gopi487krishna/Boost Writeup.md

## Boost Writeup.md

      
    Raw
  

              Boost Writeup.md
            
          
    FITS ( Flexible Image Transport System ) is an open standard defining a digital file format that serves as the de facto standard for storage, transmission, and processing of astronomical data. It provides support for storing images, multidimensional data in the form of tables.
During the GSoC period, my task was to complete the development of the existing FITS parser. That involved improvising the current FITS parser and developing an external API for communicating with the FITS module.
For a better understanding of the FITS module, the first few weeks( during the community bonding period) were spent in writing Unit tests and completing the documentation for the existing codebase. It helped me in understanding the idealogy and design of the previous fits codebase/module.
During the second phase, our primary concern was to complete the reading part of the FITS module. We replaced the existing code of the FITS module ( HDU, header, card parsing) with a policy-based design on the principles of Andrei Alexandrescu to make the library as much extensible as possible. Our main motto here was to reduce the friction that people would face while using the library.
During this phase, we also faced a lot of performance problems due to the dynamic nature of FITS files ( Here "dynamic" refers to the deduction of "type" of data at runtime ). To improve the performance, we moved a large part of parsing from runtime to compile-time and used boost spirit for parsing and variant types to handle the "type" of data. This helped us improve performance by a large factor.
During the Third and the last Phase of GSoC, we implemented the writing portion of the FITS module. We also implemented a 2 level caching system for lazy parsing of data. It helped us in improving the performance of both the reading and writing portion of the FITS module.