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Pipeline Code Internal Organization

Major software components and object classes

The GPI data pipeline is implemented in object-oriented fashion using IDL classes. Some classes provide GUI windows, other provide internal components that don’t directly draw to the screen.

This page briefly summarizes the different components. For detailed documentation on the functions and variables internal to the following, please see the comments in the source code directly.

Internals: (mostly in pipeline/backbone directory)

The following are all object classes, so see e.g. for the source code for the “launcher” object.

The main object class of the pipeline! Loops forever waiting for recipe files and processes them one at a time when they arrive.
High level wrapper class for recipe files (aka DRFs). The actual work of parsing the XML is done in the gpidrfparser class, but the interface of that one is not so user friendly due to how IDL’s XML parsing system (ffXMLParser class) works.
Lower-level class for parsing an XML recipe file. Avoid using this directly if you can - the drf class is generally more convenient.
Lower level class for parsing an XML primitives config file (that is, the list of all available primitives).
The Calibration Database class. Maintains an index of available calibration files and has tools for looking up the best one for a given task.
This class provides the bidirectional communication flow between the two IDL sessions. This class can be both an internal and a GUI, depending on how it’s invoked. In one IDL session, it is started directly to create and run the Launcher window that provides buttons to start the other programs. Another copy of it gets loaded inside gpipipelinebackbone, where it provides the inter-process communication pipeline that lets the backbone talk to the Launcher window running in the other IDL session.


See description above.
Status Console window object definition. This is the one GUI that runs in the same IDL session with the backbone itself, allowing direct control of it.
Not used directly, just a base class from which the other windows are derived. Provides common infrastructure
Autoreducer window object definition
Recipe Editor window object definition
Data Parser window object definition
The Queue Viewer window object definition

Function Call Hierarchy when Running Recipes

The main loop of the pipeline occurs inside the gpipipelinebackbone::run_queue method.

The call hierarchy inside gpipipelinebackbone is something like the following. Each indentation indicates being one level deeper in the call stack or inside a loop Each of these methods is part of gpipipelinebackbone.

gpipipelinebackbone::Run_queue               (loops forever checking the queue)
     gpipipelinebackbone::run_one_recipe     (called when a recipe is found)
             parses recipe
                 loops over input files in that recipe
                     loops over modules in that recipe
                                     invokes actual primitive code here...
                             update log and status window for each primitive
                  update log and status window for each file
             update status console, clean up recipe file
     Check for user input from status console buttons
     Check for any new recipe files to process
     loop to continue running queue

Common Blocks

The pipeline uses some IDL common blocks to pass global variables between different routines.



Document here the common block variables in the code, in both the APP_CONSTANTS and PIP common blocks. TBD if it is possible to merge both? There is some low level stuff here that is probably obsolete and could be cleaned up.