Maintain one Templar for the lifetime of VariableManager, calling
set_available_variables() prior to each use, enabling _get_filter()'s
cache to function correctly.
It does not seem possible for concurrent calls into one (non-copied)
VariableManager instance, and so it need not be reentrant. If that
became a requirement, serializing its or Templar's entry points would be
fine, as it's so CPU-heavy other threads will only fight with it for the
GIL anyway.
Reduces _get_filters() runtime 91%, get_vars() runtime 19%, function
call count 16%, overall runtime 10%.
Tested aginst dummy load comprised of the 12 disabled steps of
debops.auth with an inventory of 80 hosts, which stresses variable
processing and task setup. Before:
7447296 function calls (7253994 primitive calls) in 32.611 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 32.762 32.762 ansible-playbook:3(<module>)
1 0.007 0.007 31.733 31.733 ansible-playbook:21(<module>)
...
1371/971 0.671 0.000 21.332 0.022 manager.py:154(get_vars)
...
3044 0.315 0.000 5.166 0.002 __init__.py:295(_get_filters)
After:
6252978 function calls (6059638 primitive calls) in 29.055 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 29.218 29.218 ansible-playbook:3(<module>)
1 0.007 0.007 28.159 28.159 ansible-playbook:21(<module>)
...
1371/971 0.675 0.000 17.211 0.018 manager.py:154(get_vars)
...
3044 0.028 0.000 0.441 0.000 __init__.py:295(_get_filters)
6069d09b9d