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Diffstat (limited to 'mysys/checksum.c')
-rw-r--r-- | mysys/checksum.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/mysys/checksum.c b/mysys/checksum.c new file mode 100644 index 00000000000..00861853945 --- /dev/null +++ b/mysys/checksum.c @@ -0,0 +1,30 @@ +/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; 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 <global.h> +#include "my_sys.h" + +ulong checksum(const byte *mem, uint count) +{ + ulong crc; + for (crc=0; count-- ; mem++) + crc=((crc << 1) + *((uchar*) mem)) + + test(crc & ((ulong) 1L << (8*sizeof(ulong)-1))); + return crc; +} |