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/** @file include/ha0ha.h
 The hash table with external chains

 Created 8/18/1994 Heikki Tuuri
 *******************************************************/

#ifndef ha0ha_h
#define ha0ha_h

#include "univ.i"

#include "buf0types.h"
#include "hash0hash.h"
#include "page0types.h"
#include "rem0types.h"

/** Looks for an element in a hash table.
@param[in]	table	hash table
@param[in]	fold	folded value of the searched data
@return pointer to the data of the first hash table node in chain
having the fold number, NULL if not found */
UNIV_INLINE
const rec_t *ha_search_and_get_data(hash_table_t *table, ulint fold);

/** Looks for an element when we know the pointer to the data and updates
 the pointer to data if found.
 @return true if found */
ibool ha_search_and_update_if_found_func(
    hash_table_t *table, /*!< in/out: hash table */
    ulint fold,          /*!< in: folded value of the searched data */
    const rec_t *data,   /*!< in: pointer to the data */
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
    buf_block_t *new_block, /*!< in: block containing new_data */
#endif                      /* UNIV_AHI_DEBUG || UNIV_DEBUG */
    const rec_t *new_data); /*!< in: new pointer to the data */

#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
/** Looks for an element when we know the pointer to the data and
updates the pointer to data if found.
@param table in/out: hash table
@param fold in: folded value of the searched data
@param data in: pointer to the data
@param new_block in: block containing new_data
@param new_data in: new pointer to the data */
#define ha_search_and_update_if_found(table, fold, data, new_block, new_data) \
  ha_search_and_update_if_found_func(table, fold, data, new_block, new_data)
#else /* UNIV_AHI_DEBUG || UNIV_DEBUG */
/** Looks for an element when we know the pointer to the data and
updates the pointer to data if found.
@param table in/out: hash table
@param fold in: folded value of the searched data
@param data in: pointer to the data
@param new_block ignored: block containing new_data
@param new_data in: new pointer to the data */
#define ha_search_and_update_if_found(table, fold, data, new_block, new_data) \
  ha_search_and_update_if_found_func(table, fold, data, new_data)
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */

/** Creates a hash table with at least n array cells.  The actual number
 of cells is chosen to be a prime number slightly bigger than n.
 @return own: created table */
hash_table_t *ib_create(
    ulint n,         /*!< in: number of array cells */
    latch_id_t id,   /*!< in: latch ID */
    ulint n_mutexes, /*!< in: number of mutexes to protect the
                   hash table: must be a power of 2, or 0 */
    ulint type);     /*!< in: type of datastructure for which
                     the memory heap is going to be used e.g.:
                     MEM_HEAP_FOR_BTR_SEARCH or
                     MEM_HEAP_FOR_PAGE_HASH */

/** Recreate a hash table with at least n array cells. The actual number
of cells is chosen to be a prime number slightly bigger than n.
The new cells are all cleared. The heaps are recreated.
The sync objects are reused.
@param[in,out]	table	hash table to be resuzed (to be freed later)
@param[in]	n	number of array cells
@return	resized new table */
hash_table_t *ib_recreate(hash_table_t *table, ulint n);

/** Empties a hash table and frees the memory heaps. */
void ha_clear(hash_table_t *table); /*!< in, own: hash table */

/** Inserts an entry into a hash table. If an entry with the same fold number
 is found, its node is updated to point to the new data, and no new node
 is inserted.
 @return true if succeed, false if no more memory could be allocated */
ibool ha_insert_for_fold_func(
    hash_table_t *table, /*!< in: hash table */
    ulint fold,          /*!< in: folded value of data; if a node with
                         the same fold value already exists, it is
                         updated to point to the same data, and no new
                         node is created! */
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
    buf_block_t *block, /*!< in: buffer block containing the data */
#endif                  /* UNIV_AHI_DEBUG || UNIV_DEBUG */
    const rec_t *data); /*!< in: data, must not be NULL */

#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
/**
Inserts an entry into a hash table. If an entry with the same fold number
is found, its node is updated to point to the new data, and no new node
is inserted.
@return true if succeed, false if no more memory could be allocated
@param t in: hash table
@param f in: folded value of data
@param b in: buffer block containing the data
@param d in: data, must not be NULL */
#define ha_insert_for_fold(t, f, b, d)            \
  do {                                            \
    ha_insert_for_fold_func(t, f, b, d);          \
    MONITOR_INC(MONITOR_ADAPTIVE_HASH_ROW_ADDED); \
  } while (0)
#else /* UNIV_AHI_DEBUG || UNIV_DEBUG */
/**
Inserts an entry into a hash table. If an entry with the same fold number
is found, its node is updated to point to the new data, and no new node
is inserted.
@return true if succeed, false if no more memory could be allocated
@param t in: hash table
@param f in: folded value of data
@param b ignored: buffer block containing the data
@param d in: data, must not be NULL */
#define ha_insert_for_fold(t, f, b, d)            \
  do {                                            \
    ha_insert_for_fold_func(t, f, d);             \
    MONITOR_INC(MONITOR_ADAPTIVE_HASH_ROW_ADDED); \
  } while (0)
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */

/** Looks for an element when we know the pointer to the data and deletes it
from the hash table if found.
@param[in]	table	hash table
@param[in]	fold	folded value of the searched data
@param[in]	data	pointer to the data
@return true if found */
UNIV_INLINE
ibool ha_search_and_delete_if_found(hash_table_t *table, ulint fold,
                                    const rec_t *data);

#ifndef UNIV_HOTBACKUP
/** Removes from the chain determined by fold all nodes whose data pointer
 points to the page given. */
void ha_remove_all_nodes_to_page(hash_table_t *table, /*!< in: hash table */
                                 ulint fold,          /*!< in: fold value */
                                 const page_t *page); /*!< in: buffer page */
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
/** Validates a given range of the cells in hash table.
 @return true if ok */
ibool ha_validate(hash_table_t *table, /*!< in: hash table */
                  ulint start_index,   /*!< in: start index */
                  ulint end_index);    /*!< in: end index */
#endif /* defined UNIV_AHI_DEBUG || defined UNIV_DEBUG */
/** Prints info of a hash table. */
void ha_print_info(FILE *file,           /*!< in: file where to print */
                   hash_table_t *table); /*!< in: hash table */
#endif                                   /* !UNIV_HOTBACKUP */

/** The hash table external chain node */
struct ha_node_t {
  ulint fold;      /*!< fold value for the data */
  ha_node_t *next; /*!< next chain node or NULL if none */
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
  buf_block_t *block; /*!< buffer block containing the data, or NULL */
#endif                /* UNIV_AHI_DEBUG || UNIV_DEBUG */
  const rec_t *data;  /*!< pointer to the data */
};

#ifdef UNIV_DEBUG
/** Assert that the synchronization object in a hash operation involving
possible change in the hash table is held.
Note that in case of mutexes we assert that mutex is owned while in case of
rw-locks we assert that it is held in exclusive mode.
@param[in]	table	hash table
@param[in]	fold	fold value */
UNIV_INLINE
void hash_assert_can_modify(hash_table_t *table, ulint fold);

/** Assert that the synchronization object in a hash search operation is held.
Note that in case of mutexes we assert that mutex is owned while in case of
rw-locks we assert that it is held either in x-mode or s-mode.
@param[in]	table	hash table
@param[in]	fold	fold value */
UNIV_INLINE
void hash_assert_can_search(hash_table_t *table, ulint fold);
#else /* UNIV_DEBUG */
#define hash_assert_can_modify(t, f)
#define hash_assert_can_search(t, f)
#endif /* UNIV_DEBUG */

#include "ha0ha.ic"

#endif