Drop compatibility with Python < 2.6 and ZODB < 3.9

Also simplify some code by using some new Python syntax.

CHANGES

 Change History
 ==============
 
+1.0 (unreleased)
+----------------
+
+- Drop compatibility with Python < 2.6 and ZODB < 3.9
+
 0.10 (2011-10-17)
 -----------------
 

README

@@ -54,19 +54,13 @@ Requirements
 
 - Linux 2.6 or later
 
-- Python 2.4 or later
-
-- For python 2.4: `ctypes <http://python.net/crew/theller/ctypes/>`_
-  (packaged with later python versions)
-
-  Note that setup.py does not define any dependency to 'ctypes' so you will
-  have to install it explicitely.
+- Python 2.6.x or 2.7.x
 
 - For storage nodes:
 
   - MySQLdb: http://sourceforge.net/projects/mysql-python
 
-- For client nodes: ZODB 3.10.x but it should work with ZODB >= 3.4
+- For client nodes: ZODB 3.10.x but it should work with ZODB 3.9.x
 
 Installation
 ============

neo/client/Storage.py

@@ -35,18 +35,6 @@ def check_read_only(func):
         return func(self, *args, **kw)
     return wraps(func)(wrapped)
 
-def old_history_api(func):
-    try:
-        if ZODB.interfaces.IStorage['history'].positional[1] != 'version':
-            return func # ZODB >= 3.9
-    except KeyError: # ZODB < 3.8
-        pass
-    def history(self, oid, version=None, *args, **kw):
-        if version is None:
-            return func(self, oid, *args, **kw)
-        raise ValueError('Versions are not supported')
-    return wraps(func)(history)
-
 class Storage(BaseStorage.BaseStorage,
               ConflictResolution.ConflictResolvingStorage):
     """Wrapper class for neoclient."""
@@ -72,8 +60,8 @@ class Storage(BaseStorage.BaseStorage,
         # - transaction isolation is not done
         # ZODB.interfaces.IStorageIteration,
         ZODB.interfaces.IStorageUndoable,
-        getattr(ZODB.interfaces, 'IExternalGC', None), # XXX ZODB < 3.9
-        getattr(ZODB.interfaces, 'ReadVerifyingStorage', None), # XXX ZODB 3.9
+        ZODB.interfaces.IExternalGC,
+        getattr(ZODB.interfaces, 'ReadVerifyingStorage', None), # BBB ZODB 3.9
     )))
 
     def __init__(self, master_nodes, name, read_only=False,
@@ -227,7 +215,6 @@ class Storage(BaseStorage.BaseStorage,
     def registerDB(self, db, limit=None):
         self.app.registerDB(db, limit)
 
-    @old_history_api
     def history(self, oid, *args, **kw):
         try:
             return self.app.history(oid, *args, **kw)

neo/client/__init__.py

@@ -28,8 +28,7 @@ if 1:
         """Indicate confirmation that the transaction is done."""
 
         def callback(tid):
-            # BBB: _mvcc_storage not supported on older ZODB
-            if getattr(self, '_mvcc_storage', False):
+            if self._mvcc_storage:
                 # Inter-connection invalidation is not needed when the
                 # storage provides MVCC.
                 return
@@ -73,8 +72,8 @@ if 1:
             def _flush_invalidations():
                 acquire = self._db._a
                 try:
-                    self._db._r()                      # this is a RLock
-                except (AssertionError, RuntimeError): # old Python uses assert
+                    self._db._r() # this is a RLock
+                except RuntimeError:
                     acquire = lambda: None
                 try:
                     del self._flush_invalidations
@@ -87,12 +86,9 @@ if 1:
                 Connection_open(self, *args, **kw)
             finally:
                 del self._flush_invalidations
-        try:
-            Connection_open = Connection._setDB
-            Connection._setDB = open
-        except AttributeError: # recent ZODB
-            Connection_open = Connection.open
-            Connection.open = open
+
+        Connection_open = Connection.open
+        Connection.open = open
 
         # Storage.sync usually implements a "network barrier" (at least
         # in NEO, but ZEO should be fixed to do the same), which is quite
@@ -107,7 +103,7 @@ if 1:
         def afterCompletion(self, *ignored):
             try:
                 self._readCurrent.clear()
-            except AttributeError: # old ZODB (e.g. ZODB 3.4)
+            except AttributeError: # BBB: ZODB < 3.10
                 pass
             self._flush_invalidations()
         #Connection.afterCompletion = afterCompletion
@@ -118,8 +114,7 @@ if 1:
         Wrapper to DB instance that properly initialize Connection objects
         with NEO storages.
         It forces the connection to always create a new instance of the
-        storage, for compatibility with ZODB 3.4, and because we don't
-        implement IMVCCStorage completely.
+        storage, because we don't implement IMVCCStorage completely.
         """
 
         def __new__(cls, db, connection):
@@ -132,23 +127,11 @@ if 1:
 
         def __getattr__(self, attr):
             result = getattr(self._db, attr)
-            if attr in ('storage', '_storage'):
-                result = result.new_instance()
+            if attr == 'storage':
+                self.storage = result = result.new_instance()
                 self._connection._db = self._db
-                setattr(self, attr, result)
             return result
 
-    try:
-        Connection_setDB = Connection._setDB
-    except AttributeError: # recent ZODB
-        Connection_init = Connection.__init__
-        Connection.__init__ = lambda self, db, *args, **kw: \
-            Connection_init(self, _DB(db, self), *args, **kw)
-    else: # old ZODB (e.g. ZODB 3.4)
-        Connection._setDB = lambda self, odb, *args, **kw: \
-            Connection_setDB(self, _DB(odb, self), *args, **kw)
-
-        from ZODB.DB import DB
-        DB_invalidate = DB.invalidate
-        DB.invalidate = lambda self, tid, oids, *args, **kw: \
-            DB_invalidate(self, tid, dict.fromkeys(oids, None), *args, **kw)
+    Connection_init = Connection.__init__
+    Connection.__init__ = lambda self, db, *args, **kw: \
+        Connection_init(self, _DB(db, self), *args, **kw)

neo/client/app.py

@@ -835,9 +835,7 @@ class Application(object):
             # key, so that all cells with the same (smallest) key has
             # identical chance to be chosen.
             shuffle(cell_list)
-            # BBB: min(..., key=...) requires Python >= 2.5
-            cell_list.sort(key=getCellSortKey)
-            storage_conn = getConnForCell(cell_list[0])
+            storage_conn = getConnForCell(min(cell_list, key=getCellSortKey))
             storage_conn.ask(Packets.AskObjectUndoSerial(ttid,
                 snapshot_tid, undone_tid, oid_list), queue=queue)
 

neo/client/poll.py

@@ -26,7 +26,7 @@ class _ThreadedPoll(Thread):
     def __init__(self, em, **kw):
         Thread.__init__(self, **kw)
         self.em = em
-        self.setDaemon(True)
+        self.daemon = True
         self._stop = Event()
 
     def run(self):

neo/client/pool.py

@@ -151,11 +151,9 @@ class ConnectionPool(object):
     def getConnForNode(self, node):
         """Return a locked connection object to a given node
         If no connection exists, create a new one"""
-        if not node.isRunning():
-            return None
-        uuid = node.getUUID()
-        self.connection_lock_acquire()
-        try:
+        if node.isRunning():
+            uuid = node.getUUID()
+            self.connection_lock_acquire()
             try:
                 # Already connected to node
                 return self.connection_dict[uuid]
@@ -164,15 +162,12 @@ class ConnectionPool(object):
                     # must drop some unused connections
                     self._dropConnections()
                 # Create new connection to node
-                while True:
-                    conn = self._initNodeConnection(node)
-                    if conn is not None:
-                        self.connection_dict[uuid] = conn
-                        return conn
-                    else:
-                        return None
-        finally:
-            self.connection_lock_release()
+                conn = self._initNodeConnection(node)
+                if conn is not None:
+                    self.connection_dict[uuid] = conn
+                return conn
+            finally:
+                self.connection_lock_release()
 
     @profiler_decorator
     def removeConnection(self, node):

neo/lib/__init__.py

@@ -15,7 +15,6 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
-import neo.lib.python
 import logging as logging_std
 
 FMT = ('%(asctime)s %(levelname)-9s %(name)-10s'

neo/lib/debug.py

@@ -17,7 +17,6 @@
 
 import traceback
 import signal
-import ctypes
 import imp
 import os
 import sys
@@ -41,20 +40,14 @@ ENABLED = False
 #     SIGUSR2:
 #       Triggers a pdb prompt on process' controlling TTY.
 
-libc = ctypes.cdll.LoadLibrary('libc.so.6')
-errno = ctypes.c_int.in_dll(libc, 'errno')
-
 def decorate(func):
     def decorator(sig, frame):
-        # Save errno value, to restore it after sig handler returns
-        old_errno = errno.value
         try:
             func(sig, frame)
         except:
             # Prevent exception from exiting signal handler, so mistakes in
             # "debug" module don't kill process.
             traceback.print_exc()
-        errno.value = old_errno
     return wraps(func)(decorator)
 
 @decorate

neo/lib/epoll.py

@@ -15,25 +15,17 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 
-r"""This is an epoll(4) interface available in Linux 2.6. This requires
-ctypes <http://python.net/crew/theller/ctypes/>."""
+"""This is an epoll(4) interface available in Linux 2.6."""
 
-from ctypes import cdll, Union, Structure, \
-        c_void_p, c_int, byref
-try:
-    from ctypes import c_uint32, c_uint64
-except ImportError:
-    from ctypes import c_uint, c_ulonglong
-    c_uint32 = c_uint
-    c_uint64 = c_ulonglong
+from ctypes import CDLL, get_errno, Union, Structure
+from ctypes import c_void_p, c_int, byref, c_uint32, c_uint64
 from os import close
 from errno import EINTR, EAGAIN
 
-libc = cdll.LoadLibrary('libc.so.6')
+libc = CDLL('libc.so.6', use_errno=True)
 epoll_create = libc.epoll_create
 epoll_wait = libc.epoll_wait
 epoll_ctl = libc.epoll_ctl
-errno = c_int.in_dll(libc, 'errno')
 
 EPOLLIN = 0x001
 EPOLLPRI = 0x002
@@ -69,7 +61,7 @@ class Epoll(object):
     def __init__(self):
         self.efd = epoll_create(10)
         if self.efd == -1:
-            raise OSError(errno.value, 'epoll_create failed')
+            raise OSError(get_errno(), 'epoll_create failed')
 
         self.maxevents = 1024 # XXX arbitrary
         epoll_event_array = EpollEvent * self.maxevents
@@ -85,8 +77,8 @@ class Epoll(object):
             n = epoll_wait(self.efd, byref(self.events), self.maxevents,
                            timeout)
             if n == -1:
-                e = errno.value
-                # XXX: Why 0 ? Maybe due to partial workaround in neo.lib.debug.
+                e = get_errno()
+                # XXX: Why 0 ?
                 if e in (0, EINTR, EAGAIN):
                     continue
                 else:
@@ -111,7 +103,7 @@ class Epoll(object):
         ev.data.fd = fd
         ret = epoll_ctl(self.efd, EPOLL_CTL_ADD, fd, byref(ev))
         if ret == -1:
-            raise OSError(errno.value, 'epoll_ctl failed')
+            raise OSError(get_errno(), 'epoll_ctl failed')
 
     def modify(self, fd, readable, writable):
         ev = EpollEvent()
@@ -124,13 +116,13 @@ class Epoll(object):
         ev.events = events
         ret = epoll_ctl(self.efd, EPOLL_CTL_MOD, fd, byref(ev))
         if ret == -1:
-            raise OSError(errno.value, 'epoll_ctl failed')
+            raise OSError(get_errno(), 'epoll_ctl failed')
 
     def unregister(self, fd):
         ev = EpollEvent()
         ret = epoll_ctl(self.efd, EPOLL_CTL_DEL, fd, byref(ev))
         if ret == -1:
-            raise OSError(errno.value, 'epoll_ctl failed')
+            raise OSError(get_errno(), 'epoll_ctl failed')
 
     def __del__(self):
         efd = self.efd

neo/lib/python.py

-# Copyright (C) 2011  Nexedi SA
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU General Public License
-# as published by the Free Software Foundation; either version 2
-# of the License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-
-import sys, types
-
-if sys.version_info < (2, 5):
-    import __builtin__, imp
-
-    def all(iterable):
-      """
-      Return True if bool(x) is True for all values x in the iterable.
-      """
-      for x in iterable:
-        if not x:
-          return False
-      return True
-    __builtin__.all = all
-
-    def any(iterable):
-      """
-      Return True if bool(x) is True for any x in the iterable.
-      """
-      for x in iterable:
-        if x:
-          return True
-      return False
-    __builtin__.any = any
-
-    import md5, sha
-    sys.modules['hashlib'] = hashlib = imp.new_module('hashlib')
-    hashlib.md5 = md5.new
-    hashlib.sha1 = sha.new
-
-    import struct
-
-    class Struct(object):
-
-        def __init__(self, fmt):
-            self._fmt = fmt
-            self.size = struct.calcsize(fmt)
-
-        def pack(self, *args):
-            return struct.pack(self._fmt, *args)
-
-        def unpack(self, *args):
-            return struct.unpack(self._fmt, *args)
-
-    struct.Struct = Struct
-
-    sys.modules['functools'] = functools = imp.new_module('functools')
-
-    def wraps(wrapped):
-        """Simple backport of functools.wraps from Python >= 2.5"""
-        def decorator(wrapper):
-            wrapper.__module__ = wrapped.__module__
-            wrapper.__name__ = wrapped.__name__
-            wrapper.__doc__ = wrapped.__doc__
-            wrapper.__dict__.update(wrapped.__dict__)
-            return wrapper
-        return decorator
-
-    functools.wraps = wraps

neo/scripts/neoadmin.py

+#!/usr/bin/env python
+#
 # neoadmin - run an administrator  node of NEO
 #
 # Copyright (C) 2009  Nexedi SA

neo/scripts/neoctl.py

+#!/usr/bin/env python
+#
 # neoadmin - run an administrator node of NEO
 #
 # Copyright (C) 2009  Nexedi SA

neo/scripts/neomaster.py

+#!/usr/bin/env python
+#
 # neomaster - run a master node of NEO
 #
 # Copyright (C) 2006  Nexedi SA

neo/scripts/neomigrate.py

-#! /usr/bin/env python2.4
+#!/usr/bin/env python
 #
 # neomaster - run a master node of NEO
 #

neo/scripts/neostorage.py

-#! /usr/bin/env python2.4
+#!/usr/bin/env python
 #
 # neostorage - run a storage node of NEO
 #

neo/scripts/runner.py

-#! /usr/bin/env python
+#!/usr/bin/env python
 #
 # Copyright (C) 2009  Nexedi SA
 #

neo/storage/database/btree.py

@@ -263,8 +263,7 @@ class BTreeDatabaseManager(DatabaseManager):
         uncommitted_data = self._uncommitted_data
         def deleter_callback(tree, key_list):
             for tid in key_list:
-                checksum = tree[tid][0] # BBB: recent ZODB provides pop()
-                del tree[tid]           #
+                checksum = tree.pop(tid)[0]
                 if checksum:
                     index = data[checksum][2]
                     index.remove((oid, tid))
@@ -277,7 +276,7 @@ class BTreeDatabaseManager(DatabaseManager):
         checksum_list = []
         checksum_set = set()
         for oid in key_list:
-            tserial = tree[oid]; del tree[oid] # BBB: recent ZODB provides pop()
+            tserial = tree.pop(oid)
             for tid, (checksum, _) in tserial.items():
                 if checksum:
                     index = data[checksum][2]

neo/storage/database/mysqldb.py

@@ -557,9 +557,7 @@ class MySQLDatabaseManager(DatabaseManager):
                 oid = u64(oid)
                 sql = " FROM obj WHERE partition=%d AND oid=%d AND serial=%d" \
                    % (getPartition(oid), oid, tid)
-                hash_list = q("SELECT hash" + sql)
-                if hash_list: # BBB: Python < 2.6
-                    checksum_set.update(*hash_list)
+                checksum_set.update(*q("SELECT hash" + sql))
                 q("DELETE" + sql)
             checksum_set.discard(None)
             self._pruneData(checksum_set)

neo/tests/cluster.py

@@ -81,13 +81,10 @@ class ClusterDict(dict):
         self._r, self._w = os.pipe()
         # shm_open(3) would be better but Python doesn't provide it.
         # See also http://nikitathespider.com/python/shm/
-        f = tempfile.TemporaryFile()
-        try:
+        with tempfile.TemporaryFile() as f:
             f.write(dumps(self.copy(), -1))
             f.flush()
             self._shared = mmap.mmap(f.fileno(), f.tell())
-        finally:
-            f.close()
         self.release()
 
     def __del__(self):

neo/tests/functional/__init__.py

@@ -634,7 +634,7 @@ class NEOFunctionalTest(NeoTestBase):
             except:
                 exc_list.append(sys.exc_info())
         thread = threading.Thread(None, excWrapper, args=args, kwargs=kwargs)
-        thread.setDaemon(True)
+        thread.daemon = True
         thread.start()
         thread.join(timeout)
         self.assertFalse(thread.isAlive(), 'Run timeout')

neo/tests/threaded/__init__.py

@@ -107,12 +107,9 @@ class Serialized(object):
 
     @classmethod
     def background(cls):
-        cls._lock_lock.acquire()
-        try:
+        with cls._lock_lock:
             if cls._lock_list:
                 cls._lock_list.popleft().release()
-        finally:
-            cls._lock_lock.release()
 
 class SerializedEventManager(EventManager):
 
@@ -186,7 +183,7 @@ class ServerNode(Node):
     def __init__(self, cluster, address, **kw):
         self._init_args = (cluster, address), dict(kw)
         threading.Thread.__init__(self)
-        self.setDaemon(True)
+        self.daemon = True
         h, p = address
         self.node_type = getattr(NodeTypes,
             SERVER_TYPE[VIRTUAL_IP.index(h)].upper())
@@ -394,8 +391,7 @@ class ConnectionFilter(object):
         return queue
 
     def __call__(self, revert=1):
-        self.lock.acquire()
-        try:
+        with self.lock:
             self.filter_dict.clear()
             self._retry()
             if revert:
@@ -403,8 +399,6 @@ class ConnectionFilter(object):
                     assert not queue
                     del conn._addPacket
                 del self.conn_list[:]
-        finally:
-            self.lock.release()
 
     def _retry(self):
         for conn, queue in self.conn_list:
@@ -423,20 +417,14 @@ class ConnectionFilter(object):
         self(0)
 
     def add(self, filter, *patches):
-        self.lock.acquire()
-        try:
+        with self.lock:
             self.filter_dict[filter] = patches
-        finally:
-            self.lock.release()
 
     def remove(self, *filters):
-        self.lock.acquire()
-        try:
+        with self.lock:
             for filter in filters:
                 del self.filter_dict[filter]
             self._retry()
-        finally:
-            self.lock.release()
 
     def __contains__(self, filter):
         return filter in self.filter_dict
@@ -665,7 +653,7 @@ class NEOThreadedTest(NeoTestBase):
         def __init__(self, func, *args, **kw):
             threading.Thread.__init__(self)
             self.__target = func, args, kw
-            self.setDaemon(True)
+            self.daemon = True
             self.start()
 
         def run(self):

setup.py

@@ -9,17 +9,18 @@ Framework :: ZODB
 Intended Audience :: Developers
 License :: OSI Approved :: GNU General Public License (GPL)
 Operating System :: POSIX :: Linux
-Programming Language :: Python
+Programming Language :: Python :: 2.6
+Programming Language :: Python :: 2.7
 Topic :: Database
 Topic :: Software Development :: Libraries :: Python Modules
 """
 
 if not os.path.exists('mock.py'):
-    import cStringIO, md5, urllib, zipfile
+    import cStringIO, hashlib, urllib, zipfile
     mock_py = zipfile.ZipFile(cStringIO.StringIO(urllib.urlopen(
         'http://downloads.sf.net/sourceforge/python-mock/pythonmock-0.1.0.zip'
         ).read())).read('mock.py')
-    if md5.md5(mock_py).hexdigest() != '79f42f390678e5195d9ce4ae43bd18ec':
+    if hashlib.md5(mock_py).hexdigest() != '79f42f390678e5195d9ce4ae43bd18ec':
         raise EnvironmentError("MD5 checksum mismatch downloading 'mock.py'")
     open('mock.py', 'w').write(mock_py)
 
@@ -36,7 +37,7 @@ extras_require['tests'] = ['zope.testing', 'psutil',
 
 setup(
     name = 'neoppod',
-    version = '0.10',
+    version = '1.0-dev',
     description = __doc__.strip(),
     author = 'NEOPPOD',
     author_email = 'neo-dev@erp5.org',
@@ -62,8 +63,6 @@ setup(
             'stat_zodb=neo.tests.stat_zodb:main',
         ],
     },
-    # Raah!!! I wish I could write something like:
-    #  install_requires = ['python>=2.5|ctypes'],
     extras_require = extras_require,
     package_data = {
         'neo.client': [