Description

With the reduction in cooperative load module view size limits in Gen 7.6 there has been an increased potential for developers to encounter the limit during a Consistency Check or code generation. This document outlines how an estimate of total view size can be calculated.

Solution

Overview

For Gen non-Java/.NET applications, depending on an application's target environment and type, there are different limits to the size of views and the amount of data that can be passed between Procedure Steps on a flow. In some cases, Consistency Check will report an error if you have exceeded the view size limit. This document will help explain Consistency Check rules as well as code generation limits for view sizes.

View Size Limits
Size limits for views vary depending on the application type i.e. Block Mode, Cooperative Client/Server, GUI. The limits only apply to the size of the entire import and export view section of a Procedure Step. The Gen 7.6 view size limits for C and Cobol applications are:

Procedure Step Type	Import	Export
Block mode	31744	31744
Cooperative client or server	31400	31400
GUI client	Unlimited*	Unlimited*

*This is for GUI only client applications and flows across Procedure steps can be within the same or different load modules. Effectively this value is only limited by system resources and the group view subscript limit of 32Kb. Under a desktop test (not a full QA test) passing an export group view of size ~290 Mb has been successful.

Java/.NET
Pure Java and .NET (C#) applications have no view size limits, but Java/.NET clients that flow to non-Java/.NET servers or non-Java/.NET clients that flow to Java/.NET servers will also be subject to the above limits.

Gen 7.6 datatypes and byte lengths for different programming languages
Numbers without decimal places:

Length	C datatype	Bytes	COBOL datatype	Bytes	Java/.NET  datatype	Bytes
1-4	short (short int)	21	PIC X(Length)	Length	short	2
5-9	long (long int)	41	PIC X(Length)	Length	int	4
>=10	double	81	PIC X(Length)	Length	double	8

Numbers with decimal places:

Decimal Precision	C datatype	Bytes	COBOL datatype	Bytes	Java  datatype	Bytes	.NET datatype	Bytes
No	double	81	PIC X(Length)	Length	double	8	double	8
Yes	DPrec [Length + 3]	Length + 32	N/A3	N/A2	BigDecimal	N/A4	decimal	12

Others:

Gen datatype	C datatype	Bytes	COBOL datatype	Bytes	Java/.NET  datatype	Bytes
Fixed Text	char	Length + 1	PIC X(Length)	Length	string	Length + 1
Varying Text	char	Length + 1	PIC X(Length+2)	Length + 2	string	Length + 1
Date	long (long int)	41	PIC X(8)	8	int	4
Time	long (long int)	41	PIC X(6)	6	int	4
Timestamp	char	21	PIC X(20)	20	string	21

NOTE: Length represents the length of the attribute as defined in the Gen data model.

¹The size of the various C datatypes is compiler dependent and so these are only typical values (check your compiler documentation).
²An attribute defined with Decimal Precision is implemented as a DPrec character array whose size is the length of the attribute plus three (for the sign, decimal point, and null terminator).
³Decimal Precision does not impact COBOL.
⁴The size of a BigDecimal is arbitrary and will depend upon the length and number of decimal places.

Calculating View Size
The actual size of the import or export view is greater than the sum of the length of all attributes because of overheads. The following information can be used to help manually calculate view sizes.

• Add 1 additional byte for each attribute of type `text' required for the null terminator (not applicable to Cobol).
• Add 1 additional byte for each attribute in the import view.
• Add 7 additional bytes for each attribute in the export view.
• Add 5 additional bytes for each repeating group view.
• Add <max cardinality> additional bytes for each repeating group view.

Examples

1. This example shows how the additional bytes should be uses in the calculations and represents a scenario where the views size limits for Import & Export views fall well within the limits described above:

   IMPORTS:
                  Group View in_group (optional, 100, implicit, import only)
                               Entity View in employee (optional, transient)
                                           first_name (optional) <--- text attribute of length 20
                                           last_name (optional) <--- text attribute of length 20
   
   EXPORTS:
                  Group View out_group (100, implicit, export only)
                               Entity View out employee (transient)
                                            first_name <--- text attribute of length 20
                                            last_name <--- text attribute of length 20
   

   Calculating import view size (generated for C)

   <Please see attached file for image>

   

   Calculating export view size (generated for C)

   <Please see attached file for image>

   

2. This example shows a total export view size that will conform to the Block Mode limit but will exceed the Cooperative limit and will therefore give the following Consistency Check and generation error:
   ICCBR17S The total export view length will exceed the supported maximum length of 31400 bytes if generating C code for cooperative servers.

EXPORTS:
               Group View out_group (355, implicit, export only)
                            Entity View out employee (transient)
                                        first_name <--- text attribute of length 20
                                        last_name <--- text attribute of length 20
                                        id <--- numeric attribute of length 12 (no decimal precision)
                                        monthly_salary <--- numeric attribute of length 7 with 2 decimal places                                         (decimal precision)

Calculating export view size (generated for C)

<Please see attached file for image>

Release: KGNCRK05500-7.6-Gen-CLS Runtime Kit-for Unisys
Component: