[PREVIEW-WIP] PERF: Improve startup time by 8% with lazy loading of wrapped libraries
Created by: jcfr
*** WORK IN PROGRESS: For now, you have to make sure SlicerApp-real and Slicer launcher are built to ensure the successful generation of the json files ***
Startup time reduced from 3.8s to 3.5s with a "cold cache" and from 2.7s to 2.38s with a "warm cache".
For each logic/mrml/dm/widgets python modules, a json files listing the associated attributes is generated. Then, when the application is initialized, the "slicer" module is created as a "lazy" module with the attributes associated with logic/mrml/dm/widgets set as "not loaded".
Finally, as soon as an attribute not yet loaded is accessed, the specialized
__getattribute__ loads the associated python module and update the module
The "lazy" module has been adapted from "itkLazy.py"
Results have been gathered on Ubuntu 15.10 on a workstation with the following specs: 64GB / M.2 PCIe NVMe SSD / Quad Core 3.80GHz