statichttprepo: implement __enter__ and __exit__ on httprangeheader

httprangeheader behaves like a file object. Implement __enter__ and
__exit__ so it can be used as a context manager, just like file objects.

mercurial/statichttprepo.py

@@ -1,179 +1,186
 # statichttprepo.py - simple http repository class for mercurial
 #
 # This provides read-only repo access to repositories exported via static http
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # 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
 import os
 import urllib
 import urllib2
 
 from .i18n import _
 from . import (
     byterange,
     changelog,
     error,
     localrepo,
     manifest,
     namespaces,
     scmutil,
     store,
     url,
     util,
 )
 
 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 = urllib2.Request(self.url)
         end = ''
         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 urllib2.HTTPError as inst:
             num = inst.code == 404 and errno.ENOENT or None
             raise IOError(num, inst)
         except urllib2.URLError as inst:
             raise IOError(None, inst.reason[1])
 
         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
 
 def build_opener(ui, authinfo):
     # urllib cannot handle URLs with embedded user or passwd
     urlopener = url.opener(ui, authinfo)
     urlopener.add_handler(byterange.HTTPRangeHandler())
 
     class statichttpvfs(scmutil.abstractvfs):
         def __init__(self, base):
             self.base = base
 
         def __call__(self, path, mode='r', *args, **kw):
             if mode not in ('r', 'rb'):
                 raise IOError('Permission denied')
             f = "/".join((self.base, urllib.quote(path)))
             return httprangereader(f, urlopener)
 
         def join(self, path):
             if path:
                 return os.path.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):
     supported = localrepo.localrepository._basesupported
 
     def __init__(self, ui, path):
         self._url = path
         self.ui = ui
 
         self.root = path
         u = util.url(path.rstrip('/') + "/.hg")
         self.path, authinfo = u.authinfo()
 
         opener = build_opener(ui, authinfo)
         self.opener = opener(self.path)
         self.vfs = self.opener
         self._phasedefaults = []
 
         self.names = namespaces.namespaces()
 
         try:
             requirements = scmutil.readrequires(self.vfs, self.supported)
         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("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 = _("'%s' does not appear to be an hg repository") % path
                 raise error.RepoError(msg)
 
         # setup store
         self.store = store.store(requirements, self.path, opener)
         self.spath = self.store.path
         self.svfs = self.store.opener
         self.sjoin = self.store.join
         self._filecache = {}
         self.requirements = requirements
 
         self.manifest = manifest.manifest(self.svfs)
         self.changelog = changelog.changelog(self.svfs)
         self._tags = None
         self.nodetagscache = None
         self._branchcaches = {}
         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(["pushkey"])
 
     def url(self):
         return self._url
 
     def local(self):
         return False
 
     def peer(self):
         return statichttppeer(self)
 
     def lock(self, wait=True):
         raise error.Abort(_('cannot lock static-http repository'))
 
 def instance(ui, path, create):
     if create:
         raise error.Abort(_('cannot create new static-http repository'))
     return statichttprepository(ui, path[7:])