hgwebdir: avoid systematic full garbage collection
Forcing a systematic full garbage collection upon each request
can serioulsy harm performance. This is reported as
https://bz.mercurial-scm.org/show_bug.cgi?id=6075
With this change we're performing the full collection according
to a new setting, `experimental.web.full-garbage-collection-rate`.
The default value is 1, which doesn't change the behavior and will
allow us to test on real use cases. If the value is 0, no full garbage
collection occurs.
Regardless of the value of the setting, a partial garbage collection
still occurs upon each request (not attempting to collect objects from
the oldest generation). This should be enough to take care of
reference cycles that have been created by the last request
(assessment of this requires changing the setting, not to be 1).
In my experience chasing memory leaks in Mercurial servers,
the full collection never reclaimed any memory, but this is with
Python 3 and biased towards small repositories.
On the other hand, as explained in the Python developer docs [1],
frequent full collections are very harmful in terms of performance if
lots of objects survive the collection, and hence stay in the
oldest generation. Note that `gc.collect()` is indeed trying to
collect the oldest generation [2]. This happens usually in two cases:
- unwanted lingering objects (i.e., an actual memory leak that
the GC cannot do anything about). Sadly, we have lots of those
these days.
- desireable long-term objects, typically in caches (not inner caches
carried by repositories, which should be collected with them). This
is a subject of interest for the Heptapod project.
In short, the flat rate that this change still permits is
probably a bad idea in most cases, and the default value can
be tweaked later on (or even be set to 0) according to experiments
in the wild.
The test is inspired from test-hgwebdir-paths.py
[1] https://devguide.python.org/garbage_collector/#collecting-the-oldest-generation
[2] https://docs.python.org/3/library/gc.html#gc.collect
Differential Revision: https://phab.mercurial-scm.org/D11204
from __future__ import absolute_import, print_function
import unittest
from mercurial.hgweb import request as requestmod
from mercurial import error, pycompat
DEFAULT_ENV = {
'REQUEST_METHOD': 'GET',
'SERVER_NAME': 'testserver',
'SERVER_PORT': '80',
'SERVER_PROTOCOL': 'http',
'wsgi.version': (1, 0),
'wsgi.url_scheme': 'http',
'wsgi.input': None,
'wsgi.errors': None,
'wsgi.multithread': False,
'wsgi.multiprocess': True,
'wsgi.run_once': False,
}
def parse(env, reponame=None, altbaseurl=None, extra=None):
env = dict(env)
env.update(extra or {})
return requestmod.parserequestfromenv(
env, reponame=reponame, altbaseurl=altbaseurl
)
class ParseRequestTests(unittest.TestCase):
def testdefault(self):
r = parse(DEFAULT_ENV)
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.method, b'GET')
self.assertIsNone(r.remoteuser)
self.assertIsNone(r.remotehost)
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
self.assertEqual(r.querystring, b'')
self.assertEqual(len(r.qsparams), 0)
self.assertEqual(len(r.headers), 0)
def testcustomport(self):
r = parse(
DEFAULT_ENV,
extra={
'SERVER_PORT': '8000',
},
)
self.assertEqual(r.url, b'http://testserver:8000')
self.assertEqual(r.baseurl, b'http://testserver:8000')
self.assertEqual(r.advertisedurl, b'http://testserver:8000')
self.assertEqual(r.advertisedbaseurl, b'http://testserver:8000')
r = parse(
DEFAULT_ENV,
extra={
'SERVER_PORT': '4000',
'wsgi.url_scheme': 'https',
},
)
self.assertEqual(r.url, b'https://testserver:4000')
self.assertEqual(r.baseurl, b'https://testserver:4000')
self.assertEqual(r.advertisedurl, b'https://testserver:4000')
self.assertEqual(r.advertisedbaseurl, b'https://testserver:4000')
def testhttphost(self):
r = parse(
DEFAULT_ENV,
extra={
'HTTP_HOST': 'altserver',
},
)
self.assertEqual(r.url, b'http://altserver')
self.assertEqual(r.baseurl, b'http://altserver')
self.assertEqual(r.advertisedurl, b'http://testserver')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
def testscriptname(self):
r = parse(
DEFAULT_ENV,
extra={
'SCRIPT_NAME': '',
},
)
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
r = parse(
DEFAULT_ENV,
extra={
'SCRIPT_NAME': '/script',
},
)
self.assertEqual(r.url, b'http://testserver/script')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/script')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/script')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
r = parse(
DEFAULT_ENV,
extra={
'SCRIPT_NAME': '/multiple words',
},
)
self.assertEqual(r.url, b'http://testserver/multiple%20words')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/multiple%20words')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/multiple words')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
def testpathinfo(self):
r = parse(
DEFAULT_ENV,
extra={
'PATH_INFO': '',
},
)
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertEqual(r.dispatchpath, b'')
r = parse(
DEFAULT_ENV,
extra={
'PATH_INFO': '/pathinfo',
},
)
self.assertEqual(r.url, b'http://testserver/pathinfo')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/pathinfo')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [b'pathinfo'])
self.assertEqual(r.dispatchpath, b'pathinfo')
r = parse(
DEFAULT_ENV,
extra={
'PATH_INFO': '/one/two/',
},
)
self.assertEqual(r.url, b'http://testserver/one/two/')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/one/two/')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [b'one', b'two'])
self.assertEqual(r.dispatchpath, b'one/two')
def testscriptandpathinfo(self):
r = parse(
DEFAULT_ENV,
extra={
'SCRIPT_NAME': '/script',
'PATH_INFO': '/pathinfo',
},
)
self.assertEqual(r.url, b'http://testserver/script/pathinfo')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/script/pathinfo')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/script')
self.assertEqual(r.dispatchparts, [b'pathinfo'])
self.assertEqual(r.dispatchpath, b'pathinfo')
r = parse(
DEFAULT_ENV,
extra={
'SCRIPT_NAME': '/script1/script2',
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(
r.url, b'http://testserver/script1/script2/path1/path2'
)
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://testserver/script1/script2/path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/script1/script2')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
r = parse(
DEFAULT_ENV,
extra={
'HTTP_HOST': 'hostserver',
'SCRIPT_NAME': '/script',
'PATH_INFO': '/pathinfo',
},
)
self.assertEqual(r.url, b'http://hostserver/script/pathinfo')
self.assertEqual(r.baseurl, b'http://hostserver')
self.assertEqual(r.advertisedurl, b'http://testserver/script/pathinfo')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/script')
self.assertEqual(r.dispatchparts, [b'pathinfo'])
self.assertEqual(r.dispatchpath, b'pathinfo')
if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
# Python 3.7 deprecates the regex*p* version, but 2.7 lacks
# the regex version.
assertRaisesRegex = ( # camelcase-required
unittest.TestCase.assertRaisesRegexp
)
def testreponame(self):
"""repository path components get stripped from URL."""
with self.assertRaisesRegex(
error.ProgrammingError, 'reponame requires PATH_INFO'
):
parse(DEFAULT_ENV, reponame=b'repo')
with self.assertRaisesRegex(
error.ProgrammingError, 'PATH_INFO does not begin with repo ' 'name'
):
parse(
DEFAULT_ENV,
reponame=b'repo',
extra={
'PATH_INFO': '/pathinfo',
},
)
with self.assertRaisesRegex(
error.ProgrammingError, 'reponame prefix of PATH_INFO'
):
parse(
DEFAULT_ENV,
reponame=b'repo',
extra={
'PATH_INFO': '/repoextra/path',
},
)
r = parse(
DEFAULT_ENV,
reponame=b'repo',
extra={
'PATH_INFO': '/repo/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/repo/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://testserver/repo/path1/path2')
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/repo')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertEqual(r.reponame, b'repo')
r = parse(
DEFAULT_ENV,
reponame=b'prefix/repo',
extra={
'PATH_INFO': '/prefix/repo/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/prefix/repo/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://testserver/prefix/repo/path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://testserver')
self.assertEqual(r.apppath, b'/prefix/repo')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertEqual(r.reponame, b'prefix/repo')
def testaltbaseurl(self):
# Simple hostname remap.
r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver')
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# With a custom port.
r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver:8000')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver:8000')
self.assertEqual(r.advertisedbaseurl, b'http://altserver:8000')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# With a changed protocol.
r = parse(DEFAULT_ENV, altbaseurl=b'https://altserver')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'https://altserver')
self.assertEqual(r.advertisedbaseurl, b'https://altserver')
# URL scheme is defined as the actual scheme, not advertised.
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# Need to specify explicit port number for proper https:// alt URLs.
r = parse(DEFAULT_ENV, altbaseurl=b'https://altserver:443')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'https://altserver')
self.assertEqual(r.advertisedbaseurl, b'https://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# With only PATH_INFO defined.
r = parse(
DEFAULT_ENV,
altbaseurl=b'http://altserver',
extra={
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver/path1/path2')
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertIsNone(r.reponame)
# Path on alt URL.
r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver/altpath')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver/altpath')
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'/altpath')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# With a trailing slash.
r = parse(DEFAULT_ENV, altbaseurl=b'http://altserver/altpath/')
self.assertEqual(r.url, b'http://testserver')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver/altpath/')
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'/altpath/')
self.assertEqual(r.dispatchparts, [])
self.assertIsNone(r.dispatchpath)
self.assertIsNone(r.reponame)
# PATH_INFO + path on alt URL.
r = parse(
DEFAULT_ENV,
altbaseurl=b'http://altserver/altpath',
extra={
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://altserver/altpath/path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'/altpath')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertIsNone(r.reponame)
# PATH_INFO + path on alt URL with trailing slash.
r = parse(
DEFAULT_ENV,
altbaseurl=b'http://altserver/altpath/',
extra={
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://altserver/altpath//path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'/altpath/')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertIsNone(r.reponame)
# Local SCRIPT_NAME is ignored.
r = parse(
DEFAULT_ENV,
altbaseurl=b'http://altserver',
extra={
'SCRIPT_NAME': '/script',
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/script/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(r.advertisedurl, b'http://altserver/path1/path2')
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertIsNone(r.reponame)
# Use remote's path for script name, app path
r = parse(
DEFAULT_ENV,
altbaseurl=b'http://altserver/altroot',
extra={
'SCRIPT_NAME': '/script',
'PATH_INFO': '/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/script/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://altserver/altroot/path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.urlscheme, b'http')
self.assertEqual(r.apppath, b'/altroot')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertIsNone(r.reponame)
# reponame is factored in properly.
r = parse(
DEFAULT_ENV,
reponame=b'repo',
altbaseurl=b'http://altserver/altroot',
extra={
'SCRIPT_NAME': '/script',
'PATH_INFO': '/repo/path1/path2',
},
)
self.assertEqual(r.url, b'http://testserver/script/repo/path1/path2')
self.assertEqual(r.baseurl, b'http://testserver')
self.assertEqual(
r.advertisedurl, b'http://altserver/altroot/repo/path1/path2'
)
self.assertEqual(r.advertisedbaseurl, b'http://altserver')
self.assertEqual(r.apppath, b'/altroot/repo')
self.assertEqual(r.dispatchparts, [b'path1', b'path2'])
self.assertEqual(r.dispatchpath, b'path1/path2')
self.assertEqual(r.reponame, b'repo')
def testenvencoding(self):
if pycompat.iswindows:
# On Windows, we can't generally know which non-ASCII characters
# are supported.
r = parse(DEFAULT_ENV, extra={'foo': 'bar'})
self.assertEqual(r.rawenv[b'foo'], b'bar')
else:
# Unix is byte-based. Therefore we test all possible bytes.
b = b''.join(pycompat.bytechr(i) for i in range(256))
r = parse(DEFAULT_ENV, extra={'foo': pycompat.fsdecode(b)})
self.assertEqual(r.rawenv[b'foo'], b)
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)