// 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 timeline import ( "container/list" ) func (t *timeline) Prune(desiredPreparedItemsLength int, desiredIndexedItemsLength int) int { t.Lock() defer t.Unlock() l := t.items.data if l == nil { // Nothing to prune. return 0 } var ( position int totalPruned int toRemove *[]*list.Element ) // Only initialize toRemove if we know we're // going to need it, otherwise skiperino. if toRemoveLen := t.items.data.Len() - desiredIndexedItemsLength; toRemoveLen > 0 { toRemove = func() *[]*list.Element { tr := make([]*list.Element, 0, toRemoveLen); return &tr }() } // Work from the front of the list until we get // to the point where we need to start pruning. for e := l.Front(); e != nil; e = e.Next() { position++ if position <= desiredPreparedItemsLength { // We're still within our allotted // prepped length, nothing to do yet. continue } // We need to *at least* unprepare this entry. // If we're beyond our indexed length already, // we can just remove the item completely. if position > desiredIndexedItemsLength { *toRemove = append(*toRemove, e) totalPruned++ continue } entry := e.Value.(*indexedItemsEntry) //nolint:forcetypeassert if entry.prepared == nil { // It's already unprepared (mood). continue } entry.prepared = nil // <- eat this up please garbage collector nom nom nom totalPruned++ } if toRemove != nil { for _, e := range *toRemove { l.Remove(e) } } return totalPruned }