gotosocial/internal/media/manager.go
2021-12-28 16:36:00 +01:00

275 lines
10 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"
"errors"
"fmt"
"net/url"
"strings"
"time"
"codeberg.org/gruf/go-store/kv"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
"github.com/superseriousbusiness/gotosocial/internal/id"
"github.com/superseriousbusiness/gotosocial/internal/transport"
"github.com/superseriousbusiness/gotosocial/internal/uris"
)
// ProcessCallback is triggered by the media manager when an attachment has finished undergoing
// image processing (generation of a blurhash, thumbnail etc) but hasn't yet been inserted into
// the database. It is provided to allow callers to a) access the processed media attachment and b)
// make any last-minute changes to the media attachment before it enters the database.
type ProcessCallback func(*gtsmodel.MediaAttachment) *gtsmodel.MediaAttachment
// defaultCB will be used when a nil ProcessCallback is passed to one of the manager's interface functions.
// It just returns the processed media attachment with no additional changes.
var defaultCB ProcessCallback = func(a *gtsmodel.MediaAttachment) *gtsmodel.MediaAttachment {
return a
}
// Manager provides an interface for managing media: parsing, storing, and retrieving media objects like photos, videos, and gifs.
type Manager interface {
ProcessAttachment(ctx context.Context, data []byte, accountID string, cb ProcessCallback) (*gtsmodel.MediaAttachment, error)
}
type manager struct {
db db.DB
storage *kv.KVStore
}
// New returns a media manager with the given db and underlying storage.
func New(database db.DB, storage *kv.KVStore) Manager {
return &manager{
db: database,
storage: storage,
}
}
/*
INTERFACE FUNCTIONS
*/
func (m *manager) ProcessAttachment(ctx context.Context, data []byte, accountID string, cb ProcessCallback) (*gtsmodel.MediaAttachment, error) {
contentType, err := parseContentType(data)
if err != nil {
return nil, err
}
mainType := strings.Split(contentType, "/")[0]
switch mainType {
case mimeImage:
if !supportedImage(contentType) {
return nil, fmt.Errorf("image type %s not supported", contentType)
}
if len(data) == 0 {
return nil, errors.New("image was of size 0")
}
return m.processImage(attachmentBytes, minAttachment)
default:
return nil, fmt.Errorf("content type %s not (yet) supported", contentType)
}
}
// ProcessHeaderOrAvatar takes a new header image for an account, checks it out, removes exif data from it,
// puts it in whatever storage backend we're using, sets the relevant fields in the database for the new image,
// and then returns information to the caller about the new header.
func (m *manager) ProcessHeader(ctx context.Context, data []byte, accountID string, cb ProcessCallback) (*gtsmodel.MediaAttachment, error) {
// make sure we have a type we can handle
contentType, err := parseContentType(data)
if err != nil {
return nil, err
}
if !supportedImage(contentType) {
return nil, fmt.Errorf("%s is not an accepted image type", contentType)
}
if len(data) == 0 {
return nil, fmt.Errorf("passed reader was of size 0")
}
// process it
ma, err := m.processHeaderOrAvi(attachment, contentType, mediaType, accountID, remoteURL)
if err != nil {
return nil, fmt.Errorf("error processing %s: %s", mediaType, err)
}
// set it in the database
if err := m.db.SetAccountHeaderOrAvatar(ctx, ma, accountID); err != nil {
return nil, fmt.Errorf("error putting %s in database: %s", mediaType, err)
}
return ma, nil
}
// ProcessLocalEmoji takes a new emoji and a shortcode, cleans it up, puts it in storage, and creates a new
// *gts.Emoji for it, then returns it to the caller. It's the caller's responsibility to put the returned struct
// in the database.
func (m *manager) ProcessLocalEmoji(ctx context.Context, emojiBytes []byte, shortcode string) (*gtsmodel.Emoji, error) {
var clean []byte
var err error
var original *imageAndMeta
var static *imageAndMeta
// check content type of the submitted emoji and make sure it's supported by us
contentType, err := parseContentType(emojiBytes)
if err != nil {
return nil, err
}
if !supportedEmoji(contentType) {
return nil, fmt.Errorf("content type %s not supported for emojis", contentType)
}
if len(emojiBytes) == 0 {
return nil, errors.New("emoji was of size 0")
}
if len(emojiBytes) > EmojiMaxBytes {
return nil, fmt.Errorf("emoji size %d bytes exceeded max emoji size of %d bytes", len(emojiBytes), EmojiMaxBytes)
}
// clean any exif data from png but leave gifs alone
switch contentType {
case mimePng:
if clean, err = purgeExif(emojiBytes); err != nil {
return nil, fmt.Errorf("error cleaning exif data: %s", err)
}
case mimeGif:
clean = emojiBytes
default:
return nil, errors.New("media type unrecognized")
}
// unlike with other attachments we don't need to derive anything here because we don't care about the width/height etc
original = &imageAndMeta{
image: clean,
}
static, err = deriveStaticEmoji(clean, contentType)
if err != nil {
return nil, fmt.Errorf("error deriving static emoji: %s", err)
}
// since emoji aren't 'owned' by an account, but we still want to use the same pattern for serving them through the filserver,
// (ie., fileserver/ACCOUNT_ID/etc etc) we need to fetch the INSTANCE ACCOUNT from the database. That is, the account that's created
// with the same username as the instance hostname, which doesn't belong to any particular user.
instanceAccount, err := m.db.GetInstanceAccount(ctx, "")
if err != nil {
return nil, fmt.Errorf("error fetching instance account: %s", err)
}
// the file extension (either png or gif)
extension := strings.Split(contentType, "/")[1]
// generate a ulid for the new emoji
newEmojiID, err := id.NewRandomULID()
if err != nil {
return nil, err
}
// activitypub uri for the emoji -- unrelated to actually serving the image
// will be something like https://example.org/emoji/01FPSVBK3H8N7V8XK6KGSQ86EC
emojiURI := uris.GenerateURIForEmoji(newEmojiID)
// serve url and storage path for the original emoji -- can be png or gif
emojiURL := uris.GenerateURIForAttachment(instanceAccount.ID, string(TypeEmoji), string(SizeOriginal), newEmojiID, extension)
emojiPath := fmt.Sprintf("%s/%s/%s/%s.%s", instanceAccount.ID, TypeEmoji, SizeOriginal, newEmojiID, extension)
// serve url and storage path for the static version -- will always be png
emojiStaticURL := uris.GenerateURIForAttachment(instanceAccount.ID, string(TypeEmoji), string(SizeStatic), newEmojiID, "png")
emojiStaticPath := fmt.Sprintf("%s/%s/%s/%s.png", instanceAccount.ID, TypeEmoji, SizeStatic, newEmojiID)
// Store the original emoji
if err := m.storage.Put(emojiPath, original.image); err != nil {
return nil, fmt.Errorf("storage error: %s", err)
}
// Store the static emoji
if err := m.storage.Put(emojiStaticPath, static.image); err != nil {
return nil, fmt.Errorf("storage error: %s", err)
}
// and finally return the new emoji data to the caller -- it's up to them what to do with it
e := &gtsmodel.Emoji{
ID: newEmojiID,
Shortcode: shortcode,
Domain: "", // empty because this is a local emoji
CreatedAt: time.Now(),
UpdatedAt: time.Now(),
ImageRemoteURL: "", // empty because this is a local emoji
ImageStaticRemoteURL: "", // empty because this is a local emoji
ImageURL: emojiURL,
ImageStaticURL: emojiStaticURL,
ImagePath: emojiPath,
ImageStaticPath: emojiStaticPath,
ImageContentType: contentType,
ImageStaticContentType: mimePng, // static version will always be a png
ImageFileSize: len(original.image),
ImageStaticFileSize: len(static.image),
ImageUpdatedAt: time.Now(),
Disabled: false,
URI: emojiURI,
VisibleInPicker: true,
CategoryID: "", // empty because this is a new emoji -- no category yet
}
return e, nil
}
func (m *manager) ProcessRemoteHeaderOrAvatar(ctx context.Context, t transport.Transport, currentAttachment *gtsmodel.MediaAttachment, accountID string) (*gtsmodel.MediaAttachment, error) {
if !currentAttachment.Header && !currentAttachment.Avatar {
return nil, errors.New("provided attachment was set to neither header nor avatar")
}
if currentAttachment.Header && currentAttachment.Avatar {
return nil, errors.New("provided attachment was set to both header and avatar")
}
var headerOrAvi Type
if currentAttachment.Header {
headerOrAvi = TypeHeader
} else if currentAttachment.Avatar {
headerOrAvi = TypeAvatar
}
if currentAttachment.RemoteURL == "" {
return nil, errors.New("no remote URL on media attachment to dereference")
}
remoteIRI, err := url.Parse(currentAttachment.RemoteURL)
if err != nil {
return nil, fmt.Errorf("error parsing attachment url %s: %s", currentAttachment.RemoteURL, err)
}
// for content type, we assume we don't know what to expect...
expectedContentType := "*/*"
if currentAttachment.File.ContentType != "" {
// ... and then narrow it down if we do
expectedContentType = currentAttachment.File.ContentType
}
attachmentBytes, err := t.DereferenceMedia(ctx, remoteIRI, expectedContentType)
if err != nil {
return nil, fmt.Errorf("dereferencing remote media with url %s: %s", remoteIRI.String(), err)
}
return m.ProcessHeaderOrAvatar(ctx, attachmentBytes, accountID, headerOrAvi, currentAttachment.RemoteURL)
}