1 files changed, 88 insertions, 0 deletions
diff --git a/modules/queue/base_levelqueue_unique.go b/modules/queue/base_levelqueue_unique.go
new file mode 100644
index 0000000..968a4e9
--- /dev/null
+++ b/modules/queue/base_levelqueue_unique.go
@@ -0,0 +1,88 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package queue
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"code.gitea.io/gitea/modules/nosql"
+	"code.gitea.io/gitea/modules/queue/lqinternal"
+
+	"gitea.com/lunny/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
+}