+"""Event loop implementation that uses the `asyncio` standard module.
+
+The `asyncio` module was added to python standard library on 3.4, and it
+provides a pure python implementation of an event loop library. It is used
+as a fallback in case pyuv is not available(on python implementations other
+than CPython).
+
+Earlier python versions are supported through the `trollius` package, which
+is a backport of `asyncio` that works on Python 2.6+.
+"""
+from __future__ import absolute_import
+
+import logging
+import os
+import sys
+from collections import deque
+
+try:
+ # For python 3.4+, use the standard library module
+ import asyncio
+except (ImportError, SyntaxError):
+ # Fallback to trollius
+ import trollius as asyncio
+
+from pynvim.msgpack_rpc.event_loop.base import BaseEventLoop
+
+logger = logging.getLogger(__name__)
+debug, info, warn = (logger.debug, logger.info, logger.warning,)
+
+loop_cls = asyncio.SelectorEventLoop
+if os.name == 'nt':
+ from asyncio.windows_utils import PipeHandle
+ import msvcrt
+
+ # On windows use ProactorEventLoop which support pipes and is backed by the
+ # more powerful IOCP facility
+ # NOTE: we override in the stdio case, because it doesn't work.
+ loop_cls = asyncio.ProactorEventLoop
+
+
+class AsyncioEventLoop(BaseEventLoop, asyncio.Protocol,
+ asyncio.SubprocessProtocol):
+
+ """`BaseEventLoop` subclass that uses `asyncio` as a backend."""
+
+ def connection_made(self, transport):
+ """Used to signal `asyncio.Protocol` of a successful connection."""
+ self._transport = transport
+ self._raw_transport = transport
+ if isinstance(transport, asyncio.SubprocessTransport):
+ self._transport = transport.get_pipe_transport(0)
+
+ def connection_lost(self, exc):
+ """Used to signal `asyncio.Protocol` of a lost connection."""
+ self._on_error(exc.args[0] if exc else 'EOF')
+
+ def data_received(self, data):
+ """Used to signal `asyncio.Protocol` of incoming data."""
+ if self._on_data:
+ self._on_data(data)
+ return
+ self._queued_data.append(data)
+
+ def pipe_connection_lost(self, fd, exc):
+ """Used to signal `asyncio.SubprocessProtocol` of a lost connection."""
+ self._on_error(exc.args[0] if exc else 'EOF')
+
+ def pipe_data_received(self, fd, data):
+ """Used to signal `asyncio.SubprocessProtocol` of incoming data."""
+ if fd == 2: # stderr fd number
+ self._on_stderr(data)
+ elif self._on_data:
+ self._on_data(data)
+ else:
+ self._queued_data.append(data)
+
+ def process_exited(self):
+ """Used to signal `asyncio.SubprocessProtocol` when the child exits."""
+ self._on_error('EOF')
+
+ def _init(self):
+ self._loop = loop_cls()
+ self._queued_data = deque()
+ self._fact = lambda: self
+ self._raw_transport = None
+
+ def _connect_tcp(self, address, port):
+ coroutine = self._loop.create_connection(self._fact, address, port)
+ self._loop.run_until_complete(coroutine)
+
+ def _connect_socket(self, path):
+ if os.name == 'nt':
+ coroutine = self._loop.create_pipe_connection(self._fact, path)
+ else:
+ coroutine = self._loop.create_unix_connection(self._fact, path)
+ self._loop.run_until_complete(coroutine)
+
+ def _connect_stdio(self):
+ if os.name == 'nt':
+ pipe = PipeHandle(msvcrt.get_osfhandle(sys.stdin.fileno()))
+ else:
+ pipe = sys.stdin
+ coroutine = self._loop.connect_read_pipe(self._fact, pipe)
+ self._loop.run_until_complete(coroutine)
+ pass # replaces next logging statement
+ #debug("native stdin connection successful")
+
+ # Make sure subprocesses don't clobber stdout,
+ # send the output to stderr instead.
+ rename_stdout = os.dup(sys.stdout.fileno())
+ os.dup2(sys.stderr.fileno(), sys.stdout.fileno())
+
+ if os.name == 'nt':
+ pipe = PipeHandle(msvcrt.get_osfhandle(rename_stdout))
+ else:
+ pipe = os.fdopen(rename_stdout, 'wb')
+ coroutine = self._loop.connect_write_pipe(self._fact, pipe)
+ self._loop.run_until_complete(coroutine)
+ pass # replaces next logging statement
+ #debug("native stdout connection successful")
+
+ def _connect_child(self, argv):
+ if os.name != 'nt':
+ self._child_watcher = asyncio.get_child_watcher()
+ self._child_watcher.attach_loop(self._loop)
+ coroutine = self._loop.subprocess_exec(self._fact, *argv)
+ self._loop.run_until_complete(coroutine)
+
+ def _start_reading(self):
+ pass
+
+ def _send(self, data):
+ self._transport.write(data)
+
+ def _run(self):
+ while self._queued_data:
+ self._on_data(self._queued_data.popleft())
+ self._loop.run_forever()
+
+ def _stop(self):
+ self._loop.stop()
+
+ def _close(self):
+ if self._raw_transport is not None:
+ self._raw_transport.close()
+ self._loop.close()
+
+ def _threadsafe_call(self, fn):
+ self._loop.call_soon_threadsafe(fn)
+
+ def _setup_signals(self, signals):
+ if os.name == 'nt':
+ # add_signal_handler is not supported in win32
+ self._signals = []
+ return
+
+ self._signals = list(signals)
+ for signum in self._signals:
+ self._loop.add_signal_handler(signum, self._on_signal, signum)
+
+ def _teardown_signals(self):
+ for signum in self._signals:
+ self._loop.remove_signal_handler(signum)