Data Transformation Engine Services Guide

Chapter 21 – Adding the Adapter to Mercator Command Server
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Chapter 21 – Adding the
Adapter to Mercator Command
Server
In order to add your new adapter to Mercator Command Server, you must change 3
files and then rebuild Mercator Command Server. The files you must change are
described below. Similar changes have already been made to these files to add the
sample adapter “useradapter”. These can be used as an example of how you must make
the changes for your new adapter.
Note: You should try to begin any externalized entry points in your adapter with some 2
or 3 character ID value that is unique. All modules in the Mercator Command Server
are linked together and therefore all entry points must be unique or the linker will give an
error of “duplicate entry point name” (or something similar).
Since the Mercator Command Server was originally designed with shared libraries, it
was not necessary to take these steps; but now that there are no shared libraries and all
modules are linked together, there is always a possibility of having duplicates. We did
not change all of the Mercator supplied adapter entry points to have a unique 2 or 3
character ID value.
vtableu.c
This is a C program that must be compiled and then linked with Mercator Command
Server. It defines the entry points into your new adapter. Only those entry points that
will be visible to the Resource Manager component of Mercator Command Server need
be added here. Miscellaneous supporting functions (global data) need not be defined.
Note that this file also contains entry points for all the Mercator supplied adapters. That
section of the file is not shown here. You should NOT alter that section of the file.
/* vtableu.c */
#include <stdio.h>
#include <stdlib.h>
#include <vtable.h>
/*
HAVE_USER_ADAPTERS determines if we have user written adapters or not.
User Adapters must be defined in the adapters.xml configuration file.
*/
/* define the externs for sample adapter entry points */
#ifdef HAVE_USER_ADAPTERS
ENTRY_X( useradapter_config )
ENTRY_X( UA_CompareWatches )
ENTRY_X( UA_CompareResources )
ENTRY_X( UA_Get )
ENTRY_X( UA_Put )
ENTRY_X( UA_BeginTransaction )
ENTRY_X( UA_EndTransaction )