""" Payload implemenation for coroutines as data provider.
As a simple case, you can upload data from file::
@aiohttp.streamer
async def file_sender(writer, file_name=None):
with open(file_name, 'rb') as f:
chunk = f.read(2**16)
while chunk:
await writer.write(chunk)
chunk = f.read(2**16)
Then you can use `file_sender` like this:
async with session.post('http://httpbin.org/post',
data=file_sender(file_name='huge_file')) as resp:
print(await resp.text())
..note:: Coroutine must accept `writer` as first argument
"""
import asyncio
from .payload import Payload, payload_type
__all__ = ('streamer',)
class _stream_wrapper:
def __init__(self, coro, args, kwargs):
self.coro = asyncio.coroutine(coro)
self.args = args
self.kwargs = kwargs
async def __call__(self, writer):
await self.coro(writer, *self.args, **self.kwargs)
class streamer:
def __init__(self, coro):
self.coro = coro
def __call__(self, *args, **kwargs):
return _stream_wrapper(self.coro, args, kwargs)
@payload_type(_stream_wrapper)
class StreamWrapperPayload(Payload):
async def write(self, writer):
await self._value(writer)
@payload_type(streamer)
class StreamPayload(StreamWrapperPayload):
def __init__(self, value, *args, **kwargs):
super().__init__(value(), *args, **kwargs)
async def write(self, writer):
await self._value(writer)