UNINSTALL_PROTECT in Paludis #3

After a fair time of using the hook described in the previous post I realized that it noticeably slows down the uninstalls of packages with lots of files like sys-kernel/gentoo-sources and hence I decided to rewrite it as a Python hook to see how it performs:

UNINSTALL_PROTECT=["/lib64/modules/"]

def hook_run_unmerger_unlink_file_override(env, hook_env):
    for path in UNINSTALL_PROTECT:
        if hook_env["UNLINK_TARGET"].startswith(path):
            return "skip"
        else:
            return ""

I was expecting a pretty big difference as for Python hooks an embedded interpreter is used and .hook hooks need a separate bash interpreter each time they are run. Nonetheless I was still surprised to see how big the difference really was for sys-kernel/gentoo-sources-2.6.23-rX uninstallation:

.hook hook ~ 8m
python hook ~ 1m 15s
no hook ~ 1m

Python hook is not much slower than no hook at all and hence I didn't care to try and write it as a .so hook, which probably would be even faster.