Merge pull request #23 from syrusakbary/async-dataloader

Re-Implementation + Provisional dataloader

.coveragerc

@@ -1,2 +1,2 @@
 [run]
-omit = promise/compat.py,promise/iterate_promise.py
+omit = promise/compat.py,promise/iterate_promise.py,promise/utils.py

.travis.yml

@@ -5,6 +5,21 @@ python:
 - 3.3
 - 3.4
 - 3.5
+- pypy
+before_install:
+- |
+  if [ "$TRAVIS_PYTHON_VERSION" = "pypy" ]; then
+    export PYENV_ROOT="$HOME/.pyenv"
+    if [ -f "$PYENV_ROOT/bin/pyenv" ]; then
+      cd "$PYENV_ROOT" && git pull
+    else
+      rm -rf "$PYENV_ROOT" && git clone --depth 1 https://github.com/yyuu/pyenv.git "$PYENV_ROOT"
+    fi
+    export PYPY_VERSION="4.0.1"
+    "$PYENV_ROOT/bin/pyenv" install "pypy-$PYPY_VERSION"
+    virtualenv --python="$PYENV_ROOT/versions/pypy-$PYPY_VERSION/bin/python" "$HOME/virtualenvs/pypy-$PYPY_VERSION"
+    source "$HOME/virtualenvs/pypy-$PYPY_VERSION/bin/activate"
+  fi
 cache: pip
 install:
 - pip install -e .[test]
@@ -20,5 +35,5 @@ matrix:
     script: flake8
   - python: '3.5'
     script: |
-      pip install mypy-lang
-      mypy promise/  --check-untyped-defs
+      pip install mypy
+      mypy promise/  --check-untyped-defs  --ignore-missing-imports

README.md

@@ -56,7 +56,7 @@ This creates and returns a new promise.  `resolver` must be a function.  The `re
 
 Converts values and foreign promises into Promises/A+ promises.  If you pass it a value then it returns a Promise for that value.  If you pass it something that is close to a promise (such as a jQuery attempt at a promise) it returns a Promise that takes on the state of `value` (rejected or fulfilled).
 
-#### Promise.rejected(value)
+#### Promise.reject(value)
 
 Returns a rejected promise with the given value.
 
@@ -71,10 +71,11 @@ p = Promise.all([Promise.resolve('a'), 'b', Promise.resolve('c')]) \
 assert p.get() is True
 ```
 
-#### Promise.promisify(obj)
+#### Promise.cast(obj)
 
 This function wraps the `obj` act as a `Promise` if possible.
 Python `Future`s are supported, with a callback to `promise.done` when resolved.
+Have the same effects as `Promise.resolve(obj)`.
 
 
 #### Promise.for_dict(d)
@@ -85,41 +86,40 @@ an dictionary of promises for values into a promise for a dictionary
 of values.
 
 
+#### Promise.is_thenable(obj)
+
+This function checks if the `obj` is a `Promise`, or could be `promisify`ed.
+
+
 ### Instance Methods
 
 These methods are invoked on a promise instance by calling `myPromise.methodName`
 
-### promise.then(on_fulfilled, on_rejected)
+### promise.then(did_fulfill, did_reject)
 
 This method follows the [Promises/A+ spec](http://promises-aplus.github.io/promises-spec/).  It explains things very clearly so I recommend you read it.
 
-Either `on_fulfilled` or `on_rejected` will be called and they will not be called more than once.  They will be passed a single argument and will always be called asynchronously (in the next turn of the event loop).
+Either `did_fulfill` or `did_reject` will be called and they will not be called more than once.  They will be passed a single argument and will always be called asynchronously (in the next turn of the event loop).
 
-If the promise is fulfilled then `on_fulfilled` is called.  If the promise is rejected then `on_rejected` is called.
+If the promise is fulfilled then `did_fulfill` is called.  If the promise is rejected then `did_reject` is called.
 
 The call to `.then` also returns a promise.  If the handler that is called returns a promise, the promise returned by `.then` takes on the state of that returned promise.  If the handler that is called returns a value that is not a promise, the promise returned by `.then` will be fulfilled with that value. If the handler that is called throws an exception then the promise returned by `.then` is rejected with that exception.
 
-#### promise.catch(on_rejected)
+#### promise.catch(did_reject)
 
-Sugar for `promise.then(None, on_rejected)`, to mirror `catch` in synchronous code.
+Sugar for `promise.then(None, did_reject)`, to mirror `catch` in synchronous code.
 
-#### promise.done(on_fulfilled, on_rejected)
+#### promise.done(did_fulfill, did_reject)
 
 The same semantics as `.then` except that it does not return a promise and any exceptions are re-thrown so that they can be logged (crashing the application in non-browser environments)
 
-## Other package functions
-
-### is_thenable(obj)
-
-This function checks if the `obj` is a `Promise`, or could be `promisify`ed.
-
 
 # Contributing
 
 After cloning this repo, ensure dependencies are installed by running:
 
 ```sh
-pip install .[test]
+pip install -e ".[test]"
 ```
 
 After developing, the full test suite can be evaluated by running:

README.rst

@@ -71,8 +71,8 @@ something that is close to a promise (such as a jQuery attempt at a
 promise) it returns a Promise that takes on the state of ``value``
 (rejected or fulfilled).
 
-Promise.rejected(value)
-^^^^^^^^^^^^^^^^^^^^^^^
+Promise.reject(value)
+^^^^^^^^^^^^^^^^^^^^^
 
 Returns a rejected promise with the given value.
 
@@ -90,12 +90,12 @@ replaced by their fulfilled values. e.g.
 
     assert p.get() is True
 
-Promise.promisify(obj)
-^^^^^^^^^^^^^^^^^^^^^^
+Promise.cast(obj)
+^^^^^^^^^^^^^^^^^
 
 This function wraps the ``obj`` act as a ``Promise`` if possible. Python
 ``Future``\ s are supported, with a callback to ``promise.done`` when
-resolved.
+resolved. Have the same effects as ``Promise.resolve(obj)``.
 
 Promise.for\_dict(d)
 ^^^^^^^^^^^^^^^^^^^^
@@ -105,26 +105,32 @@ into a promise for a dictionary of values. In other words, this turns an
 dictionary of promises for values into a promise for a dictionary of
 values.
 
+Promise.is\_thenable(obj)
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+This function checks if the ``obj`` is a ``Promise``, or could be
+``promisify``\ ed.
+
 Instance Methods
 ~~~~~~~~~~~~~~~~
 
 These methods are invoked on a promise instance by calling
 ``myPromise.methodName``
 
-promise.then(on\_fulfilled, on\_rejected)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+promise.then(did\_fulfill, did\_reject)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 This method follows the `Promises/A+
 spec <http://promises-aplus.github.io/promises-spec/>`__. It explains
 things very clearly so I recommend you read it.
 
-Either ``on_fulfilled`` or ``on_rejected`` will be called and they will
+Either ``did_fulfill`` or ``did_reject`` will be called and they will
 not be called more than once. They will be passed a single argument and
 will always be called asynchronously (in the next turn of the event
 loop).
 
-If the promise is fulfilled then ``on_fulfilled`` is called. If the
-promise is rejected then ``on_rejected`` is called.
+If the promise is fulfilled then ``did_fulfill`` is called. If the
+promise is rejected then ``did_reject`` is called.
 
 The call to ``.then`` also returns a promise. If the handler that is
 called returns a promise, the promise returned by ``.then`` takes on the
@@ -134,27 +140,39 @@ fulfilled with that value. If the handler that is called throws an
 exception then the promise returned by ``.then`` is rejected with that
 exception.
 
-promise.catch(on\_rejected)
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
+promise.catch(did\_reject)
+^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Sugar for ``promise.then(None, on_rejected)``, to mirror ``catch`` in
+Sugar for ``promise.then(None, did_reject)``, to mirror ``catch`` in
 synchronous code.
 
-promise.done(on\_fulfilled, on\_rejected)
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+promise.done(did\_fulfill, did\_reject)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 The same semantics as ``.then`` except that it does not return a promise
 and any exceptions are re-thrown so that they can be logged (crashing
 the application in non-browser environments)
 
-Other package functions
------------------------
+Contributing
+============
 
-is\_thenable(obj)
-~~~~~~~~~~~~~~~~~
+After cloning this repo, ensure dependencies are installed by running:
 
-This function checks if the ``obj`` is a ``Promise``, or could be
-``promisify``\ ed.
+.. code:: sh
+
+    pip install -e ".[test]"
+
+After developing, the full test suite can be evaluated by running:
+
+.. code:: sh
+
+    py.test tests --cov=promise --benchmark-skip # Use -v -s for verbose mode
+
+You can also run the benchmarks with:
+
+.. code:: sh
+
+    py.test tests --benchmark-only
 
 Notes
 =====

promise/__init__.py

@@ -1,3 +1,20 @@
-from .promise import Promise, promise_for_dict, promisify, is_thenable
+from .pyutils.version import get_version
 
-__all__ = ['Promise', 'promise_for_dict', 'promisify', 'is_thenable']
+
+try:
+    # This variable is injected in the __builtins__ by the build
+    # process. It used to enable importing subpackages when
+    # the required packages are not installed
+    __SETUP__  # type: ignore
+except NameError:
+    __SETUP__ = False
+
+
+VERSION = (2, 0, 0, 'alpha', 0)
+
+__version__ = get_version(VERSION)
+
+if not __SETUP__:
+    from .promise import Promise, promise_for_dict, promisify, is_thenable, async_instance
+
+    __all__ = ['Promise', 'promise_for_dict', 'promisify', 'is_thenable', 'async_instance']

promise/async_.py

@@ -0,0 +1,126 @@
+# from threading import Timer, Thread
+
+from .compat import Queue
+# from .context import Context
+
+# Based on https://github.com/petkaantonov/bluebird/blob/master/src/async.js
+
+
+class Scheduler(object):
+
+    def call(self, fn):
+        # thread = Thread(target=fn)
+        # thread = Timer(0.01, fn)
+        # fn = thread.start
+        try:
+            # c = Context.peek_context()
+            # if not c:
+            fn()
+            # else:
+            #     c.on_exit(fn)
+        except:
+            pass
+        # thread = Thread(target=fn)
+        # thread = Timer(0.001, fn)
+        # thread.start()
+
+
+def get_default_scheduler():
+    return Scheduler()
+
+
+# https://docs.python.org/2/library/queue.html#Queue.Queue
+LATE_QUEUE_CAPACITY = 0  # The queue size is infinite
+NORMAL_QUEUE_CAPACITY = 0  # The queue size is infinite
+
+
+class Async(object):
+
+    def __init__(self, schedule=None):
+        self.is_tick_used = False
+        self.late_queue = Queue(LATE_QUEUE_CAPACITY)
+        self.normal_queue = Queue(NORMAL_QUEUE_CAPACITY)
+        self.have_drained_queues = False
+        self.trampoline_enabled = True
+        self.schedule = schedule or get_default_scheduler()
+
+    def enable_trampoline(self):
+        self.trampoline_enabled = True
+
+    def disable_trampoline(self):
+        self.trampoline_enabled = False
+
+    def have_items_queued(self):
+        return self.is_tick_used or self.have_drained_queues
+
+    def _async_invoke_later(self, fn, context):
+        self.late_queue.put(fn)
+        self.queue_tick(context)
+
+    def _async_invoke(self, fn, context):
+        self.normal_queue.put(fn)
+        self.queue_tick(context)
+
+    def _async_settle_promise(self, promise):
+        self.normal_queue.put(promise)
+        self.queue_tick(context=promise._trace)
+
+    def invoke_later(self, fn, context):
+        if self.trampoline_enabled:
+            self._async_invoke_later(fn, context)
+        else:
+            self.schedule.call_later(0.1, fn)
+
+    def invoke(self, fn, context):
+        if self.trampoline_enabled:
+            self._async_invoke(fn, context)
+        else:
+            self.schedule.call(
+                fn
+            )
+
+    def settle_promises(self, promise):
+        if self.trampoline_enabled:
+            self._async_settle_promise(promise)
+        else:
+            self.schedule.call(
+                promise._settle_promises
+            )
+
+    def throw_later(self, reason):
+        def fn():
+            raise reason
+
+        self.schedule.call(fn)
+
+    fatal_error = throw_later
+
+    def drain_queue(self, queue):
+        from .promise import Promise
+        while not queue.empty():
+            fn = queue.get()
+            if (isinstance(fn, Promise)):
+                fn._settle_promises()
+                continue
+            fn()
+
+    def drain_queues(self):
+        assert self.is_tick_used
+        self.drain_queue(self.normal_queue)
+        self.reset()
+        self.have_drained_queues = True
+        self.drain_queue(self.late_queue)
+
+    def queue_context_tick(self):
+        if not self.is_tick_used:
+            self.is_tick_used = True
+            self.schedule.call(self.drain_queues)
+
+    def queue_tick(self, context):
+        if not context:
+            self.queue_context_tick()
+        else:
+            context.on_exit(self.queue_context_tick)
+
+    def reset(self):
+        self.is_tick_used = False

promise/compat.py

@@ -3,6 +3,7 @@
 except ImportError:
 
     class Future:  # type: ignore
+
         def __init__(self):
             raise Exception("You need asyncio for using Futures")
 
@@ -18,6 +19,10 @@ def ensure_future():  # type: ignore
     def iscoroutine(obj):  # type: ignore
         return False
 
+try:
+    from Queue import Queue  # type: ignore # flake8: noqa
+except ImportError:
+    from queue import Queue  # type: ignore # flake8: noqa
 
 try:
     from .iterate_promise import iterate_promise