[feature] Custom emoji updates (serve emoji via s2s api, tune db models) (#805)

* migrate emojis

* add get emoji to s2s (federation) API

* add new emoji db + cache functions

* add shortcodeDomain lookup for emojis

* check existing emojis w/cache, not w/constraints

* go fmt

* add putEmoji func

* use new db emoji funcs instead of where

* remove emojistringstotags func

* add unique constraint back in

* fix up broken migration

* update index

internal/db/bundb/migrations/20220905150505_custom_emoji_updates.go

@@ -0,0 +1,111 @@
+/*
+   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 migrations
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/superseriousbusiness/gotosocial/internal/db/bundb/migrations/20220905150505_custom_emoji_updates"
+	"github.com/uptrace/bun"
+)
+
+func init() {
+	up := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			// create the new emojis table
+			if _, err := tx.
+				NewCreateTable().
+				Model(&gtsmodel.Emoji{}).
+				ModelTableExpr("new_emojis").
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			// move all old emojis to the new table
+			currentEmojis := []*gtsmodel.Emoji{}
+			if err := tx.
+				NewSelect().
+				Model(&currentEmojis).
+				Scan(ctx); err != nil && err != sql.ErrNoRows {
+				return err
+			}
+
+			for _, currentEmoji := range currentEmojis {
+				if _, err := tx.
+					NewInsert().
+					Model(currentEmoji).
+					ModelTableExpr("new_emojis").
+					Exec(ctx); err != nil {
+					return err
+				}
+			}
+
+			// we have all the data we need from the old table, so we can safely drop it now
+			if _, err := tx.NewDropTable().Model(&gtsmodel.Emoji{}).Exec(ctx); err != nil {
+				return err
+			}
+
+			// rename the new table to the same name as the old table was
+			if _, err := tx.ExecContext(ctx, "ALTER TABLE new_emojis RENAME TO emojis;"); err != nil {
+				return err
+			}
+
+			// add indexes to the new table
+			if _, err := tx.
+				NewCreateIndex().
+				Model(&gtsmodel.Emoji{}).
+				Index("emojis_id_idx").
+				Column("id").
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			if _, err := tx.
+				NewCreateIndex().
+				Model(&gtsmodel.Emoji{}).
+				Index("emojis_uri_idx").
+				Column("uri").
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			if _, err := tx.
+				NewCreateIndex().
+				Model(&gtsmodel.Emoji{}).
+				Index("emojis_available_custom_idx").
+				Column("visible_in_picker", "disabled", "shortcode").
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			return nil
+		})
+	}
+
+	down := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			return nil
+		})
+	}
+
+	if err := Migrations.Register(up, down); err != nil {
+		panic(err)
+	}
+}