I took the liberty of renaming ModuleFinder.STDLIB_DIRS to
_STDLIB_PATHS, since it felt like an implementation detail that
shouldn't be baked into a public API and stdlib can also be imported
from e.g. a zip file.
I also changed it to a set to handle any duplicates.
Fixes#86
The solution was that Mitogen's loader should emulate the behaviour of
ansible.executor.module_common, which restricts dependency scanning to
the ansible.module_utils namespace.
Using the same test as in 7af97c0365,
transmitted wire bytes drops from 135,531 to 133,071 (-1.81%), while
received drops from 21,073 to 14,775 (-30%).
Combined, both changes shave 13,914 bytes (-8.6%) off aggregate
bandwidth usage.
Make it configurable as compression hurts in some scenarios.
For the 52 submodules of ansible.modules.system, this produced a 1602
byte pkg_present list. After stripping it becomes 406 bytes, and the
entire LOAD_MODULE size drops from 1988 bytes to 792 bytes (-60%).
For the 68 submodules of ansible.module_utils, 1902 bytes pkg_present
becomes 474 bytes (-75%), and LOAD_MODULE size drops from 2867 bytes to
1439 bytes (-49%).
In a simple test running Ansible's "setup" module followed by its "apt"
module, wire bytes sent drops from 140,357 to 135,531 (-3.4%).
It looks ugly as sin, but this nets about a 20% drop in user CPU time,
and close to 15% increase in throughput.
The average log call is around 10 opcodes, prefixing with '_v and' costs
an extra 2, but both are simple operations, and the remaining 10 are
skipped entirely when _v or _vv are False.
David Wilson