def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
python类is_future()的实例源码
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def _write_body(self, start_read):
if self.request.body is not None:
self.connection.write(self.request.body)
elif self.request.body_producer is not None:
fut = self.request.body_producer(self.connection.write)
if is_future(fut):
def on_body_written(fut):
fut.result()
self.connection.finish()
if start_read:
self._read_response()
self.io_loop.add_future(fut, on_body_written)
return
self.connection.finish()
if start_read:
self._read_response()
def convert_yielded(yielded):
"""Convert a yielded object into a `.Future`.
The default implementation accepts lists, dictionaries, and Futures.
If the `~functools.singledispatch` library is available, this function
may be extended to support additional types. For example::
@convert_yielded.register(asyncio.Future)
def _(asyncio_future):
return tornado.platform.asyncio.to_tornado_future(asyncio_future)
.. versionadded:: 4.1
"""
# Lists and dicts containing YieldPoints were handled separately
# via Multi().
if isinstance(yielded, (list, dict)):
return multi_future(yielded)
elif is_future(yielded):
return yielded
else:
raise BadYieldError("yielded unknown object %r" % (yielded,))
def _write_body(self, start_read):
if self.request.body is not None:
self.connection.write(self.request.body)
elif self.request.body_producer is not None:
fut = self.request.body_producer(self.connection.write)
if is_future(fut):
def on_body_written(fut):
fut.result()
self.connection.finish()
if start_read:
self._read_response()
self.io_loop.add_future(fut, on_body_written)
return
self.connection.finish()
if start_read:
self._read_response()
def convert_yielded(yielded):
"""Convert a yielded object into a `.Future`.
The default implementation accepts lists, dictionaries, and Futures.
If the `~functools.singledispatch` library is available, this function
may be extended to support additional types. For example::
@convert_yielded.register(asyncio.Future)
def _(asyncio_future):
return tornado.platform.asyncio.to_tornado_future(asyncio_future)
.. versionadded:: 4.1
"""
# Lists and dicts containing YieldPoints were handled separately
# via Multi().
if isinstance(yielded, (list, dict)):
return multi_future(yielded)
elif is_future(yielded):
return yielded
else:
raise BadYieldError("yielded unknown object %r" % (yielded,))
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def execute_next_for_async(self, request, types, process_object, *args, **kwargs):
midd = self._call_mapper.get(types, None)
if midd:
while 1:
method = self._get_func(request, midd[0], midd[1])
if method and callable(method):
clear = partial(self.clear_all, request)
result = method(process_object, clear, *args, **kwargs)
if is_future(result):
result = yield result
if result:
break
else:
break
def _do_all_execute_forasync(self, handler, clear, method_name, **kwargs):
for c_module in self.common_modules:
result = self._execute_module(handler, clear, c_module, getattr(c_module, method_name), **kwargs)
if is_future(result):
result = yield result
if result:
raise gen.Return(1)
for name, r_module in self.route_modules.items():
for md in r_module:
result = self._execute_module(handler, clear, md, getattr(md, method_name), name, **kwargs)
if is_future(result):
result = yield result
if result:
raise gen.Return(1)
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def maybe_future(x):
"""Converts ``x`` into a `.Future`.
If ``x`` is already a `.Future`, it is simply returned; otherwise
it is wrapped in a new `.Future`. This is suitable for use as
``result = yield gen.maybe_future(f())`` when you don't know whether
``f()`` returns a `.Future` or not.
.. deprecated:: 4.3
This function only handles ``Futures``, not other yieldable objects.
Instead of `maybe_future`, check for the non-future result types
you expect (often just ``None``), and ``yield`` anything unknown.
"""
if is_future(x):
return x
else:
fut = Future()
fut.set_result(x)
return fut
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def __init__(self, children, quiet_exceptions=()):
self.keys = None
if isinstance(children, dict):
self.keys = list(children.keys())
children = children.values()
self.children = []
for i in children:
if not isinstance(i, YieldPoint):
i = convert_yielded(i)
if is_future(i):
i = YieldFuture(i)
self.children.append(i)
assert all(isinstance(i, YieldPoint) for i in self.children)
self.unfinished_children = set(self.children)
self.quiet_exceptions = quiet_exceptions
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def __init__(self, children, quiet_exceptions=()):
self.keys = None
if isinstance(children, dict):
self.keys = list(children.keys())
children = children.values()
self.children = []
for i in children:
if not isinstance(i, YieldPoint):
i = convert_yielded(i)
if is_future(i):
i = YieldFuture(i)
self.children.append(i)
assert all(isinstance(i, YieldPoint) for i in self.children)
self.unfinished_children = set(self.children)
self.quiet_exceptions = quiet_exceptions
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def __init__(self, children, quiet_exceptions=()):
self.keys = None
if isinstance(children, dict):
self.keys = list(children.keys())
children = children.values()
self.children = []
for i in children:
if not isinstance(i, YieldPoint):
i = convert_yielded(i)
if is_future(i):
i = YieldFuture(i)
self.children.append(i)
assert all(isinstance(i, YieldPoint) for i in self.children)
self.unfinished_children = set(self.children)
self.quiet_exceptions = quiet_exceptions
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def __init__(self, children, quiet_exceptions=()):
self.keys = None
if isinstance(children, dict):
self.keys = list(children.keys())
children = children.values()
self.children = []
for i in children:
if not isinstance(i, YieldPoint):
i = convert_yielded(i)
if is_future(i):
i = YieldFuture(i)
self.children.append(i)
assert all(isinstance(i, YieldPoint) for i in self.children)
self.unfinished_children = set(self.children)
self.quiet_exceptions = quiet_exceptions
def add_future(self, future, callback):
"""Schedules a callback on the ``IOLoop`` when the given
`.Future` is finished.
The callback is invoked with one argument, the
`.Future`.
"""
assert is_future(future)
callback = stack_context.wrap(callback)
future.add_done_callback(
lambda future: self.add_callback(callback, future))
def _run_callback(self, callback):
"""Runs a callback with error handling.
For use in subclasses.
"""
try:
ret = callback()
if ret is not None and is_future(ret):
# Functions that return Futures typically swallow all
# exceptions and store them in the Future. If a Future
# makes it out to the IOLoop, ensure its exception (if any)
# gets logged too.
self.add_future(ret, lambda f: f.result())
except Exception:
self.handle_callback_exception(callback)
