Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtinfo/DtMmdb/utility/randomize.C

@@ -0,0 +1,34 @@
+// $XConsortium: randomize.cc /main/3 1996/06/11 17:38:40 cde-hal $
+
+#include "utility/randomize.h"
+
+randomize::randomize(int sd) : rdn(sd)
+{
+}
+
+void randomize::scramble(buffer& original)
+{
+   int bytes = original.content_sz();
+   char* buf = original.get_base();
+
+   for ( int i=0; i<bytes-1; i++ ) 
+      char_swap(buf[i], buf[rdn.rand() % ( bytes - i ) + i]);
+}   
+
+void randomize::restore(buffer& scrambled)
+{
+   int bytes = scrambled.content_sz();
+   char* buf = scrambled.get_base();
+
+   int *pos = new int[bytes-1];
+
+   for ( int i=0; i<bytes-1; i++ ) {
+      pos[i] = rdn.rand() % ( bytes - i ) + i;
+   }
+
+   for ( i=bytes-2; i>=0; i-- ) {
+      char_swap(buf[i], buf[pos[i]]);
+   }
+
+   delete pos;
+}