gotosocial/internal/federation/federatingdb/lock.go
Daenney 5e2bf0bdca
[chore] Improve copyright header handling (#1608)
* [chore] Remove years from all license headers

Years or year ranges aren't required in license headers. Many projects
have removed them in recent years and it avoids a bit of yearly toil.

In many cases our copyright claim was also a bit dodgy since we added
the 2021-2023 header to files created after 2021 but you can't claim
copyright into the past that way.

* [chore] Add license header check

This ensures a license header is always added to any new file. This
avoids maintainers/reviewers needing to remember to check for and ask
for it in case a contribution doesn't include it.

* [chore] Add missing license headers

* [chore] Further updates to license header

* Use the more common // indentend comment format
* Remove the hack we had for the linter now that we use the // format
* Add SPDX license identifier
2023-03-12 16:00:57 +01:00

43 lines
1.5 KiB
Go

// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// 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 federatingdb
import (
"context"
"errors"
"net/url"
)
// Lock takes a lock for the object at the specified id. If an error
// is returned, the lock must not have been taken.
//
// The lock must be able to succeed for an id that does not exist in
// the database. This means acquiring the lock does not guarantee the
// entry exists in the database.
//
// Locks are encouraged to be lightweight and in the Go layer, as some
// processes require tight loops acquiring and releasing locks.
//
// Used to ensure race conditions in multiple requests do not occur.
func (f *federatingDB) Lock(c context.Context, id *url.URL) (func(), error) {
if id == nil {
return nil, errors.New("Lock: id was nil")
}
unlock := f.locks.Lock(id.String())
return unlock, nil
}