// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// 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

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied.  See the License for the

// specific language governing permissions and limitations

// under the License.

#pragma once

#include <gen_cpp/cloud.pb.h>

#include <glog/logging.h>

#include <atomic>

#include <condition_variable>

#include <cstdint>

#include <deque>

#include <functional>

#include <memory>

#include <string>

#include <string_view>

#include <thread>

#include <unordered_map>

#include <unordered_set>

#include <utility>

#include "common/bvars.h"

#include "meta-service/delete_bitmap_lock_white_list.h"

#include "meta-service/txn_lazy_committer.h"

#include "meta-store/versionstamp.h"

#include "recycler/snapshot_chain_compactor.h"

#include "recycler/snapshot_data_migrator.h"

#include "recycler/storage_vault_accessor.h"

#include "snapshot/snapshot_manager.h"

namespace brpc {

class Server;

} // namespace brpc

namespace doris::cloud {

class TxnKv;

class InstanceRecycler;

class StorageVaultAccessor;

class Checker;

class SimpleThreadPool;

class RecyclerMetricsContext;

class TabletRecyclerMetricsContext;

class SegmentRecyclerMetricsContext;

struct RecyclerThreadPoolGroup {

    RecyclerThreadPoolGroup() = default;

    RecyclerThreadPoolGroup(std::shared_ptr<SimpleThreadPool> s3_producer_pool,

                            std::shared_ptr<SimpleThreadPool> recycle_tablet_pool,

                            std::shared_ptr<SimpleThreadPool> group_recycle_function_pool)

            : s3_producer_pool(std::move(s3_producer_pool)),

              recycle_tablet_pool(std::move(recycle_tablet_pool)),

              group_recycle_function_pool(std::move(group_recycle_function_pool)) {}

    ~RecyclerThreadPoolGroup() = default;

    RecyclerThreadPoolGroup(const RecyclerThreadPoolGroup&) = default;

    RecyclerThreadPoolGroup& operator=(RecyclerThreadPoolGroup& other) = default;

    RecyclerThreadPoolGroup& operator=(RecyclerThreadPoolGroup&& other) = default;

    RecyclerThreadPoolGroup(RecyclerThreadPoolGroup&&) = default;

    // used for accessor.delete_files, accessor.delete_directory

    std::shared_ptr<SimpleThreadPool> s3_producer_pool;

    // used for InstanceRecycler::recycle_tablet

    std::shared_ptr<SimpleThreadPool> recycle_tablet_pool;

    std::shared_ptr<SimpleThreadPool> group_recycle_function_pool;

};

class Recycler {

public:

    explicit Recycler(std::shared_ptr<TxnKv> txn_kv);

    ~Recycler();

    // returns 0 for success otherwise error

    int start(brpc::Server* server);

    void stop();

    bool stopped() const { return stopped_.load(std::memory_order_acquire); }

    RecyclerThreadPoolGroup& thread_pool_group() { return _thread_pool_group; }

private:

    void recycle_callback();

    void instance_scanner_callback();

    void lease_recycle_jobs();

    void check_recycle_tasks();

private:

    friend class RecyclerServiceImpl;

    std::shared_ptr<TxnKv> txn_kv_;

    std::atomic_bool stopped_ {false};

    std::vector<std::thread> workers_;

    std::mutex mtx_;

    // notify recycle workers

    std::condition_variable pending_instance_cond_;

    std::deque<InstanceInfoPB> pending_instance_queue_;

    std::unordered_set<std::string> pending_instance_set_;

    std::unordered_map<std::string, std::shared_ptr<InstanceRecycler>> recycling_instance_map_;

    // notify instance scanner and lease thread

    std::condition_variable notifier_;

    std::string ip_port_;

    std::unique_ptr<Checker> checker_;

    RecyclerThreadPoolGroup _thread_pool_group;

    std::shared_ptr<TxnLazyCommitter> txn_lazy_committer_;

    std::shared_ptr<SnapshotManager> snapshot_manager_;

    std::shared_ptr<SnapshotDataMigrator> snapshot_data_migrator_;

    std::shared_ptr<SnapshotChainCompactor> snapshot_chain_compactor_;

};

enum class RowsetRecyclingState {

    FORMAL_ROWSET,

    TMP_ROWSET,

};

// Represents a single rowset deletion task for batch delete

struct RowsetDeleteTask {

    RowsetMetaCloudPB rowset_meta;

    std::string recycle_rowset_key;       // Primary key marking "pending recycle"

    std::string non_versioned_rowset_key; // Legacy non-versioned rowset meta key

    std::string versioned_rowset_key;     // Versioned meta rowset key

    Versionstamp versionstamp;

    std::string rowset_ref_count_key;

};

class RecyclerMetricsContext {

public:

    RecyclerMetricsContext() = default;

    RecyclerMetricsContext(std::string instance_id, std::string operation_type)

            : operation_type(std::move(operation_type)), instance_id(std::move(instance_id)) {

        start();

    }

    ~RecyclerMetricsContext() = default;

    std::atomic_ullong total_need_recycle_data_size = 0;

    std::atomic_ullong total_need_recycle_num = 0;

    std::atomic_ullong total_recycled_data_size = 0;

    std::atomic_ullong total_recycled_num = 0;

    std::string operation_type;

    std::string instance_id;

    double start_time = 0;

    void start() {

        start_time = duration_cast<std::chrono::milliseconds>(

                             std::chrono::system_clock::now().time_since_epoch())

                             .count();

    }

    double duration() const {

        return duration_cast<std::chrono::milliseconds>(

                       std::chrono::system_clock::now().time_since_epoch())

                       .count() -

               start_time;

    }

    void reset() {

        total_need_recycle_data_size = 0;

        total_need_recycle_num = 0;

        total_recycled_data_size = 0;

        total_recycled_num = 0;

        start_time = duration_cast<std::chrono::milliseconds>(

                             std::chrono::system_clock::now().time_since_epoch())

                             .count();

    }

    void finish_report() {

        if (!operation_type.empty()) {

            double cost = duration();

            g_bvar_recycler_instance_last_round_recycle_elpased_ts.put(

                    {instance_id, operation_type}, cost);

            g_bvar_recycler_instance_recycle_round.put({instance_id, operation_type}, 1);

            g_bvar_recycler_instance_recycle_total_bytes_since_started.put(

                    {instance_id, operation_type}, total_recycled_data_size.load());

            g_bvar_recycler_instance_recycle_total_num_since_started.put(

                    {instance_id, operation_type}, total_recycled_num.load());

            LOG(INFO) << "recycle instance: " << instance_id

                      << ", operation type: " << operation_type << ", cost: " << cost

                      << " ms, total recycled num: " << total_recycled_num.load()

                      << ", total recycled data size: " << total_recycled_data_size.load()

                      << " bytes";

            if (cost != 0) {

                if (total_recycled_num.load() != 0) {

                    g_bvar_recycler_instance_recycle_time_per_resource.put(

                            {instance_id, operation_type}, cost / total_recycled_num.load());

                }

                g_bvar_recycler_instance_recycle_bytes_per_ms.put(

                        {instance_id, operation_type}, total_recycled_data_size.load() / cost);

            }

        }

    }

    // `is_begin` is used to initialize total num of items need to be recycled

    void report(bool is_begin = false) {

        if (!operation_type.empty()) {

            // is init

            if (is_begin) {

                auto value = total_need_recycle_num.load();

                g_bvar_recycler_instance_last_round_to_recycle_bytes.put(

                        {instance_id, operation_type}, total_need_recycle_data_size.load());

                g_bvar_recycler_instance_last_round_to_recycle_num.put(

                        {instance_id, operation_type}, value);

            } else {

                g_bvar_recycler_instance_last_round_recycled_bytes.put(

                        {instance_id, operation_type}, total_recycled_data_size.load());

                g_bvar_recycler_instance_last_round_recycled_num.put({instance_id, operation_type},

                                                                     total_recycled_num.load());

            }

        }

    }

};

class TabletRecyclerMetricsContext : public RecyclerMetricsContext {

public:

    TabletRecyclerMetricsContext() : RecyclerMetricsContext("global_recycler", "recycle_tablet") {}

};

class SegmentRecyclerMetricsContext : public RecyclerMetricsContext {

public:

    SegmentRecyclerMetricsContext()

            : RecyclerMetricsContext("global_recycler", "recycle_segment") {}

};

struct OplogRecycleStats;

class InstanceRecycler {

public:

    struct PackedFileRecycleStats {

        int64_t num_scanned = 0;          // packed-file kv scanned

        int64_t num_corrected = 0;        // packed-file kv corrected

        int64_t num_deleted = 0;          // packed-file kv deleted

        int64_t num_failed = 0;           // packed-file kv failed

        int64_t bytes_deleted = 0;        // packed-file kv bytes deleted from txn-kv

        int64_t num_object_deleted = 0;   // packed-file objects deleted from storage (vault/HDFS)

        int64_t bytes_object_deleted = 0; // bytes deleted from storage objects

        int64_t rowset_scan_count = 0;    // rowset metas scanned during correction

    };

    explicit InstanceRecycler(std::shared_ptr<TxnKv> txn_kv, const InstanceInfoPB& instance,

                              RecyclerThreadPoolGroup thread_pool_group,

                              std::shared_ptr<TxnLazyCommitter> txn_lazy_committer);

    ~InstanceRecycler();

    std::string_view instance_id() const { return instance_id_; }

    const InstanceInfoPB& instance_info() const { return instance_info_; }

    // returns 0 for success otherwise error

    int init();

    void stop() { stopped_.store(true, std::memory_order_release); }

    bool stopped() const { return stopped_.load(std::memory_order_acquire); }

    // returns 0 for success otherwise error

    int do_recycle();

    // remove all kv and data in this instance, ONLY be called when instance has been deleted

    // returns 0 for success otherwise error

    int recycle_deleted_instance();

    // scan and recycle expired indexes:

    // 1. dropped table, dropped mv

    // 2. half-successtable/index when create

    // returns 0 for success otherwise error

    int recycle_indexes();

    // scan and recycle expired partitions:

    // 1. dropped parttion

    // 2. half-success partition when create

    // returns 0 for success otherwise error

    int recycle_partitions();

    // scan and recycle expired rowsets:

    // 1. prepare_rowset will produce recycle_rowset before uploading data to remote storage (memo)

    // 2. compaction will change the input rowsets to recycle_rowset

    // returns 0 for success otherwise error

    int recycle_rowsets();

    // like `recycle_rowsets`, but for versioned rowsets.

    int recycle_versioned_rowsets();

    // scan and recycle expired tmp rowsets:

    // 1. commit_rowset will produce tmp_rowset when finish upload data (load or compaction) to remote storage

    // returns 0 for success otherwise error

    int recycle_tmp_rowsets();

    /**

     * recycle all tablets belonging to the index specified by `index_id`

     *

     * @param partition_id if positive, only recycle tablets in this partition belonging to the specified index

     * @return 0 for success otherwise error

     */

    int recycle_tablets(int64_t table_id, int64_t index_id, RecyclerMetricsContext& ctx,

                        int64_t partition_id = -1);

    /**

     * recycle all rowsets belonging to the tablet specified by `tablet_id`

     *

     * @return 0 for success otherwise error

     */

    int recycle_tablet(int64_t tablet_id, RecyclerMetricsContext& metrics_context);

    /**

     * like `recycle_tablet`, but for versioned tablet

     */

    int recycle_versioned_tablet(int64_t tablet_id, RecyclerMetricsContext& metrics_context);

    // scan and recycle useless partition version kv

    int recycle_versions();

    // scan and recycle the orphan partitions

    int recycle_orphan_partitions();

    // scan and abort timeout txn label

    // returns 0 for success otherwise error

    int abort_timeout_txn();

    //scan and recycle expire txn label

    // returns 0 for success otherwise error

    int recycle_expired_txn_label();

    // scan and recycle finished or timeout copy jobs

    // returns 0 for success otherwise error

    int recycle_copy_jobs();

    // scan and recycle dropped internal stage

    // returns 0 for success otherwise error

    int recycle_stage();

    // scan and recycle expired stage objects

    // returns 0 for success otherwise error

    int recycle_expired_stage_objects();

    // scan and recycle operation logs

    // returns 0 for success otherwise error

    int recycle_operation_logs();

    // scan and recycle expired restore jobs

    // returns 0 for success otherwise error

    int recycle_restore_jobs();

    /**

     * Scan packed-file metadata, correct reference counters, and recycle unused packed files.

     *

     * @return 0 on success, non-zero error code otherwise

     */

    int recycle_packed_files();

    // scan and recycle snapshots

    // returns 0 for success otherwise error

    int recycle_cluster_snapshots();

    // scan and recycle ref rowsets for deleted instance

    // returns 0 for success otherwise error

    int recycle_ref_rowsets(bool* has_unrecycled_rowsets);

    bool check_recycle_tasks();

    int scan_and_statistics_indexes();

    int scan_and_statistics_partitions();

    int scan_and_statistics_rowsets();

    int scan_and_statistics_tmp_rowsets();

    int scan_and_statistics_abort_timeout_txn();

    int scan_and_statistics_expired_txn_label();

    int scan_and_statistics_copy_jobs();

    int scan_and_statistics_stage();

    int scan_and_statistics_expired_stage_objects();

    int scan_and_statistics_versions();

    int scan_and_statistics_restore_jobs();

    void scan_and_statistics_operation_logs();

    /**

     * Decode the key of a packed-file metadata record into the persisted object path.

     *

     * @param key raw key persisted in txn-kv

     * @param packed_path output object storage path referenced by the key

     * @return true if decoding succeeds, false otherwise

     */

    static bool decode_packed_file_key(std::string_view key, std::string* packed_path);

    void TEST_add_accessor(std::string_view id, std::shared_ptr<StorageVaultAccessor> accessor) {

        accessor_map_.insert({std::string(id), std::move(accessor)});

    }

    // Recycle snapshot meta and data, return 0 for success otherwise error.

    int recycle_snapshot_meta_and_data(const std::string& instance_id,

                                       const std::string& resource_id,

                                       Versionstamp snapshot_version,

                                       const SnapshotPB& snapshot_pb);

private:

    // returns 0 for success otherwise error

    int init_obj_store_accessors();

    // returns 0 for success otherwise error

    int init_storage_vault_accessors();

    /**

     * Scan key-value pairs between [`begin`, `end`) with multiple rounds of range get(`RangeGetIterator`),

     * and perform `recycle_func` on each key-value pair.

     *

     * @param recycle_func defines how to recycle resources corresponding to a key-value pair.

     *                     The scan will stop if recycle_func() returns non-zero.

     *                     recycle_func() returns 0 if the recycling is successful or the scan can continue with ignorable errors.

     * @param loop_done is called after a round (`RangeGetIterator`) in the scan has no next kv. Usually used to perform a batch recycling.

     *                  The scan will stop if loop_done() returns non-zero.

     *                  loop_done() returns 0 if the recycling is successful or the scan can continue with ignorable errors.

     * @return 0 if all corresponding resources are recycled successfully, otherwise non-zero

     */

    int scan_and_recycle(std::string begin, std::string_view end,

                         std::function<int(std::string_view k, std::string_view v)> recycle_func,

                         std::function<int()> loop_done = nullptr);

    // return 0 for success otherwise error

    int delete_rowset_data(const doris::RowsetMetaCloudPB& rs_meta_pb);

    // return 0 for success otherwise error

    // NOTE: this function ONLY be called when the file paths cannot be calculated

    int delete_rowset_data(const std::string& resource_id, int64_t tablet_id,

                           const std::string& rowset_id);

    // return 0 for success otherwise error

    int delete_rowset_data(const std::map<std::string, doris::RowsetMetaCloudPB>& rowsets,

                           RowsetRecyclingState type, RecyclerMetricsContext& metrics_context);

    // Decrement packed file ref counts for rowset segments.

    // Returns 0 for success, -1 for error.

    int decrement_packed_file_ref_counts(const doris::RowsetMetaCloudPB& rs_meta_pb);

    enum class DeleteBitmapStorageType {

        NOT_FOUND,

        IN_FDB,

        STANDALONE_FILE,

        PACKED_FILE,

    };

    // Process delete bitmap storage and decrement packed file ref count when needed.

    // Returns 0 for success, -1 for error.

    // out_storage_type: if not null, will be set to the delete bitmap storage type.

    int decrement_delete_bitmap_packed_file_ref_counts(int64_t tablet_id,

                                                       const std::string& rowset_id,

                                                       DeleteBitmapStorageType* out_storage_type);

    int delete_packed_file_and_kv(const std::string& packed_file_path,

                                  const std::string& packed_key,

                                  const cloud::PackedFileInfoPB& packed_info);

    /**

     * Get stage storage info from instance and init StorageVaultAccessor

     * @return 0 if accessor is successfully inited, 1 if stage not found, negative for error

     */

    int init_copy_job_accessor(const std::string& stage_id, const StagePB::StageType& stage_type,

                               std::shared_ptr<StorageVaultAccessor>* accessor);

    void register_recycle_task(const std::string& task_name, int64_t start_time);

    void unregister_recycle_task(const std::string& task_name);

    // for scan all tablets and statistics metrics

    int scan_tablets_and_statistics(int64_t tablet_id, int64_t index_id,

                                    RecyclerMetricsContext& metrics_context,

                                    int64_t partition_id = -1, bool is_empty_tablet = false);

    // for scan all rs of tablet and statistics metrics

    int scan_tablet_and_statistics(int64_t tablet_id, RecyclerMetricsContext& metrics_context);

    // Recycle operation log and the log keys. The log keys are specified by `raw_keys`.

    //

    // Both `operation_log` and `raw_keys` will be removed in the same transaction, to ensure atomicity.

    int recycle_operation_log(Versionstamp log_version, const std::vector<std::string>& raw_keys,

                              OperationLogPB operation_log,

                              OplogRecycleStats* oplog_stats = nullptr);

    // Recycle rowset meta and data, return 0 for success otherwise error

    //

    // This function will decrease the rowset ref count and remove the rowset meta and data if the ref count is 1.

    int recycle_rowset_meta_and_data(const RowsetDeleteTask& task);

    // Classify rowset task by ref_count, return 0 to add to batch delete, 1 if handled (ref>1), -1 on error

    int classify_rowset_task_by_ref_count(RowsetDeleteTask& task,

                                          std::vector<RowsetDeleteTask>& batch_delete_tasks);

    // Cleanup metadata for deleted rowsets, return 0 for success otherwise error

    int cleanup_rowset_metadata(const std::vector<RowsetDeleteTask>& tasks);

    // Whether the instance has any snapshots, return 0 for success otherwise error.

    int has_cluster_snapshots(bool* any);

    // Whether need to recycle versioned keys

    bool should_recycle_versioned_keys() const;

    /**

     * Parse the path of a packed-file fragment and output the owning tablet and rowset identifiers.

     *

     * @param path packed-file fragment path to decode

     * @param tablet_id output tablet identifier extracted from the path

     * @param rowset_id output rowset identifier extracted from the path

     * @return true if both identifiers are successfully parsed, false otherwise

     */

    static bool parse_packed_slice_path(std::string_view path, int64_t* tablet_id,

                                        std::string* rowset_id);

    // Check whether a rowset referenced by a packed file still exists in metadata.

    // @param stats optional recycle statistics collector.

    int check_rowset_exists(int64_t tablet_id, const std::string& rowset_id, bool* exists,

                            PackedFileRecycleStats* stats = nullptr);

    int check_recycle_and_tmp_rowset_exists(int64_t tablet_id, const std::string& rowset_id,

                                            int64_t txn_id, bool* recycle_exists, bool* tmp_exists);

    /**

     * Resolve which storage accessor should be used for a packed file.

     *

     * @param hint preferred storage resource identifier persisted with the file

     * @return pair of the resolved resource identifier and accessor; the accessor can be null if unavailable

     */

    std::pair<std::string, std::shared_ptr<StorageVaultAccessor>> resolve_packed_file_accessor(

            const std::string& hint);

    // Recompute packed-file counters and lifecycle state after validating contained fragments.

    // @param stats optional recycle statistics collector.

    int correct_packed_file_info(cloud::PackedFileInfoPB* packed_info, bool* changed,

                                 const std::string& packed_file_path,

                                 PackedFileRecycleStats* stats = nullptr);

    // Correct and recycle a single packed-file record, updating metadata and accounting statistics.

    // @param stats optional recycle statistics collector.

    int process_single_packed_file(const std::string& packed_key,

                                   const std::string& packed_file_path,

                                   PackedFileRecycleStats* stats);

    // Process a packed-file KV while scanning and aggregate recycling statistics.

    int handle_packed_file_kv(std::string_view key, std::string_view value,

                              PackedFileRecycleStats* stats, int* ret);

    // Abort the transaction/job associated with a rowset that is about to be recycled.

    // This function is called during rowset recycling to prevent data loss by ensuring that

    // the transaction/job cannot be committed after its rowset data has been deleted.

    //

    // Scenario:

    // When recycler detects an expired prepared rowset (e.g., from a failed load transaction/job),

    // it needs to recycle the rowset data. However, if the transaction/job is still active and gets

    // committed after the data is deleted, it would lead to data loss - the transaction/job would

    // reference non-existent data.

    //

    // Solution:

    // Before recycling the rowset data, this function aborts the associated transaction/job to ensure

    // it cannot be committed. This guarantees that:

    // 1. The transaction/job state is marked as ABORTED

    // 2. Any subsequent commit_rowset/commit_txn attempts will fail

    // 3. The rowset data can be safely deleted without risk of data loss

    //

    // Parameters:

    //   txn_id: The transaction/job ID associated with the rowset to be recycled

    //

    // Returns:

    //   0 on success, -1 on failure

    int abort_txn_for_related_rowset(int64_t txn_id);

    int abort_job_for_related_rowset(const RowsetMetaCloudPB& rowset_meta);

    template <typename T>

    int batch_abort_txn_or_job_for_recycle(const std::vector<std::string>& keys,

                                           bool skip_base_version);

private:

    std::atomic_bool stopped_ {false};

    std::shared_ptr<TxnKv> txn_kv_;

    std::string instance_id_;

    InstanceInfoPB instance_info_;

    // TODO(plat1ko): Add new accessor to map in runtime for new created storage vaults

    std::unordered_map<std::string, std::shared_ptr<StorageVaultAccessor>> accessor_map_;

    using InvertedIndexInfo =

            std::pair<InvertedIndexStorageFormatPB, std::vector<std::pair<int64_t, std::string>>>;

    class InvertedIndexIdCache;

    std::unique_ptr<InvertedIndexIdCache> inverted_index_id_cache_;

    std::mutex recycled_tablets_mtx_;

    // Store recycled tablets, we can skip deleting rowset data of these tablets because these data has already been deleted.

    std::unordered_set<int64_t> recycled_tablets_;

    std::mutex recycle_tasks_mutex;

    // <task_name, start_time>>

    std::map<std::string, int64_t> running_recycle_tasks;

    RecyclerThreadPoolGroup _thread_pool_group;

    std::shared_ptr<TxnLazyCommitter> txn_lazy_committer_;

    std::shared_ptr<SnapshotManager> snapshot_manager_;

    std::shared_ptr<DeleteBitmapLockWhiteList> delete_bitmap_lock_white_list_;

    std::shared_ptr<ResourceManager> resource_mgr_;

    TabletRecyclerMetricsContext tablet_metrics_context_;

    SegmentRecyclerMetricsContext segment_metrics_context_;

};

struct OperationLogReferenceInfo {

    bool referenced_by_instance = false;

    bool referenced_by_snapshot = false;

    Versionstamp referenced_snapshot_timestamp;

};

struct OplogRecycleStats {

    // Total oplog count scanned per round

    std::atomic<int64_t> total_num {0};

    // Oplogs not recycled this round (per round, written to mBvarStatus)

    std::atomic<int64_t> not_recycled_num {0};

    // Recycle failures (per round, accumulated to mBvarIntAdder at end)

    std::atomic<int64_t> failed_num {0};

    // Per-oplog-type recycled counts (incremented after successful commit)

    std::atomic<int64_t> recycled_commit_partition {0};

    std::atomic<int64_t> recycled_drop_partition {0};

    std::atomic<int64_t> recycled_commit_index {0};

    std::atomic<int64_t> recycled_drop_index {0};

    std::atomic<int64_t> recycled_update_tablet {0};

    std::atomic<int64_t> recycled_compaction {0};

    std::atomic<int64_t> recycled_schema_change {0};

    std::atomic<int64_t> recycled_commit_txn {0};

};

// Helper class to check if operation logs can be recycled based on snapshots and versionstamps

class OperationLogRecycleChecker {

public:

    OperationLogRecycleChecker(std::string_view instance_id, TxnKv* txn_kv,

                               const InstanceInfoPB& instance_info)

            : instance_id_(instance_id), txn_kv_(txn_kv), instance_info_(instance_info) {}

    // Initialize the checker by loading snapshots and setting max version stamp

    int init();

    // Check if an operation log can be recycled

    bool can_recycle(const Versionstamp& log_versionstamp, int64_t log_min_timestamp,

                     OperationLogReferenceInfo* reference_info) const;

    Versionstamp max_versionstamp() const { return max_versionstamp_; }

    const std::vector<std::pair<SnapshotPB, Versionstamp>>& get_snapshots() const {

        return snapshots_;

    }

private:

    std::string_view instance_id_;

    TxnKv* txn_kv_;

    const InstanceInfoPB& instance_info_;

    Versionstamp max_versionstamp_;

    Versionstamp source_snapshot_versionstamp_;

    std::map<Versionstamp, size_t> snapshot_indexes_;

    std::vector<std::pair<SnapshotPB, Versionstamp>> snapshots_;

};

class SnapshotDataSizeCalculator {

public:

    SnapshotDataSizeCalculator(std::string_view instance_id, std::shared_ptr<TxnKv> txn_kv)

            : instance_id_(instance_id), txn_kv_(std::move(txn_kv)) {}

    void init(const std::vector<std::pair<SnapshotPB, Versionstamp>>& snapshots);

    int calculate_operation_log_data_size(const std::string_view& log_key,

                                          OperationLogPB& operation_log,

                                          OperationLogReferenceInfo& reference_info);

    int save_snapshot_data_size_with_retry();

private:

    int get_all_index_partitions(int64_t db_id, int64_t table_id, int64_t index_id,

                                 std::vector<int64_t>* partition_ids);

    int get_index_partition_data_size(int64_t db_id, int64_t table_id, int64_t index_id,

                                      int64_t partition_id, int64_t* data_size);

    int save_operation_log(const std::string_view& log_key, OperationLogPB& operation_log);

    int save_snapshot_data_size();

    std::string_view instance_id_;

    std::shared_ptr<TxnKv> txn_kv_;

    int64_t instance_retained_data_size_ = 0;

    std::map<Versionstamp, int64_t> retained_data_size_;

    std::set<std::string> calculated_partitions_;

};

} // namespace doris::cloud