1 files changed, 128 insertions, 0 deletions
diff --git a/python/gevent/_fileobjectcommon.py b/python/gevent/_fileobjectcommon.py
new file mode 100644
index 0000000..435f0d8
--- /dev/null
+++ b/python/gevent/_fileobjectcommon.py
@@ -0,0 +1,128 @@
+
+try:
+    from errno import EBADF
+except ImportError:
+    EBADF = 9
+
+from io import TextIOWrapper
+
+class cancel_wait_ex(IOError):
+
+    def __init__(self):
+        super(cancel_wait_ex, self).__init__(
+            EBADF, 'File descriptor was closed in another greenlet')
+
+
+class FileObjectClosed(IOError):
+
+    def __init__(self):
+        super(FileObjectClosed, self).__init__(
+            EBADF, 'Bad file descriptor (FileObject was closed)')
+
+class FileObjectBase(object):
+    """
+    Internal base class to ensure a level of consistency
+    between FileObjectPosix and FileObjectThread
+    """
+
+    # List of methods we delegate to the wrapping IO object, if they
+    # implement them and we do not.
+    _delegate_methods = (
+        # General methods
+        'flush',
+        'fileno',
+        'writable',
+        'readable',
+        'seek',
+        'seekable',
+        'tell',
+
+        # Read
+        'read',
+        'readline',
+        'readlines',
+        'read1',
+
+        # Write
+        'write',
+        'writelines',
+        'truncate',
+    )
+
+
+    # Whether we are translating universal newlines or not.
+    _translate = False
+
+    def __init__(self, io, closefd):
+        """
+        :param io: An io.IOBase-like object.
+        """
+        self._io = io
+        # We don't actually use this property ourself, but we save it (and
+        # pass it along) for compatibility.
+        self._close = closefd
+
+        if self._translate:
+            # This automatically handles delegation.
+            self.translate_newlines(None)
+        else:
+            self._do_delegate_methods()
+
+
+    io = property(lambda s: s._io,
+                  # Historically we either hand-wrote all the delegation methods
+                  # to use self.io, or we simply used __getattr__ to look them up at
+                  # runtime. This meant people could change the io attribute on the fly
+                  # and it would mostly work (subprocess.py used to do that). We don't recommend
+                  # that, but we still support it.
+                  lambda s, nv: setattr(s, '_io', nv) or s._do_delegate_methods())
+
+    def _do_delegate_methods(self):
+        for meth_name in self._delegate_methods:
+            meth = getattr(self._io, meth_name, None)
+            implemented_by_class = hasattr(type(self), meth_name)
+            if meth and not implemented_by_class:
+                setattr(self, meth_name, self._wrap_method(meth))
+            elif hasattr(self, meth_name) and not implemented_by_class:
+                delattr(self, meth_name)
+
+    def _wrap_method(self, method):
+        """
+        Wrap a method we're copying into our dictionary from the underlying
+        io object to do something special or different, if necessary.
+        """
+        return method
+
+    def translate_newlines(self, mode, *text_args, **text_kwargs):
+        wrapper = TextIOWrapper(self._io, *text_args, **text_kwargs)
+        if mode:
+            wrapper.mode = mode
+        self.io = wrapper
+        self._translate = True
+
+    @property
+    def closed(self):
+        """True if the file is closed"""
+        return self._io is None
+
+    def close(self):
+        if self._io is None:
+            return
+
+        io = self._io
+        self._io = None
+        self._do_close(io, self._close)
+
+    def _do_close(self, fobj, closefd):
+        raise NotImplementedError()
+
+    def __getattr__(self, name):
+        if self._io is None:
+            raise FileObjectClosed()
+        return getattr(self._io, name)
+
+    def __repr__(self):
+        return '<%s _fobj=%r%s>' % (self.__class__.__name__, self.io, self._extra_repr())
+
+    def _extra_repr(self):
+        return ''