[feature] Add postDataCallbackFunc to allow cleanup (#408)

internal/federation/dereferencing/account.go

@@ -285,7 +285,7 @@ func (d *deref) fetchRemoteAccountMedia(ctx context.Context, targetAccount *gtsm
 			}
 
 			avatar := true
-			newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, targetAccount.ID, &media.AdditionalMediaInfo{
+			newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, nil, targetAccount.ID, &media.AdditionalMediaInfo{
 				RemoteURL: &targetAccount.AvatarRemoteURL,
 				Avatar:    &avatar,
 			})
@@ -343,7 +343,7 @@ func (d *deref) fetchRemoteAccountMedia(ctx context.Context, targetAccount *gtsm
 			}
 
 			header := true
-			newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, targetAccount.ID, &media.AdditionalMediaInfo{
+			newProcessing, err := d.mediaManager.ProcessMedia(ctx, data, nil, targetAccount.ID, &media.AdditionalMediaInfo{
 				RemoteURL: &targetAccount.HeaderRemoteURL,
 				Header:    &header,
 			})

internal/federation/dereferencing/media.go

@@ -46,7 +46,7 @@ func (d *deref) GetRemoteMedia(ctx context.Context, requestingUsername string, a
 		return t.DereferenceMedia(innerCtx, derefURI)
 	}
 
-	processingMedia, err := d.mediaManager.ProcessMedia(ctx, dataFunc, accountID, ai)
+	processingMedia, err := d.mediaManager.ProcessMedia(ctx, dataFunc, nil, accountID, ai)
 	if err != nil {
 		return nil, fmt.Errorf("GetRemoteMedia: error processing attachment: %s", err)
 	}

internal/media/manager.go

@@ -32,16 +32,35 @@ import (
 // Manager provides an interface for managing media: parsing, storing, and retrieving media objects like photos, videos, and gifs.
 type Manager interface {
 	// ProcessMedia begins the process of decoding and storing the given data as an attachment.
-	// It will return a pointer to a Media struct upon which further actions can be performed, such as getting
+	// It will return a pointer to a ProcessingMedia struct upon which further actions can be performed, such as getting
 	// the finished media, thumbnail, attachment, etc.
 	//
-	// data should be a function that the media manager can call to return raw bytes of a piece of media.
+	// data should be a function that the media manager can call to return a reader containing the media data.
+	//
+	// postData will be called after data has been called; it can be used to clean up any remaining resources.
+	// The provided function can be nil, in which case it will not be executed.
 	//
 	// accountID should be the account that the media belongs to.
 	//
 	// ai is optional and can be nil. Any additional information about the attachment provided will be put in the database.
-	ProcessMedia(ctx context.Context, data DataFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error)
-	ProcessEmoji(ctx context.Context, data DataFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error)
+	ProcessMedia(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error)
+	// ProcessEmoji begins the process of decoding and storing the given data as an emoji.
+	// It will return a pointer to a ProcessingEmoji struct upon which further actions can be performed, such as getting
+	// the finished media, thumbnail, attachment, etc.
+	//
+	// data should be a function that the media manager can call to return a reader containing the emoji data.
+	//
+	// postData will be called after data has been called; it can be used to clean up any remaining resources.
+	// The provided function can be nil, in which case it will not be executed.
+	//
+	// shortcode should be the emoji shortcode without the ':'s around it.
+	//
+	// id is the database ID that should be used to store the emoji.
+	//
+	// uri is the ActivityPub URI/ID of the emoji.
+	//
+	// ai is optional and can be nil. Any additional information about the emoji provided will be put in the database.
+	ProcessEmoji(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error)
 	// NumWorkers returns the total number of workers available to this manager.
 	NumWorkers() int
 	// QueueSize returns the total capacity of the queue.
@@ -101,8 +120,8 @@ func NewManager(database db.DB, storage *kv.KVStore) (Manager, error) {
 	return m, nil
 }
 
-func (m *manager) ProcessMedia(ctx context.Context, data DataFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error) {
-	processingMedia, err := m.preProcessMedia(ctx, data, accountID, ai)
+func (m *manager) ProcessMedia(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error) {
+	processingMedia, err := m.preProcessMedia(ctx, data, postData, accountID, ai)
 	if err != nil {
 		return nil, err
 	}
@@ -125,8 +144,8 @@ func (m *manager) ProcessMedia(ctx context.Context, data DataFunc, accountID str
 	return processingMedia, nil
 }
 
-func (m *manager) ProcessEmoji(ctx context.Context, data DataFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error) {
-	processingEmoji, err := m.preProcessEmoji(ctx, data, shortcode, id, uri, ai)
+func (m *manager) ProcessEmoji(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error) {
+	processingEmoji, err := m.preProcessEmoji(ctx, data, postData, shortcode, id, uri, ai)
 	if err != nil {
 		return nil, err
 	}

internal/media/manager_test.go

@@ -54,7 +54,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessBlocking() {
 	accountID := "01FS1X72SK9ZPW0J1QQ68BD264"
 
 	// process the media with no additional info provided
-	processingMedia, err := suite.manager.ProcessMedia(ctx, data, accountID, nil)
+	processingMedia, err := suite.manager.ProcessMedia(ctx, data, nil, accountID, nil)
 	suite.NoError(err)
 	// fetch the attachment id from the processing media
 	attachmentID := processingMedia.AttachmentID()
@@ -111,6 +111,89 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessBlocking() {
 	suite.Equal(processedThumbnailBytesExpected, processedThumbnailBytes)
 }
 
+func (suite *ManagerTestSuite) TestSimpleJpegProcessBlockingWithCallback() {
+	ctx := context.Background()
+
+	data := func(_ context.Context) (io.Reader, int, error) {
+		// load bytes from a test image
+		b, err := os.ReadFile("./test/test-jpeg.jpg")
+		if err != nil {
+			panic(err)
+		}
+		return bytes.NewBuffer(b), len(b), nil
+	}
+
+	// test the callback function by setting a simple boolean
+	var calledPostData bool
+	postData := func(_ context.Context) error {
+		calledPostData = true
+		return nil
+	}
+	suite.False(calledPostData) // not called yet (obvs)
+
+	accountID := "01FS1X72SK9ZPW0J1QQ68BD264"
+
+	// process the media with no additional info provided
+	processingMedia, err := suite.manager.ProcessMedia(ctx, data, postData, accountID, nil)
+	suite.NoError(err)
+	// fetch the attachment id from the processing media
+	attachmentID := processingMedia.AttachmentID()
+
+	// do a blocking call to fetch the attachment
+	attachment, err := processingMedia.LoadAttachment(ctx)
+	suite.NoError(err)
+	suite.NotNil(attachment)
+
+	// the post data callback should have been called
+	suite.True(calledPostData)
+
+	// make sure it's got the stuff set on it that we expect
+	// the attachment ID and accountID we expect
+	suite.Equal(attachmentID, attachment.ID)
+	suite.Equal(accountID, attachment.AccountID)
+
+	// file meta should be correctly derived from the image
+	suite.EqualValues(gtsmodel.Original{
+		Width: 1920, Height: 1080, Size: 2073600, Aspect: 1.7777777777777777,
+	}, attachment.FileMeta.Original)
+	suite.EqualValues(gtsmodel.Small{
+		Width: 512, Height: 288, Size: 147456, Aspect: 1.7777777777777777,
+	}, attachment.FileMeta.Small)
+	suite.Equal("image/jpeg", attachment.File.ContentType)
+	suite.Equal("image/jpeg", attachment.Thumbnail.ContentType)
+	suite.Equal(269739, attachment.File.FileSize)
+	suite.Equal("LjBzUo#6RQR._NvzRjWF?urqV@a$", attachment.Blurhash)
+
+	// now make sure the attachment is in the database
+	dbAttachment, err := suite.db.GetAttachmentByID(ctx, attachmentID)
+	suite.NoError(err)
+	suite.NotNil(dbAttachment)
+
+	// make sure the processed file is in storage
+	processedFullBytes, err := suite.storage.Get(attachment.File.Path)
+	suite.NoError(err)
+	suite.NotEmpty(processedFullBytes)
+
+	// load the processed bytes from our test folder, to compare
+	processedFullBytesExpected, err := os.ReadFile("./test/test-jpeg-processed.jpg")
+	suite.NoError(err)
+	suite.NotEmpty(processedFullBytesExpected)
+
+	// the bytes in storage should be what we expected
+	suite.Equal(processedFullBytesExpected, processedFullBytes)
+
+	// now do the same for the thumbnail and make sure it's what we expected
+	processedThumbnailBytes, err := suite.storage.Get(attachment.Thumbnail.Path)
+	suite.NoError(err)
+	suite.NotEmpty(processedThumbnailBytes)
+
+	processedThumbnailBytesExpected, err := os.ReadFile("./test/test-jpeg-thumbnail.jpg")
+	suite.NoError(err)
+	suite.NotEmpty(processedThumbnailBytesExpected)
+
+	suite.Equal(processedThumbnailBytesExpected, processedThumbnailBytes)
+}
+
 func (suite *ManagerTestSuite) TestSimpleJpegProcessAsync() {
 	ctx := context.Background()
 
@@ -126,7 +209,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessAsync() {
 	accountID := "01FS1X72SK9ZPW0J1QQ68BD264"
 
 	// process the media with no additional info provided
-	processingMedia, err := suite.manager.ProcessMedia(ctx, data, accountID, nil)
+	processingMedia, err := suite.manager.ProcessMedia(ctx, data, nil, accountID, nil)
 	suite.NoError(err)
 	// fetch the attachment id from the processing media
 	attachmentID := processingMedia.AttachmentID()
@@ -210,7 +293,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegQueueSpamming() {
 	inProcess := []*media.ProcessingMedia{}
 	for i := 0; i < spam; i++ {
 		// process the media with no additional info provided
-		processingMedia, err := suite.manager.ProcessMedia(ctx, data, accountID, nil)
+		processingMedia, err := suite.manager.ProcessMedia(ctx, data, nil, accountID, nil)
 		suite.NoError(err)
 		inProcess = append(inProcess, processingMedia)
 	}
@@ -305,7 +388,7 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessBlockingWithDiskStorage() {
 	suite.manager = diskManager
 
 	// process the media with no additional info provided
-	processingMedia, err := diskManager.ProcessMedia(ctx, data, accountID, nil)
+	processingMedia, err := diskManager.ProcessMedia(ctx, data, nil, accountID, nil)
 	suite.NoError(err)
 	// fetch the attachment id from the processing media
 	attachmentID := processingMedia.AttachmentID()

internal/media/processingemoji.go

@@ -47,9 +47,10 @@ type ProcessingEmoji struct {
 		emoji will be updated incrementally as media goes through processing
 	*/
 
-	emoji *gtsmodel.Emoji
-	data  DataFunc
-	read  bool // bool indicating that data function has been triggered already
+	emoji    *gtsmodel.Emoji
+	data     DataFunc
+	postData PostDataCallbackFunc
+	read     bool // bool indicating that data function has been triggered already
 
 	/*
 		below fields represent the processing state of the static of the emoji
@@ -212,10 +213,15 @@ func (p *ProcessingEmoji) store(ctx context.Context) error {
 	}
 
 	p.read = true
+
+	if p.postData != nil {
+		return p.postData(ctx)
+	}
+
 	return nil
 }
 
-func (m *manager) preProcessEmoji(ctx context.Context, data DataFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error) {
+func (m *manager) preProcessEmoji(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, shortcode string, id string, uri string, ai *AdditionalEmojiInfo) (*ProcessingEmoji, error) {
 	instanceAccount, err := m.db.GetInstanceAccount(ctx, "")
 	if err != nil {
 		return nil, fmt.Errorf("preProcessEmoji: error fetching this instance account from the db: %s", err)
@@ -281,6 +287,7 @@ func (m *manager) preProcessEmoji(ctx context.Context, data DataFunc, shortcode
 		instanceAccountID: instanceAccount.ID,
 		emoji:             emoji,
 		data:              data,
+		postData:          postData,
 		staticState:       int32(received),
 		database:          m.db,
 		storage:           m.storage,

internal/media/processingmedia.go

@@ -48,6 +48,7 @@ type ProcessingMedia struct {
 
 	attachment *gtsmodel.MediaAttachment
 	data       DataFunc
+	postData   PostDataCallbackFunc
 	read       bool // bool indicating that data function has been triggered already
 
 	thumbState    int32 // the processing state of the media thumbnail
@@ -313,10 +314,15 @@ func (p *ProcessingMedia) store(ctx context.Context) error {
 	}
 
 	p.read = true
+
+	if p.postData != nil {
+		return p.postData(ctx)
+	}
+
 	return nil
 }
 
-func (m *manager) preProcessMedia(ctx context.Context, data DataFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error) {
+func (m *manager) preProcessMedia(ctx context.Context, data DataFunc, postData PostDataCallbackFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error) {
 	id, err := id.NewRandomULID()
 	if err != nil {
 		return nil, err
@@ -403,6 +409,7 @@ func (m *manager) preProcessMedia(ctx context.Context, data DataFunc, accountID
 	processingMedia := &ProcessingMedia{
 		attachment:    attachment,
 		data:          data,
+		postData:      postData,
 		thumbState:    int32(received),
 		fullSizeState: int32(received),
 		database:      m.db,

internal/media/types.go

@@ -119,3 +119,9 @@ type AdditionalEmojiInfo struct {
 
 // DataFunc represents a function used to retrieve the raw bytes of a piece of media.
 type DataFunc func(ctx context.Context) (reader io.Reader, fileSize int, err error)
+
+// PostDataCallbackFunc represents a function executed after the DataFunc has been executed,
+// and the returned reader has been read. It can be used to clean up any remaining resources.
+//
+// This can be set to nil, and will then not be executed.
+type PostDataCallbackFunc func(ctx context.Context) error

internal/processing/account/update.go

@@ -150,7 +150,7 @@ func (p *processor) UpdateAvatar(ctx context.Context, avatar *multipart.FileHead
 		Avatar: &isAvatar,
 	}
 
-	processingMedia, err := p.mediaManager.ProcessMedia(ctx, dataFunc, accountID, ai)
+	processingMedia, err := p.mediaManager.ProcessMedia(ctx, dataFunc, nil, accountID, ai)
 	if err != nil {
 		return nil, fmt.Errorf("UpdateAvatar: error processing avatar: %s", err)
 	}
@@ -177,7 +177,7 @@ func (p *processor) UpdateHeader(ctx context.Context, header *multipart.FileHead
 		Header: &isHeader,
 	}
 
-	processingMedia, err := p.mediaManager.ProcessMedia(ctx, dataFunc, accountID, ai)
+	processingMedia, err := p.mediaManager.ProcessMedia(ctx, dataFunc, nil, accountID, ai)
 	if err != nil {
 		return nil, fmt.Errorf("UpdateHeader: error processing header: %s", err)
 	}

internal/processing/admin/emoji.go

@@ -49,7 +49,7 @@ func (p *processor) EmojiCreate(ctx context.Context, account *gtsmodel.Account,
 
 	emojiURI := uris.GenerateURIForEmoji(emojiID)
 
-	processingEmoji, err := p.mediaManager.ProcessEmoji(ctx, data, form.Shortcode, emojiID, emojiURI, nil)
+	processingEmoji, err := p.mediaManager.ProcessEmoji(ctx, data, nil, form.Shortcode, emojiID, emojiURI, nil)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error processing emoji: %s", err), "error processing emoji")
 	}

internal/processing/media/create.go

@@ -40,7 +40,7 @@ func (p *processor) Create(ctx context.Context, account *gtsmodel.Account, form
 	}
 
 	// process the media attachment and load it immediately
-	media, err := p.mediaManager.ProcessMedia(ctx, data, account.ID, &media.AdditionalMediaInfo{
+	media, err := p.mediaManager.ProcessMedia(ctx, data, nil, account.ID, &media.AdditionalMediaInfo{
 		Description: &form.Description,
 		FocusX:      &focusX,
 		FocusY:      &focusY,