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Developing Data Services

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Updated: August 2018

Managing Configuration Properties

All callback methods require access to the configuration properties.

    The DSDL supports access to properties in these ways:

  • Initializing the environment

  • Providing a set of convenience functions to retrieve property values

    The scds_initialize() function, which must be called at the beginning of each callback method, does the following:

  • Checks and processes the command-line arguments (argc and argv[]) that the RGM passes to the callback method, obviating the need for you to write a command-line parsing function.

  • Sets up internal data structures for use by other DSDL functions. For example, the convenience functions that retrieve property values from the RGM store the values in these structures. Likewise, values from the command line, which take precedence over values retrieved from the RGM, are stored in these data structures.

  • Initializes the logging environment and validates fault monitor probe settings.

Note -  For the Validate method, scds_initialize() parses the property values that are passed on the command line, obviating the need to write a parse function for Validate.

The DSDL provides sets of functions to retrieve resource type, resource, and resource group properties as well as commonly used extension properties.

    These functions standardize access to properties by using the following conventions:

  • Each function takes only a handle argument (returned by scds_initialize()).

  • Each function corresponds to a particular property. The return value type of the function matches the type of the property value that it retrieves.

  • Functions do not return errors as the values have been precomputed by scds_initialize(). Functions retrieve values from the RGM unless a new value is passed on the command line.