gotosocial/internal/media/media.go

258 lines
7.1 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 (
"context"
"fmt"
"sync"
"time"
"codeberg.org/gruf/go-store/kv"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
)
type processState int
const (
received processState = iota // processing order has been received but not done yet
complete // processing order has been completed successfully
errored // processing order has been completed with an error
)
type Media 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 // will only be set if the media is an attachment
emoji *gtsmodel.Emoji // will only be set if the media is an emoji
rawData []byte
/*
below fields represent the processing state of the media thumbnail
*/
thumbstate processState
thumb *ImageMeta
/*
below fields represent the processing state of the full-sized media
*/
fullSizeState processState
fullSize *ImageMeta
/*
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
}
func (m *Media) Thumb(ctx context.Context) (*ImageMeta, error) {
m.mu.Lock()
defer m.mu.Unlock()
switch m.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 m.attachment.Blurhash == "" {
// no blurhash created yet
createBlurhash = true
}
thumb, err := deriveThumbnail(m.rawData, m.attachment.File.ContentType, createBlurhash)
if err != nil {
m.err = fmt.Errorf("error deriving thumbnail: %s", err)
m.thumbstate = errored
return nil, m.err
}
// put the thumbnail in storage
if err := m.storage.Put(m.attachment.Thumbnail.Path, thumb.image); err != nil {
m.err = fmt.Errorf("error storing thumbnail: %s", err)
m.thumbstate = errored
return nil, m.err
}
// set appropriate fields on the attachment based on the thumbnail we derived
if createBlurhash {
m.attachment.Blurhash = thumb.blurhash
}
m.attachment.FileMeta.Small = gtsmodel.Small{
Width: thumb.width,
Height: thumb.height,
Size: thumb.size,
Aspect: thumb.aspect,
}
m.attachment.Thumbnail.FileSize = thumb.size
if err := putOrUpdateAttachment(ctx, m.database, m.attachment); err != nil {
m.err = err
m.thumbstate = errored
return nil, err
}
// set the thumbnail of this media
m.thumb = thumb
// we're done processing the thumbnail!
m.thumbstate = complete
fallthrough
case complete:
return m.thumb, nil
case errored:
return nil, m.err
}
return nil, fmt.Errorf("thumbnail processing status %d unknown", m.thumbstate)
}
func (m *Media) FullSize(ctx context.Context) (*ImageMeta, error) {
m.mu.Lock()
defer m.mu.Unlock()
switch m.fullSizeState {
case received:
var clean []byte
var err error
var decoded *ImageMeta
ct := m.attachment.File.ContentType
switch ct {
case mimeImageJpeg, mimeImagePng:
// first 'clean' image by purging exif data from it
var exifErr error
if clean, exifErr = purgeExif(m.rawData); exifErr != nil {
err = exifErr
break
}
decoded, err = decodeImage(clean, ct)
case mimeImageGif:
// gifs are already clean - no exif data to remove
clean = m.rawData
decoded, err = decodeGif(clean)
default:
err = fmt.Errorf("content type %s not a processible image type", ct)
}
if err != nil {
m.err = err
m.fullSizeState = errored
return nil, err
}
// put the full size in storage
if err := m.storage.Put(m.attachment.File.Path, decoded.image); err != nil {
m.err = fmt.Errorf("error storing full size image: %s", err)
m.fullSizeState = errored
return nil, m.err
}
// set appropriate fields on the attachment based on the image we derived
m.attachment.FileMeta.Original = gtsmodel.Original{
Width: decoded.width,
Height: decoded.height,
Size: decoded.size,
Aspect: decoded.aspect,
}
m.attachment.File.FileSize = decoded.size
m.attachment.File.UpdatedAt = time.Now()
m.attachment.Processing = gtsmodel.ProcessingStatusProcessed
if err := putOrUpdateAttachment(ctx, m.database, m.attachment); err != nil {
m.err = err
m.fullSizeState = errored
return nil, err
}
// set the fullsize of this media
m.fullSize = decoded
// we're done processing the full-size image
m.fullSizeState = complete
fallthrough
case complete:
return m.fullSize, nil
case errored:
return nil, m.err
}
return nil, fmt.Errorf("full size processing status %d unknown", m.fullSizeState)
}
// AttachmentID returns the ID of the underlying media attachment without blocking processing.
func (m *Media) AttachmentID() string {
return m.attachment.ID
}
// preLoad begins the process of deriving the thumbnail and encoding the full-size image.
// It does this in a non-blocking way, so you can call it and then come back later and check
// if it's finished.
func (m *Media) preLoad(ctx context.Context) {
go m.Thumb(ctx)
go m.FullSize(ctx)
}
// Load is the blocking equivalent of pre-load. It makes sure the thumbnail and full-size
// image have been processed, then it returns the completed attachment.
func (m *Media) LoadAttachment(ctx context.Context) (*gtsmodel.MediaAttachment, error) {
if _, err := m.Thumb(ctx); err != nil {
return nil, err
}
if _, err := m.FullSize(ctx); err != nil {
return nil, err
}
return m.attachment, nil
}
func (m *Media) LoadEmoji(ctx context.Context) (*gtsmodel.Emoji, error) {
return nil, nil
}
// putOrUpdateAttachment is just a convenience function for first trying to PUT the attachment in the database,
// and then if that doesn't work because the attachment already exists, updating it instead.
func putOrUpdateAttachment(ctx context.Context, database db.DB, attachment *gtsmodel.MediaAttachment) error {
if err := database.Put(ctx, attachment); err != nil {
if err != db.ErrAlreadyExists {
return fmt.Errorf("putOrUpdateAttachment: proper error while putting attachment: %s", err)
}
if err := database.UpdateByPrimaryKey(ctx, attachment); err != nil {
return fmt.Errorf("putOrUpdateAttachment: error while updating attachment: %s", err)
}
}
return nil
}