// 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 <butil/macros.h>

#include <fmt/format.h>

#include <gen_cpp/olap_file.pb.h>

#include <gen_cpp/types.pb.h>

#include <stddef.h>

#include <stdint.h>

#include <atomic>

#include <memory>

#include <mutex>

#include <ostream>

#include <string>

#include <vector>

#include "common/logging.h"

#include "common/status.h"

#include "olap/olap_common.h"

#include "olap/rowset/rowset_meta.h"

#include "olap/tablet_schema.h"

namespace doris {

class Rowset;

namespace io {

class RemoteFileSystem;

} // namespace io

using RowsetSharedPtr = std::shared_ptr<Rowset>;

class RowsetReader;

// the rowset state transfer graph:

//    ROWSET_UNLOADED    <--|

//          ↓               |

//    ROWSET_LOADED         |

//          ↓               |

//    ROWSET_UNLOADING   -->|

enum RowsetState {

    // state for new created rowset

    ROWSET_UNLOADED,

    // state after load() called

    ROWSET_LOADED,

    // state for closed() called but owned by some readers

    ROWSET_UNLOADING

};

class RowsetStateMachine {

public:

    RowsetStateMachine() : _rowset_state(ROWSET_UNLOADED) {}

    Status on_load() {

        switch (_rowset_state) {

        case ROWSET_UNLOADED:

            _rowset_state = ROWSET_LOADED;

            break;

        default:

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

                    "RowsetStateMachine meet invalid state");

        }

        return Status::OK();

    }

    Status on_close(uint64_t refs_by_reader) {

        switch (_rowset_state) {

        case ROWSET_LOADED:

            if (refs_by_reader == 0) {

                _rowset_state = ROWSET_UNLOADED;

            } else {

                _rowset_state = ROWSET_UNLOADING;

            }

            break;

        default:

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

                    "RowsetStateMachine meet invalid state");

        }

        return Status::OK();

    }

    Status on_release() {

        switch (_rowset_state) {

        case ROWSET_UNLOADING:

            _rowset_state = ROWSET_UNLOADED;

            break;

        default:

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

                    "RowsetStateMachine meet invalid state");

        }

        return Status::OK();

    }

    RowsetState rowset_state() { return _rowset_state; }

private:

    RowsetState _rowset_state;

};

class Rowset : public std::enable_shared_from_this<Rowset> {

public:

    virtual ~Rowset();

    // Open all segment files in this rowset and load necessary metadata.

    // - `use_cache` : whether to use fd cache, only applicable to alpha rowset now

    //

    // May be called multiple times, subsequent calls will no-op.

    // Derived class implements the load logic by overriding the `do_load_once()` method.

    Status load(bool use_cache = true);

    // returns Status::Error<ErrorCode::ROWSET_CREATE_READER>() when failed to create reader

    virtual Status create_reader(std::shared_ptr<RowsetReader>* result) = 0;

    const RowsetMetaSharedPtr& rowset_meta() const { return _rowset_meta; }

    void merge_rowset_meta(const RowsetMeta& other);

    bool is_pending() const { return _is_pending; }

    bool is_local() const { return _rowset_meta->is_local(); }

    // publish rowset to make it visible to read

    void make_visible(Version version);

    const TabletSchemaSPtr& tablet_schema() { return _schema; }

    // helper class to access RowsetMeta

    int64_t start_version() const { return rowset_meta()->version().first; }

    int64_t end_version() const { return rowset_meta()->version().second; }

    size_t index_disk_size() const { return rowset_meta()->index_disk_size(); }

    size_t data_disk_size() const { return rowset_meta()->data_disk_size(); }

    size_t total_disk_size() const { return rowset_meta()->total_disk_size(); }

    bool empty() const { return rowset_meta()->empty(); }

    bool zero_num_rows() const { return rowset_meta()->num_rows() == 0; }

    size_t num_rows() const { return rowset_meta()->num_rows(); }

    Version version() const { return rowset_meta()->version(); }

    RowsetId rowset_id() const { return rowset_meta()->rowset_id(); }

    int64_t creation_time() const { return rowset_meta()->creation_time(); }

    PUniqueId load_id() const { return rowset_meta()->load_id(); }

    int64_t txn_id() const { return rowset_meta()->txn_id(); }

    int64_t partition_id() const { return rowset_meta()->partition_id(); }

    // flag for push delete rowset

    bool delete_flag() const { return rowset_meta()->delete_flag(); }

    int64_t num_segments() const { return rowset_meta()->num_segments(); }

    void to_rowset_pb(RowsetMetaPB* rs_meta) const { return rowset_meta()->to_rowset_pb(rs_meta); }

    RowsetMetaPB get_rowset_pb() const { return rowset_meta()->get_rowset_pb(); }

    // The writing time of the newest data in rowset, to measure the freshness of a rowset.

    int64_t newest_write_timestamp() const { return rowset_meta()->newest_write_timestamp(); }

    bool is_segments_overlapping() const { return rowset_meta()->is_segments_overlapping(); }

    KeysType keys_type() { return _schema->keys_type(); }

    RowsetStatePB rowset_meta_state() const { return rowset_meta()->rowset_state(); }

    bool produced_by_compaction() const { return rowset_meta()->produced_by_compaction(); }

    // remove all files in this rowset

    // TODO should we rename the method to remove_files() to be more specific?

    virtual Status remove() = 0;

    // used for partial update, when publish, partial update may add a new rowset

    // and we should update rowset meta

    void merge_rowset_meta(const RowsetMetaSharedPtr& other);

    // close to clear the resource owned by rowset

    // including: open files, indexes and so on

    // NOTICE: can not call this function in multithreads

    void close() {

        RowsetState old_state = _rowset_state_machine.rowset_state();

        if (old_state != ROWSET_LOADED) {

            return;

        }

        Status st = Status::OK();

        {

            std::lock_guard close_lock(_lock);

            uint64_t current_refs = _refs_by_reader;

            old_state = _rowset_state_machine.rowset_state();

            if (old_state != ROWSET_LOADED) {

                return;

            }

            if (current_refs == 0) {

                do_close();

            }

            st = _rowset_state_machine.on_close(current_refs);

        }

        if (!st.ok()) {

            LOG(WARNING) << "state transition failed from:" << _rowset_state_machine.rowset_state();

            return;

        }

        VLOG_NOTICE << "rowset is close. rowset state from:" << old_state << " to "

                    << _rowset_state_machine.rowset_state() << ", version:" << start_version()

                    << "-" << end_version() << ", tabletid:" << _rowset_meta->tablet_id();

    }

    // hard link all files in this rowset to `dir` to form a new rowset with id `new_rowset_id`.

    virtual Status link_files_to(const std::string& dir, RowsetId new_rowset_id,

                                 size_t new_rowset_start_seg_id = 0,

                                 std::set<int64_t>* without_index_uids = nullptr) = 0;

    // copy all files to `dir`

    virtual Status copy_files_to(const std::string& dir, const RowsetId& new_rowset_id) = 0;

    virtual Status upload_to(io::RemoteFileSystem* dest_fs, const RowsetId& new_rowset_id) {

        return Status::OK();

    }

    virtual Status remove_old_files(std::vector<std::string>* files_to_remove) = 0;

    // return whether `path` is one of the files in this rowset

    virtual bool check_path(const std::string& path) = 0;

    virtual bool check_file_exist() = 0;

    bool need_delete_file() const { return _need_delete_file; }

    void set_need_delete_file() { _need_delete_file = true; }

    bool contains_version(Version version) const {

        return rowset_meta()->version().contains(version);

    }

    static bool comparator(const RowsetSharedPtr& left, const RowsetSharedPtr& right) {

        return left->end_version() < right->end_version();

    }

    // this function is called by reader to increase reference of rowset

    void acquire() { ++_refs_by_reader; }

    void release() {

        // if the refs by reader is 0 and the rowset is closed, should release the resouce

        uint64_t current_refs = --_refs_by_reader;

        if (current_refs == 0 && _rowset_state_machine.rowset_state() == ROWSET_UNLOADING) {

            {

                std::lock_guard release_lock(_lock);

                // rejudge _refs_by_reader because we do not add lock in create reader

                if (_refs_by_reader == 0 &&

                    _rowset_state_machine.rowset_state() == ROWSET_UNLOADING) {

                    // first do close, then change state

                    do_close();

                    static_cast<void>(_rowset_state_machine.on_release());

                }

            }

            if (_rowset_state_machine.rowset_state() == ROWSET_UNLOADED) {

                VLOG_NOTICE

                        << "close the rowset. rowset state from ROWSET_UNLOADING to ROWSET_UNLOADED"

                        << ", version:" << start_version() << "-" << end_version()

                        << ", tabletid:" << _rowset_meta->tablet_id();

            }

        }

    }

    void update_delayed_expired_timestamp(uint64_t delayed_expired_timestamp) {

        if (delayed_expired_timestamp > _delayed_expired_timestamp) {

            _delayed_expired_timestamp = delayed_expired_timestamp;

        }

    }

    uint64_t delayed_expired_timestamp() { return _delayed_expired_timestamp; }

    virtual Status get_segments_key_bounds(std::vector<KeyBoundsPB>* segments_key_bounds) {

        _rowset_meta->get_segments_key_bounds(segments_key_bounds);

        return Status::OK();

    }

    // min key of the first segment

    bool first_key(std::string* min_key) {

        KeyBoundsPB key_bounds;

        bool ret = _rowset_meta->get_first_segment_key_bound(&key_bounds);

        if (!ret) {

            return false;

        }

        *min_key = key_bounds.min_key();

        return true;

    }

    // max key of the last segment

    bool last_key(std::string* max_key) {

        KeyBoundsPB key_bounds;

        bool ret = _rowset_meta->get_last_segment_key_bound(&key_bounds);

        if (!ret) {

            return false;

        }

        *max_key = key_bounds.max_key();

        return true;

    }

    bool check_rowset_segment();

    [[nodiscard]] virtual Status add_to_binlog() { return Status::OK(); }

    // is skip index compaction this time

    bool is_skip_index_compaction(int32_t column_id) const {

        return skip_index_compaction.find(column_id) != skip_index_compaction.end();

    }

    // set skip index compaction next time

    void set_skip_index_compaction(int32_t column_id) { skip_index_compaction.insert(column_id); }

    virtual void clear_inverted_index_cache() { LOG(INFO) << "should not reach here"; }

    void clear_cache();

protected:

    friend class RowsetFactory;

    DISALLOW_COPY_AND_ASSIGN(Rowset);

    // this is non-public because all clients should use RowsetFactory to obtain pointer to initialized Rowset

    Rowset(const TabletSchemaSPtr& schema, const RowsetMetaSharedPtr& rowset_meta);

    // this is non-public because all clients should use RowsetFactory to obtain pointer to initialized Rowset

    virtual Status init() = 0;

    // The actual implementation of load(). Guaranteed by to called exactly once.

    virtual Status do_load(bool use_cache) = 0;

    // release resources in this api

    virtual void do_close() = 0;

    virtual bool check_current_rowset_segment() = 0;

    TabletSchemaSPtr _schema;

    RowsetMetaSharedPtr _rowset_meta;

    // init in constructor

    bool _is_pending;    // rowset is pending iff it's not in visible state

    bool _is_cumulative; // rowset is cumulative iff it's visible and start version < end version

    // mutex lock for load/close api because it is costly

    std::mutex _lock;

    bool _need_delete_file = false;

    // variable to indicate how many rowset readers owned this rowset

    std::atomic<uint64_t> _refs_by_reader;

    // rowset state machine

    RowsetStateMachine _rowset_state_machine;

    std::atomic<uint64_t> _delayed_expired_timestamp = 0;

    // <column_uniq_id>, skip index compaction

    std::set<int32_t> skip_index_compaction;

};

} // namespace doris