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	Help to recover from corrupted levelqueue (#24912)
gitea.com experienced the corrupted LevelQueue bug again.
I think the problem is clear now: if the keys in LevelDB went
out-of-sync, the LevelQueue itself doesn't have the ability to recover,
eg:
* LevelQueue.Len() reports 100
* LevelQueue.LPop() reports ErrNotFound = errors.New("no key found")
So it needs to dive into the LevelDB to remove all keys to recover the
corrupted LevelQueue.
More comments are in TestCorruptedLevelQueue.
			
			
This commit is contained in:
		@@ -5,16 +5,21 @@ package queue
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import (
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	"context"
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	"sync/atomic"
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	"code.gitea.io/gitea/modules/nosql"
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	"code.gitea.io/gitea/modules/queue/lqinternal"
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	"gitea.com/lunny/levelqueue"
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	"github.com/syndtr/goleveldb/leveldb"
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)
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type baseLevelQueue struct {
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	internal *levelqueue.Queue
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	conn     string
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	cfg      *BaseConfig
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	internal atomic.Pointer[levelqueue.Queue]
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	conn string
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	cfg  *BaseConfig
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	db   *leveldb.DB
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}
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var _ baseQueue = (*baseLevelQueue)(nil)
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@@ -31,21 +36,23 @@ func newBaseLevelQueueSimple(cfg *BaseConfig) (baseQueue, error) {
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	if err != nil {
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		return nil, err
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	}
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	q := &baseLevelQueue{conn: conn, cfg: cfg}
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	q.internal, err = levelqueue.NewQueue(db, []byte(cfg.QueueFullName), false)
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	q := &baseLevelQueue{conn: conn, cfg: cfg, db: db}
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	lq, err := levelqueue.NewQueue(db, []byte(cfg.QueueFullName), false)
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	if err != nil {
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		return nil, err
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	}
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	q.internal.Store(lq)
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	return q, nil
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}
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func (q *baseLevelQueue) PushItem(ctx context.Context, data []byte) error {
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	return baseLevelQueueCommon(q.cfg, q.internal, nil).PushItem(ctx, data)
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	c := baseLevelQueueCommon(q.cfg, nil, func() baseLevelQueuePushPoper { return q.internal.Load() })
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	return c.PushItem(ctx, data)
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}
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func (q *baseLevelQueue) PopItem(ctx context.Context) ([]byte, error) {
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	return baseLevelQueueCommon(q.cfg, q.internal, nil).PopItem(ctx)
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	c := baseLevelQueueCommon(q.cfg, nil, func() baseLevelQueuePushPoper { return q.internal.Load() })
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	return c.PopItem(ctx)
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}
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func (q *baseLevelQueue) HasItem(ctx context.Context, data []byte) (bool, error) {
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@@ -53,20 +60,24 @@ func (q *baseLevelQueue) HasItem(ctx context.Context, data []byte) (bool, error)
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}
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func (q *baseLevelQueue) Len(ctx context.Context) (int, error) {
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	return int(q.internal.Len()), nil
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	return int(q.internal.Load().Len()), nil
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}
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func (q *baseLevelQueue) Close() error {
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	err := q.internal.Close()
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	err := q.internal.Load().Close()
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	_ = nosql.GetManager().CloseLevelDB(q.conn)
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	q.db = nil // the db is not managed by us, it's managed by the nosql manager
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	return err
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}
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func (q *baseLevelQueue) RemoveAll(ctx context.Context) error {
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	for q.internal.Len() > 0 {
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		if _, err := q.internal.LPop(); err != nil {
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			return err
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		}
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	lqinternal.RemoveLevelQueueKeys(q.db, []byte(q.cfg.QueueFullName))
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	lq, err := levelqueue.NewQueue(q.db, []byte(q.cfg.QueueFullName), false)
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	if err != nil {
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		return err
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	}
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	old := q.internal.Load()
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	q.internal.Store(lq)
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	_ = 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
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	return nil
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}
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@@ -17,6 +17,7 @@ import (
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	"github.com/syndtr/goleveldb/leveldb"
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)
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// baseLevelQueuePushPoper is the common interface for levelqueue.Queue and levelqueue.UniqueQueue
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type baseLevelQueuePushPoper interface {
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	RPush(data []byte) error
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	LPop() ([]byte, error)
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@@ -24,9 +25,9 @@ type baseLevelQueuePushPoper interface {
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}
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type baseLevelQueueCommonImpl struct {
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	length   int
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	internal baseLevelQueuePushPoper
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	mu       *sync.Mutex
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	length       int
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	internalFunc func() baseLevelQueuePushPoper
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	mu           *sync.Mutex
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}
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func (q *baseLevelQueueCommonImpl) PushItem(ctx context.Context, data []byte) error {
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@@ -36,11 +37,11 @@ func (q *baseLevelQueueCommonImpl) PushItem(ctx context.Context, data []byte) er
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			defer q.mu.Unlock()
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		}
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		cnt := int(q.internal.Len())
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		cnt := int(q.internalFunc().Len())
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		if cnt >= q.length {
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			return true, nil
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		}
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		retry, err = false, q.internal.RPush(data)
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		retry, err = false, q.internalFunc().RPush(data)
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		if err == levelqueue.ErrAlreadyInQueue {
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			err = ErrAlreadyInQueue
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		}
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@@ -55,7 +56,7 @@ func (q *baseLevelQueueCommonImpl) PopItem(ctx context.Context) ([]byte, error)
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			defer q.mu.Unlock()
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		}
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		data, err = q.internal.LPop()
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		data, err = q.internalFunc().LPop()
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		if err == levelqueue.ErrNotFound {
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			return true, nil, nil
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		}
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@@ -66,8 +67,8 @@ func (q *baseLevelQueueCommonImpl) PopItem(ctx context.Context) ([]byte, error)
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	})
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}
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func baseLevelQueueCommon(cfg *BaseConfig, internal baseLevelQueuePushPoper, mu *sync.Mutex) *baseLevelQueueCommonImpl {
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	return &baseLevelQueueCommonImpl{length: cfg.Length, internal: internal}
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func baseLevelQueueCommon(cfg *BaseConfig, mu *sync.Mutex, internalFunc func() baseLevelQueuePushPoper) *baseLevelQueueCommonImpl {
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	return &baseLevelQueueCommonImpl{length: cfg.Length, mu: mu, internalFunc: internalFunc}
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}
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func prepareLevelDB(cfg *BaseConfig) (conn string, db *leveldb.DB, err error) {
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@@ -6,9 +6,12 @@ package queue
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import (
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	"testing"
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	"code.gitea.io/gitea/modules/queue/lqinternal"
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	"code.gitea.io/gitea/modules/setting"
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	"gitea.com/lunny/levelqueue"
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	"github.com/stretchr/testify/assert"
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	"github.com/syndtr/goleveldb/leveldb"
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)
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func TestBaseLevelDB(t *testing.T) {
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@@ -21,3 +24,55 @@ func TestBaseLevelDB(t *testing.T) {
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	testQueueBasic(t, newBaseLevelQueueSimple, toBaseConfig("baseLevelQueue", setting.QueueSettings{Datadir: t.TempDir() + "/queue-test", Length: 10}), false)
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	testQueueBasic(t, newBaseLevelQueueUnique, toBaseConfig("baseLevelQueueUnique", setting.QueueSettings{ConnStr: "leveldb://" + t.TempDir() + "/queue-test", Length: 10}), true)
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}
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func TestCorruptedLevelQueue(t *testing.T) {
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	// sometimes the levelqueue could be in a corrupted state, this test is to make sure it can recover from it
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	dbDir := t.TempDir() + "/levelqueue-test"
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	db, err := leveldb.OpenFile(dbDir, nil)
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	if !assert.NoError(t, err) {
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		return
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	}
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	defer db.Close()
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	assert.NoError(t, db.Put([]byte("other-key"), []byte("other-value"), nil))
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	nameQueuePrefix := []byte("queue_name")
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	nameSetPrefix := []byte("set_name")
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	lq, err := levelqueue.NewUniqueQueue(db, nameQueuePrefix, nameSetPrefix, false)
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	assert.NoError(t, err)
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	assert.NoError(t, lq.RPush([]byte("item-1")))
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	itemKey := lqinternal.QueueItemKeyBytes(nameQueuePrefix, 1)
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	itemValue, err := db.Get(itemKey, nil)
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	assert.NoError(t, err)
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	assert.Equal(t, []byte("item-1"), itemValue)
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	// there should be 5 keys in db: queue low, queue high, 1 queue item, 1 set item, and "other-key"
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	keys := lqinternal.ListLevelQueueKeys(db)
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	assert.Len(t, keys, 5)
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	// delete the queue item key, to corrupt the queue
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	assert.NoError(t, db.Delete(itemKey, nil))
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	// now the queue is corrupted, it never works again
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	_, err = lq.LPop()
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	assert.ErrorIs(t, err, levelqueue.ErrNotFound)
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	assert.NoError(t, lq.Close())
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	// remove all the queue related keys to reset the queue
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	lqinternal.RemoveLevelQueueKeys(db, nameQueuePrefix)
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	lqinternal.RemoveLevelQueueKeys(db, nameSetPrefix)
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	// now there should be only 1 key in db: "other-key"
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	keys = lqinternal.ListLevelQueueKeys(db)
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	assert.Len(t, keys, 1)
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	assert.Equal(t, []byte("other-key"), keys[0])
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	// re-create a queue from db
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	lq, err = levelqueue.NewUniqueQueue(db, nameQueuePrefix, nameSetPrefix, false)
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	assert.NoError(t, err)
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	assert.NoError(t, lq.RPush([]byte("item-new-1")))
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	// now the queue works again
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	itemValue, err = lq.LPop()
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	assert.NoError(t, err)
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	assert.Equal(t, []byte("item-new-1"), itemValue)
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	assert.NoError(t, lq.Close())
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}
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@@ -6,18 +6,21 @@ package queue
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import (
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	"context"
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	"sync"
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	"unsafe"
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	"sync/atomic"
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	"code.gitea.io/gitea/modules/nosql"
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	"code.gitea.io/gitea/modules/queue/lqinternal"
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	"gitea.com/lunny/levelqueue"
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	"github.com/syndtr/goleveldb/leveldb"
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)
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type baseLevelQueueUnique struct {
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	internal *levelqueue.UniqueQueue
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	conn     string
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	cfg      *BaseConfig
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	internal atomic.Pointer[levelqueue.UniqueQueue]
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	conn string
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	cfg  *BaseConfig
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	db   *leveldb.DB
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	mu sync.Mutex // the levelqueue.UniqueQueue is not thread-safe, there is no mutex protecting the underlying queue&set together
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}
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@@ -29,39 +32,42 @@ func newBaseLevelQueueUnique(cfg *BaseConfig) (baseQueue, error) {
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	if err != nil {
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		return nil, err
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	}
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	q := &baseLevelQueueUnique{conn: conn, cfg: cfg}
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	q.internal, err = levelqueue.NewUniqueQueue(db, []byte(cfg.QueueFullName), []byte(cfg.SetFullName), false)
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	q := &baseLevelQueueUnique{conn: conn, cfg: cfg, db: db}
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	lq, err := levelqueue.NewUniqueQueue(db, []byte(cfg.QueueFullName), []byte(cfg.SetFullName), false)
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	if err != nil {
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		return nil, err
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	}
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	q.internal.Store(lq)
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	return q, nil
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}
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func (q *baseLevelQueueUnique) PushItem(ctx context.Context, data []byte) error {
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	return baseLevelQueueCommon(q.cfg, q.internal, &q.mu).PushItem(ctx, data)
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	c := baseLevelQueueCommon(q.cfg, &q.mu, func() baseLevelQueuePushPoper { return q.internal.Load() })
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	return c.PushItem(ctx, data)
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}
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func (q *baseLevelQueueUnique) PopItem(ctx context.Context) ([]byte, error) {
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	return baseLevelQueueCommon(q.cfg, q.internal, &q.mu).PopItem(ctx)
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	c := baseLevelQueueCommon(q.cfg, &q.mu, func() baseLevelQueuePushPoper { return q.internal.Load() })
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	return c.PopItem(ctx)
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}
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 | 
			
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func (q *baseLevelQueueUnique) HasItem(ctx context.Context, data []byte) (bool, error) {
 | 
			
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	q.mu.Lock()
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	defer q.mu.Unlock()
 | 
			
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	return q.internal.Has(data)
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	return q.internal.Load().Has(data)
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		||||
}
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		||||
 | 
			
		||||
func (q *baseLevelQueueUnique) Len(ctx context.Context) (int, error) {
 | 
			
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	q.mu.Lock()
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	defer q.mu.Unlock()
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	return int(q.internal.Len()), nil
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	return int(q.internal.Load().Len()), nil
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		||||
}
 | 
			
		||||
 | 
			
		||||
func (q *baseLevelQueueUnique) Close() error {
 | 
			
		||||
	q.mu.Lock()
 | 
			
		||||
	defer q.mu.Unlock()
 | 
			
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	err := q.internal.Close()
 | 
			
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	err := q.internal.Load().Close()
 | 
			
		||||
	q.db = nil // the db is not managed by us, it's managed by the nosql manager
 | 
			
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	_ = nosql.GetManager().CloseLevelDB(q.conn)
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		||||
	return err
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		||||
}
 | 
			
		||||
@@ -69,28 +75,14 @@ func (q *baseLevelQueueUnique) Close() error {
 | 
			
		||||
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))
 | 
			
		||||
 | 
			
		||||
	for lq.q.Len() > 0 {
 | 
			
		||||
		if _, err := lq.q.LPop(); err != nil {
 | 
			
		||||
			return err
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	// the "set" must be cleared after the "list" because there is no transaction.
 | 
			
		||||
	// it's better to have duplicate items than losing items.
 | 
			
		||||
	members, err := lq.set.Members()
 | 
			
		||||
	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 // seriously corrupted
 | 
			
		||||
	}
 | 
			
		||||
	for _, v := range members {
 | 
			
		||||
		_, _ = lq.set.Remove(v)
 | 
			
		||||
		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
 | 
			
		||||
}
 | 
			
		||||
 
 | 
			
		||||
							
								
								
									
										48
									
								
								modules/queue/lqinternal/lqinternal.go
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										48
									
								
								modules/queue/lqinternal/lqinternal.go
									
									
									
									
									
										Normal file
									
								
							@@ -0,0 +1,48 @@
 | 
			
		||||
// Copyright 2023 The Gitea Authors. All rights reserved.
 | 
			
		||||
// SPDX-License-Identifier: MIT
 | 
			
		||||
 | 
			
		||||
package lqinternal
 | 
			
		||||
 | 
			
		||||
import (
 | 
			
		||||
	"bytes"
 | 
			
		||||
	"encoding/binary"
 | 
			
		||||
 | 
			
		||||
	"github.com/syndtr/goleveldb/leveldb"
 | 
			
		||||
	"github.com/syndtr/goleveldb/leveldb/opt"
 | 
			
		||||
)
 | 
			
		||||
 | 
			
		||||
func QueueItemIDBytes(id int64) []byte {
 | 
			
		||||
	buf := make([]byte, 8)
 | 
			
		||||
	binary.PutVarint(buf, id)
 | 
			
		||||
	return buf
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func QueueItemKeyBytes(prefix []byte, id int64) []byte {
 | 
			
		||||
	key := make([]byte, len(prefix), len(prefix)+1+8)
 | 
			
		||||
	copy(key, prefix)
 | 
			
		||||
	key = append(key, '-')
 | 
			
		||||
	return append(key, QueueItemIDBytes(id)...)
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func RemoveLevelQueueKeys(db *leveldb.DB, namePrefix []byte) {
 | 
			
		||||
	keyPrefix := make([]byte, len(namePrefix)+1)
 | 
			
		||||
	copy(keyPrefix, namePrefix)
 | 
			
		||||
	keyPrefix[len(namePrefix)] = '-'
 | 
			
		||||
 | 
			
		||||
	it := db.NewIterator(nil, &opt.ReadOptions{Strict: opt.NoStrict})
 | 
			
		||||
	defer it.Release()
 | 
			
		||||
	for it.Next() {
 | 
			
		||||
		if bytes.HasPrefix(it.Key(), keyPrefix) {
 | 
			
		||||
			_ = db.Delete(it.Key(), nil)
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
func ListLevelQueueKeys(db *leveldb.DB) (res [][]byte) {
 | 
			
		||||
	it := db.NewIterator(nil, &opt.ReadOptions{Strict: opt.NoStrict})
 | 
			
		||||
	defer it.Release()
 | 
			
		||||
	for it.Next() {
 | 
			
		||||
		res = append(res, it.Key())
 | 
			
		||||
	}
 | 
			
		||||
	return res
 | 
			
		||||
}
 | 
			
		||||
		Reference in New Issue
	
	Block a user