Files
postmoogle/vendor/go.mau.fi/util/dbutil/upgrades.go
2024-02-11 20:47:04 +02:00

208 lines
6.3 KiB
Go

// Copyright (c) 2023 Tulir Asokan
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
package dbutil
import (
"context"
"database/sql"
"errors"
"fmt"
)
type upgradeFunc func(context.Context, *Database) error
type upgrade struct {
message string
fn upgradeFunc
upgradesTo int
compatVersion int
transaction bool
}
var ErrUnsupportedDatabaseVersion = errors.New("unsupported database schema version")
var ErrForeignTables = errors.New("the database contains foreign tables")
var ErrNotOwned = errors.New("the database is owned by")
var ErrUnsupportedDialect = errors.New("unsupported database dialect")
func (db *Database) upgradeVersionTable(ctx context.Context) error {
if compatColumnExists, err := db.ColumnExists(ctx, db.VersionTable, "compat"); err != nil {
return fmt.Errorf("failed to check if version table is up to date: %w", err)
} else if !compatColumnExists {
if tableExists, err := db.TableExists(ctx, db.VersionTable); err != nil {
return fmt.Errorf("failed to check if version table exists: %w", err)
} else if !tableExists {
_, err = db.Exec(ctx, fmt.Sprintf("CREATE TABLE %s (version INTEGER, compat INTEGER)", db.VersionTable))
if err != nil {
return fmt.Errorf("failed to create version table: %w", err)
}
} else {
_, err = db.Exec(ctx, fmt.Sprintf("ALTER TABLE %s ADD COLUMN compat INTEGER", db.VersionTable))
if err != nil {
return fmt.Errorf("failed to add compat column to version table: %w", err)
}
}
}
return nil
}
func (db *Database) getVersion(ctx context.Context) (version, compat int, err error) {
if err = db.upgradeVersionTable(ctx); err != nil {
return
}
var compatNull sql.NullInt32
err = db.QueryRow(ctx, fmt.Sprintf("SELECT version, compat FROM %s LIMIT 1", db.VersionTable)).Scan(&version, &compatNull)
if errors.Is(err, sql.ErrNoRows) {
err = nil
}
if compatNull.Valid && compatNull.Int32 != 0 {
compat = int(compatNull.Int32)
} else {
compat = version
}
return
}
const (
tableExistsPostgres = "SELECT EXISTS(SELECT 1 FROM information_schema.tables WHERE table_name=$1)"
tableExistsSQLite = "SELECT EXISTS(SELECT 1 FROM sqlite_master WHERE type='table' AND tbl_name=?1)"
)
func (db *Database) TableExists(ctx context.Context, table string) (exists bool, err error) {
switch db.Dialect {
case SQLite:
err = db.QueryRow(ctx, tableExistsSQLite, table).Scan(&exists)
case Postgres:
err = db.QueryRow(ctx, tableExistsPostgres, table).Scan(&exists)
default:
err = ErrUnsupportedDialect
}
return
}
const (
columnExistsPostgres = "SELECT EXISTS(SELECT 1 FROM information_schema.columns WHERE table_name=$1 AND column_name=$2)"
columnExistsSQLite = "SELECT EXISTS(SELECT 1 FROM pragma_table_info(?1) WHERE name=?2)"
)
func (db *Database) ColumnExists(ctx context.Context, table, column string) (exists bool, err error) {
switch db.Dialect {
case SQLite:
err = db.QueryRow(ctx, columnExistsSQLite, table, column).Scan(&exists)
case Postgres:
err = db.QueryRow(ctx, columnExistsPostgres, table, column).Scan(&exists)
default:
err = ErrUnsupportedDialect
}
return
}
func (db *Database) tableExistsNoError(ctx context.Context, table string) bool {
exists, err := db.TableExists(ctx, table)
if err != nil {
panic(fmt.Errorf("failed to check if table exists: %w", err))
}
return exists
}
const createOwnerTable = `
CREATE TABLE IF NOT EXISTS database_owner (
key INTEGER PRIMARY KEY DEFAULT 0,
owner TEXT NOT NULL
)
`
func (db *Database) checkDatabaseOwner(ctx context.Context) error {
var owner string
if !db.IgnoreForeignTables {
if db.tableExistsNoError(ctx, "state_groups_state") {
return fmt.Errorf("%w (found state_groups_state, likely belonging to Synapse)", ErrForeignTables)
} else if db.tableExistsNoError(ctx, "roomserver_rooms") {
return fmt.Errorf("%w (found roomserver_rooms, likely belonging to Dendrite)", ErrForeignTables)
}
}
if db.Owner == "" {
return nil
}
if _, err := db.Exec(ctx, createOwnerTable); err != nil {
return fmt.Errorf("failed to ensure database owner table exists: %w", err)
} else if err = db.QueryRow(ctx, "SELECT owner FROM database_owner WHERE key=0").Scan(&owner); errors.Is(err, sql.ErrNoRows) {
_, err = db.Exec(ctx, "INSERT INTO database_owner (key, owner) VALUES (0, $1)", db.Owner)
if err != nil {
return fmt.Errorf("failed to insert database owner: %w", err)
}
} else if err != nil {
return fmt.Errorf("failed to check database owner: %w", err)
} else if owner != db.Owner {
return fmt.Errorf("%w %s", ErrNotOwned, owner)
}
return nil
}
func (db *Database) setVersion(ctx context.Context, version, compat int) error {
_, err := db.Exec(ctx, fmt.Sprintf("DELETE FROM %s", db.VersionTable))
if err != nil {
return err
}
_, err = db.Exec(ctx, fmt.Sprintf("INSERT INTO %s (version, compat) VALUES ($1, $2)", db.VersionTable), version, compat)
return err
}
func (db *Database) Upgrade(ctx context.Context) error {
err := db.checkDatabaseOwner(ctx)
if err != nil {
return err
}
version, compat, err := db.getVersion(ctx)
if err != nil {
return err
}
if compat > len(db.UpgradeTable) {
if db.IgnoreUnsupportedDatabase {
db.Log.WarnUnsupportedVersion(version, compat, len(db.UpgradeTable))
return nil
}
return fmt.Errorf("%w: currently on v%d (compatible down to v%d), latest known: v%d", ErrUnsupportedDatabaseVersion, version, compat, len(db.UpgradeTable))
}
db.Log.PrepareUpgrade(version, compat, len(db.UpgradeTable))
logVersion := version
for version < len(db.UpgradeTable) {
upgradeItem := db.UpgradeTable[version]
if upgradeItem.fn == nil {
version++
continue
}
doUpgrade := func(ctx context.Context) error {
err = upgradeItem.fn(ctx, db)
if err != nil {
return fmt.Errorf("failed to run upgrade #%d: %w", version, err)
}
version = upgradeItem.upgradesTo
logVersion = version
err = db.setVersion(ctx, version, upgradeItem.compatVersion)
if err != nil {
return err
}
return nil
}
db.Log.DoUpgrade(logVersion, upgradeItem.upgradesTo, upgradeItem.message, upgradeItem.transaction)
if upgradeItem.transaction {
err = db.DoTxn(ctx, nil, doUpgrade)
} else {
err = doUpgrade(ctx)
}
if err != nil {
return err
}
}
return nil
}