sshserver: use `iter(callable, sentinel)` instead of while True

This is functionally equivalent, but is a little more concise.

mercurial/sshserver.py

@@ -1,135 +1,131 b''
 # sshserver.py - ssh protocol server support for mercurial
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[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 os
 import sys
 
 from .i18n import _
 from . import (
     error,
     hook,
     util,
     wireproto,
 )
 
 class sshserver(wireproto.abstractserverproto):
     def __init__(self, ui, repo):
         self.ui = ui
         self.repo = repo
         self.lock = None
         self.fin = ui.fin
         self.fout = ui.fout
 
         hook.redirect(True)
         ui.fout = repo.ui.fout = ui.ferr
 
         # Prevent insertion/deletion of CRs
         util.setbinary(self.fin)
         util.setbinary(self.fout)
 
     def getargs(self, args):
         data = {}
         keys = args.split()
         for n in xrange(len(keys)):
             argline = self.fin.readline()[:-1]
             arg, l = argline.split()
             if arg not in keys:
                 raise error.Abort(_("unexpected parameter %r") % arg)
             if arg == '*':
                 star = {}
                 for k in xrange(int(l)):
                     argline = self.fin.readline()[:-1]
                     arg, l = argline.split()
                     val = self.fin.read(int(l))
                     star[arg] = val
                 data['*'] = star
             else:
                 val = self.fin.read(int(l))
                 data[arg] = val
         return [data[k] for k in keys]
 
     def getarg(self, name):
         return self.getargs(name)[0]
 
     def getfile(self, fpout):
         self.sendresponse('')
         count = int(self.fin.readline())
         while count:
             fpout.write(self.fin.read(count))
             count = int(self.fin.readline())
 
     def redirect(self):
         pass
 
     def groupchunks(self, changegroup):
-        while True:
-            d = changegroup.read(4096)
-            if not d:
-                break
-            yield d
+        return iter(lambda: changegroup.read(4096), '')
 
     def sendresponse(self, v):
         self.fout.write("%d\n" % len(v))
         self.fout.write(v)
         self.fout.flush()
 
     def sendstream(self, source):
         write = self.fout.write
         for chunk in source.gen:
             write(chunk)
         self.fout.flush()
 
     def sendpushresponse(self, rsp):
         self.sendresponse('')
         self.sendresponse(str(rsp.res))
 
     def sendpusherror(self, rsp):
         self.sendresponse(rsp.res)
 
     def sendooberror(self, rsp):
         self.ui.ferr.write('%s\n-\n' % rsp.message)
         self.ui.ferr.flush()
         self.fout.write('\n')
         self.fout.flush()
 
     def serve_forever(self):
         try:
             while self.serve_one():
                 pass
         finally:
             if self.lock is not None:
                 self.lock.release()
         sys.exit(0)
 
     handlers = {
         str: sendresponse,
         wireproto.streamres: sendstream,
         wireproto.pushres: sendpushresponse,
         wireproto.pusherr: sendpusherror,
         wireproto.ooberror: sendooberror,
     }
 
     def serve_one(self):
         cmd = self.fin.readline()[:-1]
         if cmd and cmd in wireproto.commands:
             rsp = wireproto.dispatch(self.repo, self, cmd)
             self.handlers[rsp.__class__](self, rsp)
         elif cmd:
             impl = getattr(self, 'do_' + cmd, None)
             if impl:
                 r = impl()
                 if r is not None:
                     self.sendresponse(r)
             else: self.sendresponse("")
         return cmd != ''
 
     def _client(self):
         client = os.environ.get('SSH_CLIENT', '').split(' ', 1)[0]
         return 'remote:ssh:' + client