phases: avoid a potentially costly dictionary interation in some case
If we retract for the draft phase, there is not non-public item to be retracted
and we can skip this part. This part is was apparently super costly thanks to
Python.
On mozilla-try-2019-02-18, a perf::unbundle call with a 10 000 changesets
bundle gives give use the following timing.
e57d4b868a3e: 4.6 seconds
ac1c75188440: 102.5 seconds
this-changeset: 30.0 seconds
So we recovered about ⅔ of the regression, the next changeset will give us the
rest back.
import argparse
import zipfile
ap = argparse.ArgumentParser()
ap.add_argument("out", metavar="some.zip", type=str, nargs=1)
args = ap.parse_args()
with zipfile.ZipFile(args.out[0], "w", zipfile.ZIP_STORED) as zf:
zf.writestr(
"greek-tree",
"\n".join(
[
"iota",
"A/mu",
"A/B/lambda",
"A/B/E/alpha",
"A/B/E/beta",
"A/D/gamma",
"A/D/G/pi",
"A/D/G/rho",
"A/D/G/tau",
"A/D/H/chi",
"A/D/H/omega",
"A/D/H/psi",
]
),
)