[Python-checkins] cpython: Issue #19842: Refactor BaseSelector to make it an actual usable ABC.
charles-francois.natali
python-checkins at python.org
Sun Dec 1 11:05:00 CET 2013
http://hg.python.org/cpython/rev/f48f302f54aa
changeset: 87677:f48f302f54aa
user: Charles-François Natali <cf.natali at gmail.com>
date: Sun Dec 01 11:04:17 2013 +0100
summary:
Issue #19842: Refactor BaseSelector to make it an actual usable ABC.
files:
Lib/asyncio/test_utils.py | 14 +++
Lib/selectors.py | 112 +++++++++++++++---------
Lib/test/test_telnetlib.py | 7 +-
3 files changed, 86 insertions(+), 47 deletions(-)
diff --git a/Lib/asyncio/test_utils.py b/Lib/asyncio/test_utils.py
--- a/Lib/asyncio/test_utils.py
+++ b/Lib/asyncio/test_utils.py
@@ -142,9 +142,23 @@
class TestSelector(selectors.BaseSelector):
+ def __init__(self):
+ self.keys = {}
+
+ def register(self, fileobj, events, data=None):
+ key = selectors.SelectorKey(fileobj, 0, events, data)
+ self.keys[fileobj] = key
+ return key
+
+ def unregister(self, fileobj):
+ return self.keys.pop(fileobj)
+
def select(self, timeout):
return []
+ def get_map(self):
+ return self.keys
+
class TestLoop(base_events.BaseEventLoop):
"""Loop for unittests.
diff --git a/Lib/selectors.py b/Lib/selectors.py
--- a/Lib/selectors.py
+++ b/Lib/selectors.py
@@ -64,7 +64,7 @@
class BaseSelector(metaclass=ABCMeta):
- """Base selector class.
+ """Selector abstract base class.
A selector supports registering file objects to be monitored for specific
I/O events.
@@ -78,12 +78,7 @@
performant implementation on the current platform.
"""
- def __init__(self):
- # this maps file descriptors to keys
- self._fd_to_key = {}
- # read-only mapping returned by get_map()
- self._map = _SelectorMapping(self)
-
+ @abstractmethod
def register(self, fileobj, events, data=None):
"""Register a file object.
@@ -95,18 +90,9 @@
Returns:
SelectorKey instance
"""
- if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)):
- raise ValueError("Invalid events: {!r}".format(events))
+ raise NotImplementedError
- key = SelectorKey(fileobj, _fileobj_to_fd(fileobj), events, data)
-
- if key.fd in self._fd_to_key:
- raise KeyError("{!r} (FD {}) is already "
- "registered".format(fileobj, key.fd))
-
- self._fd_to_key[key.fd] = key
- return key
-
+ @abstractmethod
def unregister(self, fileobj):
"""Unregister a file object.
@@ -116,11 +102,7 @@
Returns:
SelectorKey instance
"""
- try:
- key = self._fd_to_key.pop(_fileobj_to_fd(fileobj))
- except KeyError:
- raise KeyError("{!r} is not registered".format(fileobj)) from None
- return key
+ raise NotImplementedError
def modify(self, fileobj, events, data=None):
"""Change a registered file object monitored events or attached data.
@@ -133,19 +115,8 @@
Returns:
SelectorKey instance
"""
- # TODO: Subclasses can probably optimize this even further.
- try:
- key = self._fd_to_key[_fileobj_to_fd(fileobj)]
- except KeyError:
- raise KeyError("{!r} is not registered".format(fileobj)) from None
- if events != key.events:
- self.unregister(fileobj)
- key = self.register(fileobj, events, data)
- elif data != key.data:
- # Use a shortcut to update the data.
- key = key._replace(data=data)
- self._fd_to_key[key.fd] = key
- return key
+ self.unregister(fileobj)
+ return self.register(fileobj, events, data)
@abstractmethod
def select(self, timeout=None):
@@ -164,14 +135,14 @@
list of (key, events) for ready file objects
`events` is a bitwise mask of EVENT_READ|EVENT_WRITE
"""
- raise NotImplementedError()
+ raise NotImplementedError
def close(self):
"""Close the selector.
This must be called to make sure that any underlying resource is freed.
"""
- self._fd_to_key.clear()
+ pass
def get_key(self, fileobj):
"""Return the key associated to a registered file object.
@@ -179,14 +150,16 @@
Returns:
SelectorKey for this file object
"""
+ mapping = self.get_map()
try:
- return self._fd_to_key[_fileobj_to_fd(fileobj)]
+ return mapping[fileobj]
except KeyError:
raise KeyError("{!r} is not registered".format(fileobj)) from None
+ @abstractmethod
def get_map(self):
"""Return a mapping of file objects to selector keys."""
- return self._map
+ raise NotImplementedError
def __enter__(self):
return self
@@ -194,6 +167,57 @@
def __exit__(self, *args):
self.close()
+
+class _BaseSelectorImpl(BaseSelector):
+ """Base selector implementation."""
+
+ def __init__(self):
+ # this maps file descriptors to keys
+ self._fd_to_key = {}
+ # read-only mapping returned by get_map()
+ self._map = _SelectorMapping(self)
+
+ def register(self, fileobj, events, data=None):
+ if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)):
+ raise ValueError("Invalid events: {!r}".format(events))
+
+ key = SelectorKey(fileobj, _fileobj_to_fd(fileobj), events, data)
+
+ if key.fd in self._fd_to_key:
+ raise KeyError("{!r} (FD {}) is already "
+ "registered".format(fileobj, key.fd))
+
+ self._fd_to_key[key.fd] = key
+ return key
+
+ def unregister(self, fileobj):
+ try:
+ key = self._fd_to_key.pop(_fileobj_to_fd(fileobj))
+ except KeyError:
+ raise KeyError("{!r} is not registered".format(fileobj)) from None
+ return key
+
+ def modify(self, fileobj, events, data=None):
+ # TODO: Subclasses can probably optimize this even further.
+ try:
+ key = self._fd_to_key[_fileobj_to_fd(fileobj)]
+ except KeyError:
+ raise KeyError("{!r} is not registered".format(fileobj)) from None
+ if events != key.events:
+ self.unregister(fileobj)
+ key = self.register(fileobj, events, data)
+ elif data != key.data:
+ # Use a shortcut to update the data.
+ key = key._replace(data=data)
+ self._fd_to_key[key.fd] = key
+ return key
+
+ def close(self):
+ self._fd_to_key.clear()
+
+ def get_map(self):
+ return self._map
+
def _key_from_fd(self, fd):
"""Return the key associated to a given file descriptor.
@@ -209,7 +233,7 @@
return None
-class SelectSelector(BaseSelector):
+class SelectSelector(_BaseSelectorImpl):
"""Select-based selector."""
def __init__(self):
@@ -262,7 +286,7 @@
if hasattr(select, 'poll'):
- class PollSelector(BaseSelector):
+ class PollSelector(_BaseSelectorImpl):
"""Poll-based selector."""
def __init__(self):
@@ -306,7 +330,7 @@
if hasattr(select, 'epoll'):
- class EpollSelector(BaseSelector):
+ class EpollSelector(_BaseSelectorImpl):
"""Epoll-based selector."""
def __init__(self):
@@ -358,7 +382,7 @@
if hasattr(select, 'kqueue'):
- class KqueueSelector(BaseSelector):
+ class KqueueSelector(_BaseSelectorImpl):
"""Kqueue-based selector."""
def __init__(self):
diff --git a/Lib/test/test_telnetlib.py b/Lib/test/test_telnetlib.py
--- a/Lib/test/test_telnetlib.py
+++ b/Lib/test/test_telnetlib.py
@@ -114,7 +114,6 @@
class MockSelector(selectors.BaseSelector):
def __init__(self):
- super().__init__()
self.keys = {}
def register(self, fileobj, events, data=None):
@@ -123,8 +122,7 @@
return key
def unregister(self, fileobj):
- key = self.keys.pop(fileobj)
- return key
+ return self.keys.pop(fileobj)
def select(self, timeout=None):
block = False
@@ -137,6 +135,9 @@
else:
return [(key, key.events) for key in self.keys.values()]
+ def get_map(self):
+ return self.keys
+
@contextlib.contextmanager
def test_socket(reads):
--
Repository URL: http://hg.python.org/cpython
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