1 files changed, 93 insertions, 0 deletions
diff --git a/modules/queue/base_levelqueue_unique.go b/modules/queue/base_levelqueue_unique.go
new file mode 100644
index 0000000000..7546221631
--- /dev/null
+++ b/modules/queue/base_levelqueue_unique.go
@@ -0,0 +1,93 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package queue
+
+import (
+	"context"
+	"sync"
+	"unsafe"
+
+	"code.gitea.io/gitea/modules/nosql"
+
+	"gitea.com/lunny/levelqueue"
+	"github.com/syndtr/goleveldb/leveldb"
+)
+
+type baseLevelQueueUnique struct {
+	internal *levelqueue.UniqueQueue
+	conn     string
+	cfg      *BaseConfig
+
+	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}
+	q.internal, err = levelqueue.NewUniqueQueue(db, []byte(cfg.QueueFullName), []byte(cfg.SetFullName), false)
+	if err != nil {
+		return nil, err
+	}
+
+	return q, nil
+}
+
+func (q *baseLevelQueueUnique) PushItem(ctx context.Context, data []byte) error {
+	return baseLevelQueueCommon(q.cfg, q.internal, &q.mu).PushItem(ctx, data)
+}
+
+func (q *baseLevelQueueUnique) PopItem(ctx context.Context) ([]byte, error) {
+	return baseLevelQueueCommon(q.cfg, q.internal, &q.mu).PopItem(ctx)
+}
+
+func (q *baseLevelQueueUnique) HasItem(ctx context.Context, data []byte) (bool, error) {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	return q.internal.Has(data)
+}
+
+func (q *baseLevelQueueUnique) Len(ctx context.Context) (int, error) {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	return int(q.internal.Len()), nil
+}
+
+func (q *baseLevelQueueUnique) Close() error {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+	err := q.internal.Close()
+	_ = nosql.GetManager().CloseLevelDB(q.conn)
+	return err
+}
+
+func (q *baseLevelQueueUnique) RemoveAll(ctx context.Context) error {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	type levelUniqueQueue struct {
+		q   *levelqueue.Queue
+		set *levelqueue.Set
+		db  *leveldb.DB
+	}
+	lq := (*levelUniqueQueue)(unsafe.Pointer(q.internal))
+
+	members, err := lq.set.Members()
+	if err != nil {
+		return err // seriously corrupted
+	}
+	for _, v := range members {
+		_, _ = lq.set.Remove(v)
+	}
+	for lq.q.Len() > 0 {
+		if _, err = lq.q.LPop(); err != nil {
+			return err
+		}
+	}
+	return nil
+}