speeding up of app load: 40 seconds -> 4 seconds

[knorth55]

UPDATE: I update this PR to speed up more.

Loading apps takes long time, which drops my productivity.
I change not to use roslib.packages.find_resource for speed up.
I change to share the same rospack object between multiple functions to make roslib.packages.find_resource faster.

Current kinetic-devel takes 39 seconds to load 12 app.
This PR reduces it to 4 seconds.

kinetic-devel branch

[ERROR] [1640440511.654021]: total time: 39.4751198292

cProfile output

         67248708 function calls (62972939 primitive calls) in 39.464 seconds

   Ordered by: cumulative time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    0.000    0.000   39.463   39.463 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app_list.py:215(update)
        1    0.000    0.000   39.462   39.462 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app_list.py:167(_load)
       14    0.000    0.000   39.451    2.818 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app_list.py:122(update)
        7    0.000    0.000   39.451    5.636 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app_list.py:93(__init__)
        7    0.000    0.000   39.451    5.636 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app_list.py:101(_load)
       25    0.000    0.000   39.431    1.577 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:306(load_AppDefinition_by_name)
      100    0.041    0.000   39.352    0.394 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:117(find_resource)
      100    0.002    0.000   39.310    0.393 /opt/ros/melodic/lib/python2.7/dist-packages/roslib/packages.py:487(find_resource)
       25    0.001    0.000   29.561    1.182 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:278(load_AppDefinition_from_file)
      100    0.027    0.000   27.902    0.279 /opt/ros/melodic/lib/python2.7/dist-packages/catkin/find_in_workspaces.py:95(find_in_workspaces)
    12148    0.062    0.000   27.395    0.002 /usr/local/lib/python2.7/dist-packages/catkin_pkg/packages.py:75(find_packages)
    12148    0.084    0.000   27.324    0.002 /usr/local/lib/python2.7/dist-packages/catkin_pkg/packages.py:112(find_packages_allowing_duplicates)
    12148    1.674    0.000   25.028    0.002 /usr/local/lib/python2.7/dist-packages/catkin_pkg/package.py:583(parse_package_string)
4152808/188764    4.308    0.000   11.479    0.000 /usr/lib/python2.7/copy.py:145(deepcopy)
      100    0.000    0.000   11.206    0.112 /usr/lib/python2.7/dist-packages/rospkg/rospack.py:199(get_path)
      100    0.117    0.001   11.205    0.112 /usr/lib/python2.7/dist-packages/rospkg/rospack.py:173(_update_location_cache)
    32500    0.863    0.000   11.088    0.000 /usr/lib/python2.7/dist-packages/rospkg/rospack.py:49(list_by_path)
   188764    1.031    0.000    9.937    0.000 /usr/lib/python2.7/copy.py:306(_reconstruct)
       25    0.000    0.000    9.837    0.393 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:191(_AppDefinition_load_interface_entry)
       25    0.000    0.000    9.836    0.393 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:153(_AppDefinition_load_icon_entry)
       25    0.000    0.000    9.832    0.393 /home/knorth55/ros/vive_ws/src/PR2/app_manager/src/app_manager/app.py:174(_AppDefinition_load_launch_entry)
   377528    1.017    0.000    7.454    0.000 /usr/lib/python2.7/copy.py:234(_deepcopy_tuple)
     6472    0.296    0.000    5.672    0.001 /usr/local/lib/python2.7/dist-packages/catkin_pkg/package.py:115(__getattr__)
327164/163962    0.888    0.000    5.613    0.000 /usr/lib/python2.7/os.py:209(walk)

This PR

[ERROR] [1640619177.785652]: total time: 4.10533118248

[knorth55]

I update this PR, and now it only takes 1 seconds to load the app definition.

@708yamaguchi can you check this PR in your PC and report how fast it is?

[708yamaguchi]

I think this is very useful PR.

I have 619 ROS packages in my workspaces,

$ rospack list | wc -l
619

and I have 18 apps in 4 packages in my workspaces.

[INFO] [1640495997.563157]: 1 apps found in /home/leus/ros/melodic/src/jsk-ros-pkg/jsk_pr2eus/pr2eus_tutorials/apps/app.installed
[INFO] [1640495999.662914]: 2 apps found in /home/leus/ros/melodic/src/jsk-ros-pkg/jsk_robot/jsk_robot_common/jsk_robot_startup/apps/robot_apps.installed
[INFO] [1640496012.381850]: 12 apps found in /home/leus/ros/melodic/src/jsk-ros-pkg/jsk_robot/jsk_fetch_robot/jsk_fetch_startup/apps/fetch_apps.installed
[INFO] [1640496015.567683]: 3 apps found in /home/leus/ros/melodic/src/jsk-ros-pkg/jsk_robot/jsk_pr2_robot/jsk_pr2_startup/apps/pr2_apps.installed

Without this PR,

35818241 function calls (33742020 primitive calls) in 19.040 seconds

[ERROR] [1640496024.228704]: total time: 27.6996641159 

With this PR,

478007 function calls (462837 primitive calls) in 0.423 seconds

[ERROR] [1640495916.035495]: total time: 0.429724931717

[v4hn]

I didn't test any of this but now the changes make sense looking at the source code.
Please review and merge @k-okada .

[Affonso-Gui]

@k-okada Kindly ping