hgweb: config option to control zlib compression level
Before this patch, the HTTP transport protocol would always zlib
compress certain responses (notably "getbundle" wire protocol commands)
at zlib compression level 6.
zlib can be a massive CPU resource sink for servers. Some server
operators may wish to reduce server-side CPU requirements while
requiring more bandwidth. This is common on corporate intranets, for
example. Others may wish to use more CPU but reduce bandwidth.
This patch introduces a config option to allow server operators
to control the zlib compression level.
On the "mozilla-unified" generaldelta repository, setting this
value to "0" (disable compression) results in server-side CPU
utilization for a `hg clone` going from ~180s to ~124s CPU time on
my i7-6700K. A level of "1" (which increases the transfer size from
~1,074 MB at level 6 to ~1,222 MB) utilizes ~132s CPU time.
#!/usr/bin/env python
#
# check-py3-compat - check Python 3 compatibility of Mercurial files
#
# Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import, print_function
import ast
import imp
import os
import sys
import traceback
def check_compat_py2(f):
"""Check Python 3 compatibility for a file with Python 2"""
with open(f, 'rb') as fh:
content = fh.read()
root = ast.parse(content)
# Ignore empty files.
if not root.body:
return
futures = set()
haveprint = False
for node in ast.walk(root):
if isinstance(node, ast.ImportFrom):
if node.module == '__future__':
futures |= set(n.name for n in node.names)
elif isinstance(node, ast.Print):
haveprint = True
if 'absolute_import' not in futures:
print('%s not using absolute_import' % f)
if haveprint and 'print_function' not in futures:
print('%s requires print_function' % f)
def check_compat_py3(f):
"""Check Python 3 compatibility of a file with Python 3."""
with open(f, 'rb') as fh:
content = fh.read()
try:
ast.parse(content)
except SyntaxError as e:
print('%s: invalid syntax: %s' % (f, e))
return
# Try to import the module.
# For now we only support mercurial.* and hgext.* modules because figuring
# out module paths for things not in a package can be confusing.
if f.startswith(('hgext/', 'mercurial/')) and not f.endswith('__init__.py'):
assert f.endswith('.py')
name = f.replace('/', '.')[:-3]
with open(f, 'r') as fh:
try:
imp.load_module(name, fh, '', ('py', 'r', imp.PY_SOURCE))
except Exception as e:
exc_type, exc_value, tb = sys.exc_info()
# We walk the stack and ignore frames from our custom importer,
# import mechanisms, and stdlib modules. This kinda/sorta
# emulates CPython behavior in import.c while also attempting
# to pin blame on a Mercurial file.
for frame in reversed(traceback.extract_tb(tb)):
if frame.name == '_call_with_frames_removed':
continue
if 'importlib' in frame.filename:
continue
if 'mercurial/__init__.py' in frame.filename:
continue
if frame.filename.startswith(sys.prefix):
continue
break
if frame.filename:
filename = os.path.basename(frame.filename)
print('%s: error importing: <%s> %s (error at %s:%d)' % (
f, type(e).__name__, e, filename, frame.lineno))
else:
print('%s: error importing module: <%s> %s (line %d)' % (
f, type(e).__name__, e, frame.lineno))
if __name__ == '__main__':
if sys.version_info[0] == 2:
fn = check_compat_py2
else:
fn = check_compat_py3
for f in sys.argv[1:]:
fn(f)
sys.exit(0)