branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
# 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.
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:
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('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('Permission denied')
f = b"/".join((self.base, urlreq.quote(path)))
return httprangereader(f, urlopener)
def join(self, path, *insidef):
if path:
return pathutil.join(self.base, path, *insidef)
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 FileNotFoundError:
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 FileNotFoundError:
# 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
self._dirstate = 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, path=None, remotehidden=False):
return statichttppeer(self, path=path, remotehidden=remotehidden)
def wlock(self, wait=True):
raise error.LockUnavailable(
0,
pycompat.sysstr(_(b'lock not available')),
b'lock',
_(b'cannot lock static-http repository'),
)
def lock(self, wait=True):
raise error.LockUnavailable(
0,
pycompat.sysstr(_(b'lock not available')),
b'lock',
_(b'cannot lock static-http repository'),
)
def _writecaches(self):
pass # statichttprepository are read only
def make_peer(
ui, path, create, intents=None, createopts=None, remotehidden=False
):
if create:
raise error.Abort(_(b'cannot create new static-http repository'))
url = path.loc[7:]
return statichttprepository(ui, url).peer(
path=path, remotehidden=remotehidden
)