ha0ha.h

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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]      hash_value  hashed value of the searched data
@return pointer to the data of the first hash table node in chain
having the hash number, NULL if not found */
static inline const rec_t *ha_search_and_get_data(hash_table_t *table,
                                                  uint64_t hash_value);
 
/** Looks for an element when we know the pointer to the data and updates
 the pointer to data if found.
 @param[in,out] table hash table
 @param[in] hash_value hashed value of the searched data
 @param[in] data pointer to the data
 @param[in] new_block block containing new data
 @param[in] new_data new pointer to the data
 @return true if found */
bool ha_search_and_update_if_found_func(hash_table_t *table,
                                        uint64_t hash_value, const rec_t *data,
                                        IF_AHI_DEBUG(buf_block_t *new_block, )
                                            const rec_t *new_data);
 
/** 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 hash_value in: hashed 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 */
static inline bool ha_search_and_update_if_found(hash_table_t *table,
                                                 uint64_t hash_value,
                                                 const rec_t *data,
                                                 buf_block_t *new_block,
                                                 const rec_t *new_data) {
  return ha_search_and_update_if_found_func(table, hash_value, data,
                                            IF_AHI_DEBUG(new_block, ) new_data);
}
/** 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.
 @param[in] n           number of array cells
 @param[in] id          latch ID
 @param[in] n_sync_obj  Number of sync objects protecting the hash table.
                        Must be a power of 2, or 0.
 @param[in] type        type of datastructure for which the memory heap is going
                        to be used:
                        MEM_HEAP_FOR_BTR_SEARCH or
                        MEM_HEAP_FOR_PAGE_HASH
 @return own: created table */
hash_table_t *ib_create(size_t n, latch_id_t id, size_t n_sync_obj,
                        uint32_t type);
 
/** 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 hash number
 is found, its node is updated to point to the new data, and no new node
 is inserted. If btr_search_enabled is set to false, we will only allow
 updating existing nodes, but no new node is allowed to be added.
 @param[in] table hash table
 @param[in] hash_value hashed value of data; if a node with the same hash value
 already exists, it is updated to point to the same data, and no new node is
 created!
 @param[in] block buffer block containing the data
 @param[in] data data, must not be NULL
 @return true if succeeded, false if no more memory could be allocated */
bool ha_insert_for_hash_func(hash_table_t *table, uint64_t hash_value,
                             IF_AHI_DEBUG(buf_block_t *block, )
                                 const rec_t *data);
 
/**
Inserts an entry into a hash table. If an entry with the same hash number
is found, its node is updated to point to the new data, and no new node
is inserted.
@param[in] t  hash table
@param[in] f  hashed value of data
@param[in] b  buffer block containing the data
@param[in] d  data, must not be NULL */
static inline void ha_insert_for_hash(hash_table_t *t, uint64_t f,
                                      buf_block_t *b, const rec_t *d) {
  ha_insert_for_hash_func(t, f, IF_AHI_DEBUG(b, ) d);
  MONITOR_ATOMIC_INC(MONITOR_ADAPTIVE_HASH_ROW_ADDED);
}
 
/** 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]      hash_value  hashed value of the searched data
@param[in]      data        pointer to the data
@return true if found */
static inline bool ha_search_and_delete_if_found(hash_table_t *table,
                                                 uint64_t hash_value,
                                                 const rec_t *data);
 
#ifndef UNIV_HOTBACKUP
 
/** Removes from the chain determined by hash value a single node whose data
pointer points to the page given. Note that the node deleted can have a
different hash value.
@param[in] table Hash table
@param[in] hash_value Hash value
@param[in] page Buffer page */
void ha_remove_a_node_to_page(hash_table_t *table, uint64_t hash_value,
                              const page_t *page);
 
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
/** Validates a given range of the cells in hash table.
@param[in] table Hash table
@param[in] start_index Start index
@param[in] end_index End index
@return true if ok */
bool ha_validate(hash_table_t *table, uint64_t start_index, uint64_t end_index);
#endif /* defined UNIV_AHI_DEBUG || defined UNIV_DEBUG */
 
/** Prints info of a hash table.
@param[in] file File where to print
@param[in] table Hash table */
void ha_print_info(FILE *file, hash_table_t *table);
 
#endif /* !UNIV_HOTBACKUP */
 
/** The hash table external chain node */
struct ha_node_t {
  /** hash value for the data  */
  uint64_t hash_value;
  /** next chain node or NULL if none */
  ha_node_t *next;
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
  /** buffer block containing the data, or NULL */
  buf_block_t *block;
#endif
  /** pointer to the data */
  const rec_t *data;
};
 
#include "ha0ha.ic"
 
#endif