/*****************************************************************************

Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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, version 2.0,
as published by the Free Software Foundation.

This program is also distributed with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation.  The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have included with MySQL.

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, version 2.0, 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 Street, Suite 500, Boston, MA 02110-1335 USA

*****************************************************************************/

/**************************************************//**
@file ha/hash0hash.cc
The simple hash table utility

Created 5/20/1997 Heikki Tuuri
*******************************************************/

#include "hash0hash.h"
#ifdef UNIV_NONINL
#include "hash0hash.ic"
#endif

#include "mem0mem.h"

#ifndef UNIV_HOTBACKUP

# ifdef UNIV_PFS_MUTEX
UNIV_INTERN mysql_pfs_key_t	hash_table_mutex_key;
# endif /* UNIV_PFS_MUTEX */

# ifdef UNIV_PFS_RWLOCK
UNIV_INTERN mysql_pfs_key_t	hash_table_rw_lock_key;
# endif /* UNIV_PFS_RWLOCK */
/************************************************************//**
Reserves the mutex for a fold value in a hash table. */
UNIV_INTERN
void
hash_mutex_enter(
/*=============*/
	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{
	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
	mutex_enter(hash_get_mutex(table, fold));
}

/************************************************************//**
Releases the mutex for a fold value in a hash table. */
UNIV_INTERN
void
hash_mutex_exit(
/*============*/
	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{
	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
	mutex_exit(hash_get_mutex(table, fold));
}

/************************************************************//**
Reserves all the mutexes of a hash table, in an ascending order. */
UNIV_INTERN
void
hash_mutex_enter_all(
/*=================*/
	hash_table_t*	table)	/*!< in: hash table */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
	for (i = 0; i < table->n_sync_obj; i++) {

		mutex_enter(table->sync_obj.mutexes + i);
	}
}

/************************************************************//**
Releases all the mutexes of a hash table. */
UNIV_INTERN
void
hash_mutex_exit_all(
/*================*/
	hash_table_t*	table)	/*!< in: hash table */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
	for (i = 0; i < table->n_sync_obj; i++) {

		mutex_exit(table->sync_obj.mutexes + i);
	}
}

/************************************************************//**
Releases all but the passed in mutex of a hash table. */
UNIV_INTERN
void
hash_mutex_exit_all_but(
/*====================*/
	hash_table_t*	table,		/*!< in: hash table */
	ib_mutex_t*	keep_mutex)	/*!< in: mutex to keep */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_MUTEX);
	for (i = 0; i < table->n_sync_obj; i++) {

		ib_mutex_t* mutex = table->sync_obj.mutexes + i;
		if (UNIV_LIKELY(keep_mutex != mutex)) {
			mutex_exit(mutex);
		}
	}

	ut_ad(mutex_own(keep_mutex));
}

/************************************************************//**
s-lock a lock for a fold value in a hash table. */
UNIV_INTERN
void
hash_lock_s(
/*========*/
	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{

	rw_lock_t* lock = hash_get_lock(table, fold);

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	ut_ad(lock);

#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
	ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

	rw_lock_s_lock(lock);
}

/************************************************************//**
x-lock a lock for a fold value in a hash table. */
UNIV_INTERN
void
hash_lock_x(
/*========*/
	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{

	rw_lock_t* lock = hash_get_lock(table, fold);

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	ut_ad(lock);

#ifdef UNIV_SYNC_DEBUG
	ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
	ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

	rw_lock_x_lock(lock);
}

/************************************************************//**
unlock an s-lock for a fold value in a hash table. */
UNIV_INTERN
void
hash_unlock_s(
/*==========*/

	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{

	rw_lock_t* lock = hash_get_lock(table, fold);

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	ut_ad(lock);

#ifdef UNIV_SYNC_DEBUG
	ut_ad(rw_lock_own(lock, RW_LOCK_SHARED));
#endif /* UNIV_SYNC_DEBUG */

	rw_lock_s_unlock(lock);
}

/************************************************************//**
unlock x-lock for a fold value in a hash table. */
UNIV_INTERN
void
hash_unlock_x(
/*==========*/
	hash_table_t*	table,	/*!< in: hash table */
	ulint		fold)	/*!< in: fold */
{
	rw_lock_t* lock = hash_get_lock(table, fold);

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	ut_ad(lock);

#ifdef UNIV_SYNC_DEBUG
	ut_ad(rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

	rw_lock_x_unlock(lock);
}

/************************************************************//**
Reserves all the locks of a hash table, in an ascending order. */
UNIV_INTERN
void
hash_lock_x_all(
/*============*/
	hash_table_t*	table)	/*!< in: hash table */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	for (i = 0; i < table->n_sync_obj; i++) {

		rw_lock_t* lock = table->sync_obj.rw_locks + i;
#ifdef UNIV_SYNC_DEBUG
		ut_ad(!rw_lock_own(lock, RW_LOCK_SHARED));
		ut_ad(!rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

		rw_lock_x_lock(lock);
	}
}

/************************************************************//**
Releases all the locks of a hash table, in an ascending order. */
UNIV_INTERN
void
hash_unlock_x_all(
/*==============*/
	hash_table_t*	table)	/*!< in: hash table */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	for (i = 0; i < table->n_sync_obj; i++) {

		rw_lock_t* lock = table->sync_obj.rw_locks + i;
#ifdef UNIV_SYNC_DEBUG
		ut_ad(rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

		rw_lock_x_unlock(lock);
	}
}

/************************************************************//**
Releases all but passed in lock of a hash table, */
UNIV_INTERN
void
hash_unlock_x_all_but(
/*==================*/
	hash_table_t*	table,		/*!< in: hash table */
	rw_lock_t*	keep_lock)	/*!< in: lock to keep */
{
	ulint	i;

	ut_ad(table->type == HASH_TABLE_SYNC_RW_LOCK);
	for (i = 0; i < table->n_sync_obj; i++) {

		rw_lock_t* lock = table->sync_obj.rw_locks + i;
#ifdef UNIV_SYNC_DEBUG
		ut_ad(rw_lock_own(lock, RW_LOCK_EX));
#endif /* UNIV_SYNC_DEBUG */

		if (UNIV_LIKELY(keep_lock != lock)) {
			rw_lock_x_unlock(lock);
		}
	}
}

#endif /* !UNIV_HOTBACKUP */

/*************************************************************//**
Creates a hash table with >= 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*
hash_create(
/*========*/
	ulint	n)	/*!< in: number of array cells */
{
	hash_cell_t*	array;
	ulint		prime;
	hash_table_t*	table;

	prime = ut_find_prime(n);

	table = static_cast<hash_table_t*>(mem_alloc(sizeof(hash_table_t)));

	array = static_cast<hash_cell_t*>(
		ut_malloc(sizeof(hash_cell_t) * prime));

	/* The default type of hash_table is HASH_TABLE_SYNC_NONE i.e.:
	the caller is responsible for access control to the table. */
	table->type = HASH_TABLE_SYNC_NONE;
	table->array = array;
	table->n_cells = prime;
#ifndef UNIV_HOTBACKUP
# if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
	table->adaptive = FALSE;
# endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
	table->n_sync_obj = 0;
	table->sync_obj.mutexes = NULL;
	table->heaps = NULL;
#endif /* !UNIV_HOTBACKUP */
	table->heap = NULL;
	ut_d(table->magic_n = HASH_TABLE_MAGIC_N);

	/* Initialize the cell array */
	hash_table_clear(table);

	return(table);
}

/*************************************************************//**
Frees a hash table. */
UNIV_INTERN
void
hash_table_free(
/*============*/
	hash_table_t*	table)	/*!< in, own: hash table */
{
	ut_ad(table);
	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);

	ut_free(table->array);
	mem_free(table);
}

#ifndef UNIV_HOTBACKUP
/*************************************************************//**
Creates a sync object array to protect a hash table.
::sync_obj can be mutexes or rw_locks depening on the type of
hash table. */
UNIV_INTERN
void
hash_create_sync_obj_func(
/*======================*/
	hash_table_t*		table,	/*!< in: hash table */
	enum hash_table_sync_t	type,	/*!< in: HASH_TABLE_SYNC_MUTEX
					or HASH_TABLE_SYNC_RW_LOCK */
#ifdef UNIV_SYNC_DEBUG
	ulint			sync_level,/*!< in: latching order level
					of the mutexes: used in the
					debug version */
#endif /* UNIV_SYNC_DEBUG */
	ulint			n_sync_obj)/*!< in: number of sync objects,
					must be a power of 2 */
{
	ulint	i;

	ut_ad(table);
	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
	ut_a(n_sync_obj > 0);
	ut_a(ut_is_2pow(n_sync_obj));

	table->type = type;

	switch (type) {
	case HASH_TABLE_SYNC_MUTEX:
		table->sync_obj.mutexes = static_cast<ib_mutex_t*>(
			mem_alloc(n_sync_obj * sizeof(ib_mutex_t)));

		for (i = 0; i < n_sync_obj; i++) {
			mutex_create(hash_table_mutex_key,
			     table->sync_obj.mutexes + i, sync_level);
		}

		break;

	case HASH_TABLE_SYNC_RW_LOCK:
		table->sync_obj.rw_locks = static_cast<rw_lock_t*>(
			mem_alloc(n_sync_obj * sizeof(rw_lock_t)));

		for (i = 0; i < n_sync_obj; i++) {
			rw_lock_create(hash_table_rw_lock_key,
			     table->sync_obj.rw_locks + i, sync_level);
		}

		break;

	case HASH_TABLE_SYNC_NONE:
		ut_error;
	}

	table->n_sync_obj = n_sync_obj;
}
#endif /* !UNIV_HOTBACKUP */
