1c1b70c98d
Apparently, the tarfile Python module spends a lot of time in
grp.getgrid for retrieving a piece information (the name of the
primary group) which we don't need anyway. There is no
proper way to disable these slow calls, but there's a workaround
which relies on the way in which grp (and pwd) is used.
In fact, pwd and grp are imported in this fashion:
try:
import grp, pwd
except ImportError:
grp = pwd = None
and then used with the following pattern [2]:
if grp:
try:
tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
except KeyError:
pass
By setting grp and pwd to None, thus skipping the calls, I was
able to achieve a 35x speedup on my workstation.
The user and group names are set to test262 when building the tar.
The downside to this approach is that we are relying on an
implementation detail, which is not in the public API.
However, the blamelist shows that the relevant bits of the module
have not been updated since 2003 [3], so we might as well assume
that the workaround will keep working, on cPython 2.x at least.
---
[1] https://hg.python.org/cpython/file/2.7/Lib/tarfile.py#l56
[2] https://hg.python.org/cpython/file/2.7/Lib/tarfile.py#l1933
[3] https://hg.python.org/cpython/rev/f9a5ed092660
BUG=chromium:535160
LOG=N
Review URL: https://codereview.chromium.org/1727773002
Cr-Commit-Position: refs/heads/master@{#34245}
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| .. | ||
| archive.py | ||
| harness-adapt.js | ||
| list.py | ||
| README | ||
| test262.gyp | ||
| test262.isolate | ||
| test262.status | ||
| testcfg.py | ||
This directory contains code for binding the test262 test suite into the v8 test harness. The tests are checked out as a dependency from https://chromium.googlesource.com/external/github.com/tc39/test262 at a revision specified in the DEPS file as 'data' in this directory. They are fetched with 'gclient sync'. To update to a newer version, please change the DEPS file. Using a newer version, e.g. 'deadbeef' may be possible but the tests are only known to pass (and indeed run) with the DEPS revision. Example: cd data git fetch git checkout deadbeef If you do update to a newer revision you may have to change the test harness adapter code since it uses internal functionality from the harness that comes bundled with the tests. You will most likely also have to update the test expectation file.