originally discussed in here

Problem

• roslaunch is slow if catkin workspace has a lot of files
• catkin_pkg.packages.find_packages always scan workspace and it's not fast enough
• When rosbuild was used, roslaunch was not so slow, as far as I remember

Approach

• During running roslaunch, catkin workspace must not be changed, so we can cache catkin_pkg.packages.find_packages like old rospack
• In order to keep backward compatibility, add keyword arguments to functions

Benchmark

• Use test.rosinstall to build workspace

  $ find src | wc -l
  17239
  $ find src -name package.xml | wc -l
  286
  $ find src -name manifest.xml | wc -l
  146
  

• Measure time of roslaunch openni2_launch openni2.launch

• Result

  • without caching -- 17 sec
  • with caching -- 5 sec
  • Movie
    • without caching
    • with caching