// Copyright 2023 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package queue import (	"context"	"sync"	"sync/atomic" 	"forgejo.org/modules/nosql"	"forgejo.org/modules/queue/lqinternal" 	"code.forgejo.org/forgejo/levelqueue"	"github.com/syndtr/goleveldb/leveldb") type baseLevelQueueUnique struct {	internal atomic.Pointer[levelqueue.UniqueQueue] 	conn string	cfg  *BaseConfig	db   *leveldb.DB 	mu sync.Mutex // the levelqueue.UniqueQueue is not thread-safe, there is no mutex protecting the underlying queue&set together} var _ baseQueue = (*baseLevelQueueUnique)(nil) func newBaseLevelQueueUnique(cfg *BaseConfig) (baseQueue, error) {	conn, db, err := prepareLevelDB(cfg)	if err != nil {		return nil, err	}	q := &baseLevelQueueUnique{conn: conn, cfg: cfg, db: db}	lq, err := levelqueue.NewUniqueQueue(db, []byte(cfg.QueueFullName), []byte(cfg.SetFullName), false)	if err != nil {		return nil, err	}	q.internal.Store(lq)	return q, nil} func (q *baseLevelQueueUnique) PushItem(ctx context.Context, data []byte) error {	c := baseLevelQueueCommon(q.cfg, &q.mu, func() baseLevelQueuePushPoper { return q.internal.Load() })	return c.PushItem(ctx, data)} func (q *baseLevelQueueUnique) PopItem(ctx context.Context) ([]byte, error) {	c := baseLevelQueueCommon(q.cfg, &q.mu, func() baseLevelQueuePushPoper { return q.internal.Load() })	return c.PopItem(ctx)} func (q *baseLevelQueueUnique) HasItem(ctx context.Context, data []byte) (bool, error) {	q.mu.Lock()	defer q.mu.Unlock()	return q.internal.Load().Has(data)} func (q *baseLevelQueueUnique) Len(ctx context.Context) (int, error) {	q.mu.Lock()	defer q.mu.Unlock()	return int(q.internal.Load().Len()), nil} func (q *baseLevelQueueUnique) Close() error {	q.mu.Lock()	defer q.mu.Unlock()	err := q.internal.Load().Close()	q.db = nil // the db is not managed by us, it's managed by the nosql manager	_ = nosql.GetManager().CloseLevelDB(q.conn)	return err} func (q *baseLevelQueueUnique) RemoveAll(ctx context.Context) error {	q.mu.Lock()	defer q.mu.Unlock()	lqinternal.RemoveLevelQueueKeys(q.db, []byte(q.cfg.QueueFullName))	lqinternal.RemoveLevelQueueKeys(q.db, []byte(q.cfg.SetFullName))	lq, err := levelqueue.NewUniqueQueue(q.db, []byte(q.cfg.QueueFullName), []byte(q.cfg.SetFullName), false)	if err != nil {		return err	}	old := q.internal.Load()	q.internal.Store(lq)	_ = old.Close() // Not ideal for concurrency. Luckily, the levelqueue only sets its db=nil because it doesn't manage the db, so far so good	return nil}