hgweb: parse WSGI request into a data structure
Currently, our WSGI applications (hgweb_mod and hgwebdir_mod) process
the raw WSGI request instance themselves. This means they have to
talk in terms of system strings. And they need to know details
about what's in the WSGI request. And in the case of hgweb_mod, it
is doing some very funky things with URL parsing to impact
dispatching. The code is difficult to read and maintain.
This commit introduces parsing of the WSGI request into a higher-level
and easier-to-reason-about data structure.
To prove it works, we hook it up to hgweb_mod and use it for populating
the relative URL on the request instance.
We hold off on using it in more places because the logic in hgweb_mod
is crazy and I don't want to involve those changes with review of
the parsing code.
The URL construction code has variations that use the HTTP: Host header
(the canonical WSGI way of reconstructing the URL) and with the use
of SERVER_NAME. We need to differentiate because hgweb is currently
using SERVER_NAME for URL construction.
Differential Revision: https://phab.mercurial-scm.org/D2734
#!/usr/bin/env python
# Measure the performance of a list of revsets against multiple revisions
# defined by parameter. Checkout one by one and run perfrevset with every
# revset in the list to benchmark its performance.
#
# You should run this from the root of your mercurial repository.
#
# call with --help for details
from __future__ import absolute_import, print_function
import math
import optparse # cannot use argparse, python 2.7 only
import os
import re
import subprocess
import sys
DEFAULTVARIANTS = ['plain', 'min', 'max', 'first', 'last',
'reverse', 'reverse+first', 'reverse+last',
'sort', 'sort+first', 'sort+last']
def check_output(*args, **kwargs):
kwargs.setdefault('stderr', subprocess.PIPE)
kwargs.setdefault('stdout', subprocess.PIPE)
proc = subprocess.Popen(*args, **kwargs)
output, error = proc.communicate()
if proc.returncode != 0:
raise subprocess.CalledProcessError(proc.returncode, ' '.join(args[0]))
return output
def update(rev):
"""update the repo to a revision"""
try:
subprocess.check_call(['hg', 'update', '--quiet', '--check', str(rev)])
check_output(['make', 'local'],
stderr=None) # suppress output except for error/warning
except subprocess.CalledProcessError as exc:
print('update to revision %s failed, aborting'%rev, file=sys.stderr)
sys.exit(exc.returncode)
def hg(cmd, repo=None):
"""run a mercurial command
<cmd> is the list of command + argument,
<repo> is an optional repository path to run this command in."""
fullcmd = ['./hg']
if repo is not None:
fullcmd += ['-R', repo]
fullcmd += ['--config',
'extensions.perf=' + os.path.join(contribdir, 'perf.py')]
fullcmd += cmd
return check_output(fullcmd, stderr=subprocess.STDOUT)
def perf(revset, target=None, contexts=False):
"""run benchmark for this very revset"""
try:
args = ['perfrevset', revset]
if contexts:
args.append('--contexts')
output = hg(args, repo=target)
return parseoutput(output)
except subprocess.CalledProcessError as exc:
print('abort: cannot run revset benchmark: %s'%exc.cmd, file=sys.stderr)
if getattr(exc, 'output', None) is None: # no output before 2.7
print('(no output)', file=sys.stderr)
else:
print(exc.output, file=sys.stderr)
return None
outputre = re.compile(r'! wall (\d+.\d+) comb (\d+.\d+) user (\d+.\d+) '
'sys (\d+.\d+) \(best of (\d+)\)')
def parseoutput(output):
"""parse a textual output into a dict
We cannot just use json because we want to compare with old
versions of Mercurial that may not support json output.
"""
match = outputre.search(output)
if not match:
print('abort: invalid output:', file=sys.stderr)
print(output, file=sys.stderr)
sys.exit(1)
return {'comb': float(match.group(2)),
'count': int(match.group(5)),
'sys': float(match.group(3)),
'user': float(match.group(4)),
'wall': float(match.group(1)),
}
def printrevision(rev):
"""print data about a revision"""
sys.stdout.write("Revision ")
sys.stdout.flush()
subprocess.check_call(['hg', 'log', '--rev', str(rev), '--template',
'{if(tags, " ({tags})")} '
'{rev}:{node|short}: {desc|firstline}\n'])
def idxwidth(nbidx):
"""return the max width of number used for index
This is similar to log10(nbidx), but we use custom code here
because we start with zero and we'd rather not deal with all the
extra rounding business that log10 would imply.
"""
nbidx -= 1 # starts at 0
idxwidth = 0
while nbidx:
idxwidth += 1
nbidx //= 10
if not idxwidth:
idxwidth = 1
return idxwidth
def getfactor(main, other, field, sensitivity=0.05):
"""return the relative factor between values for 'field' in main and other
Return None if the factor is insignificant (less than <sensitivity>
variation)."""
factor = 1
if main is not None:
factor = other[field] / main[field]
low, high = 1 - sensitivity, 1 + sensitivity
if (low < factor < high):
return None
return factor
def formatfactor(factor):
"""format a factor into a 4 char string
22%
156%
x2.4
x23
x789
x1e4
x5x7
"""
if factor is None:
return ' '
elif factor < 2:
return '%3i%%' % (factor * 100)
elif factor < 10:
return 'x%3.1f' % factor
elif factor < 1000:
return '%4s' % ('x%i' % factor)
else:
order = int(math.log(factor)) + 1
while 1 < math.log(factor):
factor //= 0
return 'x%ix%i' % (factor, order)
def formattiming(value):
"""format a value to strictly 8 char, dropping some precision if needed"""
if value < 10**7:
return ('%.6f' % value)[:8]
else:
# value is HUGE very unlikely to happen (4+ month run)
return '%i' % value
_marker = object()
def printresult(variants, idx, data, maxidx, verbose=False, reference=_marker):
"""print a line of result to stdout"""
mask = '%%0%ii) %%s' % idxwidth(maxidx)
out = []
for var in variants:
if data[var] is None:
out.append('error ')
out.append(' ' * 4)
continue
out.append(formattiming(data[var]['wall']))
if reference is not _marker:
factor = None
if reference is not None:
factor = getfactor(reference[var], data[var], 'wall')
out.append(formatfactor(factor))
if verbose:
out.append(formattiming(data[var]['comb']))
out.append(formattiming(data[var]['user']))
out.append(formattiming(data[var]['sys']))
out.append('%6d' % data[var]['count'])
print(mask % (idx, ' '.join(out)))
def printheader(variants, maxidx, verbose=False, relative=False):
header = [' ' * (idxwidth(maxidx) + 1)]
for var in variants:
if not var:
var = 'iter'
if 8 < len(var):
var = var[:3] + '..' + var[-3:]
header.append('%-8s' % var)
if relative:
header.append(' ')
if verbose:
header.append('%-8s' % 'comb')
header.append('%-8s' % 'user')
header.append('%-8s' % 'sys')
header.append('%6s' % 'count')
print(' '.join(header))
def getrevs(spec):
"""get the list of rev matched by a revset"""
try:
out = check_output(['hg', 'log', '--template={rev}\n', '--rev', spec])
except subprocess.CalledProcessError as exc:
print("abort, can't get revision from %s"%spec, file=sys.stderr)
sys.exit(exc.returncode)
return [r for r in out.split() if r]
def applyvariants(revset, variant):
if variant == 'plain':
return revset
for var in variant.split('+'):
revset = '%s(%s)' % (var, revset)
return revset
helptext="""This script will run multiple variants of provided revsets using
different revisions in your mercurial repository. After the benchmark are run
summary output is provided. Use it to demonstrate speed improvements or pin
point regressions. Revsets to run are specified in a file (or from stdin), one
revsets per line. Line starting with '#' will be ignored, allowing insertion of
comments."""
parser = optparse.OptionParser(usage="usage: %prog [options] <revs>",
description=helptext)
parser.add_option("-f", "--file",
help="read revset from FILE (stdin if omitted)",
metavar="FILE")
parser.add_option("-R", "--repo",
help="run benchmark on REPO", metavar="REPO")
parser.add_option("-v", "--verbose",
action='store_true',
help="display all timing data (not just best total time)")
parser.add_option("", "--variants",
default=','.join(DEFAULTVARIANTS),
help="comma separated list of variant to test "
"(eg: plain,min,sorted) (plain = no modification)")
parser.add_option('', '--contexts',
action='store_true',
help='obtain changectx from results instead of integer revs')
(options, args) = parser.parse_args()
if not args:
parser.print_help()
sys.exit(255)
# the directory where both this script and the perf.py extension live.
contribdir = os.path.dirname(__file__)
revsetsfile = sys.stdin
if options.file:
revsetsfile = open(options.file)
revsets = [l.strip() for l in revsetsfile if not l.startswith('#')]
revsets = [l for l in revsets if l]
print("Revsets to benchmark")
print("----------------------------")
for idx, rset in enumerate(revsets):
print("%i) %s" % (idx, rset))
print("----------------------------")
print()
revs = []
for a in args:
revs.extend(getrevs(a))
variants = options.variants.split(',')
results = []
for r in revs:
print("----------------------------")
printrevision(r)
print("----------------------------")
update(r)
res = []
results.append(res)
printheader(variants, len(revsets), verbose=options.verbose)
for idx, rset in enumerate(revsets):
varres = {}
for var in variants:
varrset = applyvariants(rset, var)
data = perf(varrset, target=options.repo, contexts=options.contexts)
varres[var] = data
res.append(varres)
printresult(variants, idx, varres, len(revsets),
verbose=options.verbose)
sys.stdout.flush()
print("----------------------------")
print("""
Result by revset
================
""")
print('Revision:')
for idx, rev in enumerate(revs):
sys.stdout.write('%i) ' % idx)
sys.stdout.flush()
printrevision(rev)
print()
print()
for ridx, rset in enumerate(revsets):
print("revset #%i: %s" % (ridx, rset))
printheader(variants, len(results), verbose=options.verbose, relative=True)
ref = None
for idx, data in enumerate(results):
printresult(variants, idx, data[ridx], len(results),
verbose=options.verbose, reference=ref)
ref = data[ridx]
print()