Enhanced support of decimal float numbers in the client: use better names for SQL_ constants, added interfaces supporting access to decimal float fields in native format, use them in isql instead direct library access, added decimal float support in messages and a sample of it

Author: AlexPeshkoff

examples/interfaces/06.fb_message.cpp

@@ -4,6 +4,9 @@
  *	DESCRIPTION:	A sample of using static messages.
  *					Prints user-defined tables with comments.
  *
+ *					Example for the following interface:
+ *					IDecFloat16 - support for IEEE-754 64-bit decimal float numbers
+ *
  *					Example for the following macro:
  *
  *					FB_MESSAGE - defines static messages
@@ -32,6 +35,7 @@
 #include <firebird/Message.h>
 
 static IMaster* master = fb_get_master_interface();
+static IDecFloat16* idf = NULL;
 
 int main()
 {
@@ -51,6 +55,8 @@ int main()
 
 	try
 	{
+		idf = master->getUtilInterface()->getDecFloat16(&status);
+
 		att = prov->attachDatabase(&status, dbName, 0, NULL);
 		tra = att->startTransaction(&status, 0, NULL);
 
@@ -72,13 +78,15 @@ int main()
 			(FB_SMALLINT, relationId)
 			(FB_VARCHAR(31), relationName)
 			(FB_VARCHAR(100), description)
+			(FB_DECFLOAT16, df16)
 		) output(&status, master);
 
 		input.clear();
 		input->systemFlag = 0;
 
 		rs = att->openCursor(&status, tra, 0,
-			"select rdb$relation_id, rdb$relation_name, rdb$description"
+			"select rdb$relation_id, rdb$relation_name, rdb$description,"
+			"    cast (rdb$relation_id as decfloat(16)) * 0.05 as df16"
 			"  from rdb$relations"
 			"  where rdb$system_flag = ?"
 			"  order by rdb$relation_id",
@@ -89,10 +97,13 @@ int main()
 		{
 			unsigned lRelName = output->relationNameNull ? 0 : output->relationName.length;
 			unsigned lDesc = output->descriptionNull ? 0 : output->description.length;
-			printf("%4d %*.*s%c%*.*s\n", output->relationId,
+			char t[IDecFloat16::STRING_SIZE];
+			idf->toStr(&output->df16, t);
+
+			printf("%4d %*.*s%c%*.*s (%s)\n", output->relationId,
 				lRelName, lRelName, output->relationName.str,
 				lDesc ? '/' : ' ',
-				lDesc, lDesc, output->description.str);
+				lDesc, lDesc, output->description.str, t);
 		}
 
 		rs->close(&status);

src/common/classes/InternalMessageBuffer.cpp

@@ -173,12 +173,12 @@ MetadataFromBlr::MetadataFromBlr(unsigned aBlrLength, const unsigned char* aBlr,
 			break;
 
 		case blr_dec64:
-			item->type = SQL_DEC64;
+			item->type = SQL_DEC16;
 			item->length = sizeof(Decimal64);
 			break;
 
 		case blr_dec128:
-			item->type = SQL_DEC128;
+			item->type = SQL_DEC34;
 			item->length = sizeof(Decimal128);
 			break;
 

src/common/dsc.cpp

@@ -1338,12 +1338,12 @@ void dsc::getSqlInfo(SLONG* sqlLength, SLONG* sqlSubType, SLONG* sqlScale, SLONG
 			break;
 
 		case dtype_dec64:
-			*sqlType = SQL_DEC64;
+			*sqlType = SQL_DEC16;
 			*sqlScale = 0;
 			break;
 
 		case dtype_dec128:
-			*sqlType = SQL_DEC128;
+			*sqlType = SQL_DEC34;
 			*sqlScale = 0;
 			break;
 

src/common/utils.cpp

@@ -1516,9 +1516,9 @@ UCHAR sqlTypeToDscType(SSHORT sqlType)
 		return dtype_quad;
 	case SQL_BOOLEAN:
 		return dtype_boolean;
-	case SQL_DEC64:
+	case SQL_DEC16:
 		return dtype_dec64;
-	case SQL_DEC128:
+	case SQL_DEC34:
 		return dtype_dec128;
 	default:
 		return dtype_unknown;

src/dsql/sqlda_pub.h

@@ -78,8 +78,8 @@ typedef struct
 #define SQL_TYPE_TIME                      560
 #define SQL_TYPE_DATE                      570
 #define SQL_INT64                          580
-#define SQL_DEC64                        32760
-#define SQL_DEC128                       32762
+#define SQL_DEC16                        32760
+#define SQL_DEC34                        32762
 #define SQL_BOOLEAN                      32764
 #define SQL_NULL                         32766
 

src/include/firebird/FirebirdInterface.idl

@@ -29,6 +29,8 @@
 typedef ISC_DATE;
 typedef ISC_QUAD;
 typedef ISC_TIME;
+typedef FB_DEC16;
+typedef FB_DEC34;
 
 // Versioned interface - base for all FB interfaces
 interface Versioned
@@ -985,6 +987,8 @@ interface Util : Versioned
 
 version:
 	EventBlock createEventBlock(Status status, const string* events);
+	DecFloat16 getDecFloat16(Status status);
+	DecFloat34 getDecFloat34(Status status);
 }
 
 interface OffsetsCallback : Versioned
@@ -1365,3 +1369,23 @@ interface UdrPlugin : Versioned
 	void registerProcedure(Status status, const string name, UdrProcedureFactory factory);
 	void registerTrigger(Status status, const string name, UdrTriggerFactory factory);
 }
+
+interface DecFloat16 : Versioned
+{
+	const uint BCD_SIZE = 16;
+	const uint STRING_SIZE = 25;	// includes terminating \0
+	void scatter(const FB_DEC16* from, int* sign, uchar* bcd, int* exp);
+	void toStr(const FB_DEC16* from, string to);
+	void gather(int sign, const uchar* bcd, int exp, FB_DEC16* to);
+	void fromStr(Status status, const string from, FB_DEC16* to);
+}
+
+interface DecFloat34 : Versioned
+{
+	const uint BCD_SIZE = 34;
+	const uint STRING_SIZE = 43;	// includes terminating \0
+	void scatter(const FB_DEC34* from, int* sign, uchar* bcd, int* exp);
+	void toStr(const FB_DEC34* from, string to);
+	void gather(int sign, const uchar* bcd, int exp, FB_DEC34* to);
+	void fromStr(Status status, const string from, FB_DEC34* to);
+}