/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef OB_TABLE_STORE_STAT_MGR_H_
#define OB_TABLE_STORE_STAT_MGR_H_
#include <stdint.h>
#include "lib/oblog/ob_log_module.h"
#include "lib/utility/ob_print_utils.h"
#include "lib/lock/ob_spin_rwlock.h"
#include "lib/allocator/page_arena.h"
#include "lib/hash_func/murmur_hash.h"
#include "lib/hash/ob_hashmap.h"
#include "lib/task/ob_timer.h"
#include "common/ob_tablet_id.h"
#include "share/ob_ls_id.h"

namespace oceanbase
{
namespace storage
{
struct ObMergeIterStat
{
public:
  ObMergeIterStat() { reset(); };
  ~ObMergeIterStat() = default;
  OB_INLINE void reset() { MEMSET(this, 0, sizeof(ObMergeIterStat)); }
  bool is_valid() const;
  int add(const ObMergeIterStat& other);
  ObMergeIterStat & operator=(const ObMergeIterStat &other);
  TO_STRING_KV(K_(call_cnt), K_(output_row_cnt));

  int64_t call_cnt_;
  int64_t output_row_cnt_;
};

struct ObBlockAccessStat
{
public:
  ObBlockAccessStat() { reset(); };
  ~ObBlockAccessStat() = default;
  OB_INLINE void reset() { MEMSET(this, 0, sizeof(ObBlockAccessStat)); }
  bool is_valid() const;
  int add(const ObBlockAccessStat& other);
  ObBlockAccessStat & operator=(const ObBlockAccessStat &other);
  TO_STRING_KV(K_(effect_read_cnt), K_(empty_read_cnt));

  int64_t effect_read_cnt_;
  int64_t empty_read_cnt_;
};

struct ObTableStoreStat
{
public:
  ObTableStoreStat();
  ~ObTableStoreStat() = default;

  void reset();
  void reuse();
  bool is_valid() const;
  int add(const ObTableStoreStat& other);
  ObTableStoreStat &operator=(const ObTableStoreStat& other);
  OB_INLINE bool enable_get_row_cache() const
  {
    return row_cache_miss_cnt_ < common::MAX_MULTI_GET_CACHE_AWARE_ROW_NUM
           || row_cache_hit_cnt_ > row_cache_miss_cnt_ / 2;
  }
  OB_INLINE bool enable_put_row_cache() const
  {
    return row_cache_put_cnt_ < common::MAX_MULTI_GET_CACHE_AWARE_ROW_NUM;
  }
  OB_INLINE bool enable_put_fuse_row_cache(const int64_t threshold) const
  {
    return fuse_row_cache_put_cnt_ < threshold;
  }
  OB_INLINE bool enable_get_fuse_row_cache(const int64_t threshold) const
  {
    return fuse_row_cache_miss_cnt_ < threshold
           || fuse_row_cache_hit_cnt_ > fuse_row_cache_miss_cnt_ / 4;
  }
  OB_INLINE bool enable_bf_cache() const
  {
    return (bf_access_cnt_ < common::MAX_MULTI_GET_CACHE_AWARE_ROW_NUM
           || bf_filter_cnt_ > (bf_access_cnt_ / 8));
  }
  OB_INLINE bool enable_sstable_bf_cache() const
  {
    return (sstable_bf_access_cnt_ < common::MAX_MULTI_GET_CACHE_AWARE_ROW_NUM / 5
           || sstable_bf_filter_cnt_ > sstable_bf_access_cnt_ / 4);
  }
  OB_INLINE int64_t get_empty_read_cnt() const
  {
    return exist_row_.empty_read_cnt_ + get_row_.empty_read_cnt_ + scan_row_.empty_read_cnt_;
  }
  TO_STRING_KV(K_(ls_id), K_(tablet_id), K_(table_id),
               K_(row_cache_hit_cnt), K_(row_cache_miss_cnt), K_(row_cache_put_cnt),
               K_(bf_filter_cnt), K_(bf_empty_read_cnt), K_(bf_access_cnt),
               K_(block_cache_hit_cnt), K_(block_cache_miss_cnt),
               K_(access_row_cnt), K_(output_row_cnt), K_(fuse_row_cache_hit_cnt),
               K_(fuse_row_cache_miss_cnt), K_(fuse_row_cache_put_cnt),
               K_(macro_access_cnt), K_(micro_access_cnt), K_(pushdown_micro_access_cnt),
               K_(pushdown_row_access_cnt), K_(pushdown_row_select_cnt),
               K_(single_get_stat), K_(multi_get_stat), K_(index_back_stat),
               K_(single_scan_stat), K_(multi_scan_stat),
               K_(exist_row), K_(get_row), K_(scan_row),
               K_(sstable_bf_filter_cnt), K_(sstable_bf_empty_read_cnt),
               K_(sstable_bf_access_cnt), K_(rowkey_prefix),
               K_(logical_read_cnt), K_(physical_read_cnt));

  share::ObLSID ls_id_;
  common::ObTabletID tablet_id_;
  common::ObTableID table_id_;
  int64_t row_cache_hit_cnt_;
  int64_t row_cache_miss_cnt_;
  int64_t row_cache_put_cnt_;
  int64_t bf_filter_cnt_;
  int64_t bf_empty_read_cnt_;
  int64_t bf_access_cnt_;
  int64_t block_cache_hit_cnt_;
  int64_t block_cache_miss_cnt_;
  int64_t index_block_cache_hit_cnt_;
  int64_t index_block_cache_miss_cnt_;
  int64_t access_row_cnt_;
  int64_t output_row_cnt_;
  int64_t fuse_row_cache_hit_cnt_;
  int64_t fuse_row_cache_miss_cnt_;
  int64_t fuse_row_cache_put_cnt_;
  int64_t macro_access_cnt_;
  int64_t micro_access_cnt_;
  int64_t pushdown_micro_access_cnt_;
  int64_t pushdown_row_access_cnt_;
  int64_t pushdown_row_select_cnt_;
  ObMergeIterStat single_get_stat_;
  ObMergeIterStat multi_get_stat_;
  ObMergeIterStat index_back_stat_; // index back only works in multi_get mode
  ObMergeIterStat single_scan_stat_;
  ObMergeIterStat multi_scan_stat_;
  ObBlockAccessStat exist_row_;
  ObBlockAccessStat get_row_;
  ObBlockAccessStat scan_row_;
  int64_t sstable_bf_filter_cnt_;
  int64_t sstable_bf_empty_read_cnt_;
  int64_t sstable_bf_access_cnt_;
  int64_t rowkey_prefix_;
  int64_t logical_read_cnt_;
  int64_t physical_read_cnt_;
};

struct ObTableStoreStatKey
{
public:
  ObTableStoreStatKey() : table_id_(common::OB_INVALID_ID), tablet_id_(common::OB_INVALID_ID) {}
  ObTableStoreStatKey(const ObTableID table_id, const ObTabletID tablet_id) : table_id_(table_id), tablet_id_(tablet_id) {}
  ~ObTableStoreStatKey() {}
  OB_INLINE uint64_t hash() const
  {
    uint64_t hash_ret = 0;
    hash_ret = common::murmurhash(&table_id_, sizeof(ObTableID), 0);
    hash_ret = common::murmurhash(&tablet_id_, sizeof(ObTabletID), hash_ret);
    return hash_ret;
  }
  int hash(uint64_t &hash_val) const
  {
    hash_val = hash();
    return OB_SUCCESS;
  }
  OB_INLINE bool operator ==(const ObTableStoreStatKey &other) const
  {
    return (table_id_ == other.table_id_) && (tablet_id_ == other.tablet_id_);
  }
  OB_INLINE bool operator !=(const ObTableStoreStatKey &other) const
  {
    return (*this == other);
  }
  TO_STRING_KV(K_(table_id), K_(tablet_id));
  common::ObTableID table_id_;
  common::ObTabletID tablet_id_;
};

struct ObTableStoreStatNode
{
public:
  ObTableStoreStatNode() : pre_(NULL), next_(NULL), stat_(NULL) {}
  ~ObTableStoreStatNode() { reset(); }
  OB_INLINE void reset() { pre_ = next_ = NULL; stat_ = NULL; }
  ObTableStoreStatNode *pre_;
  ObTableStoreStatNode *next_;
  ObTableStoreStat *stat_;
};

class ObTableStoreStatIterator
{
public:
  ObTableStoreStatIterator();
  virtual ~ObTableStoreStatIterator();
  int open();
  int get_next_stat(ObTableStoreStat &stat);
  void reset();
private:
  int64_t cur_idx_;
  bool is_opened_;
};

// TODO(@DanLing) remove ObTableStoreStatMgr
class ObTableStoreStatMgr
{
public:
  int init(const int64_t limit_cnt = DEFAULT_MAX_CNT);
  void stop();
  void wait();
  void reset();
  void destroy();
  static ObTableStoreStatMgr &get_instance();
  int report_stat(const ObTableStoreStat &stat);
private:
  ObTableStoreStatMgr();
  virtual ~ObTableStoreStatMgr();
  void move_node_to_head(ObTableStoreStatNode *node);
  int get_table_store_stat(const int64_t idx, ObTableStoreStat &stat);
  void run_report_task();
  int add_stat(const ObTableStoreStat &stat);

  friend class ObTableStoreStatIterator;
  typedef common::hash::ObHashMap<ObTableStoreStatKey, ObTableStoreStatNode*, common::hash::NoPthreadDefendMode> TableStoreMap;
  static const int64_t DEFAULT_MAX_CNT = 40000; // 40000 * (sizeof(key)(16) + sizeof(node*)(8) + sizeof(node)(24) + sizeof(stat)(96)) = 6.25MB
  static const int64_t MAX_PENDDING_CNT = 100000; // 100000 * sizeof(stat)(96) = 9.2MB
  static const int64_t REPORT_TASK_INTERVAL_US = 1000 * 1000; // 1 seconds

  class ReportTask : public common::ObTimerTask
  {
  public:
    ReportTask() : stat_mgr_(NULL) {}
    virtual ~ReportTask() { destroy(); }
    int init(ObTableStoreStatMgr *stat_mgr);
    void destroy() { stat_mgr_ = NULL; }
    virtual void runTimerTask();
  private:
    ObTableStoreStatMgr *stat_mgr_;
    DISALLOW_COPY_AND_ASSIGN(ReportTask);
  };

  bool is_inited_;
  common::SpinRWLock lock_;
  TableStoreMap quick_map_;
  int64_t cur_cnt_;
  int64_t limit_cnt_;
  ObTableStoreStatNode *lru_head_;
  ObTableStoreStatNode *lru_tail_;
  ObTableStoreStat stat_array_[DEFAULT_MAX_CNT];
  ObTableStoreStatNode node_pool_[DEFAULT_MAX_CNT];

  // stat buffer area
  ObTableStoreStat stat_queue_[MAX_PENDDING_CNT];
  uint64_t report_cursor_ CACHE_ALIGNED;
  uint64_t pending_cursor_ CACHE_ALIGNED;
  ReportTask report_task_;
};

} //namespace storage
} //namespace oceanbase
#endif /* OB_TABLE_STORE_STAT_MGR_H_ */