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/**********************************************************************
Utilities for converting data from the database file
to the machine format.
(c) 1995 Innobase Oy
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. */
byte*
mach_parse_compressed(
/*==================*/
/* out: pointer to end of the stored field, NULL if
not complete */
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. */
byte*
mach_dulint_parse_compressed(
/*=========================*/
/* out: pointer to end of the stored field, NULL if
not complete */
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);
}
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