mariadb/include/ut0rnd.h
marko 41b29de7ac branches/innodb+: Merge revisions 5091:5143 from branches/zip:
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  r5092 | marko | 2009-05-25 09:54:17 +0300 (Mon, 25 May 2009) | 1 line

  branches/zip: Adjust some function comments after r5091.
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  r5100 | marko | 2009-05-25 12:09:45 +0300 (Mon, 25 May 2009) | 1 line

  branches/zip: Split some long lines that were introduced in r5091.
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  r5101 | marko | 2009-05-25 12:42:47 +0300 (Mon, 25 May 2009) | 2 lines

  branches/zip: Introduce the macro TEMP_INDEX_PREFIX_STR.
  This is to avoid triggering an error in Doxygen.
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  r5102 | marko | 2009-05-25 13:47:14 +0300 (Mon, 25 May 2009) | 1 line

  branches/zip: Add missing file comments.
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  r5103 | marko | 2009-05-25 13:52:29 +0300 (Mon, 25 May 2009) | 10 lines

  branches/zip: Add @file comments, and convert decorative
  /*********************************
  comments to Doxygen /** style like this:
  /*****************************//**

  This conversion was performed by the following command:

  perl -i -e 'while(<ARGV>){if (m|^/\*{30}\**$|) {
  s|\*{4}$|//**| if ++$com>1; $_ .= "\@file $ARGV\n" if $com==2}
  print; if(eof){$.=0;undef $com}}' */*[ch] include/univ.i
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  r5104 | marko | 2009-05-25 14:39:07 +0300 (Mon, 25 May 2009) | 2 lines

  branches/zip: Revert ut0auxconf_* to r5102,
  that is, make Doxygen ignore these test programs.
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  r5105 | marko | 2009-05-25 14:52:20 +0300 (Mon, 25 May 2009) | 2 lines

  branches/zip: Enclose some #error checks inside #ifndef DOXYGEN
  to prevent bogus Doxygen errors.
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  r5106 | marko | 2009-05-25 16:09:24 +0300 (Mon, 25 May 2009) | 2 lines

  branches/zip: Add some Doxygen comments, mainly to structs, typedefs,
  macros and global variables.  Many more to go.
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  r5108 | marko | 2009-05-26 00:32:35 +0300 (Tue, 26 May 2009) | 2 lines

  branches/zip: lexyy.c: Remove the inadvertently added @file directive.
  There is nothing for Doxygen to see in this file, move along.
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  r5125 | marko | 2009-05-26 16:28:49 +0300 (Tue, 26 May 2009) | 3 lines

  branches/zip: Add some Doxygen comments for many structs, typedefs,
  #defines and global variables.  Many are still missing.
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  r5134 | marko | 2009-05-27 09:08:43 +0300 (Wed, 27 May 2009) | 1 line

  branches/zip: Add some Doxygen @return comments.
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  r5139 | marko | 2009-05-27 10:01:40 +0300 (Wed, 27 May 2009) | 1 line

  branches/zip: Add Doxyfile.
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  r5143 | marko | 2009-05-27 10:57:25 +0300 (Wed, 27 May 2009) | 3 lines

  branches/zip: buf0buf.h, Doxyfile: Fix the Doxygen translation.
  @defgroup is for source code modules, not for field groups.
  Tell Doxygen to expand the UT_LIST declarations.
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2009-05-27 09:52:16 +00:00

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4.3 KiB
C

/*****************************************************************************
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 include/ut0rnd.h
Random numbers and hashing
Created 1/20/1994 Heikki Tuuri
***********************************************************************/
#ifndef ut0rnd_h
#define ut0rnd_h
#include "univ.i"
#include "ut0byte.h"
/** The 'character code' for end of field or string (used
in folding records */
#define UT_END_OF_FIELD 257
/********************************************************//**
This is used to set the random number seed. */
UNIV_INLINE
void
ut_rnd_set_seed(
/*============*/
ulint seed); /*!< in: seed */
/********************************************************//**
The following function generates a series of 'random' ulint integers.
@return the next 'random' number */
UNIV_INLINE
ulint
ut_rnd_gen_next_ulint(
/*==================*/
ulint rnd); /*!< in: the previous random number value */
/*********************************************************//**
The following function generates 'random' ulint integers which
enumerate the value space (let there be N of them) of ulint integers
in a pseudo-random fashion. Note that the same integer is repeated
always after N calls to the generator.
@return the 'random' number */
UNIV_INLINE
ulint
ut_rnd_gen_ulint(void);
/*==================*/
/********************************************************//**
Generates a random integer from a given interval.
@return the 'random' number */
UNIV_INLINE
ulint
ut_rnd_interval(
/*============*/
ulint low, /*!< in: low limit; can generate also this value */
ulint high); /*!< in: high limit; can generate also this value */
/*********************************************************//**
Generates a random iboolean value.
@return the random value */
UNIV_INLINE
ibool
ut_rnd_gen_ibool(void);
/*=================*/
/*******************************************************//**
The following function generates a hash value for a ulint integer
to a hash table of size table_size, which should be a prime or some
random number to work reliably.
@return hash value */
UNIV_INLINE
ulint
ut_hash_ulint(
/*==========*/
ulint key, /*!< in: value to be hashed */
ulint table_size); /*!< in: hash table size */
/*************************************************************//**
Folds a pair of ulints.
@return folded value */
UNIV_INLINE
ulint
ut_fold_ulint_pair(
/*===============*/
ulint n1, /*!< in: ulint */
ulint n2) /*!< in: ulint */
__attribute__((const));
/*************************************************************//**
Folds a dulint.
@return folded value */
UNIV_INLINE
ulint
ut_fold_dulint(
/*===========*/
dulint d) /*!< in: dulint */
__attribute__((const));
/*************************************************************//**
Folds a character string ending in the null character.
@return folded value */
UNIV_INLINE
ulint
ut_fold_string(
/*===========*/
const char* str) /*!< in: null-terminated string */
__attribute__((pure));
/*************************************************************//**
Folds a binary string.
@return folded value */
UNIV_INLINE
ulint
ut_fold_binary(
/*===========*/
const byte* str, /*!< in: string of bytes */
ulint len) /*!< in: length */
__attribute__((pure));
/***********************************************************//**
Looks for a prime number slightly greater than the given argument.
The prime is chosen so that it is not near any power of 2.
@return prime */
UNIV_INTERN
ulint
ut_find_prime(
/*==========*/
ulint n) /*!< in: positive number > 100 */
__attribute__((const));
#ifndef UNIV_NONINL
#include "ut0rnd.ic"
#endif
#endif