// 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.

#include "cloud/cloud_schema_change_job.h"

#include <gen_cpp/Types_types.h>

#include <gen_cpp/cloud.pb.h>

#include <algorithm>

#include <chrono>

#include <memory>

#include <mutex>

#include <random>

#include <ranges>

#include <thread>

#include "cloud/cloud_meta_mgr.h"

#include "cloud/cloud_tablet_mgr.h"

#include "common/status.h"

#include "service/backend_options.h"

#include "storage/delete/delete_handler.h"

#include "storage/index/inverted/inverted_index_desc.h"

#include "storage/olap_define.h"

#include "storage/rowset/beta_rowset.h"

#include "storage/rowset/rowset.h"

#include "storage/rowset/rowset_factory.h"

#include "storage/storage_engine.h"

#include "storage/tablet/tablet.h"

#include "storage/tablet/tablet_fwd.h"

#include "storage/tablet/tablet_meta.h"

#include "util/debug_points.h"

namespace doris {

using namespace ErrorCode;

static constexpr int ALTER_TABLE_BATCH_SIZE = 4096;

static constexpr int SCHEMA_CHANGE_DELETE_BITMAP_LOCK_ID = -2;

std::unique_ptr<SchemaChange> get_sc_procedure(const BlockChanger& changer, bool sc_sorting,

                                               int64_t mem_limit) {

    if (sc_sorting) {

        return std::make_unique<VBaseSchemaChangeWithSorting>(changer, mem_limit);

    }

    // else sc_directly

    return std::make_unique<VSchemaChangeDirectly>(changer);

}

CloudSchemaChangeJob::CloudSchemaChangeJob(CloudStorageEngine& cloud_storage_engine,

                                           std::string job_id, int64_t expiration)

        : _cloud_storage_engine(cloud_storage_engine),

          _job_id(std::move(job_id)),

          _expiration(expiration) {

    _initiator = boost::uuids::hash_value(UUIDGenerator::instance()->next_uuid()) &

                 std::numeric_limits<int64_t>::max();

}

CloudSchemaChangeJob::~CloudSchemaChangeJob() = default;

Status CloudSchemaChangeJob::process_alter_tablet(const TAlterTabletReqV2& request) {

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::process_alter_tablet.block", DBUG_BLOCK);

    // new tablet has to exist

    _new_tablet = DORIS_TRY(_cloud_storage_engine.tablet_mgr().get_tablet(request.new_tablet_id));

    if (_new_tablet->tablet_state() == TABLET_RUNNING) {

        LOG(INFO) << "schema change job has already finished. base_tablet_id="

                  << request.base_tablet_id << ", new_tablet_id=" << request.new_tablet_id

                  << ", alter_version=" << request.alter_version << ", job_id=" << _job_id;

        return Status::OK();

    }

    _base_tablet = DORIS_TRY(_cloud_storage_engine.tablet_mgr().get_tablet(request.base_tablet_id));

    static constexpr long TRY_LOCK_TIMEOUT = 30;

    std::unique_lock schema_change_lock(_base_tablet->get_schema_change_lock(), std::defer_lock);

    bool owns_lock = schema_change_lock.try_lock_for(std::chrono::seconds(TRY_LOCK_TIMEOUT));

    _new_tablet->set_alter_failed(false);

    Defer defer([this] {

        // if tablet state is not TABLET_RUNNING when return, indicates that alter has failed.

        if (_new_tablet->tablet_state() != TABLET_RUNNING) {

            _new_tablet->set_alter_failed(true);

        }

    });

    if (!owns_lock) {

        LOG(WARNING) << "Failed to obtain schema change lock, there might be inverted index being "

                        "built on base_tablet="

                     << request.base_tablet_id;

        return Status::Error<TRY_LOCK_FAILED>(

                "Failed to obtain schema change lock, there might be inverted index being "

                "built on base_tablet=",

                request.base_tablet_id);

    }

    // MUST sync rowsets before capturing rowset readers and building DeleteHandler

    SyncOptions options;

    options.query_version = request.alter_version;

    RETURN_IF_ERROR(_base_tablet->sync_rowsets(options));

    // ATTN: Only convert rowsets of version larger than 1, MUST let the new tablet cache have rowset [0-1]

    _output_cumulative_point = _base_tablet->cumulative_layer_point();

    std::vector<RowSetSplits> rs_splits;

    int64_t base_max_version = _base_tablet->max_version_unlocked();

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::process_alter_tablet.override_base_max_version", {

        auto v = dp->param<int64_t>("version", -1);

        if (v > 0) {

            LOG(INFO) << "override base_max_version from " << base_max_version << " to " << v;

            base_max_version = v;

        }

    });

    cloud::TabletJobInfoPB job;

    auto* idx = job.mutable_idx();

    idx->set_tablet_id(_base_tablet->tablet_id());

    idx->set_table_id(_base_tablet->table_id());

    idx->set_index_id(_base_tablet->index_id());

    idx->set_partition_id(_base_tablet->partition_id());

    auto* sc_job = job.mutable_schema_change();

    sc_job->set_id(_job_id);

    sc_job->set_initiator(BackendOptions::get_localhost() + ':' +

                          std::to_string(config::heartbeat_service_port));

    sc_job->set_alter_version(base_max_version);

    auto* new_tablet_idx = sc_job->mutable_new_tablet_idx();

    new_tablet_idx->set_tablet_id(_new_tablet->tablet_id());

    new_tablet_idx->set_table_id(_new_tablet->table_id());

    new_tablet_idx->set_index_id(_new_tablet->index_id());

    new_tablet_idx->set_partition_id(_new_tablet->partition_id());

    cloud::StartTabletJobResponse start_resp;

    auto st = _cloud_storage_engine.meta_mgr().prepare_tablet_job(job, &start_resp);

    if (!st.ok()) {

        if (start_resp.status().code() == cloud::JOB_ALREADY_SUCCESS) {

            st = _new_tablet->sync_rowsets();

            if (!st.ok()) {

                LOG_WARNING("failed to sync new tablet")

                        .tag("tablet_id", _new_tablet->tablet_id())

                        .error(st);

            }

            return Status::OK();

        }

        return st;

    }

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::process_alter_tablet.alter_fail", {

        auto res =

                Status::InternalError("inject alter tablet failed. base_tablet={}, new_tablet={}",

                                      request.base_tablet_id, request.new_tablet_id);

        LOG(WARNING) << "inject error. res=" << res;

        return res;

    });

    // Check for cross-V1 compaction rowsets on new tablet.

    // During queue wait, compaction may have committed a rowset that crosses the

    // alter_version boundary (V1). This happens when compaction commits before

    // prepare_tablet_job registers the SC job in meta-service.

    // If such a rowset exists, SC commit would create version overlap, so we

    // fail early and let FE retry (with a higher V1 next time).

    {

        RETURN_IF_ERROR(_new_tablet->sync_rowsets());

        std::shared_lock rlock(_new_tablet->get_header_lock());

        for (auto& [v, rs] : _new_tablet->rowset_map()) {

            if (v.first > 1 && v.first <= start_resp.alter_version() &&

                v.second > start_resp.alter_version()) {

                LOG(WARNING) << "cross-V1 compaction detected on new tablet"

                             << ", tablet_id=" << _new_tablet->tablet_id() << ", rowset=["

                             << v.first << "-" << v.second << "]"

                             << ", alter_version=" << start_resp.alter_version()

                             << ", job_id=" << _job_id << ". Will retry with higher alter_version.";

                return Status::Error<ErrorCode::INTERNAL_ERROR>(

                        "cross-V1 compaction detected on new tablet, tablet_id={}, "

                        "rowset=[{}-{}], alter_version={}",

                        _new_tablet->tablet_id(), v.first, v.second, start_resp.alter_version());

            }

        }

    }

    if (request.alter_version > 1) {

        // [0-1] is a placeholder rowset, no need to convert

        RETURN_IF_ERROR(_base_tablet->capture_rs_readers({2, start_resp.alter_version()},

                                                         &rs_splits,

                                                         {.skip_missing_versions = false,

                                                          .enable_prefer_cached_rowset = false,

                                                          .query_freshness_tolerance_ms = -1}));

    }

    // Between prepare_tablet_job (SC job registered in meta-service) and

    // set_alter_version (local alter_version update). Used to test cross-V1 race.

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::process_alter_tablet.after_prepare_job", DBUG_BLOCK);

    Defer defer2 {[&]() {

        _new_tablet->set_alter_version(-1);

        _base_tablet->set_alter_version(-1);

    }};

    _new_tablet->set_alter_version(start_resp.alter_version());

    _base_tablet->set_alter_version(start_resp.alter_version());

    LOG(INFO) << "Begin to alter tablet. base_tablet_id=" << request.base_tablet_id

              << ", new_tablet_id=" << request.new_tablet_id

              << ", alter_version=" << start_resp.alter_version() << ", job_id=" << _job_id;

    sc_job->set_alter_version(start_resp.alter_version());

    // FIXME(cyx): Should trigger compaction on base_tablet if there are too many rowsets to convert.

    // Create a new tablet schema, should merge with dropped columns in light weight schema change

    _base_tablet_schema = std::make_shared<TabletSchema>();

    _base_tablet_schema->update_tablet_columns(*_base_tablet->tablet_schema(), request.columns);

    _new_tablet_schema = _new_tablet->tablet_schema();

    std::vector<ColumnId> return_columns;

    return_columns.resize(_base_tablet_schema->num_columns());

    std::iota(return_columns.begin(), return_columns.end(), 0);

    // delete handlers to filter out deleted rows

    DeleteHandler delete_handler;

    std::vector<RowsetMetaSharedPtr> delete_predicates;

    for (auto& split : rs_splits) {

        auto& rs_meta = split.rs_reader->rowset()->rowset_meta();

        if (rs_meta->has_delete_predicate()) {

            _base_tablet_schema->merge_dropped_columns(*rs_meta->tablet_schema());

            delete_predicates.push_back(rs_meta);

        }

    }

    RETURN_IF_ERROR(delete_handler.init(_base_tablet_schema, delete_predicates,

                                        start_resp.alter_version()));

    // reader_context is stack variables, it's lifetime MUST keep the same with rs_readers

    RowsetReaderContext reader_context;

    reader_context.reader_type = ReaderType::READER_ALTER_TABLE;

    reader_context.tablet_schema = _base_tablet_schema;

    reader_context.need_ordered_result = true;

    reader_context.delete_handler = &delete_handler;

    reader_context.return_columns = &return_columns;

    reader_context.sequence_id_idx = reader_context.tablet_schema->sequence_col_idx();

    reader_context.is_unique = _base_tablet->keys_type() == UNIQUE_KEYS;

    reader_context.batch_size = ALTER_TABLE_BATCH_SIZE;

    reader_context.delete_bitmap = _base_tablet->tablet_meta()->delete_bitmap_ptr();

    reader_context.version = Version(0, start_resp.alter_version());

    std::vector<uint32_t> cluster_key_idxes;

    if (!_base_tablet_schema->cluster_key_uids().empty()) {

        for (const auto& uid : _base_tablet_schema->cluster_key_uids()) {

            cluster_key_idxes.emplace_back(_base_tablet_schema->field_index(uid));

        }

        reader_context.read_orderby_key_columns = &cluster_key_idxes;

        reader_context.is_unique = false;

        reader_context.sequence_id_idx = -1;

    }

    for (auto& split : rs_splits) {

        RETURN_IF_ERROR(split.rs_reader->init(&reader_context));

    }

    SchemaChangeParams sc_params;

    // cache schema change output to file cache

    std::vector<RowsetSharedPtr> rowsets;

    rowsets.resize(rs_splits.size());

    std::transform(rs_splits.begin(), rs_splits.end(), rowsets.begin(),

                   [](RowSetSplits& split) { return split.rs_reader->rowset(); });

    sc_params.output_to_file_cache = _should_cache_sc_output(rowsets);

    if (request.__isset.query_globals && request.__isset.query_options) {

        sc_params.runtime_state =

                std::make_shared<RuntimeState>(request.query_options, request.query_globals);

    } else {

        // for old version request compatibility

        sc_params.runtime_state = std::make_shared<RuntimeState>();

    }

    RETURN_IF_ERROR(DescriptorTbl::create(&sc_params.pool, request.desc_tbl, &sc_params.desc_tbl));

    sc_params.ref_rowset_readers.reserve(rs_splits.size());

    for (RowSetSplits& split : rs_splits) {

        sc_params.ref_rowset_readers.emplace_back(std::move(split.rs_reader));

    }

    sc_params.delete_handler = &delete_handler;

    sc_params.be_exec_version = request.be_exec_version;

    DCHECK(request.__isset.alter_tablet_type);

    switch (request.alter_tablet_type) {

    case TAlterTabletType::SCHEMA_CHANGE:

        sc_params.alter_tablet_type = AlterTabletType::SCHEMA_CHANGE;

        break;

    case TAlterTabletType::ROLLUP:

        sc_params.alter_tablet_type = AlterTabletType::ROLLUP;

        break;

    case TAlterTabletType::MIGRATION:

        sc_params.alter_tablet_type = AlterTabletType::MIGRATION;

        break;

    }

    sc_params.vault_id = request.storage_vault_id;

    if (!request.__isset.materialized_view_params) {

        return _convert_historical_rowsets(sc_params, job);

    }

    for (auto item : request.materialized_view_params) {

        AlterMaterializedViewParam mv_param;

        mv_param.column_name = item.column_name;

        /*

         * origin_column_name is always be set now,

         * but origin_column_name may be not set in some materialized view function. eg:count(1)

        */

        if (item.__isset.origin_column_name) {

            mv_param.origin_column_name = item.origin_column_name;

        }

        if (item.__isset.mv_expr) {

            mv_param.expr = std::make_shared<TExpr>(item.mv_expr);

        }

        sc_params.materialized_params_map.insert(

                std::make_pair(to_lower(item.column_name), mv_param));

    }

    sc_params.enable_unique_key_merge_on_write = _new_tablet->enable_unique_key_merge_on_write();

    return _convert_historical_rowsets(sc_params, job);

}

Status CloudSchemaChangeJob::_convert_historical_rowsets(const SchemaChangeParams& sc_params,

                                                         cloud::TabletJobInfoPB& job) {

    LOG(INFO) << "Begin to convert historical rowsets for new_tablet from base_tablet. base_tablet="

              << _base_tablet->tablet_id() << ", new_tablet=" << _new_tablet->tablet_id()

              << ", job_id=" << _job_id;

    // Add filter information in change, and filter column information will be set in _parse_request

    // And filter some data every time the row block changes

    BlockChanger changer(_new_tablet->tablet_schema(), *sc_params.desc_tbl,

                         sc_params.runtime_state);

    bool sc_sorting = false;

    bool sc_directly = false;

    // 1. Parse the Alter request and convert it into an internal representation

    RETURN_IF_ERROR(SchemaChangeJob::parse_request(sc_params, _base_tablet_schema.get(),

                                                   _new_tablet_schema.get(), &changer, &sc_sorting,

                                                   &sc_directly));

    if (!sc_sorting && !sc_directly && sc_params.alter_tablet_type == AlterTabletType::ROLLUP) {

        LOG(INFO) << "Don't support to add materialized view by linked schema change";

        return Status::InternalError(

                "Don't support to add materialized view by linked schema change");

    }

    LOG(INFO) << "schema change type, sc_sorting: " << sc_sorting

              << ", sc_directly: " << sc_directly << ", base_tablet=" << _base_tablet->tablet_id()

              << ", new_tablet=" << _new_tablet->tablet_id();

    // 2. Generate historical data converter

    auto sc_procedure = get_sc_procedure(

            changer, sc_sorting,

            _cloud_storage_engine.memory_limitation_bytes_per_thread_for_schema_change());

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_convert_historical_rowsets.block", DBUG_BLOCK);

    // 3. Convert historical data

    bool already_exist_any_version = false;

    for (const auto& rs_reader : sc_params.ref_rowset_readers) {

        VLOG_TRACE << "Begin to convert a history rowset. version=" << rs_reader->version();

        RowsetWriterContext context;

        context.txn_id = rs_reader->rowset()->txn_id();

        context.txn_expiration = _expiration;

        context.version = rs_reader->version();

        context.rowset_state = VISIBLE;

        context.segments_overlap = rs_reader->rowset()->rowset_meta()->segments_overlap();

        context.tablet_schema = _new_tablet->tablet_schema();

        context.newest_write_timestamp = rs_reader->newest_write_timestamp();

        context.storage_resource = _cloud_storage_engine.get_storage_resource(sc_params.vault_id);

        context.job_id = _job_id;

        context.write_file_cache = sc_params.output_to_file_cache;

        context.tablet = _new_tablet;

        if (!context.storage_resource) {

            return Status::InternalError("vault id not found, maybe not sync, vault id {}",

                                         sc_params.vault_id);

        }

        context.write_type = DataWriteType::TYPE_SCHEMA_CHANGE;

        // TODO if support VerticalSegmentWriter, also need to handle cluster key primary key index

        bool vertical = false;

        if (sc_sorting && !_new_tablet->tablet_schema()->cluster_key_uids().empty()) {

            // see VBaseSchemaChangeWithSorting::_external_sorting

            vertical = true;

        }

        auto rowset_writer = DORIS_TRY(_new_tablet->create_rowset_writer(context, vertical));

        RowsetMetaSharedPtr existed_rs_meta;

        auto st = _cloud_storage_engine.meta_mgr().prepare_rowset(*rowset_writer->rowset_meta(),

                                                                  _job_id, &existed_rs_meta);

        if (!st.ok()) {

            if (st.is<ALREADY_EXIST>()) {

                LOG(INFO) << "Rowset " << rs_reader->version() << " has already existed in tablet "

                          << _new_tablet->tablet_id();

                // Add already committed rowset to _output_rowsets.

                DCHECK(existed_rs_meta != nullptr);

                RowsetSharedPtr rowset;

                // schema is nullptr implies using RowsetMeta.tablet_schema

                RETURN_IF_ERROR(

                        RowsetFactory::create_rowset(nullptr, "", existed_rs_meta, &rowset));

                _output_rowsets.push_back(std::move(rowset));

                already_exist_any_version = true;

                continue;

            } else {

                return st;

            }

        }

        st = sc_procedure->process(rs_reader, rowset_writer.get(), _new_tablet, _base_tablet,

                                   _base_tablet_schema, _new_tablet_schema);

        if (!st.ok()) {

            return Status::InternalError(

                    "failed to process schema change on rowset, version=[{}-{}], status={}",

                    rs_reader->version().first, rs_reader->version().second, st.to_string());

        }

        RowsetSharedPtr new_rowset;

        st = rowset_writer->build(new_rowset);

        if (!st.ok()) {

            return Status::InternalError("failed to build rowset, version=[{}-{}] status={}",

                                         rs_reader->version().first, rs_reader->version().second,

                                         st.to_string());

        }

        st = _cloud_storage_engine.meta_mgr().commit_rowset(*rowset_writer->rowset_meta(), _job_id,

                                                            &existed_rs_meta);

        if (!st.ok()) {

            if (st.is<ALREADY_EXIST>()) {

                LOG(INFO) << "Rowset " << rs_reader->version() << " has already existed in tablet "

                          << _new_tablet->tablet_id();

                // Add already committed rowset to _output_rowsets.

                DCHECK(existed_rs_meta != nullptr);

                RowsetSharedPtr rowset;

                // schema is nullptr implies using RowsetMeta.tablet_schema

                RETURN_IF_ERROR(

                        RowsetFactory::create_rowset(nullptr, "", existed_rs_meta, &rowset));

                _output_rowsets.push_back(std::move(rowset));

                continue;

            } else {

                return st;

            }

        }

        _output_rowsets.push_back(std::move(new_rowset));

        VLOG_TRACE << "Successfully convert a history version " << rs_reader->version();

    }

    auto* sc_job = job.mutable_schema_change();

    if (!sc_params.ref_rowset_readers.empty()) {

        int64_t num_output_rows = 0;

        int64_t size_output_rowsets = 0;

        int64_t num_output_segments = 0;

        int64_t index_size_output_rowsets = 0;

        int64_t segment_size_output_rowsets = 0;

        for (auto& rs : _output_rowsets) {

            sc_job->add_txn_ids(rs->txn_id());

            sc_job->add_output_versions(rs->end_version());

            num_output_rows += rs->num_rows();

            size_output_rowsets += rs->total_disk_size();

            num_output_segments += rs->num_segments();

            index_size_output_rowsets += rs->index_disk_size();

            segment_size_output_rowsets += rs->data_disk_size();

        }

        sc_job->set_num_output_rows(num_output_rows);

        sc_job->set_size_output_rowsets(size_output_rowsets);

        sc_job->set_num_output_segments(num_output_segments);

        sc_job->set_num_output_rowsets(_output_rowsets.size());

        sc_job->set_index_size_output_rowsets(index_size_output_rowsets);

        sc_job->set_segment_size_output_rowsets(segment_size_output_rowsets);

    }

    _output_cumulative_point = std::min(_output_cumulative_point, sc_job->alter_version() + 1);

    sc_job->set_output_cumulative_point(_output_cumulative_point);

    DBUG_EXECUTE_IF("CloudSchemaChangeJob.process_alter_tablet.sleep", DBUG_BLOCK);

    // process delete bitmap if the table is MOW

    bool has_stop_token {false};

    bool should_clear_stop_token {true};

    Defer defer {[&]() {

        if (has_stop_token) {

            static_cast<void>(_cloud_storage_engine.unregister_compaction_stop_token(

                    _new_tablet, should_clear_stop_token));

        }

    }};

    if (_new_tablet->enable_unique_key_merge_on_write()) {

        has_stop_token = true;

        // If there are historical versions of rowsets, we need to recalculate their delete

        // bitmaps, otherwise we will miss the delete bitmaps of incremental rowsets

        int64_t start_calc_delete_bitmap_version =

                // [0-1] is a placeholder rowset, start from 2.

                already_exist_any_version ? 2 : sc_job->alter_version() + 1;

        RETURN_IF_ERROR(_process_delete_bitmap(sc_job->alter_version(),

                                               start_calc_delete_bitmap_version, _initiator,

                                               sc_params.vault_id));

        sc_job->set_delete_bitmap_lock_initiator(_initiator);

    }

    cloud::FinishTabletJobResponse finish_resp;

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_convert_historical_rowsets.test_conflict", {

        std::srand(static_cast<unsigned int>(std::time(nullptr)));

        int random_value = std::rand() % 100;

        if (random_value < 20) {

            return Status::Error<ErrorCode::DELETE_BITMAP_LOCK_ERROR>("test txn conflict");

        }

    });

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_convert_historical_rowsets.fail.before.commit_job", {

        LOG_INFO("inject retryable error before commit sc job, tablet={}",

                 _new_tablet->tablet_id());

        return Status::Error<ErrorCode::DELETE_BITMAP_LOCK_ERROR>("injected retryable error");

    });

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_convert_historical_rowsets.before.commit_job",

                    DBUG_BLOCK);

    auto st = _cloud_storage_engine.meta_mgr().commit_tablet_job(job, &finish_resp);

    if (!st.ok()) {

        if (finish_resp.status().code() == cloud::JOB_ALREADY_SUCCESS) {

            st = _new_tablet->sync_rowsets();

            if (!st.ok()) {

                LOG_WARNING("failed to sync new tablet")

                        .tag("tablet_id", _new_tablet->tablet_id())

                        .error(st);

            }

            return Status::OK();

        }

        return st;

    } else {

        should_clear_stop_token = false;

    }

    const auto& stats = finish_resp.stats();

    {

        // to prevent the converted historical rowsets be replaced by rowsets written on new tablet

        // during double write phase by `CloudMetaMgr::sync_tablet_rowsets` in another thread

        std::unique_lock lock {_new_tablet->get_sync_meta_lock()};

        std::unique_lock wlock(_new_tablet->get_header_lock());

        // Mirror MS behavior: delete rowsets in [2, alter_version] before adding

        // SC output rowsets to avoid stale compaction rowsets remaining visible.

        {

            int64_t alter_ver = sc_job->alter_version();

            std::vector<RowsetSharedPtr> to_delete;

            for (auto& [v, rs] : _new_tablet->rowset_map()) {

                if (v.first >= 2 && v.second <= alter_ver) {

                    to_delete.push_back(rs);

                }

            }

            if (!to_delete.empty()) {

                LOG_INFO(

                        "schema change: delete {} local rowsets in [2, {}] before adding SC "

                        "output, tablet_id={}, versions=[{}]",

                        to_delete.size(), alter_ver, _new_tablet->tablet_id(),

                        fmt::join(to_delete | std::views::transform([](const auto& rs) {

                                      return rs->version().to_string();

                                  }),

                                  ", "));

                _new_tablet->delete_rowsets_for_schema_change(to_delete, wlock);

            }

        }

        _new_tablet->add_rowsets(std::move(_output_rowsets), true, wlock, false);

        _new_tablet->set_cumulative_layer_point(_output_cumulative_point);

        _new_tablet->reset_approximate_stats(stats.num_rowsets(), stats.num_segments(),

                                             stats.num_rows(), stats.data_size());

        RETURN_IF_ERROR(_new_tablet->set_tablet_state(TABLET_RUNNING));

    }

    return Status::OK();

}

Status CloudSchemaChangeJob::_process_delete_bitmap(int64_t alter_version,

                                                    int64_t start_calc_delete_bitmap_version,

                                                    int64_t initiator,

                                                    const std::string& vault_id) {

    LOG_INFO("process mow table")

            .tag("new_tablet_id", _new_tablet->tablet_id())

            .tag("out_rowset_size", _output_rowsets.size())

            .tag("start_calc_delete_bitmap_version", start_calc_delete_bitmap_version)

            .tag("alter_version", alter_version);

    RETURN_IF_ERROR(_cloud_storage_engine.register_compaction_stop_token(_new_tablet, initiator));

    TabletMetaSharedPtr tmp_meta = std::make_shared<TabletMeta>(*(_new_tablet->tablet_meta()));

    tmp_meta->delete_bitmap().delete_bitmap.clear();

    // Keep only version [0-1] rowset, other rowsets will be added in _output_rowsets

    auto& rs_metas = tmp_meta->all_mutable_rs_metas();

    for (auto it = rs_metas.begin(); it != rs_metas.end();) {

        const auto& rs_meta = it->second;

        if (rs_meta->version().first == 0 && rs_meta->version().second == 1) {

            ++it;

        } else {

            it = rs_metas.erase(it);

        }

    }

    std::shared_ptr<CloudTablet> tmp_tablet =

            std::make_shared<CloudTablet>(_cloud_storage_engine, tmp_meta);

    {

        std::unique_lock wlock(tmp_tablet->get_header_lock());

        tmp_tablet->add_rowsets(_output_rowsets, true, wlock, false);

        // Set alter version to let the tmp_tablet can fill hole rowset greater than alter_version

        tmp_tablet->set_alter_version(alter_version);

    }

    // step 1, process incremental rowset without delete bitmap update lock

    RETURN_IF_ERROR(_cloud_storage_engine.meta_mgr().sync_tablet_rowsets(tmp_tablet.get()));

    int64_t max_version = tmp_tablet->max_version().second;

    LOG(INFO) << "alter table for mow table, calculate delete bitmap of "

              << "incremental rowsets without lock, version: " << start_calc_delete_bitmap_version

              << "-" << max_version << " new_table_id: " << _new_tablet->tablet_id();

    if (max_version >= start_calc_delete_bitmap_version) {

        auto ret = DORIS_TRY(tmp_tablet->capture_consistent_rowsets_unlocked(

                {start_calc_delete_bitmap_version, max_version}, CaptureRowsetOps {}));

        DBUG_EXECUTE_IF("CloudSchemaChangeJob::_process_delete_bitmap.after.capture_without_lock",

                        DBUG_BLOCK);

        {

            std::unique_lock wlock(tmp_tablet->get_header_lock());

            tmp_tablet->add_rowsets(_output_rowsets, true, wlock, false);

        }

        for (auto rowset : ret.rowsets) {

            RETURN_IF_ERROR(CloudTablet::update_delete_bitmap_without_lock(tmp_tablet, rowset));

        }

    }

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_process_delete_bitmap.before_new_inc.block",

                    DBUG_BLOCK);

    // step 2, process incremental rowset with delete bitmap update lock

    RETURN_IF_ERROR(_cloud_storage_engine.meta_mgr().get_delete_bitmap_update_lock(

            *_new_tablet, SCHEMA_CHANGE_DELETE_BITMAP_LOCK_ID, initiator));

    RETURN_IF_ERROR(_cloud_storage_engine.meta_mgr().sync_tablet_rowsets(tmp_tablet.get()));

    int64_t new_max_version = tmp_tablet->max_version().second;

    LOG(INFO) << "alter table for mow table, calculate delete bitmap of "

              << "incremental rowsets with lock, version: " << max_version + 1 << "-"

              << new_max_version << " new_tablet_id: " << _new_tablet->tablet_id();

    if (new_max_version > max_version) {

        auto ret = DORIS_TRY(tmp_tablet->capture_consistent_rowsets_unlocked(

                {max_version + 1, new_max_version}, CaptureRowsetOps {}));

        {

            std::unique_lock wlock(tmp_tablet->get_header_lock());

            tmp_tablet->add_rowsets(_output_rowsets, true, wlock, false);

        }

        for (auto rowset : ret.rowsets) {

            RETURN_IF_ERROR(CloudTablet::update_delete_bitmap_without_lock(tmp_tablet, rowset));

        }

    }

    DBUG_EXECUTE_IF("CloudSchemaChangeJob::_process_delete_bitmap.inject_sleep", {

        auto p = dp->param("percent", 0.01);

        auto sleep_time = dp->param("sleep", 100);

        std::mt19937 gen {std::random_device {}()};

        std::bernoulli_distribution inject_fault {p};

        if (inject_fault(gen)) {

            LOG_INFO("injection sleep for {} seconds, tablet_id={}, sc job_id={}", sleep_time,

                     _new_tablet->tablet_id(), _job_id);

            std::this_thread::sleep_for(std::chrono::seconds(sleep_time));

        }

    });

    auto& delete_bitmap = tmp_tablet->tablet_meta()->delete_bitmap();

    auto storage_resource = _cloud_storage_engine.get_storage_resource(vault_id);

    // step4, store delete bitmap

    RETURN_IF_ERROR(_cloud_storage_engine.meta_mgr().update_delete_bitmap(

            *_new_tablet, SCHEMA_CHANGE_DELETE_BITMAP_LOCK_ID, initiator, &delete_bitmap,

            &delete_bitmap, "", storage_resource, config::delete_bitmap_store_write_version));

    _new_tablet->tablet_meta()->delete_bitmap() = delete_bitmap;

    return Status::OK();

}

void CloudSchemaChangeJob::clean_up_on_failure() {

    if (_new_tablet == nullptr) {

        return;

    }

    if (_new_tablet->keys_type() == KeysType::UNIQUE_KEYS &&

        _new_tablet->enable_unique_key_merge_on_write()) {

        _cloud_storage_engine.meta_mgr().remove_delete_bitmap_update_lock(

                _new_tablet->table_id(), SCHEMA_CHANGE_DELETE_BITMAP_LOCK_ID, _initiator,

                _new_tablet->tablet_id());

    }

    for (const auto& output_rs : _output_rowsets) {

        if (output_rs.use_count() > 2) {

            LOG(WARNING) << "Rowset " << output_rs->rowset_id().to_string() << " has "

                         << output_rs.use_count()

                         << " references. File Cache won't be recycled when query is using it.";

            return;

        }

        output_rs->clear_cache();

    }

}

bool CloudSchemaChangeJob::_should_cache_sc_output(

        const std::vector<RowsetSharedPtr>& input_rowsets) {

    int64_t total_size = 0;

    int64_t cached_index_size = 0;

    int64_t cached_data_size = 0;

    for (const auto& rs : input_rowsets) {

        const RowsetMetaSharedPtr& rs_meta = rs->rowset_meta();

        total_size += rs_meta->total_disk_size();

        cached_index_size += rs->approximate_cache_index_size();

        cached_data_size += rs->approximate_cached_data_size();

    }

    double input_hit_rate = static_cast<double>(cached_index_size + cached_data_size) / total_size;

    LOG(INFO) << "CloudSchemaChangeJob check cache sc output strategy. "

              << "job_id=" << _job_id << ", input_rowsets_count=" << input_rowsets.size()

              << ", total_size=" << total_size << ", cached_index_size=" << cached_index_size

              << ", cached_data_size=" << cached_data_size << ", input_hit_rate=" << input_hit_rate

              << ", min_hit_ratio_threshold="

              << config::file_cache_keep_schema_change_output_min_hit_ratio << ", should_cache="

              << (input_hit_rate > config::file_cache_keep_schema_change_output_min_hit_ratio);

    if (input_hit_rate > config::file_cache_keep_schema_change_output_min_hit_ratio) {

        return true;

    }

    return false;

}

} // namespace doris