diff options
Diffstat (limited to 'mysys/checksum.c')
| -rw-r--r-- | mysys/checksum.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/mysys/checksum.c b/mysys/checksum.c index e09de7d5969..1dd135c7ad9 100644 --- a/mysys/checksum.c +++ b/mysys/checksum.c @@ -14,16 +14,24 @@ along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -/* Calculate a long checksum for a memoryblock. Used to verify pack_isam */ #include <my_global.h> #include "my_sys.h" +/* + Calculate a long checksum for a memoryblock. Used to verify pack_isam + + SYNOPSIS + checksum() + mem Pointer to memory block + count Count of bytes +*/ + ulong checksum(const byte *mem, uint count) { ulong crc; - for (crc=0; count-- ; mem++) - crc=((crc << 1) + *((uchar*) mem)) + + for (crc= 0; count-- ; mem++) + crc= ((crc << 1) + *((uchar*) mem)) + test(crc & ((ulong) 1L << (8*sizeof(ulong)-1))); return crc; } |