mirror of
https://github.com/MariaDB/server.git
synced 2025-11-03 14:33:32 +03:00
135 lines
3.1 KiB
C
135 lines
3.1 KiB
C
/*****************************************************************************
|
|
|
|
Copyright (c) 1995, 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 mach/mach0data.c
|
|
Utilities for converting data from the database file
|
|
to the machine format.
|
|
|
|
Created 11/28/1995 Heikki Tuuri
|
|
***********************************************************************/
|
|
|
|
#include "mach0data.h"
|
|
|
|
#ifdef UNIV_NONINL
|
|
#include "mach0data.ic"
|
|
#endif
|
|
|
|
/*********************************************************//**
|
|
Reads a ulint in a compressed form if the log record fully contains it.
|
|
@return pointer to end of the stored field, NULL if not complete */
|
|
UNIV_INTERN
|
|
byte*
|
|
mach_parse_compressed(
|
|
/*==================*/
|
|
byte* ptr, /*!< in: pointer to buffer from where to read */
|
|
byte* end_ptr,/*!< in: pointer to end of the buffer */
|
|
ulint* val) /*!< out: read value (< 2^32) */
|
|
{
|
|
ulint flag;
|
|
|
|
ut_ad(ptr && end_ptr && val);
|
|
|
|
if (ptr >= end_ptr) {
|
|
|
|
return(NULL);
|
|
}
|
|
|
|
flag = mach_read_from_1(ptr);
|
|
|
|
if (flag < 0x80UL) {
|
|
*val = flag;
|
|
return(ptr + 1);
|
|
|
|
} else if (flag < 0xC0UL) {
|
|
if (end_ptr < ptr + 2) {
|
|
return(NULL);
|
|
}
|
|
|
|
*val = mach_read_from_2(ptr) & 0x7FFFUL;
|
|
|
|
return(ptr + 2);
|
|
|
|
} else if (flag < 0xE0UL) {
|
|
if (end_ptr < ptr + 3) {
|
|
return(NULL);
|
|
}
|
|
|
|
*val = mach_read_from_3(ptr) & 0x3FFFFFUL;
|
|
|
|
return(ptr + 3);
|
|
} else if (flag < 0xF0UL) {
|
|
if (end_ptr < ptr + 4) {
|
|
return(NULL);
|
|
}
|
|
|
|
*val = mach_read_from_4(ptr) & 0x1FFFFFFFUL;
|
|
|
|
return(ptr + 4);
|
|
} else {
|
|
ut_ad(flag == 0xF0UL);
|
|
|
|
if (end_ptr < ptr + 5) {
|
|
return(NULL);
|
|
}
|
|
|
|
*val = mach_read_from_4(ptr + 1);
|
|
return(ptr + 5);
|
|
}
|
|
}
|
|
|
|
/*********************************************************//**
|
|
Reads a dulint in a compressed form if the log record fully contains it.
|
|
@return pointer to end of the stored field, NULL if not complete */
|
|
UNIV_INTERN
|
|
byte*
|
|
mach_dulint_parse_compressed(
|
|
/*=========================*/
|
|
byte* ptr, /*!< in: pointer to buffer from where to read */
|
|
byte* end_ptr,/*!< in: pointer to end of the buffer */
|
|
dulint* val) /*!< out: read value */
|
|
{
|
|
ulint high;
|
|
ulint low;
|
|
ulint size;
|
|
|
|
ut_ad(ptr && end_ptr && val);
|
|
|
|
if (end_ptr < ptr + 5) {
|
|
|
|
return(NULL);
|
|
}
|
|
|
|
high = mach_read_compressed(ptr);
|
|
|
|
size = mach_get_compressed_size(high);
|
|
|
|
ptr += size;
|
|
|
|
if (end_ptr < ptr + 4) {
|
|
|
|
return(NULL);
|
|
}
|
|
|
|
low = mach_read_from_4(ptr);
|
|
|
|
*val = ut_dulint_create(high, low);
|
|
|
|
return(ptr + 4);
|
|
}
|