gotosocial/internal/db/bundb/conn.go

114 lines
3.2 KiB
Go

/*
GoToSocial
Copyright (C) 2021-2023 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 bundb
import (
"context"
"database/sql"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/uptrace/bun"
"github.com/uptrace/bun/dialect"
)
// DBConn wrapps a bun.DB conn to provide SQL-type specific additional functionality
type DBConn struct {
errProc func(error) db.Error // errProc is the SQL-type specific error processor
*bun.DB // DB is the underlying bun.DB connection
}
// WrapDBConn wraps a bun DB connection to provide our own error processing dependent on DB dialect.
func WrapDBConn(dbConn *bun.DB) *DBConn {
var errProc func(error) db.Error
switch dbConn.Dialect().Name() {
case dialect.PG:
errProc = processPostgresError
case dialect.SQLite:
errProc = processSQLiteError
default:
panic("unknown dialect name: " + dbConn.Dialect().Name().String())
}
return &DBConn{
errProc: errProc,
DB: dbConn,
}
}
// RunInTx wraps execution of the supplied transaction function.
func (conn *DBConn) RunInTx(ctx context.Context, fn func(bun.Tx) error) db.Error {
return conn.ProcessError(func() error {
// Acquire a new transaction
tx, err := conn.BeginTx(ctx, nil)
if err != nil {
return err
}
var done bool
defer func() {
if !done {
_ = tx.Rollback()
}
}()
// Perform supplied transaction
if err := fn(tx); err != nil {
return err
}
// Finally, commit
err = tx.Commit() //nolint:contextcheck
done = true
return err
}())
}
// ProcessError processes an error to replace any known values with our own db.Error types,
// making it easier to catch specific situations (e.g. no rows, already exists, etc)
func (conn *DBConn) ProcessError(err error) db.Error {
switch {
case err == nil:
return nil
case err == sql.ErrNoRows:
return db.ErrNoEntries
default:
return conn.errProc(err)
}
}
// Exists checks the results of a SelectQuery for the existence of the data in question, masking ErrNoEntries errors
func (conn *DBConn) Exists(ctx context.Context, query *bun.SelectQuery) (bool, db.Error) {
exists, err := query.Exists(ctx)
// Process error as our own and check if it exists
switch err := conn.ProcessError(err); err {
case nil:
return exists, nil
case db.ErrNoEntries:
return false, nil
default:
return false, err
}
}
// NotExists is the functional opposite of conn.Exists()
func (conn *DBConn) NotExists(ctx context.Context, query *bun.SelectQuery) (bool, db.Error) {
exists, err := conn.Exists(ctx, query)
return !exists, err
}