// 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 "olap/cumulative_compaction.h"

#include <memory>

#include <mutex>

#include <ostream>

#include "common/config.h"

#include "common/logging.h"

#include "olap/cumulative_compaction_policy.h"

#include "olap/cumulative_compaction_time_series_policy.h"

#include "olap/olap_define.h"

#include "olap/rowset/rowset_meta.h"

#include "olap/tablet.h"

#include "runtime/thread_context.h"

#include "util/doris_metrics.h"

#include "util/time.h"

#include "util/trace.h"

namespace doris {

using namespace ErrorCode;

void CumulativeCompaction::find_longest_consecutive_version(std::vector<RowsetSharedPtr>* rowsets,

                                                            std::vector<Version>* missing_version) {

    if (rowsets->empty()) {

        return;

    }

    RowsetSharedPtr prev_rowset = rowsets->front();

    size_t i = 1;

    int max_start = 0;

    int max_length = 1;

    int start = 0;

    int length = 1;

    for (; i < rowsets->size(); ++i) {

        RowsetSharedPtr rowset = (*rowsets)[i];

        if (rowset->start_version() != prev_rowset->end_version() + 1) {

            if (missing_version != nullptr) {

                missing_version->push_back(prev_rowset->version());

                missing_version->push_back(rowset->version());

            }

            start = i;

            length = 1;

        } else {

            length++;

        }

        if (length > max_length) {

            max_start = start;

            max_length = length;

        }

        prev_rowset = rowset;

    }

    *rowsets = {rowsets->begin() + max_start, rowsets->begin() + max_start + max_length};

}

CumulativeCompaction::CumulativeCompaction(StorageEngine& engine, const TabletSharedPtr& tablet)

        : CompactionMixin(engine, tablet,

                          "CumulativeCompaction:" + std::to_string(tablet->tablet_id())) {}

CumulativeCompaction::~CumulativeCompaction() = default;

Status CumulativeCompaction::prepare_compact() {

    if (!tablet()->init_succeeded()) {

        return Status::Error<CUMULATIVE_INVALID_PARAMETERS, false>("_tablet init failed");

    }

    std::unique_lock<std::mutex> lock(tablet()->get_cumulative_compaction_lock(), std::try_to_lock);

    if (!lock.owns_lock()) {

        return Status::Error<TRY_LOCK_FAILED, false>(

                "The tablet is under cumulative compaction. tablet={}", _tablet->tablet_id());

    }

    tablet()->calculate_cumulative_point();

    VLOG_CRITICAL << "after calculate, current cumulative point is "

                  << tablet()->cumulative_layer_point() << ", tablet=" << _tablet->tablet_id();

    RETURN_IF_ERROR(pick_rowsets_to_compact());

    COUNTER_UPDATE(_input_rowsets_counter, _input_rowsets.size());

    return Status::OK();

}

Status CumulativeCompaction::execute_compact() {

    std::unique_lock<std::mutex> lock(tablet()->get_cumulative_compaction_lock(), std::try_to_lock);

    if (!lock.owns_lock()) {

        return Status::Error<TRY_LOCK_FAILED, false>(

                "The tablet is under cumulative compaction. tablet={}", _tablet->tablet_id());

    }

    SCOPED_ATTACH_TASK(_mem_tracker);

    RETURN_IF_ERROR(CompactionMixin::execute_compact());

    DCHECK_EQ(_state, CompactionState::SUCCESS);

    if (tablet()->tablet_meta()->time_series_compaction_level_threshold() >= 2) {

        tablet()->cumulative_compaction_policy()->update_compaction_level(tablet(), _input_rowsets,

                                                                          _output_rowset);

    }

    tablet()->cumulative_compaction_policy()->update_cumulative_point(

            tablet(), _input_rowsets, _output_rowset, _last_delete_version);

    VLOG_CRITICAL << "after cumulative compaction, current cumulative point is "

                  << tablet()->cumulative_layer_point() << ", tablet=" << _tablet->tablet_id();

    // TIME_SERIES_POLICY, generating an empty rowset doesn't need to update the timestamp.

    if (!(tablet()->tablet_meta()->compaction_policy() == CUMULATIVE_TIME_SERIES_POLICY &&

          _output_rowset->num_segments() == 0)) {

        tablet()->set_last_cumu_compaction_success_time(UnixMillis());

    }

    DorisMetrics::instance()->cumulative_compaction_deltas_total->increment(_input_rowsets.size());

    DorisMetrics::instance()->cumulative_compaction_bytes_total->increment(

            _input_rowsets_total_size);

    return Status::OK();

}

Status CumulativeCompaction::pick_rowsets_to_compact() {

    auto candidate_rowsets = tablet()->pick_candidate_rowsets_to_cumulative_compaction();

    if (candidate_rowsets.empty()) {

        return Status::Error<CUMULATIVE_NO_SUITABLE_VERSION>("candidate_rowsets is empty");

    }

    // candidate_rowsets may not be continuous

    // So we need to choose the longest continuous path from it.

    std::vector<Version> missing_versions;

    find_longest_consecutive_version(&candidate_rowsets, &missing_versions);

    if (!missing_versions.empty()) {

        DCHECK(missing_versions.size() % 2 == 0);

        LOG(WARNING) << "There are missed versions among rowsets. "

                     << "total missed version size: " << missing_versions.size() / 2

                     << " first missed version prev rowset verison=" << missing_versions[0]

                     << ", first missed version next rowset version=" << missing_versions[1]

                     << ", tablet=" << _tablet->tablet_id();

    }

    int64_t max_score = config::cumulative_compaction_max_deltas;

    auto process_memory_usage = doris::GlobalMemoryArbitrator::process_memory_usage();

    bool memory_usage_high = process_memory_usage > MemInfo::soft_mem_limit() * 0.8;

    if (tablet()->last_compaction_status.is<ErrorCode::MEM_LIMIT_EXCEEDED>() || memory_usage_high) {

        max_score = std::max(config::cumulative_compaction_max_deltas /

                                     config::cumulative_compaction_max_deltas_factor,

                             config::cumulative_compaction_min_deltas + 1);

    }

    size_t compaction_score = 0;

    tablet()->cumulative_compaction_policy()->pick_input_rowsets(

            tablet(), candidate_rowsets, max_score, config::cumulative_compaction_min_deltas,

            &_input_rowsets, &_last_delete_version, &compaction_score,

            _allow_delete_in_cumu_compaction);

    // Cumulative compaction will process with at least 1 rowset.

    // So when there is no rowset being chosen, we should return Status::Error<CUMULATIVE_NO_SUITABLE_VERSION>():

    if (_input_rowsets.empty()) {

        if (_last_delete_version.first != -1) {

            // we meet a delete version, should increase the cumulative point to let base compaction handle the delete version.

            // plus 1 to skip the delete version.

            // NOTICE: after that, the cumulative point may be larger than max version of this tablet, but it doesn't matter.

            tablet()->set_cumulative_layer_point(_last_delete_version.first + 1);

            return Status::Error<CUMULATIVE_NO_SUITABLE_VERSION>(

                    "_last_delete_version.first not equal to -1");

        }

        // we did not meet any delete version. which means compaction_score is not enough to do cumulative compaction.

        // We should wait until there are more rowsets to come, and keep the cumulative point unchanged.

        // But in order to avoid the stall of compaction because no new rowset arrives later, we should increase

        // the cumulative point after waiting for a long time, to ensure that the base compaction can continue.

        // check both last success time of base and cumulative compaction

        int64_t now = UnixMillis();

        int64_t last_cumu = tablet()->last_cumu_compaction_success_time();

        int64_t last_base = tablet()->last_base_compaction_success_time();

        if (last_cumu != 0 || last_base != 0) {

            int64_t interval_threshold = config::pick_rowset_to_compact_interval_sec * 1000;

            int64_t cumu_interval = now - last_cumu;

            int64_t base_interval = now - last_base;

            if (cumu_interval > interval_threshold && base_interval > interval_threshold) {

                // before increasing cumulative point, we should make sure all rowsets are non-overlapping.

                // if at least one rowset is overlapping, we should compact them first.

                for (auto& rs : candidate_rowsets) {

                    if (rs->rowset_meta()->is_segments_overlapping()) {

                        _input_rowsets = candidate_rowsets;

                        return Status::OK();

                    }

                }

                // all candidate rowsets are non-overlapping, increase the cumulative point

                tablet()->set_cumulative_layer_point(candidate_rowsets.back()->start_version() + 1);

            }

        } else {

            // init the compaction success time for first time

            if (last_cumu == 0) {

                tablet()->set_last_cumu_compaction_success_time(now);

            }

            if (last_base == 0) {

                tablet()->set_last_base_compaction_success_time(now);

            }

        }

        return Status::Error<CUMULATIVE_NO_SUITABLE_VERSION>("_input_rowsets is empty");

    }

    return Status::OK();

}

} // namespace doris