reactos/sdk/tools/hhpcomp/chmc/encint.h

96 lines
1.9 KiB
C

/*
Copyright (C) 2010 Alex Andreotti <alex.andreotti@gmail.com>
This file is part of chmc.
chmc 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, either version 3 of the License, or
(at your option) any later version.
chmc 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 chmc. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef CHMC_ENCINT_H
#define CHMC_ENCINT_H
// 0x7f 127
// 0x3fff 16383
// 0x1fffff 2097151
// 0xfffffff 268435455
static inline int chmc_encint_len ( const UInt32 val ) {
int len;
// FIXME should support 64 bit?
if ( val > 0xfffffffUL )
len = 0; // overflow
else if ( val > 0x1fffffUL )
len = 4;
else if ( val > 0x3fffUL )
len = 3;
else if ( val > 0x7fUL )
len = 2;
else
len = 1;
return len;
}
static inline int chmc_encint ( const UInt32 val, UChar *out ) {
int len;
UInt32 a;
UChar *p, *l;
// FIXME should support 64 bit?
if ( ! out || val > 0xfffffffUL )
return 0; // FIXME can't handle, overflow
if ( val > 0x1fffffUL )
len = 4;
else if ( val > 0x3fffUL )
len = 3;
else if ( val > 0x7fUL )
len = 2;
else
len = 1;
a = val;
l = p = out + (len - 1);
while ( p >= out ) {
*p = (a & 0x7fUL);
if ( p < l )
*p |= 0x80UL;
p--;
a >>= 7;
}
return len;
}
static inline int chmc_decint ( const UChar *in, UInt32 *value ) {
int len;
len = 0;
*value = 0;
while ( (in[len] & 0x80) && (len < 3) ) {
*value <<= 7;
*value |= in[len] & 0x7f;
len++;
}
*value <<= 7;
*value |= in[len] & 0x7f;
len++;
return len;
}
#endif /* CHMC_ENCINT_H */