"""
Payload implementation 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 types
import warnings
from typing import Any, Awaitable, Callable, Dict, Tuple
from .abc import AbstractStreamWriter
from .payload import Payload, payload_type
__all__ = ("streamer",)
class _stream_wrapper:
def __init__(
self,
coro: Callable[..., Awaitable[None]],
args: Tuple[Any, ...],
kwargs: Dict[str, Any],
) -> None:
self.coro = types.coroutine(coro)
self.args = args
self.kwargs = kwargs
async def __call__(self, writer: AbstractStreamWriter) -> None:
await self.coro(writer, *self.args, **self.kwargs)
class streamer:
def __init__(self, coro: Callable[..., Awaitable[None]]) -> None:
warnings.warn(
"@streamer is deprecated, use async generators instead",
DeprecationWarning,
stacklevel=2,
)
self.coro = coro
def __call__(self, *args: Any, **kwargs: Any) -> _stream_wrapper:
return _stream_wrapper(self.coro, args, kwargs)
@payload_type(_stream_wrapper)
class StreamWrapperPayload(Payload):
async def write(self, writer: AbstractStreamWriter) -> None:
await self._value(writer)
@payload_type(streamer)
class StreamPayload(StreamWrapperPayload):
def __init__(self, value: Any, *args: Any, **kwargs: Any) -> None:
super().__init__(value(), *args, **kwargs)
async def write(self, writer: AbstractStreamWriter) -> None:
await self._value(writer)
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