Database updates (#144)

* start moving some database stuff around

* continue moving db stuff around

* more fiddling

* more updates

* and some more

* and yet more

* i broke SOMETHING but what, it's a mystery

* tidy up

* vendor ttlcache

* use ttlcache

* fix up some tests

* rename some stuff

* little reminder

* some more updates

internal/db/pg/media.go

@@ -0,0 +1,53 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 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 pg
+
+import (
+	"context"
+
+	"github.com/go-pg/pg/v10"
+	"github.com/go-pg/pg/v10/orm"
+	"github.com/sirupsen/logrus"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+type mediaDB struct {
+	config *config.Config
+	conn   *pg.DB
+	log    *logrus.Logger
+	cancel context.CancelFunc
+}
+
+func (m *mediaDB) newMediaQ(i interface{}) *orm.Query {
+	return m.conn.Model(i).
+		Relation("Account")
+}
+
+func (m *mediaDB) GetAttachmentByID(id string) (*gtsmodel.MediaAttachment, db.Error) {
+	attachment := &gtsmodel.MediaAttachment{}
+
+	q := m.newMediaQ(attachment).
+		Where("media_attachment.id = ?", id)
+
+	err := processErrorResponse(q.Select())
+
+	return attachment, err
+}