gotosocial/internal/media/processingmedia.go
2022-01-23 14:41:58 +01:00

410 lines
12 KiB
Go

/*
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 media
import (
"bytes"
"context"
"fmt"
"io"
"strings"
"sync"
"time"
"codeberg.org/gruf/go-store/kv"
terminator "github.com/superseriousbusiness/exif-terminator"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/id"
"github.com/superseriousbusiness/gotosocial/internal/uris"
)
// ProcessingMedia represents a piece of media that is currently being processed. It exposes
// various functions for retrieving data from the process.
type ProcessingMedia struct {
mu sync.Mutex
/*
below fields should be set on newly created media;
attachment will be updated incrementally as media goes through processing
*/
attachment *gtsmodel.MediaAttachment
data DataFunc
read bool // bool indicating that data function has been triggered already
thumbstate processState // the processing state of the media thumbnail
fullSizeState processState // the processing state of the full-sized media
/*
below pointers to database and storage are maintained so that
the media can store and update itself during processing steps
*/
database db.DB
storage *kv.KVStore
err error // error created during processing, if any
// track whether this media has already been put in the databse
insertedInDB bool
}
// AttachmentID returns the ID of the underlying media attachment without blocking processing.
func (p *ProcessingMedia) AttachmentID() string {
return p.attachment.ID
}
// LoadAttachment blocks until the thumbnail and fullsize content
// has been processed, and then returns the completed attachment.
func (p *ProcessingMedia) LoadAttachment(ctx context.Context) (*gtsmodel.MediaAttachment, error) {
p.mu.Lock()
defer p.mu.Unlock()
if err := p.store(ctx); err != nil {
return nil, err
}
if err := p.loadThumb(ctx); err != nil {
return nil, err
}
if err := p.loadFullSize(ctx); err != nil {
return nil, err
}
// store the result in the database before returning it
if !p.insertedInDB {
if err := p.database.Put(ctx, p.attachment); err != nil {
return nil, err
}
p.insertedInDB = true
}
return p.attachment, nil
}
// Finished returns true if processing has finished for both the thumbnail
// and full fized version of this piece of media.
func (p *ProcessingMedia) Finished() bool {
return p.thumbstate == complete && p.fullSizeState == complete
}
func (p *ProcessingMedia) loadThumb(ctx context.Context) error {
switch p.thumbstate {
case received:
// we haven't processed a thumbnail for this media yet so do it now
// check if we need to create a blurhash or if there's already one set
var createBlurhash bool
if p.attachment.Blurhash == "" {
// no blurhash created yet
createBlurhash = true
}
// stream the original file out of storage...
stored, err := p.storage.GetStream(p.attachment.File.Path)
if err != nil {
p.err = fmt.Errorf("loadThumb: error fetching file from storage: %s", err)
p.thumbstate = errored
return p.err
}
// ... and into the derive thumbnail function
thumb, err := deriveThumbnail(stored, p.attachment.File.ContentType, createBlurhash)
if err != nil {
p.err = fmt.Errorf("loadThumb: error deriving thumbnail: %s", err)
p.thumbstate = errored
return p.err
}
if err := stored.Close(); err != nil {
p.err = fmt.Errorf("loadThumb: error closing stored full size: %s", err)
p.thumbstate = errored
return p.err
}
// put the thumbnail in storage
if err := p.storage.Put(p.attachment.Thumbnail.Path, thumb.small); err != nil {
p.err = fmt.Errorf("loadThumb: error storing thumbnail: %s", err)
p.thumbstate = errored
return p.err
}
// set appropriate fields on the attachment based on the thumbnail we derived
if createBlurhash {
p.attachment.Blurhash = thumb.blurhash
}
p.attachment.FileMeta.Small = gtsmodel.Small{
Width: thumb.width,
Height: thumb.height,
Size: thumb.size,
Aspect: thumb.aspect,
}
p.attachment.Thumbnail.FileSize = len(thumb.small)
// we're done processing the thumbnail!
p.thumbstate = complete
fallthrough
case complete:
return nil
case errored:
return p.err
}
return fmt.Errorf("loadThumb: thumbnail processing status %d unknown", p.thumbstate)
}
func (p *ProcessingMedia) loadFullSize(ctx context.Context) error {
switch p.fullSizeState {
case received:
var err error
var decoded *imageMeta
// stream the original file out of storage...
stored, err := p.storage.GetStream(p.attachment.File.Path)
if err != nil {
p.err = fmt.Errorf("loadFullSize: error fetching file from storage: %s", err)
p.fullSizeState = errored
return p.err
}
// decode the image
ct := p.attachment.File.ContentType
switch ct {
case mimeImageJpeg, mimeImagePng:
decoded, err = decodeImage(stored, ct)
case mimeImageGif:
decoded, err = decodeGif(stored)
default:
err = fmt.Errorf("loadFullSize: content type %s not a processible image type", ct)
}
if err != nil {
p.err = err
p.fullSizeState = errored
return p.err
}
if err := stored.Close(); err != nil {
p.err = fmt.Errorf("loadFullSize: error closing stored full size: %s", err)
p.thumbstate = errored
return p.err
}
// set appropriate fields on the attachment based on the image we derived
p.attachment.FileMeta.Original = gtsmodel.Original{
Width: decoded.width,
Height: decoded.height,
Size: decoded.size,
Aspect: decoded.aspect,
}
p.attachment.File.UpdatedAt = time.Now()
p.attachment.Processing = gtsmodel.ProcessingStatusProcessed
// we're done processing the full-size image
p.fullSizeState = complete
fallthrough
case complete:
return nil
case errored:
return p.err
}
return fmt.Errorf("loadFullSize: full size processing status %d unknown", p.fullSizeState)
}
// store calls the data function attached to p if it hasn't been called yet,
// and updates the underlying attachment fields as necessary. It will then stream
// bytes from p's reader directly into storage so that it can be retrieved later.
func (p *ProcessingMedia) store(ctx context.Context) error {
// check if we've already done this and bail early if we have
if p.read {
return nil
}
// execute the data function to get the reader out of it
reader, fileSize, err := p.data(ctx)
if err != nil {
return fmt.Errorf("store: error executing data function: %s", err)
}
// extract no more than 261 bytes from the beginning of the file -- this is the header
firstBytes := make([]byte, maxFileHeaderBytes)
if _, err := reader.Read(firstBytes); err != nil {
return fmt.Errorf("store: error reading initial %d bytes: %s", maxFileHeaderBytes, err)
}
// now we have the file header we can work out the content type from it
contentType, err := parseContentType(firstBytes)
if err != nil {
return fmt.Errorf("store: error parsing content type: %s", err)
}
// bail if this is a type we can't process
if !supportedImage(contentType) {
return fmt.Errorf("store: media type %s not (yet) supported", contentType)
}
// extract the file extension
split := strings.Split(contentType, "/")
if len(split) != 2 {
return fmt.Errorf("store: content type %s was not valid", contentType)
}
extension := split[1] // something like 'jpeg'
// concatenate the cleaned up first bytes with the existing bytes still in the reader (thanks Mara)
multiReader := io.MultiReader(bytes.NewBuffer(firstBytes), reader)
// we'll need to clean exif data from the first bytes; while we're
// here, we can also use the extension to derive the attachment type
var clean io.Reader
switch extension {
case mimeGif:
p.attachment.Type = gtsmodel.FileTypeGif
clean = multiReader // nothing to clean from a gif
case mimeJpeg, mimePng:
p.attachment.Type = gtsmodel.FileTypeImage
purged, err := terminator.Terminate(multiReader, fileSize, extension)
if err != nil {
return fmt.Errorf("store: exif error: %s", err)
}
clean = purged
default:
return fmt.Errorf("store: couldn't process %s", extension)
}
// now set some additional fields on the attachment since
// we know more about what the underlying media actually is
p.attachment.URL = uris.GenerateURIForAttachment(p.attachment.AccountID, string(TypeAttachment), string(SizeOriginal), p.attachment.ID, extension)
p.attachment.File.Path = fmt.Sprintf("%s/%s/%s/%s.%s", p.attachment.AccountID, TypeAttachment, SizeOriginal, p.attachment.ID, extension)
p.attachment.File.ContentType = contentType
p.attachment.File.FileSize = fileSize
// store this for now -- other processes can pull it out of storage as they please
if err := p.storage.PutStream(p.attachment.File.Path, clean); err != nil {
return fmt.Errorf("store: error storing stream: %s", err)
}
// if the original reader is a readcloser, close it since we're done with it now
if rc, ok := reader.(io.ReadCloser); ok {
if err := rc.Close(); err != nil {
return fmt.Errorf("store: error closing readcloser: %s", err)
}
}
p.read = true
return nil
}
func (m *manager) preProcessMedia(ctx context.Context, data DataFunc, accountID string, ai *AdditionalMediaInfo) (*ProcessingMedia, error) {
id, err := id.NewRandomULID()
if err != nil {
return nil, err
}
file := gtsmodel.File{
Path: "", // we don't know yet because it depends on the uncalled DataFunc
ContentType: "", // we don't know yet because it depends on the uncalled DataFunc
UpdatedAt: time.Now(),
}
thumbnail := gtsmodel.Thumbnail{
URL: uris.GenerateURIForAttachment(accountID, string(TypeAttachment), string(SizeSmall), id, mimeJpeg), // all thumbnails are encoded as jpeg,
Path: fmt.Sprintf("%s/%s/%s/%s.%s", accountID, TypeAttachment, SizeSmall, id, mimeJpeg), // all thumbnails are encoded as jpeg,
ContentType: mimeJpeg,
UpdatedAt: time.Now(),
}
// populate initial fields on the media attachment -- some of these will be overwritten as we proceed
attachment := &gtsmodel.MediaAttachment{
ID: id,
CreatedAt: time.Now(),
UpdatedAt: time.Now(),
StatusID: "",
URL: "", // we don't know yet because it depends on the uncalled DataFunc
RemoteURL: "",
Type: gtsmodel.FileTypeUnknown, // we don't know yet because it depends on the uncalled DataFunc
FileMeta: gtsmodel.FileMeta{},
AccountID: accountID,
Description: "",
ScheduledStatusID: "",
Blurhash: "",
Processing: gtsmodel.ProcessingStatusReceived,
File: file,
Thumbnail: thumbnail,
Avatar: false,
Header: false,
}
// check if we have additional info to add to the attachment,
// and overwrite some of the attachment fields if so
if ai != nil {
if ai.CreatedAt != nil {
attachment.CreatedAt = *ai.CreatedAt
}
if ai.StatusID != nil {
attachment.StatusID = *ai.StatusID
}
if ai.RemoteURL != nil {
attachment.RemoteURL = *ai.RemoteURL
}
if ai.Description != nil {
attachment.Description = *ai.Description
}
if ai.ScheduledStatusID != nil {
attachment.ScheduledStatusID = *ai.ScheduledStatusID
}
if ai.Blurhash != nil {
attachment.Blurhash = *ai.Blurhash
}
if ai.Avatar != nil {
attachment.Avatar = *ai.Avatar
}
if ai.Header != nil {
attachment.Header = *ai.Header
}
if ai.FocusX != nil {
attachment.FileMeta.Focus.X = *ai.FocusX
}
if ai.FocusY != nil {
attachment.FileMeta.Focus.Y = *ai.FocusY
}
}
processingMedia := &ProcessingMedia{
attachment: attachment,
data: data,
thumbstate: received,
fullSizeState: received,
database: m.db,
storage: m.storage,
}
return processingMedia, nil
}