status: prefer relative paths in Rust code
… when the repository root is under the current directory,
so the kernel needs to traverse fewer directory in every call
to `read_dir` or `symlink_metadata`.
Better yet would be to use libc functions like `openat` and `fstatat`
to remove such repeated traversals entirely, but the standard library
does not provide APIs based on those.
Maybe with a crate like https://crates.io/crates/openat instead?
Benchmarks of `rhg status` show that this patch is neutral in some configurations,
and makes the command up to ~20% faster in others.
Below is semi-arbitrary subset of results. The four numeric columns are:
time (in seconds) with this changeset’s parent, time with this changeset,
time difference (negative is better), time ratio (less than 1 is better).
```
mercurial-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.0061 -> 0.0059: -0.0002 (0.97)
mercurial-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0029 -> 0.0028: -0.0001 (0.97)
mozilla-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.2110 -> 0.2102: -0.0007 (1.00)
mozilla-dirstate-v2 | default-copies-clean.ignored.pbr | 0.0489 -> 0.0401: -0.0088 (0.82)
mozilla-dirstate-v2 | default-copies-clean.no-iu.pbr | 0.0479 -> 0.0393: -0.0085 (0.82)
mozilla-dirstate-v2 | default-copies-large.all.pbr | 0.1262 -> 0.1210: -0.0051 (0.96)
mozilla-dirstate-v2 | default-copies-small.ignored-unknown.pbr | 0.1262 -> 0.1200: -0.0062 (0.95)
mozilla-dirstate-v2 | default-copies-small.ignored.pbr | 0.0536 -> 0.0417: -0.0119 (0.78)
mozilla-dirstate-v2 | default-copies-small.no-iu.pbr | 0.0482 -> 0.0393: -0.0089 (0.81)
mozilla-dirstate-v2 | default-plain-clean.ignored.pbr | 0.0518 -> 0.0402: -0.0116 (0.78)
mozilla-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0481 -> 0.0392: -0.0088 (0.82)
mozilla-dirstate-v2 | default-plain-large.all.pbr | 0.1271 -> 0.1218: -0.0052 (0.96)
mozilla-dirstate-v2 | default-plain-small.ignored-unknown.pbr | 0.1225 -> 0.1202: -0.0022 (0.98)
mozilla-dirstate-v2 | default-plain-small.ignored.pbr | 0.0510 -> 0.0418: -0.0092 (0.82)
mozilla-dirstate-v2 | default-plain-small.no-iu.pbr | 0.0480 -> 0.0394: -0.0086 (0.82)
netbeans-dirstate-v1 | default-plain-clean.no-iu.pbr | 0.1442 -> 0.1422: -0.0020 (0.99)
netbeans-dirstate-v2 | default-plain-clean.no-iu.pbr | 0.0325 -> 0.0282: -0.0043 (0.87)
```
Differential Revision: https://phab.mercurial-scm.org/D12175
# statichttprepo.py - simple http repository class for mercurial
#
# This provides read-only repo access to repositories exported via static http
#
# Copyright 2005-2007 Olivia Mackall <olivia@selenic.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
import errno
from .i18n import _
from .node import sha1nodeconstants
from . import (
branchmap,
changelog,
error,
localrepo,
manifest,
namespaces,
pathutil,
pycompat,
requirements as requirementsmod,
url,
util,
vfs as vfsmod,
)
from .utils import (
urlutil,
)
urlerr = util.urlerr
urlreq = util.urlreq
class httprangereader(object):
def __init__(self, url, opener):
# we assume opener has HTTPRangeHandler
self.url = url
self.pos = 0
self.opener = opener
self.name = url
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def seek(self, pos):
self.pos = pos
def read(self, bytes=None):
req = urlreq.request(pycompat.strurl(self.url))
end = b''
if bytes:
end = self.pos + bytes - 1
if self.pos or end:
req.add_header('Range', 'bytes=%d-%s' % (self.pos, end))
try:
f = self.opener.open(req)
data = f.read()
code = f.code
except urlerr.httperror as inst:
num = inst.code == 404 and errno.ENOENT or None
# Explicitly convert the exception to str as Py3 will try
# convert it to local encoding and with as the HTTPResponse
# instance doesn't support encode.
raise IOError(num, str(inst))
except urlerr.urlerror as inst:
raise IOError(None, inst.reason)
if code == 200:
# HTTPRangeHandler does nothing if remote does not support
# Range headers and returns the full entity. Let's slice it.
if bytes:
data = data[self.pos : self.pos + bytes]
else:
data = data[self.pos :]
elif bytes:
data = data[:bytes]
self.pos += len(data)
return data
def readlines(self):
return self.read().splitlines(True)
def __iter__(self):
return iter(self.readlines())
def close(self):
pass
# _RangeError and _HTTPRangeHandler were originally in byterange.py,
# which was itself extracted from urlgrabber. See the last version of
# byterange.py from history if you need more information.
class _RangeError(IOError):
"""Error raised when an unsatisfiable range is requested."""
class _HTTPRangeHandler(urlreq.basehandler):
"""Handler that enables HTTP Range headers.
This was extremely simple. The Range header is a HTTP feature to
begin with so all this class does is tell urllib2 that the
"206 Partial Content" response from the HTTP server is what we
expected.
"""
def http_error_206(self, req, fp, code, msg, hdrs):
# 206 Partial Content Response
r = urlreq.addinfourl(fp, hdrs, req.get_full_url())
r.code = code
r.msg = msg
return r
def http_error_416(self, req, fp, code, msg, hdrs):
# HTTP's Range Not Satisfiable error
raise _RangeError(b'Requested Range Not Satisfiable')
def build_opener(ui, authinfo):
# urllib cannot handle URLs with embedded user or passwd
urlopener = url.opener(ui, authinfo)
urlopener.add_handler(_HTTPRangeHandler())
class statichttpvfs(vfsmod.abstractvfs):
def __init__(self, base):
self.base = base
self.options = {}
def __call__(self, path, mode=b'r', *args, **kw):
if mode not in (b'r', b'rb'):
raise IOError(b'Permission denied')
f = b"/".join((self.base, urlreq.quote(path)))
return httprangereader(f, urlopener)
def join(self, path):
if path:
return pathutil.join(self.base, path)
else:
return self.base
return statichttpvfs
class statichttppeer(localrepo.localpeer):
def local(self):
return None
def canpush(self):
return False
class statichttprepository(
localrepo.localrepository, localrepo.revlogfilestorage
):
supported = localrepo.localrepository._basesupported
def __init__(self, ui, path):
self._url = path
self.ui = ui
self.root = path
u = urlutil.url(path.rstrip(b'/') + b"/.hg")
self.path, authinfo = u.authinfo()
vfsclass = build_opener(ui, authinfo)
self.vfs = vfsclass(self.path)
self.cachevfs = vfsclass(self.vfs.join(b'cache'))
self._phasedefaults = []
self.names = namespaces.namespaces()
self.filtername = None
self._extrafilterid = None
self._wanted_sidedata = set()
self.features = set()
try:
requirements = set(self.vfs.read(b'requires').splitlines())
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
requirements = set()
# check if it is a non-empty old-style repository
try:
fp = self.vfs(b"00changelog.i")
fp.read(1)
fp.close()
except IOError as inst:
if inst.errno != errno.ENOENT:
raise
# we do not care about empty old-style repositories here
msg = _(b"'%s' does not appear to be an hg repository") % path
raise error.RepoError(msg)
if requirementsmod.SHARESAFE_REQUIREMENT in requirements:
storevfs = vfsclass(self.vfs.join(b'store'))
requirements |= set(storevfs.read(b'requires').splitlines())
supportedrequirements = localrepo.gathersupportedrequirements(ui)
localrepo.ensurerequirementsrecognized(
requirements, supportedrequirements
)
localrepo.ensurerequirementscompatible(ui, requirements)
self.nodeconstants = sha1nodeconstants
self.nullid = self.nodeconstants.nullid
# setup store
self.store = localrepo.makestore(requirements, self.path, vfsclass)
self.spath = self.store.path
self.svfs = self.store.opener
self.sjoin = self.store.join
self._filecache = {}
self.requirements = requirements
rootmanifest = manifest.manifestrevlog(self.nodeconstants, self.svfs)
self.manifestlog = manifest.manifestlog(
self.svfs, self, rootmanifest, self.narrowmatch()
)
self.changelog = changelog.changelog(self.svfs)
self._tags = None
self.nodetagscache = None
self._branchcaches = branchmap.BranchMapCache()
self._revbranchcache = None
self.encodepats = None
self.decodepats = None
self._transref = None
def _restrictcapabilities(self, caps):
caps = super(statichttprepository, self)._restrictcapabilities(caps)
return caps.difference([b"pushkey"])
def url(self):
return self._url
def local(self):
return False
def peer(self):
return statichttppeer(self)
def wlock(self, wait=True):
raise error.LockUnavailable(
0,
_(b'lock not available'),
b'lock',
_(b'cannot lock static-http repository'),
)
def lock(self, wait=True):
raise error.LockUnavailable(
0,
_(b'lock not available'),
b'lock',
_(b'cannot lock static-http repository'),
)
def _writecaches(self):
pass # statichttprepository are read only
def instance(ui, path, create, intents=None, createopts=None):
if create:
raise error.Abort(_(b'cannot create new static-http repository'))
return statichttprepository(ui, path[7:])