Postgres95 1.01 Distribution - Virgin Sources

src/backend/utils/adt/misc.c

@@ -0,0 +1,96 @@
+/*-------------------------------------------------------------------------
+ *
+ * misc.c--
+ *    
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/utils/adt/misc.c,v 1.1.1.1 1996/07/09 06:22:04 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <sys/file.h>
+#include "postgres.h"
+#include "utils/datum.h"
+#include "catalog/pg_type.h"
+#include "utils/builtins.h"
+
+#if !defined(PORTNAME_linux) && !defined(PORTNAME_BSD44_derived) && \
+    !defined(PORTNAME_irix5) && !defined(PORTNAME_bsdi) && !defined(PORTNAME_aix)
+extern int random();
+extern int srandom(unsigned);
+#endif
+
+
+/*-------------------------------------------------------------------------
+ * Check if data is Null 
+ */
+bool
+NullValue(Datum value, bool *isNull)
+{
+    if (*isNull) {
+	*isNull = false;
+	return(true);
+    }
+    return(false);
+    
+}
+
+/*----------------------------------------------------------------------*
+ *     check if data is not Null                                        *
+ *--------------------------------------------------------------------- */
+bool
+NonNullValue(Datum value, bool *isNull)
+{
+    if (*isNull) {
+	*isNull = false;
+	return(false);
+    }
+    return(true);
+    
+}
+
+/*
+ * oidrand (oid o, int4 X)-
+ *    takes in an oid and a int4 X, and will return 'true'
+ *  about 1/X of the time.
+ *    Useful for doing random sampling or subsetting.
+ *  if X == 0, this will always return true;
+ *
+ * Example use:
+ *     select * from TEMP where oidrand(TEMP.oid, 10)
+ * will return about 1/10 of the tuples in TEMP
+ *
+ */
+bool 
+oidrand(Oid o, int32 X)
+{
+    bool result;
+
+    if (X == 0) return true;
+
+    result = (random() % X == 0);
+    return result;
+}
+
+/*
+   oidsrand(int32 X) -
+      seeds the random number generator
+      always return true
+*/ 
+bool
+oidsrand(int32 X)
+{
+    srand(X);
+    return true;
+}
+
+
+
+int32
+userfntest(int i)
+{
+    return (i);
+}