largefiles: add abstract methods in remotestore class

Methods _put, _get, _stat were used in remotestore class as
abstract expecting that subclass would implement them. This
commit makes this fact explicit.

hgext/largefiles/remotestore.py

@@ -1,98 +1,113 b''
 # Copyright 2010-2011 Fog Creek Software
 # Copyright 2010-2011 Unity Technologies
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''remote largefile store; the base class for wirestore'''
 
 import urllib2
 
 from mercurial import util, wireproto, error
 from mercurial.i18n import _
 
 import lfutil
 import basestore
 
 class remotestore(basestore.basestore):
     '''a largefile store accessed over a network'''
     def __init__(self, ui, repo, url):
         super(remotestore, self).__init__(ui, repo, url)
 
     def put(self, source, hash):
         if self.sendfile(source, hash):
             raise error.Abort(
                 _('remotestore: could not put %s to remote store %s')
                 % (source, util.hidepassword(self.url)))
         self.ui.debug(
             _('remotestore: put %s to remote store %s\n')
             % (source, util.hidepassword(self.url)))
 
     def exists(self, hashes):
         return dict((h, s == 0) for (h, s) in # dict-from-generator
                     self._stat(hashes).iteritems())
 
     def sendfile(self, filename, hash):
         self.ui.debug('remotestore: sendfile(%s, %s)\n' % (filename, hash))
         fd = None
         try:
             fd = lfutil.httpsendfile(self.ui, filename)
             return self._put(hash, fd)
         except IOError as e:
             raise error.Abort(
                 _('remotestore: could not open file %s: %s')
                 % (filename, str(e)))
         finally:
             if fd:
                 fd.close()
 
     def _getfile(self, tmpfile, filename, hash):
         try:
             chunks = self._get(hash)
         except urllib2.HTTPError as e:
             # 401s get converted to error.Aborts; everything else is fine being
             # turned into a StoreError
             raise basestore.StoreError(filename, hash, self.url, str(e))
         except urllib2.URLError as e:
             # This usually indicates a connection problem, so don't
             # keep trying with the other files... they will probably
             # all fail too.
             raise error.Abort('%s: %s' %
                              (util.hidepassword(self.url), e.reason))
         except IOError as e:
             raise basestore.StoreError(filename, hash, self.url, str(e))
 
         return lfutil.copyandhash(chunks, tmpfile)
 
     def _verifyfile(self, cctx, cset, contents, standin, verified):
         filename = lfutil.splitstandin(standin)
         if not filename:
             return False
         fctx = cctx[standin]
         key = (filename, fctx.filenode())
         if key in verified:
             return False
 
         verified.add(key)
 
         expecthash = fctx.data()[0:40]
         stat = self._stat([expecthash])[expecthash]
         if not stat:
             return False
         elif stat == 1:
             self.ui.warn(
                 _('changeset %s: %s: contents differ\n')
                 % (cset, filename))
             return True # failed
         elif stat == 2:
             self.ui.warn(
                 _('changeset %s: %s missing\n')
                 % (cset, filename))
             return True # failed
         else:
             raise RuntimeError('verify failed: unexpected response from '
                                'statlfile (%r)' % stat)
 
     def batch(self):
         '''Support for remote batching.'''
         return wireproto.remotebatch(self)
+
+    def _put(self, hash, fd):
+        '''Put file with the given hash in the remote store.'''
+        raise NotImplementedError('abstract method')
+
+    def _get(self, hash):
+        '''Get file with the given hash from the remote store.'''
+        raise NotImplementedError('abstract method')
+
+    def _stat(self, hashes):
+        '''Get information about availability of files specified by
+        hashes in the remote store. Return dictionary mapping hashes
+        to return code where 0 means that file is available, other
+        values if not.'''
+        raise NotImplementedError('abstract method')