., the oldest) indexed post, or an error if something goes wrong.
-	// If nothing goes wrong but there's no oldest post, an empty string will be returned so make sure to check for this.
-	OldestIndexedPostID(ctx context.Context) (string, error)
-	// NewestIndexedPostID returns the id of the frontmost (ie., the newest) indexed post, or an error if something goes wrong.
-	// If nothing goes wrong but there's no newest post, an empty string will be returned so make sure to check for this.
-	NewestIndexedPostID(ctx context.Context) (string, error)
+	// OldestIndexedItemID returns the id of the rearmost (ie., the oldest) indexed item, or an error if something goes wrong.
+	// If nothing goes wrong but there's no oldest item, an empty string will be returned so make sure to check for this.
+	OldestIndexedItemID(ctx context.Context) (string, error)
+	// NewestIndexedItemID returns the id of the frontmost (ie., the newest) indexed item, or an error if something goes wrong.
+	// If nothing goes wrong but there's no newest item, an empty string will be returned so make sure to check for this.
+	NewestIndexedItemID(ctx context.Context) (string, error)
 
-	IndexBefore(ctx context.Context, statusID string, include bool, amount int) error
-	IndexBehind(ctx context.Context, statusID string, include bool, amount int) error
+	IndexBefore(ctx context.Context, itemID string, amount int) error
+	IndexBehind(ctx context.Context, itemID string, amount int) error
 
 	/*
 		PREPARATION FUNCTIONS
 	*/
 
-	// PrepareXFromTop instructs the timeline to prepare x amount of posts from the top of the timeline.
+	// PrepareXFromTop instructs the timeline to prepare x amount of items from the top of the timeline.
 	PrepareFromTop(ctx context.Context, amount int) error
 	// PrepareBehind instructs the timeline to prepare the next amount of entries for serialization, from position onwards.
-	// If include is true, then the given status ID will also be prepared, otherwise only entries behind it will be prepared.
-	PrepareBehind(ctx context.Context, statusID string, amount int) error
-	// IndexOne puts a status into the timeline at the appropriate place according to its 'createdAt' property,
+	// If include is true, then the given item ID will also be prepared, otherwise only entries behind it will be prepared.
+	PrepareBehind(ctx context.Context, itemID string, amount int) error
+	// IndexOne puts a item into the timeline at the appropriate place according to its 'createdAt' property,
 	// and then immediately prepares it.
 	//
-	// The returned bool indicates whether or not the status was actually inserted into the timeline. This will be false
-	// if the status is a boost and the original post or another boost of it already exists < boostReinsertionDepth back in the timeline.
-	IndexAndPrepareOne(ctx context.Context, statusCreatedAt time.Time, statusID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error)
-	// OldestPreparedPostID returns the id of the rearmost (ie., the oldest) prepared post, or an error if something goes wrong.
-	// If nothing goes wrong but there's no oldest post, an empty string will be returned so make sure to check for this.
-	OldestPreparedPostID(ctx context.Context) (string, error)
+	// The returned bool indicates whether or not the item was actually inserted into the timeline. This will be false
+	// if the item is a boost and the original item or another boost of it already exists < boostReinsertionDepth back in the timeline.
+	IndexAndPrepareOne(ctx context.Context, itemID string, boostOfID string, accountID string, boostOfAccountID string) (bool, error)
+	// OldestPreparedItemID returns the id of the rearmost (ie., the oldest) prepared item, or an error if something goes wrong.
+	// If nothing goes wrong but there's no oldest item, an empty string will be returned so make sure to check for this.
+	OldestPreparedItemID(ctx context.Context) (string, error)
 
 	/*
 		INFO FUNCTIONS
 	*/
 
-	// ActualPostIndexLength returns the actual length of the post index at this point in time.
-	PostIndexLength(ctx context.Context) int
+	// ActualPostIndexLength returns the actual length of the item index at this point in time.
+	ItemIndexLength(ctx context.Context) int
 
 	/*
 		UTILITY FUNCTIONS
 	*/
 
-	// Reset instructs the timeline to reset to its base state -- cache only the minimum amount of posts.
+	// Reset instructs the timeline to reset to its base state -- cache only the minimum amount of items.
 	Reset() error
-	// Remove removes a status from both the index and prepared posts.
+	// Remove removes a item from both the index and prepared items.
 	//
-	// If a status has multiple entries in a timeline, they will all be removed.
+	// If a item has multiple entries in a timeline, they will all be removed.
 	//
 	// The returned int indicates the amount of entries that were removed.
-	Remove(ctx context.Context, statusID string) (int, error)
-	// RemoveAllBy removes all statuses by the given accountID, from both the index and prepared posts.
+	Remove(ctx context.Context, itemID string) (int, error)
+	// RemoveAllBy removes all items by the given accountID, from both the index and prepared items.
 	//
 	// The returned int indicates the amount of entries that were removed.
 	RemoveAllBy(ctx context.Context, accountID string) (int, error)
@@ -126,31 +157,34 @@ type Timeline interface {
 
 // timeline fulfils the Timeline interface
 type timeline struct {
-	postIndex     *postIndex
-	preparedPosts *preparedPosts
+	itemIndex       *itemIndex
+	preparedItems   *preparedItems
+	grabFunction    GrabFunction
+	filterFunction  FilterFunction
+	prepareFunction PrepareFunction
 	accountID       string
-	account       *gtsmodel.Account
-	db            db.DB
-	filter        visibility.Filter
-	tc            typeutils.TypeConverter
 	sync.Mutex
 }
 
 // NewTimeline returns a new Timeline for the given account ID
-func NewTimeline(ctx context.Context, accountID string, db db.DB, typeConverter typeutils.TypeConverter) (Timeline, error) {
-	timelineOwnerAccount := &gtsmodel.Account{}
-	if err := db.GetByID(ctx, accountID, timelineOwnerAccount); err != nil {
-		return nil, err
-	}
-
+func NewTimeline(
+	ctx context.Context,
+	timelineAccountID string,
+	grabFunction GrabFunction,
+	filterFunction FilterFunction,
+	prepareFunction PrepareFunction,
+	skipInsertFunction SkipInsertFunction) (Timeline, error) {
 	return &timeline{
-		postIndex:     &postIndex{},
-		preparedPosts: &preparedPosts{},
-		accountID:     accountID,
-		account:       timelineOwnerAccount,
-		db:            db,
-		filter:        visibility.NewFilter(db),
-		tc:            typeConverter,
+		itemIndex: &itemIndex{
+			skipInsert: skipInsertFunction,
+		},
+		preparedItems: &preparedItems{
+			skipInsert: skipInsertFunction,
+		},
+		grabFunction:    grabFunction,
+		filterFunction:  filterFunction,
+		prepareFunction: prepareFunction,
+		accountID:       timelineAccountID,
 	}, nil
 }
 
@@ -158,10 +192,10 @@ func (t *timeline) Reset() error {
 	return nil
 }
 
-func (t *timeline) PostIndexLength(ctx context.Context) int {
-	if t.postIndex == nil || t.postIndex.data == nil {
+func (t *timeline) ItemIndexLength(ctx context.Context) int {
+	if t.itemIndex == nil || t.itemIndex.data == nil {
 		return 0
 	}
 
-	return t.postIndex.data.Len()
+	return t.itemIndex.data.Len()
 }

internal/timeline/timeline_test.go

@@ -24,12 +24,14 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/timeline"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
+	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 )
 
 type TimelineStandardTestSuite struct {
 	suite.Suite
 	db     db.DB
 	tc     typeutils.TypeConverter
+	filter visibility.Filter
 
 	testAccounts map[string]*gtsmodel.Account
 	testStatuses map[string]*gtsmodel.Status

internal/timeline/timelineable.go

@@ -0,0 +1,27 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package timeline
+
+// Timelineable represents any item that can be put in a timeline.
+type Timelineable interface {
+	GetID() string
+	GetAccountID() string
+	GetBoostOfID() string
+	GetBoostOfAccountID() string
+}

testrig/processor.go

@@ -28,5 +28,5 @@ import (
 
 // NewTestProcessor returns a Processor suitable for testing purposes
 func NewTestProcessor(db db.DB, storage *kv.KVStore, federator federation.Federator, emailSender email.Sender) processing.Processor {
-	return processing.NewProcessor(NewTestTypeConverter(db), federator, NewTestOauthServer(db), NewTestMediaHandler(db, storage), storage, NewTestTimelineManager(db), db, emailSender)
+	return processing.NewProcessor(NewTestTypeConverter(db), federator, NewTestOauthServer(db), NewTestMediaHandler(db, storage), storage, db, emailSender)
 }

testrig/timelinemanager.go

@@ -1,11 +0,0 @@
-package testrig
-
-import (
-	"github.com/superseriousbusiness/gotosocial/internal/db"
-	"github.com/superseriousbusiness/gotosocial/internal/timeline"
-)
-
-// NewTestTimelineManager retuts a new timeline.Manager, suitable for testing, using the given db.
-func NewTestTimelineManager(db db.DB) timeline.Manager {
-	return timeline.NewManager(db, NewTestTypeConverter(db))
-}