/**
 * 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 OCEANBASE_SQL_LOAD_DATA_IMPL_H_
#define OCEANBASE_SQL_LOAD_DATA_IMPL_H_

#ifndef TIME_STAT_ON
#define TIME_STAT_ON
#endif

#include "share/ob_define.h"
#include "lib/file/ob_file.h"
#include "lib/hash/ob_build_in_hashmap.h"
#include "lib/hash_func/murmur_hash.h"
#include "lib/hash/ob_array_hash_map.h"
#include "lib/queue/ob_link_queue.h"
#include "lib/container/ob_bit_set.h"
#include "lib/utility/ob_utility.h"
#include "sql/resolver/cmd/ob_load_data_stmt.h"
#include "sql/resolver/expr/ob_raw_expr_printer.h"
#include "sql/optimizer/ob_table_location.h"
#include "sql/engine/cmd/ob_load_data_rpc.h"
#include "sql/engine/ob_des_exec_context.h"

namespace oceanbase {
namespace observer {
class ObGlobalContext;
}
namespace sql {

class ObLoadDataStmt;
class ObSqlExpressionFactory;
class ObPartBufMgrHashInfo;
enum class ObLoadTaskResultFlag;
class ObLoadFileBuffer;
class ObCSVParser;
class ObLoadEscapeSM;

typedef common::hash::ObHashMap<common::ObString, int64_t> FileFieldIdxHashMap;
typedef common::hash::ObHashMap<common::ObAddr, int64_t> ServerTimestampHashMap;
typedef common::hash::ObBuildInHashMap<ObPartBufMgrHashInfo, 100> PartitionBufferHashMap;

struct ObLoadDataReplacedExprInfo {
  ObLoadDataReplacedExprInfo() : replaced_expr(NULL), correspond_file_field_idx(OB_INVALID_INDEX_INT64)
  {}
  ObConstRawExpr* replaced_expr;      // column refs and user variables will be replaced into an const expr
  int64_t correspond_file_field_idx;  // the index of column in the load file
  TO_STRING_KV(KPC(replaced_expr), K(correspond_file_field_idx));
};

struct ObLoadTableColumnDesc {
  ObLoadTableColumnDesc()
      : column_id_(common::OB_INVALID_ID),
        is_set_values_(false),
        expr_value_(NULL),
        column_type_(common::ObMaxType),
        array_ref_idx_(common::OB_INVALID_INDEX_INT64)
  {}
  common::ObString column_name_;
  uint64_t column_id_;  // for compare
  bool is_set_values_;  // values will get from set assignments
  /* is_set_values_ indicates this value is finally from set assignments
   * e.g. LOAD DATA INFILE (c1, c2) SET c1 = xxx, c3 = xxx;
   * --> c1 : is_set_values_ = TRUE
   * --> c2 : is_set_values_ = FALSE
   * --> c3 : is_set_values_ = TRUE
   */
  ObRawExpr* expr_value_;  // the expr of set value
  common::ColumnType column_type_;
  int64_t array_ref_idx_;  // index of source data array (field_str_ or set_expr_str_)
  TO_STRING_KV(K_(column_name), K_(column_id), K_(is_set_values), K_(array_ref_idx));
};

class ObInsertValueGenerator {
public:
  int gen_values(const common::ObIArray<common::ObString>& file_col_values,
      common::ObIArray<common::ObString>& table_column_values, ObExecContext& exec_ctx,
      ObLoadFileBuffer& data_buf) const;
  int replace_value_for_file_col_expr(const common::ObIArray<ObString>& file_col_values) const;

  int add_table_column_value_desc(const ObLoadTableColumnDesc& desc)
  {
    return table_column_value_desc_.push_back(desc);
  }
  int add_file_column_replace_info(const ObLoadDataReplacedExprInfo& info)
  {
    return exprs_ref_file_col_.push_back(info);
  }
  common::ObIArray<ObLoadTableColumnDesc>& get_table_column_value_descs()
  {
    return table_column_value_desc_;
  }
  bool find_table_column_value_desc_by_column_id(const uint64_t column_id, int64_t& idx);
  int gen_insert_columns_names_buff(ObExecContext& ctx, const ObLoadArgument& load_args, common::ObString& data_buff);

private:
  common::ObSEArray<ObLoadTableColumnDesc, 16> table_column_value_desc_;
  common::ObSEArray<ObLoadDataReplacedExprInfo, 8> exprs_ref_file_col_;
};

class ObPartIdCalculator {
public:
  int init(ObExecContext& ctx, const common::ObString& q_name, const uint64_t& table_id,
      ObInsertValueGenerator& generator, ObLoadFileBuffer& data_buf, common::ObIArray<common::ObString>& insert_values,
      common::ObIArray<common::ObString>& file_col_values);
  int calc_partition_id(ObExecContext& ctx, share::schema::ObSchemaGetterGuard& schema_guard,
      const common::ObIArray<ObString>& insert_values, int64_t& part_id);
  uint64_t get_table_id() const
  {
    return table_location_.get_table_id();
  }

private:
  common::ObSEArray<int64_t, 1> param_to_file_col_idx_;
  ObTableLocation table_location_;
};

// serialize row to SEArray
struct ObDataFrag : common::ObLink {
  ObDataFrag() = delete;
  ObDataFrag(int64_t struct_size)
      : shuffle_task_id(OB_INVALID_INDEX_INT64), frag_size(struct_size - sizeof(ObDataFrag)), frag_pos(0), row_cnt(0)
  {}

  static const int64_t DEFAULT_STRUCT_SIZE = 8ll * 1024;
  static const int64_t MAX_ROW_COUNT = 1024;
  int64_t get_remain()
  {
    return frag_size - frag_pos;
  }
  char* get_current()
  {
    return data + frag_pos;
  }
  void add_pos(int64_t size)
  {
    frag_pos += size;
  }
  void add_row_cnt(int64_t cnt)
  {
    row_cnt += cnt;
  }

  int64_t shuffle_task_id;
  int64_t frag_size;
  int64_t frag_pos;
  int64_t row_cnt;
  char data[];
  TO_STRING_KV(K(shuffle_task_id), K(frag_size), K(frag_pos), K(row_cnt));
};

class ObPartDataFragMgr {
public:
  ObPartDataFragMgr(ObDataFragMgr& data_frag_mgr, int64_t part_id)
      : data_frag_mgr_(data_frag_mgr), part_id_(part_id), total_row_consumed_(0), total_row_proceduced_(0)
  {}
  ~ObPartDataFragMgr()
  {}
  LINK(ObPartDataFragMgr, part_datafrag_hash_link_);

  common::ObPartitionKey& get_part_key()
  {
    return part_key_;
  }
  common::ObAddr& get_leader_addr()
  {
    return leader_addr_;
  }

  int add_datafrag(ObDataFrag* frag)
  {
    return queue_.push(frag);
  }
  inline bool has_data(int64_t batch_row_count)
  {
    return remain_row_count() >= batch_row_count;
  }
  inline int64_t remain_row_count()
  {
    return ATOMIC_LOAD(&total_row_proceduced_) - total_row_consumed_;
  }
  int reuse()
  {
    // todo
    return common::OB_SUCCESS;
  }
  int clear();

  int update_part_location(ObExecContext& ctx);

  ObDataFragMgr& data_frag_mgr_;
  int64_t part_id_;

  int64_t total_row_consumed_;

  common::ObPartitionKey part_key_;
  common::ObAddr leader_addr_;

  // multi-thread accessed:
  volatile int64_t total_row_proceduced_;
  common::ObSpLinkQueue queue_;

public:
  // for batch task
  struct InsertTaskSplitPoint {
    InsertTaskSplitPoint()
    {
      reset();
    }
    TO_STRING_KV(K(frag_row_pos_), K(frag_data_pos_));
    inline void reset()
    {
      frag_row_pos_ = 0;
      frag_data_pos_ = 0;
    }
    int64_t frag_row_pos_;
    int64_t frag_data_pos_;
  };

  // int64_t get_batch_count() { return insert_task_split_points_.count(); }
  int prepare_insert_task(int64_t batch_row_count = 1000);
  int next_insert_task(int64_t batch_row_count, ObInsertTask& task);
  int free_frags();
  TO_STRING_KV(K(frag_free_list_), K(queue_top_begin_point_));

private:
  /**
   * @brief return the pos of row_num in frag
   */
  int rowoffset2pos(ObDataFrag* frag, int64_t row_num, int64_t& pos);

  InsertTaskSplitPoint queue_top_begin_point_;  // begin cursor of queue_.top()
  // common::ObSEArray<InsertTaskSplitPoint, 8> insert_task_split_points_;
  common::ObSEArray<ObDataFrag*, 32> frag_free_list_;
};

struct ObPartDataFragHash {
  typedef const int64_t& Key;
  typedef ObPartDataFragMgr Value;
  typedef ObDLList(ObPartDataFragMgr, part_datafrag_hash_link_) ListHead;
  static uint64_t hash(Key key)
  {
    return common::murmurhash(&key, sizeof(int64_t), 0);
  }
  static Key key(Value const* value)
  {
    return value->part_id_;
  }
  static bool equal(Key lhs, Key rhs)
  {
    return lhs == rhs;
  }
};

class ObDataFragMgr {
public:
  int init(ObExecContext& ctx, uint64_t table_id);
  int get_part_datafrag(int64_t part_id, ObPartDataFragMgr*& part_datafrag_mgr);
  int64_t get_total_part_cnt()
  {
    return total_part_cnt_;
  }
  int create_datafrag(ObDataFrag*& frag, int64_t min_len);
  void distory_datafrag(ObDataFrag* frag);
  int free_unused_datafrag();
  int clear_all_datafrag();
  common::ObIArray<int64_t>& get_part_ids()
  {
    return part_ids_;
  }
  const common::ObBitSet<>& get_part_bitset()
  {
    return part_bitset_;
  }
  int64_t get_total_allocated_frag_count() const
  {
    return ATOMIC_LOAD(&total_alloc_cnt_);
  }
  int64_t get_total_freed_frag_count() const
  {
    return total_free_cnt_;
  }
  TO_STRING_KV(K_(total_part_cnt), "total_alloc_cnt", get_total_allocated_frag_count(), K_(total_free_cnt));

private:
  common::ObMemAttr attr_;
  int64_t total_part_cnt_;
  volatile int64_t total_alloc_cnt_;
  int64_t total_free_cnt_;
  common::ObSEArray<int64_t, 64> part_ids_;
  common::ObBitSet<> part_bitset_;

  // part_id -> ObPartDataFragMgr
  common::hash::ObBuildInHashMap<ObPartDataFragHash, 100> part_datafrag_map_;
};

// one buffer info for one partition
class ObPartitionBufferCtrl {
public:
  explicit ObPartitionBufferCtrl(int64_t partition_id) : part_id_(partition_id), buffer_(NULL)
  {}
  ~ObPartitionBufferCtrl()
  {}

  LINK(ObPartitionBufferCtrl, buffer_hash_link_);  // hash link list

  template <typename T>
  OB_INLINE void set_buffer(T* buffer)
  {
    buffer_ = reinterpret_cast<void*>(buffer);
  }
  template <typename T>
  OB_INLINE T* get_buffer()
  {
    return reinterpret_cast<T*>(buffer_);
  }

  TO_STRING_KV(K_(part_id), KP_(buffer));

public:
  int64_t part_id_;  // hash key
private:
  void* buffer_;
} CACHE_ALIGNED;

struct ObPartBufMgrHashInfo {
  typedef const int64_t& Key;
  typedef ObPartitionBufferCtrl Value;
  typedef ObDLList(ObPartitionBufferCtrl, buffer_hash_link_) ListHead;
  static uint64_t hash(Key key)
  {
    return common::murmurhash(&key, sizeof(int64_t), 0);
  }
  static Key key(Value const* value)
  {
    return value->part_id_;
  }
  static bool equal(Key lhs, Key rhs)
  {
    return lhs == rhs;
  }
};

//========================
class ObAllocatorSwitch : public common::ObIAllocator {
public:
  ObAllocatorSwitch() : cur_alloc_(&permanent_alloc_)
  {}
  void switch_permanent()
  {
    cur_alloc_ = &permanent_alloc_;
  }
  void switch_temporary()
  {
    cur_alloc_ = &temporary_alloc_;
  }
  inline virtual void* alloc(const int64_t size)
  {
    return cur_alloc_->alloc(size);
  }

  inline virtual void* alloc(const int64_t size, const ObMemAttr& attr)
  {
    return cur_alloc_->alloc(size, attr);
  }

  inline virtual void* realloc(const void* ptr, const int64_t size, const ObMemAttr& attr)
  {
    return cur_alloc_->realloc(ptr, size, attr);
  }

  inline virtual void* realloc(void* ptr, const int64_t oldsz, const int64_t newsz)
  {
    return cur_alloc_->realloc(ptr, oldsz, newsz);
  }

  inline virtual void free(void* ptr)
  {
    return cur_alloc_->free(ptr);
  }

  inline virtual int64_t total() const
  {
    return cur_alloc_->total();
  }

  inline virtual int64_t used() const
  {
    return cur_alloc_->used();
  }

  inline virtual void reset()
  {
    return cur_alloc_->reset();
  }

  inline virtual void reuse()
  {
    return cur_alloc_->reuse();
  }

  inline virtual void set_attr(const ObMemAttr& attr)
  {
    cur_alloc_->set_attr(attr);
  }

  TO_STRING_KV("cur_alloc_", (cur_alloc_ == &permanent_alloc_) ? "permanent" : "temporary");

private:
  common::ObIAllocator* cur_alloc_;
  ObArenaAllocator permanent_alloc_;
  ObArenaAllocator temporary_alloc_;
};

class ObLoadFileBuffer {
public:
  static const int64_t MAX_BUFFER_SIZE = OB_MALLOC_BIG_BLOCK_SIZE;

public:
  ObLoadFileBuffer() = delete;
  ObLoadFileBuffer(int64_t buffer_size) : pos_(0), buffer_size_(buffer_size)
  {}
  bool is_valid() const
  {
    return pos_ > 0;
  }
  char* current_ptr()
  {
    return buffer_ + pos_;
  }
  char* begin_ptr()
  {
    return buffer_;
  }
  void update_pos(int64_t len)
  {
    pos_ += len;
  }
  int64_t get_remain_len()
  {
    return buffer_size_ - pos_;
  }
  int64_t get_data_len()
  {
    return pos_;
  }
  int64_t get_buffer_size()
  {
    return buffer_size_;
  }
  void reset()
  {
    pos_ = 0;
  }

private:
  int64_t pos_;
  int64_t buffer_size_;
  char buffer_[];
};

struct ObCSVFormats {
  ObCSVFormats()
      : field_term_char_(0),
        line_term_char_(0),
        enclose_char_(0),
        escape_char_(0),
        null_column_fill_zero_string_(false),
        is_simple_format_(false),
        is_line_term_by_counting_field_(false)
  {}
  void init(const ObDataInFileStruct& file_formats);
  int64_t field_term_char_;
  int64_t line_term_char_;
  int64_t enclose_char_;
  int64_t escape_char_;
  /* for empty column, oracle mode do insert '';
   * mysql mode do insert '0' for nonstring-type column, '' for string-type column
   * */
  bool null_column_fill_zero_string_;
  bool is_simple_format_;
  bool is_line_term_by_counting_field_;
};

class ObLoadFileDataTrimer {
public:
  ObLoadFileDataTrimer() : incomplate_data_(NULL), incomplate_data_len_(0), lines_cnt_(0)
  {}
  int init(common::ObIAllocator& allocator, const ObCSVFormats& formats);
  // for debug
  ObString get_incomplate_data_string()
  {
    return ObString(static_cast<int32_t>(incomplate_data_len_), incomplate_data_);
  }

  int backup_incomplate_data(ObLoadFileBuffer& buffer, int64_t valid_data_len);
  int recover_incomplate_data(ObLoadFileBuffer& buffer);
  bool has_incomplate_data()
  {
    return incomplate_data_len_ > 0;
  }
  int64_t get_lines_count()
  {
    return lines_cnt_;
  }
  void commit_line_cnt(int64_t line_cnt)
  {
    lines_cnt_ += line_cnt;
  }

private:
  ObCSVFormats formats_;  // TODO [load data] change to ObInverseParser(formats)
  char* incomplate_data_;
  int64_t incomplate_data_len_;
  int64_t lines_cnt_;
};

class ObCSVParser {
public:
  static const char* ZERO_STRING;

public:
  ObCSVParser() : is_fast_parse_(false), total_field_nums_(0)
  {
    reuse();
  }
  void reuse()
  {
    is_last_buf_ = false;
    cur_pos_ = NULL;
    cur_field_begin_pos_ = NULL;
    cur_field_end_pos_ = NULL;
    cur_line_begin_pos_ = NULL;
    buf_begin_pos_ = NULL;
    buf_end_pos_ = NULL;
    last_end_enclosed_ = NULL;
    field_id_ = 0;
    in_enclose_flag_ = false;
    is_escaped_flag_ = false;
  }
  int init(int64_t file_column_nums, const ObCSVFormats& formats, const common::ObBitSet<>& string_type_column);
  void next_buf(char* buf_start, const int64_t buf_len, bool is_last_buf = false);
  int next_line(bool& yield_line);
  static int fast_parse_lines(
      ObLoadFileBuffer& buffer, ObCSVParser& parser, bool is_last_buf, int64_t& valid_len, int64_t& line_count);
  int64_t get_complete_lines_len()
  {
    return cur_line_begin_pos_ - buf_begin_pos_;
  }

  common::ObIArray<ObString>& get_line_store()
  {
    return values_in_line_;
  }

  ObCSVFormats& get_format()
  {
    return formats_;
  }
  bool is_fast_parse()
  {
    return is_fast_parse_;
  }
  void set_fast_parse()
  {
    is_fast_parse_ = true;
  }

private:
  bool is_terminate_char(char cur_char, char *&cur_pos, bool &is_line_term);
  bool is_enclosed_field_start(char *cur_pos, char &cur_char);
  void handle_one_field(char *field_end_pos, bool has_escaped);
  void deal_with_empty_field(ObString &field_str, int64_t index);
  // void deal_with_field_with_escaped_chars(ObString &field_str);
  int deal_with_irregular_line();
  void remove_enclosed_char(char*& cur_field_end_pos);

private:
  // parsing style
  bool is_fast_parse_;
  ObCSVFormats formats_;
  common::ObBitSet<> string_type_column_;
  // parsing state variables
  bool is_last_buf_;
  char *cur_pos_;
  char *cur_field_begin_pos_;
  char *cur_field_end_pos_;
  char *cur_line_begin_pos_;
  char *buf_begin_pos_;
  char *buf_end_pos_;
  char *last_end_enclosed_;
  int64_t field_id_;
  bool in_enclose_flag_;
  bool is_escaped_flag_;
  int64_t total_field_nums_;
  // ObLoadEscapeSM escape_sm_;
  // parsing result: the pointers of each value in one line
  common::ObSEArray<ObString, 1> values_in_line_;
};

struct ObParserErrRec {
  int64_t row_offset_in_task;
  int ret;
  TO_STRING_KV(K(row_offset_in_task), K(ret));
};

struct ObShuffleTaskHandle {
  ObShuffleTaskHandle(
      ObInsertValueGenerator& main_generator, ObPartIdCalculator& main_calculator, ObDataFragMgr& main_datafrag_mgr);
  ~ObShuffleTaskHandle();
  ObDesExecContext exec_ctx;
  ObLoadFileBuffer* data_buffer;
  ObCSVParser parser;
  share::schema::ObSchemaGetterGuard schema_guard;
  ObInsertValueGenerator& generator;
  ObPartIdCalculator& calculator;
  ObDataFragMgr& datafrag_mgr;
  ObShuffleResult result;
  ObSEArray<ObParserErrRec, 16> err_records;
  TO_STRING_KV("task_id", result.task_id_);
};

OB_INLINE void ObCSVParser::remove_enclosed_char(char*& cur_field_end_pos)
{
  cur_field_end_pos--;
  cur_field_begin_pos_++;
}

OB_INLINE bool ObCSVParser::is_terminate_char(char cur_char, char*& cur_pos, bool& is_line_term)
{
  bool ret_bool = false;
  bool is_field_term = (cur_char == formats_.field_term_char_);
  is_line_term = (cur_char == formats_.line_term_char_);

  if ((is_field_term || is_line_term) && !is_escaped_flag_) {
    if (!in_enclose_flag_) {
      ret_bool = true;  // return true
    } else {
      // with in_enclose_flag_ = true, a term char is valid only if an enclosed char before it
      if (last_end_enclosed_ == cur_pos - 1) {
        remove_enclosed_char(cur_pos);
        ret_bool = true;  // return true
      } else {
        // return false
      }
    }
  } else {
    // return false
  }
  return ret_bool;
}

OB_INLINE bool ObCSVParser::is_enclosed_field_start(char* cur_pos, char& cur_char)
{
  return static_cast<int64_t>(cur_char) == formats_.enclose_char_
         // anything between a pair of enclosed chars will be regarded as string data of one field
         && !in_enclose_flag_
         // enclosed field start must be the first char at the beginning of one field,
         // so cur_char is impossible to be escaped
         && cur_pos == cur_field_begin_pos_;
}

OB_INLINE void ObCSVParser::handle_one_field(char *field_end_pos, bool has_escaped)
{
  if (OB_LIKELY(field_id_ < total_field_nums_)) {
    int32_t str_len = static_cast<int32_t>(field_end_pos - cur_field_begin_pos_);
    if (OB_UNLIKELY(str_len <= 0)) {
      deal_with_empty_field(values_in_line_.at(field_id_), field_id_);
    } else {
      if (!in_enclose_flag_ &&
          ((str_len == 1 && *cur_field_begin_pos_ == 'N' && has_escaped && cur_pos_ - cur_field_begin_pos_ == 2) ||
              (formats_.enclose_char_ != INT64_MAX && !has_escaped && str_len == 4 &&
                  0 == MEMCMP(cur_field_begin_pos_, "NULL", 4)))) {
        values_in_line_.at(field_id_).assign_ptr(&ObLoadDataUtils::NULL_VALUE_FLAG, 1);
      } else {
        values_in_line_.at(field_id_).assign_ptr(cur_field_begin_pos_, str_len);
      }
    }
  } else {
    // ignored
  }
}
/*
class ObLoadDataOssReader : public ObStorageOssReader
{
public:
  ObLoadDataOssReader() :
    offset_(0),
    cached_size_(0),
    cached_limit_(0),
    cached_data_(nullptr)
  {}
  ~ObLoadDataOssReader();
  int init(int64_t cached_limit);
  int cached_pread(char *buf, const int64_t buf_size, int64_t offset, int64_t &read_size);


private:
  int64_t offset_;
  int64_t cached_size_;
  int64_t cached_limit_;
  char *cached_data_;
};
*/
class ObLoadDataBase {
public:
  ObLoadDataBase()
  {}
  virtual ~ObLoadDataBase()
  {}
  // utils
  static constexpr double MEMORY_LIMIT_THRESHOLD = 1.02;
  static const char* SERVER_TENANT_MEMORY_EXAMINE_SQL;

  static int generate_fake_field_strs(
      common::ObIArray<common::ObString>& file_col_values, common::ObIAllocator& allocator, const char id_char);
  static int calc_param_offset(const common::ObObjParam& param_a, const common::ObObjParam& param_b, int64_t& idx);
  static int construct_insert_sql(common::ObSqlString& insert_sql, const ObString& q_name,
      common::ObIArray<ObLoadTableColumnDesc>& desc, common::ObIArray<common::ObString>& insert_values,
      int64_t num_rows);
  static void set_one_field_objparam(common::ObObjParam& dest_param, const common::ObString& field_str);

  static int make_parameterize_stmt(
      ObExecContext& ctx, common::ObSqlString& insertsql, ParamStore& param_store, ObDMLStmt*& insert_stmt);

  static int memory_check_remote(uint64_t tenant_id, bool& need_wait_minor_freeze);
  static int memory_wait_local(
      ObExecContext& ctx, const ObPartitionKey& part_key, ObAddr& server_addr,
      int64_t& total_wait_secs, bool &is_leader_changed);

  virtual int execute(ObExecContext& ctx, ObLoadDataStmt& load_stmt) = 0;
};

struct ObFileReadCursor {
  ObFileReadCursor()
  {
    reset();
  }
  void reset()
  {
    read_counter_ = 0;
    file_offset_ = 0;
    read_size_ = 0;
    is_end_file_ = false;
  }
  bool inline is_end_file()
  {
    return is_end_file_;
  }
  int64_t inline get_total_read_MBs()
  {
    return file_offset_ >> 20;
  }
  int64_t inline get_total_read_GBs()
  {
    return file_offset_ >> 30;
  }
  void commit_read()
  {
    file_offset_ += read_size_;
    read_size_ = 0;
    read_counter_++;
  }
  TO_STRING_KV(K(read_counter_), K(file_offset_), K(read_size_), K(is_end_file_));
  int64_t read_counter_;
  int64_t file_offset_;
  int64_t read_size_;
  bool is_end_file_;
};

/**
 * @brief The ObLoadServerMgr struct
 *        manage server status
 */
struct ObLoadServerInfo {
  ObLoadServerInfo() : last_memory_limit_response(0)
  {}

  ObAddr addr;
  ObSEArray<ObPartDataFragMgr*, 64> part_datafrag_group;
  int64_t last_memory_limit_response;
  TO_STRING_KV(K(addr));
};

/**
 * @brief load data shuffle parallel implementation
 */
class ObLoadDataSPImpl : public ObLoadDataBase {
public:
  enum class TaskType {
    InvalidTask = -1,
    ShuffleTask = 0,
    InsertTask,
  };
  struct ToolBox {
    ToolBox() : expr_buffer(nullptr)
    {}
    int init(ObExecContext& ctx, ObLoadDataStmt& load_stmt);
    int release_resources();

    // modules
    ObFileReader file_reader;
#ifdef _WITH_OSS
    ObStorageOssReader oss_reader;
#endif
    ObFileAppender file_appender;
    ObFileReadCursor read_cursor;
    ObLoadFileDataTrimer data_trimer;
    ObInsertValueGenerator generator;
    ObPartIdCalculator calculator;
    ObDataFragMgr data_frag_mgr;

    // running control
    ObParallelTaskController shuffle_task_controller;
    ObParallelTaskController insert_task_controller;
    ObConcurrentFixedCircularArray<ObShuffleTaskHandle*> shuffle_task_reserve_queue;
    ObConcurrentFixedCircularArray<ObInsertTask*> insert_task_reserve_queue;
    common::ObArrayHashMap<ObAddr, int64_t> server_last_available_ts;
    common::ObArrayHashMap<ObAddr, ObLoadServerInfo*> server_info_map;
    common::ObSEArray<ObLoadServerInfo*, 16> server_infos;

    // exec params
    bool is_oracle_mode;
    int64_t tenant_id;
    int64_t max_cpus;  // real cpu num of a tenant
    int64_t num_of_file_column;
    int64_t num_of_table_column;
    int64_t parallel;
    int64_t batch_row_count;
    int64_t data_frag_mem_usage_limit;  // limit = data_frag_mem_usage_limit * MAX_BUFFER_SIZE
    int64_t file_size;
    int64_t ignore_rows;
    ObCSVFormats formats;
    ObCSVParser parser;
    common::ObBitSet<> string_type_column_bitset;
    common::ObAddr self_addr;
    ObLoadDupActionType insert_mode;
    ObLoadFileLocation load_file_storage;
    ObLoadDataGID gid;
    int64_t txn_timeout;

    // temp data
    ObLoadFileBuffer* expr_buffer;
    common::ObSEArray<ObString, 1> insert_values;
    common::ObSEArray<ObString, 1> field_values_in_file;
    ObPhysicalPlan plan;
    int64_t wait_secs_for_mem_release;
    int64_t affected_rows;
    int64_t insert_rt_sum;
    int64_t suffle_rt_sum;
    common::ObSEArray<int64_t, 1> file_buf_row_num;
    int64_t last_session_check_ts;

    // debug values
    int64_t insert_dispatch_rows;
    int64_t insert_task_count;
    int64_t handle_returned_insert_task_count;

    // prepared data
    common::ObString insert_stmt_head_buff;
    common::ObString exec_ctx_serialized_data;
    common::ObString log_file_name;
    common::ObString load_info;
    common::ObSEArray<ObShuffleTaskHandle*, 64> shuffle_resource;
    common::ObSEArray<ObInsertTask*, 64> insert_resource;
    common::ObSEArray<ObAllocatorSwitch*, 64> ctx_allocators;
  };

public:
  ObLoadDataSPImpl()
  {}
  ~ObLoadDataSPImpl()
  {}
  int execute(ObExecContext& ctx, ObLoadDataStmt& load_stmt);

  int shuffle_task_gen_and_dispatch(ObExecContext& ctx, ToolBox& box);
  int next_file_buffer(ToolBox& box, ObLoadFileBuffer& data_buffer, int64_t limit = INT64_MAX);
  int handle_returned_shuffle_task(ToolBox& box, ObShuffleTaskHandle& handle);
  int wait_shuffle_task_return(ToolBox& box);

  int insert_task_gen_and_dispatch(ObExecContext& ctx, ToolBox& box);
  int insert_task_send(ObInsertTask* insert_task, ToolBox& box);
  int handle_returned_insert_task(ObExecContext& ctx, ToolBox& box, ObInsertTask& insert_task, bool& need_retry);
  int log_failed_insert_task(ToolBox& box, ObInsertTask& task);
  int wait_insert_task_return(ObExecContext& ctx, ToolBox& box);

  int create_log_file(ToolBox& box);
  int log_failed_line(ToolBox& box, const char* task_type, int64_t task_id, int64_t line_num, int err_code);

  static int exec_shuffle(int64_t task_id, ObShuffleTaskHandle* handle);
  static int exec_insert(ObInsertTask& task, ObInsertResult& result);

private:
  static int build_insert_values_generator(
      ObExecContext& ctx, ObLoadDataStmt& load_stmt, ObInsertValueGenerator& generator);
  static int recursively_replace_variables(
      ObExecContext& ctx, ObLoadDataStmt& load_stmt, ObInsertValueGenerator& generator, ObRawExpr*& raw_expr);
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObLoadDataSPImpl);
  // function members
};

class ObLoadDataImpl : public ObLoadDataBase {
public:
  enum ParseStep { FIND_LINE_START = 0, FIND_LINE_TERM };

  static const int64_t FILE_READ_BUFFER_SIZE = 2 * 1024 * 1024;
  static const int64_t RESERVED_BYTES_SIZE = CACHE_ALIGN_SIZE;
  static const int64_t FILE_BUFFER_NUM = 2;  // can not changed
  static const int64_t EXPECTED_EXPR_VARABLES_TOTAL_NUM = COMMON_PARAM_NUM;
  static const char* ZERO_FIELD_STRING;
  static const int64_t INVALID_CHAR = INT64_MAX;

  typedef common::ObBitSet<EXPECTED_INSERT_COLUMN_NUM> FieldFlagBitSet;

  ObLoadDataImpl()
      :  // arguments
        part_level_(share::schema::PARTITION_LEVEL_ZERO),
        part_num_(0),
        initial_step_(FIND_LINE_START),
        dtc_params_(),
        flag_line_term_by_counting_field_(false),

        // array sizes
        file_column_number_(0),
        set_assigned_column_number_(0),
        insert_column_number_(0),
        params_count_(0),
        allocated_buffer_cnt_(0),
        non_string_type_direct_insert_column_count_(0),

        // statistics
        total_err_lines_(0),
        total_buf_read_(0),
        total_wait_secs_(0),

        // allocators
        expr_calc_allocator_(common::ObModIds::OB_SQL_EXECUTOR),
        array_allocator_(common::ObModIds::OB_SQL_EXECUTOR),

        // tools
        table_location_(expr_calc_allocator_),
        task_controller_(),

        // runtime variables
        cur_step_(FIND_LINE_START),
        parsed_line_count_(0),
        cur_line_begin_pos_(NULL),
        field_id_(0),
        cur_field_begin_pos_(NULL),
        in_enclose_flag_(false),

        // some fast access
        field_term_char_(INVALID_CHAR),
        line_term_char_(INVALID_CHAR),
        enclose_char_(INVALID_CHAR),
        escape_char_(INVALID_CHAR),

        // arrays
        set_assigns_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        file_field_def_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        replaced_expr_value_index_store_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        valid_insert_column_info_store_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        params_value_index_store_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        insert_column_names_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        allocated_buffer_store_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        expr_value_bitset_(array_allocator_),
        field_type_bit_set_(array_allocator_),

        // runtime arrays
        insert_values_per_line_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        parsed_field_strs_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        expr_strs_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_),
        partition_ids_(common::OB_MALLOC_NORMAL_BLOCK_SIZE, array_allocator_)
  {}
  virtual ~ObLoadDataImpl()
  {}
  int init_everything_first(ObExecContext& ctx, const ObLoadDataStmt& load_stmt, ObSQLSessionInfo& session);
  int init_from_load_stmt(const ObLoadDataStmt& load_stmt);
  int init_table_location_via_fake_insert_stmt(
      ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx, ObSQLSessionInfo& session_info);
  int init_separator_detectors(common::ObIAllocator& allocator);
  int init_data_buf(common::ObIAllocator& allocator);
  bool is_terminate_char(char& cur_char, int64_t& term_char, char*& cur_pos);
  bool is_terminate(char& cur_char, ObKMPStateMachine& term_state_machine, char*& cur_pos);
  bool is_enclosed_field_start(char* cur_pos, char& cur_char);
  void remove_enclosed_char(char*& cur_field_end_pos);
  int collect_insert_row_strings();
  int handle_one_file_buf(
      ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx, char* parsing_begin_pos, const int64_t data_len, bool is_eof);
  int handle_one_file_buf_fast(
      ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx, char* parsing_begin_pos, const int64_t data_len, bool is_eof);
  int handle_one_line(ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx);
  int handle_one_line_local(ObPhysicalPlanCtx& plan_ctx);
  void handle_one_field(char* field_end_pos);
  void deal_with_irregular_line();
  void deal_with_empty_field(common::ObString& field_str, int64_t index);

  bool scan_for_line_start(char*& cur_pos, const char* buf_end);
  bool scan_for_line_end(char*& cur_pos, const char* buf_end);

  int summarize_insert_columns();
  int build_file_field_var_hashmap();
  int do_local_sync_insert(ObPhysicalPlanCtx& plan_ctx);
  ObPartitionBufferCtrl* get_part_buf_ctrl(int64_t part_id)
  {
    return part_buffer_map_.get(part_id);
  }
  int create_part_buffer_ctrl(int64_t part_id, common::ObIAllocator* allocator, ObPartitionBufferCtrl*& buf_mgr);
  int create_buffer(common::ObIAllocator& allocator, ObLoadbuffer*& buffer);
  void destroy_all_buffer();
  int send_and_switch_buffer(ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx, ObPartitionBufferCtrl* part_buf_ctrl);
  int send_all_buffer_finally(ObExecContext& ctx, ObPhysicalPlanCtx& plan_ctx);
  int take_record_for_failed_rows(ObPhysicalPlanCtx& plan_ctx, ObLoadbuffer* complete_task);
  int handle_complete_task(ObPhysicalPlanCtx& plan_ctx, ObLoadbuffer* complete_task);
  int wait_server_memory_dump(ObExecContext& ctx, uint64_t partition_id);
  int wait_all_task_finished(ObPhysicalPlanCtx& plan_ctx);
  int generate_set_expr_strs(const ObSQLSessionInfo* session_info);
  bool find_insert_column_info(const uint64_t target_column_id, int64_t& found_idx);
  int recursively_replace_varables(
      ObRawExpr*& raw_expr, common::ObIAllocator& allocator, const ObSQLSessionInfo& session_info);
  int analyze_exprs_and_replace_variables(common::ObIAllocator& allocator, const ObSQLSessionInfo& session_info);
  int get_server_last_freeze_ts(const common::ObAddr& server_addr, int64_t& last_freeze_ts);

  int execute(ObExecContext& ctx, ObLoadDataStmt& load_stmt);

private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObLoadDataImpl);
  // function members
private:
  // arguments
  ObLoadArgument load_args_;
  ObDataInFileStruct data_struct_in_file_;
  common::ObString back_quoted_db_table_name_;
  share::schema::ObSchemaGetterGuard schema_guard_;
  share::schema::ObPartitionLevel part_level_;
  int64_t part_num_;
  ParseStep initial_step_;
  common::ObDataTypeCastParams dtc_params_;
  bool flag_line_term_by_counting_field_;

  // array sizes
  int64_t file_column_number_;
  int64_t set_assigned_column_number_;
  int64_t insert_column_number_;
  int64_t params_count_;
  int64_t allocated_buffer_cnt_;
  int64_t non_string_type_direct_insert_column_count_;

  // statistics
  int64_t total_err_lines_;
  int64_t total_buf_read_;
  int64_t total_wait_secs_;

  // allocators
  common::ObArenaAllocator expr_calc_allocator_;  // for table locatition calc exprs
  common::ModulePageAllocator array_allocator_;

  // buffer
  common::ObDataBuffer expr_to_string_buf_;
  common::ObDataBuffer escape_data_buffer_;

  // tools/modules
  ObFileReader reader_;
  ObRawExprPrinter expr_printer_;
  ObTableLocation table_location_;
  ObParallelTaskController task_controller_;
  CompleteTaskArray complete_task_array_;

  // runtime variables
  ParseStep cur_step_;
  int64_t parsed_line_count_;
  char* cur_line_begin_pos_;
  int64_t field_id_;
  char* cur_field_begin_pos_;
  bool in_enclose_flag_;
  ObLoadEscapeSM escape_sm_;

  // some fast access
  int64_t field_term_char_;
  int64_t line_term_char_;
  int64_t enclose_char_;
  int64_t escape_char_;

  // KMP detectors
  ObKMPStateMachine line_start_detector_;
  ObKMPStateMachine line_term_detector_;
  ObKMPStateMachine field_term_detector_;

  // timers
  ObLoadDataTimer total_timer_;
  ObLoadDataTimer file_read_timer_;
  ObLoadDataTimer parsing_execute_timer_;
  ObLoadDataTimer rpc_timer_;
  ObLoadDataTimer calc_timer_;
  ObLoadDataTimer buffer_copy_timer_;
  ObLoadDataTimer serialize_timer_;
  ObLoadDataTimer wait_task_timer_;
  ObLoadDataTimer handle_result_timer_;

  // hashmaps: use tenant 500 memory
  PartitionBufferHashMap part_buffer_map_;         // hash map(partition id -> BufferInfo)
  FileFieldIdxHashMap varname_field_idx_hashmap_;  // map the variable name to field id in file
  ServerTimestampHashMap server_last_freeze_ts_hashmap_;

  // arrays
  ObAssignments set_assigns_;
  ObSEArray<ObLoadDataStmt::FieldOrVarStruct, EXPECTED_INSERT_COLUMN_NUM> file_field_def_;
  ObSEArray<ObLoadDataReplacedExprInfo, EXPECTED_EXPR_VARABLES_TOTAL_NUM> replaced_expr_value_index_store_;
  ObSEArray<ObLoadTableColumnDesc, EXPECTED_INSERT_COLUMN_NUM> valid_insert_column_info_store_;  // PRC data define
  ObSEArray<int64_t, EXPECTED_EXPR_VARABLES_TOTAL_NUM> params_value_index_store_;
  ObSEArray<common::ObString, EXPECTED_INSERT_COLUMN_NUM> insert_column_names_;
  ObSEArray<ObLoadbuffer*, 64> allocated_buffer_store_;  // just for easy release
  ObExprValueBitSet expr_value_bitset_;
  // TODO: change this to string_type_bit_set
  FieldFlagBitSet field_type_bit_set_;  // a bit is set when field target is NOT a char/varchar/hexstring/text type
                                        // column

  // runtime arrays
  ObSEArray<common::ObString, EXPECTED_INSERT_COLUMN_NUM> insert_values_per_line_;  // only used in stop_on_dup mode
  ObSEArray<common::ObString, EXPECTED_INSERT_COLUMN_NUM> parsed_field_strs_;       // store field strs from data file
  ObSEArray<common::ObString, EXPECTED_INSERT_COLUMN_NUM> expr_strs_;
  ObSEArray<int64_t, 1> partition_ids_;
};

OB_INLINE bool ObLoadDataImpl::scan_for_line_start(char*& cur_pos, const char* buf_end)
{
  return line_start_detector_.scan_buf(cur_pos, buf_end);
}

OB_INLINE void ObLoadDataImpl::remove_enclosed_char(char*& cur_field_end_pos)
{
  cur_field_end_pos--;
  cur_field_begin_pos_++;
}

OB_INLINE void ObLoadDataImpl::deal_with_empty_field(ObString& field_str, int64_t index)
{
  if (field_type_bit_set_.has_member(index) && !share::is_oracle_mode()) {
    // a non-string value will be set to "0", "0" will be cast to zero value of target types
    field_str.assign_ptr(ZERO_FIELD_STRING, 1);
  } else {
    // a string value will be set to ''
    field_str.reset();
  }
}

OB_INLINE void ObLoadDataBase::set_one_field_objparam(ObObjParam& dest_param, const ObString& field_str)
{
  if (ObLoadDataUtils::is_null_field(field_str)) {
    dest_param.set_null();
  } else {
    dest_param.set_varchar(field_str);
  }
  dest_param.set_param_meta();
}

OB_INLINE void ObLoadDataImpl::handle_one_field(char* field_end_pos)
{
  if (OB_LIKELY(field_id_ < file_column_number_)) {
    ObString& field_str = parsed_field_strs_.at(field_id_);
    int32_t str_len = static_cast<int32_t>(field_end_pos - cur_field_begin_pos_);
    if (OB_UNLIKELY(str_len <= 0)) {
      deal_with_empty_field(field_str, field_id_);
    } else {
      field_str.assign_ptr(cur_field_begin_pos_, str_len);
    }
  }
  field_id_++;
}

OB_INLINE bool ObLoadDataImpl::is_terminate_char(char& cur_char, int64_t& term_char, char*& cur_pos)
{
  bool ret_bool = false;
  if (static_cast<int64_t>(cur_char) == term_char && !escape_sm_.is_escaping()) {
    if (!in_enclose_flag_) {
      ret_bool = true;  // return true
    } else {
      char* pre_pos = cur_pos - 1;
      if (static_cast<int64_t>(*pre_pos) ==
              enclose_char_  // with in_enclose_flag_ = true, a term char is valid only if an enclosed char before it
          && cur_field_begin_pos_ != pre_pos) {  // 123---->'---->123
        in_enclose_flag_ = false;
        remove_enclosed_char(cur_pos);
        ret_bool = true;  // return true
      } else {
        // return false
      }
    }
  } else {
    // return false
  }
  return ret_bool;
}

OB_INLINE bool ObLoadDataImpl::is_terminate(char& cur_char, ObKMPStateMachine& term_state_machine, char*& cur_pos)
{
  bool ret_bool = false;
  if (term_state_machine.accept_char(cur_char)) {
    char* field_end_pos = cur_pos - term_state_machine.get_pattern_length() + 1;
    if (!in_enclose_flag_) {
      cur_pos = field_end_pos;
      ret_bool = true;  // return true
    } else {
      char* pre_pos = field_end_pos - 1;
      if (static_cast<int64_t>(*pre_pos) == enclose_char_ && !escape_sm_.is_escaping() &&
          cur_field_begin_pos_ != field_end_pos) {  // 123---->'---->123
        in_enclose_flag_ = false;
        cur_pos = field_end_pos;
        remove_enclosed_char(cur_pos);
        ret_bool = true;  // return true
      } else {
        // return false
      }
    }
  } else {
    // return false
  }
  return ret_bool;
}

OB_INLINE bool ObLoadDataImpl::is_enclosed_field_start(char* cur_pos, char& cur_char)
{
  return static_cast<int64_t>(cur_char) == enclose_char_
         // anything between a pair of enclosed chars will be regarded as string data of one field
         && !in_enclose_flag_
         // enclosed field start must be the first char at the beginning of one field,
         // so cur_char is impossible to be escaped
         && cur_pos == cur_field_begin_pos_;
}

}  // namespace sql

}  // namespace oceanbase

#endif  // OCEANBASE_SQL_LOAD_DATA_IMPL_H_