cloud_txn_delete_bitmap_cache.h

// Licensed to the Apache Software Foundation (ASF) under one
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// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#pragma once

#include <mutex>

#include "cpp/lru_cache.h"
#include "storage/olap_common.h"
#include "storage/partial_update_info.h"
#include "storage/rowset/rowset.h"
#include "storage/tablet/tablet_meta.h"
#include "storage/txn/txn_manager.h"
#include "util/countdown_latch.h"

namespace doris {

// Record transaction related delete bitmaps using a lru cache.
class CloudTxnDeleteBitmapCache : public LRUCachePolicy {
public:
    CloudTxnDeleteBitmapCache(size_t size_in_bytes);

    ~CloudTxnDeleteBitmapCache() override;

    Status init();

    Status get_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,
                               RowsetSharedPtr* rowset, DeleteBitmapPtr* delete_bitmap,
                               RowsetIdUnorderedSet* rowset_ids, int64_t* txn_expiration,
                               std::shared_ptr<PartialUpdateInfo>* partial_update_info,
                               std::shared_ptr<PublishStatus>* publish_status,
                               TxnPublishInfo* previous_publish_info);

    void set_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,
                             DeleteBitmapPtr delete_bitmap, const RowsetIdUnorderedSet& rowset_ids,
                             RowsetSharedPtr rowset, int64_t txn_expirationm,
                             std::shared_ptr<PartialUpdateInfo> partial_update_info);

    Status update_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id,
                                  DeleteBitmapPtr delete_bitmap,
                                  const RowsetIdUnorderedSet& rowset_ids,
                                  PublishStatus publish_status, TxnPublishInfo publish_info = {});

    void remove_expired_tablet_txn_info();

    void remove_unused_tablet_txn_info(TTransactionId transaction_id, int64_t tablet_id);

    // Mark a rowset as empty/skipped (lightweight marker, no rowset stored)
    // Used for empty rowsets when skip_writing_empty_rowset_metadata is enabled
    void mark_empty_rowset(TTransactionId txn_id, int64_t tablet_id, int64_t txn_expiration);

    // Check if this is a known empty/skipped rowset
    // Returns true if was marked as empty rowset
    // Note: Does not remove the marker, as CalcDeleteBitmapTask may retry.
    // Cleanup is handled by expiration-based removal in remove_expired_tablet_txn_info()
    bool is_empty_rowset(TTransactionId txn_id, int64_t tablet_id);

    // !!!ATTENTION!!!: the delete bitmap stored in CloudTxnDeleteBitmapCache contains sentinel marks,
    // and the version in BitmapKey is DeleteBitmap::TEMP_VERSION_COMMON.
    // when using delete bitmap from this cache, the caller should manually remove these marks if don't need it
    // and should replace versions in BitmapKey by the correct version
    Status get_delete_bitmap(TTransactionId transaction_id, int64_t tablet_id,
                             DeleteBitmapPtr* delete_bitmap, RowsetIdUnorderedSet* rowset_ids,
                             std::shared_ptr<PublishStatus>* publish_status);

    // the caller should guarantee that the txn `transaction_id` has been published successfully in MS
    Result<std::pair<RowsetSharedPtr, DeleteBitmapPtr>> get_rowset_and_delete_bitmap(
            TTransactionId transaction_id, int64_t tablet_id);

private:
    void _clean_thread_callback();

    class DeleteBitmapCacheValue : public LRUCacheValueBase {
    public:
        DeleteBitmapPtr delete_bitmap;
        // records rowsets calc in commit txn
        RowsetIdUnorderedSet rowset_ids;

        DeleteBitmapCacheValue(DeleteBitmapPtr delete_bitmap_, const RowsetIdUnorderedSet& ids_)
                : delete_bitmap(std::move(delete_bitmap_)), rowset_ids(ids_) {}
    };

    struct TxnKey {
        TTransactionId txn_id;
        int64_t tablet_id;
        TxnKey(TTransactionId txn_id_, int64_t tablet_id_)
                : txn_id(txn_id_), tablet_id(tablet_id_) {}
        auto operator<=>(const TxnKey&) const = default;
    };

    struct TxnVal {
        RowsetSharedPtr rowset;
        int64_t txn_expiration;
        std::shared_ptr<PartialUpdateInfo> partial_update_info;
        std::shared_ptr<PublishStatus> publish_status = nullptr;
        // used to determine if the retry needs to re-calculate the delete bitmap
        TxnPublishInfo publish_info;
        TxnVal() : txn_expiration(0) {};
        TxnVal(RowsetSharedPtr rowset_, int64_t txn_expiration_,
               std::shared_ptr<PartialUpdateInfo> partial_update_info_,
               std::shared_ptr<PublishStatus> publish_status_)
                : rowset(std::move(rowset_)),
                  txn_expiration(txn_expiration_),
                  partial_update_info(std::move(partial_update_info_)),
                  publish_status(std::move(publish_status_)) {}
    };

    std::map<TxnKey, TxnVal> _txn_map;
    std::multimap<int64_t, TxnKey> _expiration_txn;
    // Lightweight markers for empty/skipped rowsets (only stores TxnKey, ~16 bytes per entry)
    // Used to track empty rowsets that were not committed to meta-service
    std::set<TxnKey> _empty_rowset_markers;
    std::shared_mutex _rwlock;
    std::shared_ptr<Thread> _clean_thread;
    CountDownLatch _stop_latch;
};

} // namespace doris