frond 0.0.4

Asynchronous Fan Out/In for Pyramid.

Run an asyncio loop in it's own thread for scheduling awaitables from within Pyramid views.

This adds request property loop and request methods wait_for, wait_results, and await.

The loop property returns the loop running in it's own thread. Use this loop with asyncio.run_coroutine_threadsafe to run awaitables. For example:

    import asyncio
    from concurrent import futures

    def my_view(request):
        running = asyncio.run_coroutine_threadsafe(my_coroutine(), request.loop)
        done, not_done = futures.wait([running, ...], timeout=3)
        results = [ftr.result() for ftr in done]
        return {'done': results}

The wait_for method reduces the above boiler plate by waiting for the futures. Example usage

    def my_view(request):
        done, not_done = request.wait_for([my_coroutine(), ...])
        results = [ftr.result() for ftr in done]
        return {'done': results}

The wait_results method reduces the boiler plate further by returning the results after waiting. This is useful if you don't care about unfinished tasks. Example usage:

    def my_view(request):
        results = request.wait_results([my_coroutine(), ...])
        return {'done': results}

The await method runs a single awaitable and blocks until it's results are complete or timeout passes. Example usage:

    from frond import AwaitableTimeout

    def my_view(request):
        try:
            result = request.await(my_coroutine(), timeout=3)
        except AwaitableTimeout:
            result = 'not completed'
        return {'result': result}

Use as any other Pyramid plugin:

    config.include('frond')

Currently this package only supports Python 3 (and only tested on Python >=3.6).