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/*****************************************************************************
Copyright (c) 1994, 2009, Innobase Oy. All Rights Reserved.
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., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*****************************************************************************/
/********************************************************************//**
@file ha/ha0ha.c
The hash table with external chains
Created 8/22/1994 Heikki Tuuri
*************************************************************************/
#include "ha0ha.h"
#ifdef UNIV_NONINL
#include "ha0ha.ic"
#endif
#ifdef UNIV_DEBUG
# include "buf0buf.h"
#endif /* UNIV_DEBUG */
#include "btr0sea.h"
#include "page0page.h"
/*************************************************************//**
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 */
UNIV_INTERN
hash_table_t*
ha_create_func(
/*===========*/
ulint n, /*!< in: number of array cells */
#ifdef UNIV_SYNC_DEBUG
ulint mutex_level, /*!< in: level of the mutexes in the latching
order: this is used in the debug version */
#endif /* UNIV_SYNC_DEBUG */
ulint n_mutexes) /*!< in: number of mutexes to protect the
hash table: must be a power of 2, or 0 */
{
hash_table_t* table;
#ifndef UNIV_HOTBACKUP
ulint i;
#endif /* !UNIV_HOTBACKUP */
ut_ad(ut_is_2pow(n_mutexes));
table = hash_create(n);
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
# ifndef UNIV_HOTBACKUP
table->adaptive = TRUE;
# endif /* !UNIV_HOTBACKUP */
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
/* Creating MEM_HEAP_BTR_SEARCH type heaps can potentially fail,
but in practise it never should in this case, hence the asserts. */
if (n_mutexes == 0) {
table->heap = mem_heap_create_in_btr_search(
ut_min(4096, MEM_MAX_ALLOC_IN_BUF));
ut_a(table->heap);
return(table);
}
#ifndef UNIV_HOTBACKUP
hash_create_mutexes(table, n_mutexes, mutex_level);
table->heaps = mem_alloc(n_mutexes * sizeof(void*));
for (i = 0; i < n_mutexes; i++) {
table->heaps[i] = mem_heap_create_in_btr_search(4096);
ut_a(table->heaps[i]);
}
#endif /* !UNIV_HOTBACKUP */
return(table);
}
/*************************************************************//**
Empties a hash table and frees the memory heaps. */
UNIV_INTERN
void
ha_clear(
/*=====*/
hash_table_t* table) /*!< in, own: hash table */
{
ulint i;
ulint n;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
#ifdef UNIV_SYNC_DEBUG
ut_ad(rw_lock_own(&btr_search_latch, RW_LOCK_EXCLUSIVE));
#endif /* UNIV_SYNC_DEBUG */
#ifndef UNIV_HOTBACKUP
/* Free the memory heaps. */
n = table->n_mutexes;
for (i = 0; i < n; i++) {
mem_heap_free(table->heaps[i]);
}
#endif /* !UNIV_HOTBACKUP */
/* Clear the hash table. */
n = hash_get_n_cells(table);
for (i = 0; i < n; i++) {
hash_get_nth_cell(table, i)->node = NULL;
}
}
/*************************************************************//**
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. If btr_search_enabled is set to FALSE, we will only allow
updating existing nodes, but no new node is allowed to be added.
@return TRUE if succeed, FALSE if no more memory could be allocated */
UNIV_INTERN
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 */
void* data) /*!< in: data, must not be NULL */
{
hash_cell_t* cell;
ha_node_t* node;
ha_node_t* prev_node;
ulint hash;
ut_ad(data);
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
ut_a(block->frame == page_align(data));
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
ASSERT_HASH_MUTEX_OWN(table, fold);
hash = hash_calc_hash(fold, table);
cell = hash_get_nth_cell(table, hash);
prev_node = cell->node;
while (prev_node != NULL) {
if (prev_node->fold == fold) {
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
# ifndef UNIV_HOTBACKUP
if (table->adaptive) {
buf_block_t* prev_block = prev_node->block;
ut_a(prev_block->frame
== page_align(prev_node->data));
ut_a(prev_block->n_pointers > 0);
prev_block->n_pointers--;
block->n_pointers++;
}
ut_ad(!btr_search_fully_disabled);
# endif /* !UNIV_HOTBACKUP */
prev_node->block = block;
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
prev_node->data = data;
return(TRUE);
}
prev_node = prev_node->next;
}
/* We are in the process of disabling hash index, do not add
new chain node */
if (!btr_search_enabled) {
ut_ad(!btr_search_fully_disabled);
return(TRUE);
}
/* We have to allocate a new chain node */
node = mem_heap_alloc(hash_get_heap(table, fold), sizeof(ha_node_t));
if (node == NULL) {
/* It was a btr search type memory heap and at the moment
no more memory could be allocated: return */
ut_ad(hash_get_heap(table, fold)->type & MEM_HEAP_BTR_SEARCH);
return(FALSE);
}
ha_node_set_data(node, block, data);
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
# ifndef UNIV_HOTBACKUP
if (table->adaptive) {
block->n_pointers++;
}
# endif /* !UNIV_HOTBACKUP */
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
node->fold = fold;
node->next = NULL;
prev_node = cell->node;
if (prev_node == NULL) {
cell->node = node;
return(TRUE);
}
while (prev_node->next != NULL) {
prev_node = prev_node->next;
}
prev_node->next = node;
return(TRUE);
}
/***********************************************************//**
Deletes a hash node. */
UNIV_INTERN
void
ha_delete_hash_node(
/*================*/
hash_table_t* table, /*!< in: hash table */
ha_node_t* del_node) /*!< in: node to be deleted */
{
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
# ifndef UNIV_HOTBACKUP
if (table->adaptive) {
ut_a(del_node->block->frame = page_align(del_node->data));
ut_a(del_node->block->n_pointers > 0);
del_node->block->n_pointers--;
}
# endif /* !UNIV_HOTBACKUP */
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
HASH_DELETE_AND_COMPACT(ha_node_t, next, table, del_node);
}
/*********************************************************//**
Looks for an element when we know the pointer to the data, and updates
the pointer to data, if found. */
UNIV_INTERN
void
ha_search_and_update_if_found_func(
/*===============================*/
hash_table_t* table, /*!< in/out: hash table */
ulint fold, /*!< in: folded value of the searched data */
void* 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 */
void* new_data)/*!< in: new pointer to the data */
{
ha_node_t* node;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ASSERT_HASH_MUTEX_OWN(table, fold);
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
ut_a(new_block->frame == page_align(new_data));
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
node = ha_search_with_data(table, fold, data);
if (node) {
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
# ifndef UNIV_HOTBACKUP
if (table->adaptive) {
ut_a(node->block->n_pointers > 0);
node->block->n_pointers--;
new_block->n_pointers++;
}
# endif /* !UNIV_HOTBACKUP */
node->block = new_block;
#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
node->data = new_data;
}
}
#ifndef UNIV_HOTBACKUP
/*****************************************************************//**
Removes from the chain determined by fold all nodes whose data pointer
points to the page given. */
UNIV_INTERN
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 */
{
ha_node_t* node;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ASSERT_HASH_MUTEX_OWN(table, fold);
node = ha_chain_get_first(table, fold);
while (node) {
if (page_align(ha_node_get_data(node)) == page) {
/* Remove the hash node */
ha_delete_hash_node(table, node);
/* Start again from the first node in the chain
because the deletion may compact the heap of
nodes and move other nodes! */
node = ha_chain_get_first(table, fold);
} else {
node = ha_chain_get_next(node);
}
}
#ifdef UNIV_DEBUG
/* Check that all nodes really got deleted */
node = ha_chain_get_first(table, fold);
while (node) {
ut_a(page_align(ha_node_get_data(node)) != page);
node = ha_chain_get_next(node);
}
#endif
}
#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
/*************************************************************//**
Validates a given range of the cells in hash table.
@return TRUE if ok */
UNIV_INTERN
ibool
ha_validate(
/*========*/
hash_table_t* table, /*!< in: hash table */
ulint start_index, /*!< in: start index */
ulint end_index) /*!< in: end index */
{
hash_cell_t* cell;
ha_node_t* node;
ibool ok = TRUE;
ulint i;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
ut_a(start_index <= end_index);
ut_a(start_index < hash_get_n_cells(table));
ut_a(end_index < hash_get_n_cells(table));
for (i = start_index; i <= end_index; i++) {
cell = hash_get_nth_cell(table, i);
node = cell->node;
while (node) {
if (hash_calc_hash(node->fold, table) != i) {
ut_print_timestamp(stderr);
fprintf(stderr,
"InnoDB: Error: hash table node"
" fold value %lu does not\n"
"InnoDB: match the cell number %lu.\n",
(ulong) node->fold, (ulong) i);
ok = FALSE;
}
node = node->next;
}
}
return(ok);
}
#endif /* defined UNIV_AHI_DEBUG || defined UNIV_DEBUG */
/*************************************************************//**
Prints info of a hash table. */
UNIV_INTERN
void
ha_print_info(
/*==========*/
FILE* file, /*!< in: file where to print */
hash_table_t* table) /*!< in: hash table */
{
#ifdef UNIV_DEBUG
/* Some of the code here is disabled for performance reasons in production
builds, see http://bugs.mysql.com/36941 */
#define PRINT_USED_CELLS
#endif /* UNIV_DEBUG */
#ifdef PRINT_USED_CELLS
hash_cell_t* cell;
ulint cells = 0;
ulint i;
#endif /* PRINT_USED_CELLS */
ulint n_bufs;
ut_ad(table);
ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
#ifdef PRINT_USED_CELLS
for (i = 0; i < hash_get_n_cells(table); i++) {
cell = hash_get_nth_cell(table, i);
if (cell->node) {
cells++;
}
}
#endif /* PRINT_USED_CELLS */
fprintf(file, "Hash table size %lu",
(ulong) hash_get_n_cells(table));
#ifdef PRINT_USED_CELLS
fprintf(file, ", used cells %lu", (ulong) cells);
#endif /* PRINT_USED_CELLS */
if (table->heaps == NULL && table->heap != NULL) {
/* This calculation is intended for the adaptive hash
index: how many buffer frames we have reserved? */
n_bufs = UT_LIST_GET_LEN(table->heap->base) - 1;
if (table->heap->free_block) {
n_bufs++;
}
fprintf(file, ", node heap has %lu buffer(s)\n",
(ulong) n_bufs);
}
}
#endif /* !UNIV_HOTBACKUP */
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