Pathmaker Programming Guide

Designing a Pathmaker Application
Preparing for Pathmaker Application Development
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Custom servers (used by TRNS requesters)
Standard servers (used by DB requesters)
Registered servers (servers not created with the Pathmaker product)
Application developers create custom servers by grouping together one or more
custom services. The Pathmaker product allows application developers to package
from 1 to 40 services in a server. Custom servers can only be used with TRNS
requesters. The Pathmaker product generates custom server source code and then
compiles it using either the COBOL85 or C compiler.
In the design specification, designate which custom services should be packaged into
which custom servers. A custom service can even be packaged into more than one
custom server. Refer to “Grouping Services,” following, for more guidelines on
packaging services.
Standard servers consist of a predefined set of standard services. Application
developers do not create standard Pathmaker servers; standard servers already exist
on the Pathmaker object program subvolume. Pointers to the standard servers are
added to an application’s Pathway configuration file at installation. Standard servers
can be used only with DB requesters. If you are designing a DB requester application,
you should identify the standard services that each DB requester will use in the design
specification.
Registered servers are Pathway servers not created with the Pathmaker product but
known to it. Although registering a server is not necessary to access it from a
Pathmaker application, doing so is beneficial in several ways.
Because a Pathmaker catalog contains information about registered servers and
the physical files that they access, the Pathmaker product can generate the
statements necessary for running the servers in Pathway command files.
Because the Pathmaker catalog contains the location of the object code for
registered servers, the Pathmaker product is able to move these files whenever the
other components of the associated Pathmaker application are moved.
If the application you are designing will access Pathway servers not created with the
Pathmaker product, you should identify these servers and their associated object files
in the design specification, and instruct application developers to create registered
services and servers for those outside servers.
Mapping Services to Server Classes
Prior to run time, the Pathmaker product must be used to assign each custom server to
a server class. (If a custom service has been packaged into more than one custom
server, the application developer must also designate which of the server classes
associated with the service is the active one.) This information is then used to create a
table in a special generated requester called the mapping requester.
During run time, the mapping requester is used each time an application requester
invokes a service. The mapping requester resolves a service name into its active server