Make the div function use bigint for inputs and output

sql/MyFirstUDRKit.ddl

@@ -3,9 +3,9 @@
  */
 
 create or alter	function div (
-  anumerator integer, adenominator integer
+  anumerator bigint, adenominator bigint
   )
-returns double precision
+returns bigint
 external name 'MyFirstUDRKit!MFK_div!Divide anumerator by adenominator' engine udr;
 grant execute on function div to public;
 

sql/MyFirstUDRKitPackage.sql

@@ -11,9 +11,9 @@ begin
 
 
 	function div (
-			anumerator integer, adenominator integer
+			anumerator bigint, adenominator bigint
 		)
-		returns double precision;
+		returns bigint;
 
 	function flagged (
 			flags integer, flag integer
@@ -34,9 +34,9 @@ as
 begin
 
 	function div (
-			anumerator integer, adenominator integer
+			anumerator bigint, adenominator bigint
 		)
-	returns double precision
+		returns bigint
 	external name 'MyFirstUDRKit!MFK_div!Divide anumerator by adenominator' engine udr;
 
 	function flagged (

src/MyFirstUDRKit.cpp

@@ -37,6 +37,7 @@
 #include <iostream>
 #include <fstream>
 #include <vector>
+#include <memory>
 
 #ifdef HAVE_MATH_H
 #include <math.h>
@@ -78,23 +79,25 @@ using namespace Firebird;
 
 /***
  * create function div (
- *    anumerator integer,
- *    adenominator integer
- * ) returns double precision
+ *    anumerator bigint,
+ *    adenominator bigint
+ * ) returns bigint
  *    external name 'MyFirstUDRKit!MFK_div!Divide anumerator by adenominator'
  *    engine udr;
  ***/
 FB_UDR_BEGIN_FUNCTION(MFK_div)
 
 // Divide integer anumerator 1 by integer adenominator using the stdlib
-
+// Note this differs from the example that shifts with firebird as it returns
+// a bigint, not a double precision
+//BEGIN
 FB_UDR_MESSAGE(InMessage,
-							 (FB_INTEGER, anumerator)
-							 (FB_INTEGER, adenominator)
+							 (FB_BIGINT, anumerator)
+							 (FB_BIGINT, adenominator)
 );
 
 FB_UDR_MESSAGE(OutMessage,
-							 (FB_DOUBLE, result)
+							 (FB_BIGINT, result)
 );
 
 FB_UDR_EXECUTE_FUNCTION
@@ -108,12 +111,11 @@ FB_UDR_EXECUTE_FUNCTION
 	{
 		out->resultNull = FB_FALSE;
 		if (in->adenominator) {
-			out->result = div(in->anumerator, in->adenominator).quot;
+			out->result = std::div(in->anumerator, in->adenominator).quot;
 		}
 		else
 		{
-// This is old style - surely we can do better?
-			out->result = std::numeric_limits<double>::infinity();
+			out->result = int( std::numeric_limits<double>::infinity() );
 			ISC_STATUS_ARRAY StatusVector = {isc_arg_gds, isc_arith_except,
 				isc_arg_gds, isc_exception_integer_divide_by_zero, isc_arg_end};
 				FbException::check(isc_exception_integer_divide_by_zero, status, StatusVector);
@@ -121,7 +123,7 @@ FB_UDR_EXECUTE_FUNCTION
 	}
 }
 FB_UDR_END_FUNCTION
-
+//END
 
 
 
@@ -130,11 +132,13 @@ create function flagged (
     flags integer,
     flag integer
 ) returns integer
-    external name 'MyFirstUDRKit!MFK_flagged!How is this function used?'
+    external name 'MyFirstUDRKit!MFK_flagged!Check if flag is set in flags. flag is zero-based.'
     engine udr;
+
 ***/
-FB_UDR_BEGIN_FUNCTION(MFK_flagged)
-	FB_UDR_MESSAGE(InMessage,
+FB_UDR_BEGIN_FUNCTION (MFK_flagged)
+//BEGIN
+FB_UDR_MESSAGE(InMessage,
 		(FB_INTEGER, flags)
 		(FB_INTEGER, flag)
 	);
@@ -145,10 +149,6 @@ FB_UDR_BEGIN_FUNCTION(MFK_flagged)
 
 	FB_UDR_EXECUTE_FUNCTION
 	{
-// Original code
-//  if ( flags == NULL ) {
-//    return 0;
-//  }
 		if ( in->flagsNull != 0 ) {
 			out->resultNull = FB_TRUE;
 			out->result = 0;
@@ -156,17 +156,12 @@ FB_UDR_BEGIN_FUNCTION(MFK_flagged)
 		else
 		{
 			out->resultNull = FB_FALSE;
-// Original code
-//		ISC_UINT64 i = ( 1ULL << *flag );
-//		return ( *flags & i ) ? 1 : 0;
 			ISC_UINT64 i = ( 1ULL << in->flag );
 			out->result = ( in->flags & i ) ? 1 : 0;
 		}
 	}
 FB_UDR_END_FUNCTION
-
-
-
+//END
 
 /*** DDL
  * create or alter function LoadBlobFromFile (

test/testudrkit.ddl

@@ -6,14 +6,16 @@
 create sequence test_div_seq;
 commit;
 create domain D_ID as BIGINT;
-create domain D_DOUBLE as double precision;
 create domain D_BIGINT as BIGINT;
 
 create table test_div(
  test_div_id d_id generated always as identity
  , numerator D_BIGINT
  , denominator D_BIGINT
- , result D_DOUBLE
+ , result COMPUTED BY ( DIV(numerator, denominator) )
+
 );
 
+commit;
+