cursor.h

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 *
 *  Copyright (C) 2008 Sun Microsystems, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#pragma once

#include <drizzled/atomics.h>
#include <drizzled/definitions.h>
#include <drizzled/discrete_interval.h>
#include <drizzled/error_t.h>
#include <drizzled/ha_statistics.h>
#include <drizzled/handler_structs.h>
#include <drizzled/identifier.h>
#include <drizzled/key_map.h>
#include <drizzled/message/table.h>
#include <drizzled/sql_list.h>
#include <drizzled/thr_lock.h>

#include <bitset>
#include <algorithm>

#include <drizzled/visibility.h>

namespace drizzled {

#define HA_MAX_ALTER_FLAGS 40

typedef std::bitset<HA_MAX_ALTER_FLAGS> HA_ALTER_FLAGS;

typedef List<Item> List_item;
extern KEY_CREATE_INFO default_key_create_info;

/*
  bitmap with first N+1 bits set
  (keypart_map for a key prefix of [0..N] keyparts)
*/
inline key_part_map make_keypart_map(int a)
{
  return (((key_part_map)2 << a) - 1);
}

/*
  bitmap with first N bits set
  (keypart_map for a key prefix of [0..N-1] keyparts)
*/
inline key_part_map make_prev_keypart_map(int a)
{
  return (((key_part_map)1 << a) - 1);
}

class DRIZZLED_API Cursor
{
  friend class SEAPITesterCursor;
  Table &table;               /* The current open table */
  plugin::StorageEngine &engine;      /* storage engine of this Cursor */

protected:
  ha_rows estimation_rows_to_insert;

public:
  inline plugin::StorageEngine *getEngine() const /* table_type for handler */
  {
    return &engine;
  }
  unsigned char *ref;       /* Pointer to current row */
  unsigned char *dup_ref;     /* Pointer to duplicate row */

  TableShare *getShare();

  Table *getTable() const
  {
    return &table;
  }

  ha_statistics stats;
  range_seq_t mrr_iter;    /* Interator to traverse the range sequence */
  RANGE_SEQ_IF mrr_funcs;  /* Range sequence traversal functions */

  uint32_t ranges_in_seq; /* Total number of ranges in the traversed sequence */
  /* true <=> source MRR ranges and the output are ordered */
  bool mrr_is_output_sorted;

  bool mrr_have_range;

  bool eq_range;

  KEY_MULTI_RANGE mrr_cur_range;

  key_range save_end_range, *end_range;
  KeyPartInfo *range_key_part;
  int key_compare_result_on_equal;

  uint32_t errkey;        /* Last dup key */
  uint32_t key_used_on_scan;
  uint32_t active_index;
  uint32_t ref_length;
  enum {NONE=0, INDEX, RND} inited;
  bool locked;

  uint64_t next_insert_id;
  uint64_t getNextInsertId() const
  {
    return next_insert_id;
  }

  uint64_t getAutoIncrement() const
  {
    return stats.auto_increment_value;
  }

  uint64_t insert_id_for_cur_row;
  Discrete_interval auto_inc_interval_for_cur_row;

  Cursor(plugin::StorageEngine &engine_arg, Table &share_arg);
  virtual ~Cursor(void);
  virtual Cursor *clone(memory::Root *mem_root);

  /* ha_ methods: pubilc wrappers for private virtual API */

  int ha_open(const identifier::Table &identifier, int mode, int test_if_locked);
  int startIndexScan(uint32_t idx, bool sorted) __attribute__ ((warn_unused_result));
  int endIndexScan();
  int startTableScan(bool scan) __attribute__ ((warn_unused_result));
  int endTableScan();
  int ha_reset();

  /* this is necessary in many places, e.g. in HANDLER command */
  int ha_index_or_rnd_end();

  int ha_external_lock(Session *session, int lock_type);
  int insertRecord(unsigned char * buf) __attribute__ ((warn_unused_result));
  int updateRecord(const unsigned char * old_data, unsigned char * new_data) __attribute__ ((warn_unused_result));
  int deleteRecord(const unsigned char * buf) __attribute__ ((warn_unused_result));
  void ha_release_auto_increment();
  int ha_check(Session*);
  void ha_start_bulk_insert(ha_rows rows);
  int ha_end_bulk_insert();
  int ha_delete_all_rows();
  int ha_reset_auto_increment(uint64_t value);
  int ha_analyze(Session*);

  int ha_disable_indexes(uint32_t mode);
  int ha_enable_indexes(uint32_t mode);
  int ha_discard_or_import_tablespace(bool discard);
  void closeMarkForDelete();

  void adjust_next_insert_id_after_explicit_value(uint64_t nr);
  int update_auto_increment();

  /* Estimates calculation */
  virtual double scan_time(void)
  { return static_cast<double>(stats.data_file_length) / IO_SIZE + 2; }
  virtual double read_time(uint32_t, uint32_t ranges, ha_rows rows)
  { return ranges + rows; }

  virtual double index_only_read_time(uint32_t keynr, double records);

  virtual ha_rows multi_range_read_info_const(uint32_t keyno, RANGE_SEQ_IF *seq,
                                              void *seq_init_param,
                                              uint32_t n_ranges, uint32_t *bufsz,
                                              uint32_t *flags, optimizer::CostVector *cost);
  virtual int multi_range_read_info(uint32_t keyno, uint32_t n_ranges, uint32_t keys,
                                    uint32_t *bufsz, uint32_t *flags, optimizer::CostVector *cost);
  virtual int multi_range_read_init(RANGE_SEQ_IF *seq, void *seq_init_param,
                                    uint32_t n_ranges, uint32_t mode);
  virtual int multi_range_read_next(char **range_info);


  virtual const key_map *keys_to_use_for_scanning();
  bool has_transactions();

  virtual bool is_fatal_error(int error, uint32_t flags);

  virtual ha_rows records();
  virtual uint64_t tableSize();
  virtual uint64_t rowSize();
  virtual ha_rows estimate_rows_upper_bound()
  { return stats.records+EXTRA_RECORDS; }

  virtual const char *index_type(uint32_t)
  { assert(0); return "";}


  uint32_t get_index(void) const { return active_index; }
  virtual int close(void)=0;

  virtual int index_read_map(unsigned char * buf, const unsigned char *key,
                             key_part_map keypart_map,
                             enum ha_rkey_function find_flag)
  {
    uint32_t key_len= calculate_key_len(active_index, keypart_map);
    return  index_read(buf, key, key_len, find_flag);
  }
  virtual int index_read_idx_map(unsigned char * buf, uint32_t index,
                                 const unsigned char * key,
                                 key_part_map keypart_map,
                                 enum ha_rkey_function find_flag);
  virtual int index_next(unsigned char *) __attribute__ ((warn_unused_result))
   { return  HA_ERR_WRONG_COMMAND; }
  virtual int index_prev(unsigned char *)
   { return  HA_ERR_WRONG_COMMAND; }
  virtual int index_first(unsigned char *)
   { return  HA_ERR_WRONG_COMMAND; }
  virtual int index_last(unsigned char *)
   { return  HA_ERR_WRONG_COMMAND; }
  virtual int index_next_same(unsigned char *, const unsigned char *, uint32_t);

private:
  uint32_t calculate_key_len(uint32_t key_position, key_part_map keypart_map_arg);
public:

  virtual int index_read_last_map(unsigned char * buf, const unsigned char * key,
                                  key_part_map keypart_map)
  {
    uint32_t key_len= calculate_key_len(active_index, keypart_map);
    return index_read_last(buf, key, key_len);
  }
  virtual int read_range_first(const key_range *start_key,
                               const key_range *end_key,
                               bool eq_range, bool sorted);
  virtual int read_range_next();
  int compare_key(key_range *range);
  virtual int rnd_next(unsigned char *)=0;
  virtual int rnd_pos(unsigned char *, unsigned char *)=0;
  virtual int read_first_row(unsigned char *buf, uint32_t primary_key);
  virtual int rnd_same(unsigned char *, uint32_t)
    { return HA_ERR_WRONG_COMMAND; }
  virtual ha_rows records_in_range(uint32_t, key_range *, key_range *)
    { return (ha_rows) 10; }
  virtual void position(const unsigned char *record)=0;
  virtual int info(uint32_t)=0; // see my_base.h for full description
  virtual uint32_t calculate_key_hash_value(Field **)
  { assert(0); return 0; }
  virtual int extra(enum ha_extra_function)
  { return 0; }
  virtual int extra_opt(enum ha_extra_function operation, uint32_t)
  { return extra(operation); }

  virtual bool was_semi_consistent_read() { return 0; }
  virtual void try_semi_consistent_read(bool) {}
  virtual void unlock_row(void) {}
  virtual void get_auto_increment(uint64_t offset, uint64_t increment,
                                  uint64_t nb_desired_values,
                                  uint64_t *first_value,
                                  uint64_t *nb_reserved_values)= 0;

  void set_next_insert_id(uint64_t id)
  {
    next_insert_id= id;
  }
  void restore_auto_increment(uint64_t prev_insert_id)
  {
    /*
      Insertion of a row failed, re-use the lastly generated auto_increment
      id, for the next row. This is achieved by resetting next_insert_id to
      what it was before the failed insertion (that old value is provided by
      the caller). If that value was 0, it was the first row of the INSERT;
      then if insert_id_for_cur_row contains 0 it means no id was generated
      for this first row, so no id was generated since the INSERT started, so
      we should set next_insert_id to 0; if insert_id_for_cur_row is not 0, it
      is the generated id of the first and failed row, so we use it.
    */
    next_insert_id= (prev_insert_id > 0) ? prev_insert_id :
      insert_id_for_cur_row;
  }

  /* end of the list of admin commands */

  virtual int indexes_are_disabled(void) {return 0;}
  virtual void append_create_info(String *)
  {}
  virtual char* get_foreign_key_create_info(void)
  { return NULL;}  /* gets foreign key create string from InnoDB */
  virtual bool can_switch_engines(void) { return true; }
  virtual int get_foreign_key_list(Session *, List<ForeignKeyInfo> *)
  { return 0; }
  virtual uint32_t referenced_by_foreign_key() { return 0;}
  virtual void free_foreign_key_create_info(char *) {}

  virtual THR_LOCK_DATA **store_lock(Session *,
                                     THR_LOCK_DATA **to,
                                     enum thr_lock_type)
  {
    assert(0); // Impossible programming situation

    return(to);
  }

 /*
   @retval true   Primary key (if there is one) is clustered
                  key covering all fields
   @retval false  otherwise
 */
 virtual bool primary_key_is_clustered() { return false; }
 virtual int cmp_ref(const unsigned char *ref1, const unsigned char *ref2)
 {
   return memcmp(ref1, ref2, ref_length);
 }

  virtual bool isOrdered(void)
  {
    return false;
  }


protected:
  /* Service methods for use by storage engines. */
  void ha_statistic_increment(uint64_t system_status_var::*offset) const;
  void **ha_data(Session *) const;

private:
  /* Private helpers */
  inline void setTransactionReadWrite();
private:
  /*
    Low-level primitives for storage engines.  These should be
    overridden by the storage engine class. To call these methods, use
    the corresponding 'ha_*' method above.
  */

  virtual int open(const char *, int , uint32_t ) { assert(0); return -1; }
  virtual int doOpen(const identifier::Table &identifier, int mode, uint32_t test_if_locked);
  virtual int doStartIndexScan(uint32_t idx, bool)
  { active_index= idx; return 0; }
  virtual int doEndIndexScan() { active_index= MAX_KEY; return 0; }
  virtual int doStartTableScan(bool scan) __attribute__ ((warn_unused_result)) = 0;
  virtual int doEndTableScan() { return 0; }
  virtual int doInsertRecord(unsigned char *)
  {
    return HA_ERR_WRONG_COMMAND;
  }

  virtual int doUpdateRecord(const unsigned char *, unsigned char *)
  {
    return HA_ERR_WRONG_COMMAND;
  }

  virtual int doDeleteRecord(const unsigned char *)
  {
    return HA_ERR_WRONG_COMMAND;
  }
  virtual int reset() { return 0; }

  virtual int external_lock(Session *, int)
  {
    return 0;
  }
  virtual void release_auto_increment(void) { return; }
  virtual int check(Session *)
  { return HA_ADMIN_NOT_IMPLEMENTED; }

  virtual void start_bulk_insert(ha_rows)
  {}
  virtual int end_bulk_insert(void) { return 0; }
  virtual int index_read(unsigned char *, const unsigned char *,
                         uint32_t, enum ha_rkey_function)
   { return  HA_ERR_WRONG_COMMAND; }
  virtual int index_read_last(unsigned char *, const unsigned char *, uint32_t)
   { return (errno= HA_ERR_WRONG_COMMAND); }
  virtual int delete_all_rows(void)
  { return (errno=HA_ERR_WRONG_COMMAND); }
  virtual int reset_auto_increment(uint64_t)
  { return HA_ERR_WRONG_COMMAND; }

  virtual int analyze(Session *)
  { return HA_ADMIN_NOT_IMPLEMENTED; }

  virtual int disable_indexes(uint32_t)
  { return HA_ERR_WRONG_COMMAND; }

  virtual int enable_indexes(uint32_t)
  { return HA_ERR_WRONG_COMMAND; }

  virtual int discard_or_import_tablespace(bool)
  { return (errno=HA_ERR_WRONG_COMMAND); }

  /* 
    @todo this is just for the HEAP engine, it should
    be removed at some point in the future (and
    no new engine should ever use it). Right
    now HEAP does rely on it, so we cannot remove it.
  */
  virtual void drop_table();
};

extern const char *ha_row_type[];

/* basic stuff */
void ha_init_errors(void);

SortField *make_unireg_sortorder(Order *order, uint32_t *length,
                                 SortField *sortorder);
int setup_order(Session *session, Item **ref_pointer_array, TableList *tables,
                List<Item> &fields, List <Item> &all_fields, Order *order);
int setup_group(Session *session, Item **ref_pointer_array, TableList *tables,
                List<Item> &fields, List<Item> &all_fields, Order *order,
                bool *hidden_group_fields);
bool fix_inner_refs(Session *session, List<Item> &all_fields, Select_Lex *select,
                    Item **ref_pointer_array);

bool handle_select(Session *session, LEX *lex, select_result *result,
                   uint64_t setup_tables_done_option);
void free_underlaid_joins(Session *session, Select_Lex *select);

bool handle_derived(LEX *lex, bool (*processor)(Session *session,
                                                      LEX *lex,
                                                      TableList *table));
bool derived_prepare(Session *session, LEX *lex, TableList *t);
bool derived_filling(Session *session, LEX *lex, TableList *t);
int prepare_create_field(CreateField *sql_field,
                         uint32_t *blob_columns,
                         int *timestamps, int *timestamps_with_niladic);

bool create_table(Session *session,
                  const identifier::Table &identifier,
                  HA_CREATE_INFO *create_info,
                  message::Table &table_proto,
                  AlterInfo *alter_info,
                  bool tmp_table, uint32_t select_field_count,
                  bool is_if_not_exists);

bool create_table_no_lock(Session *session,
                          const identifier::Table &identifier,
                          HA_CREATE_INFO *create_info,
                          message::Table &table_proto,
                          AlterInfo *alter_info,
                          bool tmp_table, uint32_t select_field_count,
                          bool is_if_not_exists);

bool create_like_table(Session* session,
                       const identifier::Table& destination_identifier,
                       const identifier::Table& source_identifier,
                       message::Table &create_table_proto,
                       bool is_if_not_exists,
                       bool is_engine_set);

bool rename_table(Session &session,
                        plugin::StorageEngine *base,
                        const identifier::Table &old_identifier,
                        const identifier::Table &new_identifier);

bool prepare_update(Session *session, TableList *table_list,
                          Item **conds, uint32_t order_num, Order *order);
int update_query(Session *session,TableList *tables,List<Item> &fields,
                 List<Item> &values,COND *conds,
                 uint32_t order_num, Order *order, ha_rows limit,
                 enum enum_duplicates handle_duplicates, bool ignore);
bool prepare_insert(Session *session, TableList *table_list, Table *table,
                          List<Item> &fields, List_item *values,
                          List<Item> &update_fields,
                          List<Item> &update_values, enum_duplicates duplic,
                          COND **where, bool select_insert,
                          bool check_fields, bool abort_on_warning);
bool insert_query(Session *session,TableList *table,List<Item> &fields,
                  List<List_item> &values, List<Item> &update_fields,
                  List<Item> &update_values, enum_duplicates flag,
                  bool ignore);
int check_that_all_fields_are_given_values(Session *session, Table *entry,
                                           TableList *table_list);
int prepare_delete(Session *session, TableList *table_list, Item **conds);
bool delete_query(Session *session, TableList *table_list, COND *conds,
                  SQL_LIST *order, ha_rows rows, uint64_t options,
                  bool reset_auto_increment);
bool truncate(Session& session, TableList *table_list);
TableShare *get_table_share(Session *session, TableList *table_list, char *key,
                             uint32_t key_length, uint32_t db_flags, int *error);
TableShare *get_cached_table_share(const char *db, const char *table_name);
bool reopen_name_locked_table(Session* session, TableList* table_list, bool link_in);
bool reopen_tables(Session *session,bool get_locks,bool in_refresh);
void close_handle_and_leave_table_as_lock(Table *table);
bool wait_for_tables(Session *session);
bool table_is_used(Table *table, bool wait_for_name_lock);
Table *drop_locked_tables(Session *session, const drizzled::identifier::Table &identifier);
void abort_locked_tables(Session *session, const drizzled::identifier::Table &identifier);
extern Field *not_found_field;
extern Field *view_ref_found;

Field *
find_field_in_tables(Session *session, Item_ident *item,
                     TableList *first_table, TableList *last_table,
                     Item **ref, find_item_error_report_type report_error,
                     bool register_tree_change);
Field *
find_field_in_table_ref(Session *session, TableList *table_list,
                        const char *name, uint32_t length,
                        const char *item_name, const char *db_name,
                        const char *table_name, Item **ref,
                        bool allow_rowid,
                        uint32_t *cached_field_index_ptr,
                        bool register_tree_change, TableList **actual_table);
Field *
find_field_in_table(Session *session, Table *table, const char *name, uint32_t length,
                    bool allow_rowid, uint32_t *cached_field_index_ptr);

} /* namespace drizzled */