mirror of
https://github.com/MariaDB/server.git
synced 2025-01-18 21:12:26 +01:00
125 lines
3.3 KiB
Text
125 lines
3.3 KiB
Text
/***************************************************************************//**
|
|
Copyright (c) 2011, Oracle Corpn. 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 include/ut0bh.ic
|
|
Binary min-heap implementation.
|
|
|
|
Created 2011-01-15 by Sunny Bains
|
|
*******************************************************/
|
|
|
|
#include "ut0bh.h"
|
|
#include "ut0mem.h" /* For ut_memcpy() */
|
|
|
|
/**********************************************************************//**
|
|
Get the number of elements in the binary heap.
|
|
@return number of elements */
|
|
UNIV_INLINE
|
|
ulint
|
|
ib_bh_size(
|
|
/*=======*/
|
|
const ib_bh_t* ib_bh) /*!< in: instance */
|
|
{
|
|
return(ib_bh->n_elems);
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Test if binary heap is empty.
|
|
@return TRUE if empty. */
|
|
UNIV_INLINE
|
|
ibool
|
|
ib_bh_is_empty(
|
|
/*===========*/
|
|
const ib_bh_t* ib_bh) /*!< in: instance */
|
|
{
|
|
return(ib_bh_size(ib_bh) == 0);
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Test if binary heap is full.
|
|
@return TRUE if full. */
|
|
UNIV_INLINE
|
|
ibool
|
|
ib_bh_is_full(
|
|
/*===========*/
|
|
const ib_bh_t* ib_bh) /*!< in: instance */
|
|
{
|
|
return(ib_bh_size(ib_bh) >= ib_bh->max_elems);
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Get a pointer to the element.
|
|
@return pointer to element */
|
|
UNIV_INLINE
|
|
void*
|
|
ib_bh_get(
|
|
/*=======*/
|
|
ib_bh_t* ib_bh, /*!< in: instance */
|
|
ulint i) /*!< in: index */
|
|
{
|
|
byte* ptr = (byte*) (ib_bh + 1);
|
|
|
|
ut_a(i < ib_bh_size(ib_bh));
|
|
|
|
return(ptr + (ib_bh->sizeof_elem * i));
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Copy an element to the binary heap.
|
|
@return pointer to copied element */
|
|
UNIV_INLINE
|
|
void*
|
|
ib_bh_set(
|
|
/*======*/
|
|
ib_bh_t* ib_bh, /*!< in/out: instance */
|
|
ulint i, /*!< in: index */
|
|
const void* elem) /*!< in: element to add */
|
|
{
|
|
void* ptr = ib_bh_get(ib_bh, i);
|
|
|
|
ut_memcpy(ptr, elem, ib_bh->sizeof_elem);
|
|
|
|
return(ptr);
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Return the first element from the binary heap.
|
|
@return pointer to first element or NULL if empty. */
|
|
UNIV_INLINE
|
|
void*
|
|
ib_bh_first(
|
|
/*========*/
|
|
ib_bh_t* ib_bh) /*!< in: instance */
|
|
{
|
|
return(ib_bh_is_empty(ib_bh) ? NULL : ib_bh_get(ib_bh, 0));
|
|
}
|
|
|
|
/**********************************************************************//**
|
|
Return the last element from the binary heap.
|
|
@return pointer to last element or NULL if empty. */
|
|
UNIV_INLINE
|
|
void*
|
|
ib_bh_last(
|
|
/*========*/
|
|
ib_bh_t* ib_bh) /*!< in/out: instance */
|
|
{
|
|
return(ib_bh_is_empty(ib_bh)
|
|
? NULL
|
|
: ib_bh_get(ib_bh, ib_bh_size(ib_bh) - 1));
|
|
}
|
|
|
|
|