Server Mapping Files for Natural

Server mapping enables the RPC server to correctly support special Natural syntax such as REDEFINEs, special Natural Mapping Editor operations, etc. If one of these elements is used the IDL Extractor for Natural automatically extracts a server mapping file (Designer file with extension .cvm) in addition to the IDL file (interface definition language). Also the Natural Wrapper may generate a server mapping file for RPC server generation. The server mapping file is used at runtime to marshal and unmarshal the RPC data stream. A server mapping file is wrapped into the client interface objects when an RPC client is generated. Therefore, it is important the server mapping (.cvm) is available before creating any RPC client component, that is, the server program must be extracted or generated first. This document covers the following topics:

Server Mapping Files in the Designer


The following rules apply to a server mapping file for Natural:

  • Mapping files have the extension .cvm.

  • The mapping file has to relate to an appropriate IDL file. Always keep the IDL file and the mapping file together in the same folder.

  • The mapping file is created if required by the Natural Wrapper | Extractor. See When is a Server Mapping File Required?

  • If an IDL file has a corresponding mapping file, at least one of the IDL programs in the IDL file requires server-mapping information to correctly call the target server. For those IDL programs, there is a server mapping (corresponding to a line) in the server mapping file.

  • If there is an IDL file but no corresponding mapping file, there is no IDL program that requires server mapping information.

When is a Server Mapping File Required?

IDL Extractor for Natural

Natural Syntax Natural Mapping Editor Server Mapping Reqired More Information
REDEFINE   yes Extracting Natural REDEFINES in the IDL Extractor for Natural documentation
all Rename of program yes Renaming a Program
all Multiple interfaces yes Extracting Multiple Interfaces
all Set constant yes Setting Natural Parameters to Constants
all Suppress yes Suppressing Natural Parameters
Other combinations no  

Natural Wrapper

Natural Wrapper Server Mapping Required More Information
IDL program name is not a valid Natural name and is therefore adapted, or the Natural program name is customized yes Step 2: Customize Natural Server Names under Using the Natural Wrapper for the Server Side within NaturalONE

Source Control of Server Mapping Files

Because server mapping files (Designer files with extension .cvm) contain text data only, a server mapping file is text-based (although it is not intended for human consumption). Therefore, you can include it in your source control management together with the IDL file and the Natural source(s) as a triplet that should always be kept in sync.

Comparing Server Mapping Files

For server mapping files (Designer files with extension .cvm), you can use a third party file/text compare tool to check if two files are identical.

A server mapping entry (corresponding to a line in a server mapping file) contains a creation timestamp at offset 276 (decimal) in the format YYYYMMDDHHIISST. The precision is 1/10 of a second.