Add back tornado stubs for Python 2 only (#4412)

Tornado ships with inline annotations, but it no longer is Python 2
compatible. I think that it makes sense to keep the legacy stubs for
Python 2 compatibility, at least for a while longer.

This restores stubs removed in #4321, but moves them to
`third_party/2`.

Author: JukkaL

third_party/2/tornado/__init__.pyi

@@ -0,0 +1,43 @@
+from typing import Any
+
+futures: Any
+
+class ReturnValueIgnoredError(Exception): ...
+
+class _TracebackLogger:
+    exc_info: Any
+    formatted_tb: Any
+    def __init__(self, exc_info) -> None: ...
+    def activate(self): ...
+    def clear(self): ...
+    def __del__(self): ...
+
+class Future:
+    def __init__(self) -> None: ...
+    def cancel(self): ...
+    def cancelled(self): ...
+    def running(self): ...
+    def done(self): ...
+    def result(self, timeout=...): ...
+    def exception(self, timeout=...): ...
+    def add_done_callback(self, fn): ...
+    def set_result(self, result): ...
+    def set_exception(self, exception): ...
+    def exc_info(self): ...
+    def set_exc_info(self, exc_info): ...
+    def __del__(self): ...
+
+TracebackFuture: Any
+FUTURES: Any
+
+def is_future(x): ...
+
+class DummyExecutor:
+    def submit(self, fn, *args, **kwargs): ...
+    def shutdown(self, wait=...): ...
+
+dummy_executor: Any
+
+def run_on_executor(*args, **kwargs): ...
+def return_future(f): ...
+def chain_future(a, b): ...

third_party/2/tornado/concurrent.pyi

@@ -0,0 +1,110 @@
+from typing import Any, Dict, NamedTuple, Tuple
+
+singledispatch: Any
+
+class KeyReuseError(Exception): ...
+class UnknownKeyError(Exception): ...
+class LeakedCallbackError(Exception): ...
+class BadYieldError(Exception): ...
+class ReturnValueIgnoredError(Exception): ...
+class TimeoutError(Exception): ...
+
+def engine(func): ...
+def coroutine(func, replace_callback=...): ...
+
+class Return(Exception):
+    value: Any
+    def __init__(self, value=...) -> None: ...
+
+class WaitIterator:
+    current_index: Any
+    def __init__(self, *args, **kwargs) -> None: ...
+    def done(self): ...
+    def next(self): ...
+
+class YieldPoint:
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+class Callback(YieldPoint):
+    key: Any
+    def __init__(self, key) -> None: ...
+    runner: Any
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+class Wait(YieldPoint):
+    key: Any
+    def __init__(self, key) -> None: ...
+    runner: Any
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+class WaitAll(YieldPoint):
+    keys: Any
+    def __init__(self, keys) -> None: ...
+    runner: Any
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+def Task(func, *args, **kwargs): ...
+
+class YieldFuture(YieldPoint):
+    future: Any
+    io_loop: Any
+    def __init__(self, future, io_loop=...) -> None: ...
+    runner: Any
+    key: Any
+    result_fn: Any
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+class Multi(YieldPoint):
+    keys: Any
+    children: Any
+    unfinished_children: Any
+    quiet_exceptions: Any
+    def __init__(self, children, quiet_exceptions=...) -> None: ...
+    def start(self, runner): ...
+    def is_ready(self): ...
+    def get_result(self): ...
+
+def multi_future(children, quiet_exceptions=...): ...
+def maybe_future(x): ...
+def with_timeout(timeout, future, io_loop=..., quiet_exceptions=...): ...
+def sleep(duration): ...
+
+moment: Any
+
+class Runner:
+    gen: Any
+    result_future: Any
+    future: Any
+    yield_point: Any
+    pending_callbacks: Any
+    results: Any
+    running: Any
+    finished: Any
+    had_exception: Any
+    io_loop: Any
+    stack_context_deactivate: Any
+    def __init__(self, gen, result_future, first_yielded) -> None: ...
+    def register_callback(self, key): ...
+    def is_ready(self, key): ...
+    def set_result(self, key, result): ...
+    def pop_result(self, key): ...
+    def run(self): ...
+    def handle_yield(self, yielded): ...
+    def result_callback(self, key): ...
+    def handle_exception(self, typ, value, tb): ...
+
+class Arguments(NamedTuple):
+    args: Tuple[str, ...]
+    kwargs: Dict[str, Any]
+
+def convert_yielded(yielded): ...

third_party/2/tornado/gen.pyi

@@ -0,0 +1,127 @@
+from typing import Any
+
+from tornado.util import Configurable
+
+class HTTPClient:
+    def __init__(self, async_client_class=..., **kwargs) -> None: ...
+    def __del__(self): ...
+    def close(self): ...
+    def fetch(self, request, **kwargs): ...
+
+class AsyncHTTPClient(Configurable):
+    @classmethod
+    def configurable_base(cls): ...
+    @classmethod
+    def configurable_default(cls): ...
+    def __new__(cls, io_loop=..., force_instance=..., **kwargs): ...
+    io_loop: Any
+    defaults: Any
+    def initialize(self, io_loop, defaults=...): ...
+    def close(self): ...
+    def fetch(self, request, callback=..., raise_error=..., **kwargs): ...
+    def fetch_impl(self, request, callback): ...
+    @classmethod
+    def configure(cls, impl, **kwargs): ...
+
+class HTTPRequest:
+    proxy_host: Any
+    proxy_port: Any
+    proxy_username: Any
+    proxy_password: Any
+    url: Any
+    method: Any
+    body_producer: Any
+    auth_username: Any
+    auth_password: Any
+    auth_mode: Any
+    connect_timeout: Any
+    request_timeout: Any
+    follow_redirects: Any
+    max_redirects: Any
+    user_agent: Any
+    decompress_response: Any
+    network_interface: Any
+    streaming_callback: Any
+    header_callback: Any
+    prepare_curl_callback: Any
+    allow_nonstandard_methods: Any
+    validate_cert: Any
+    ca_certs: Any
+    allow_ipv6: Any
+    client_key: Any
+    client_cert: Any
+    ssl_options: Any
+    expect_100_continue: Any
+    start_time: Any
+    def __init__(
+        self,
+        url,
+        method=...,
+        headers=...,
+        body=...,
+        auth_username=...,
+        auth_password=...,
+        auth_mode=...,
+        connect_timeout=...,
+        request_timeout=...,
+        if_modified_since=...,
+        follow_redirects=...,
+        max_redirects=...,
+        user_agent=...,
+        use_gzip=...,
+        network_interface=...,
+        streaming_callback=...,
+        header_callback=...,
+        prepare_curl_callback=...,
+        proxy_host=...,
+        proxy_port=...,
+        proxy_username=...,
+        proxy_password=...,
+        allow_nonstandard_methods=...,
+        validate_cert=...,
+        ca_certs=...,
+        allow_ipv6=...,
+        client_key=...,
+        client_cert=...,
+        body_producer=...,
+        expect_100_continue=...,
+        decompress_response=...,
+        ssl_options=...,
+    ) -> None: ...
+    @property
+    def headers(self): ...
+    @headers.setter
+    def headers(self, value): ...
+    @property
+    def body(self): ...
+    @body.setter
+    def body(self, value): ...
+
+class HTTPResponse:
+    request: Any
+    code: Any
+    reason: Any
+    headers: Any
+    buffer: Any
+    effective_url: Any
+    error: Any
+    request_time: Any
+    time_info: Any
+    def __init__(
+        self, request, code, headers=..., buffer=..., effective_url=..., error=..., request_time=..., time_info=..., reason=...
+    ) -> None: ...
+    body: bytes
+    def rethrow(self): ...
+
+class HTTPError(Exception):
+    code: Any
+    response: Any
+    def __init__(self, code, message=..., response=...) -> None: ...
+
+class _RequestProxy:
+    request: Any
+    defaults: Any
+    def __init__(self, request, defaults) -> None: ...
+    def __getattr__(self, name): ...
+
+def main(): ...

third_party/2/tornado/httpclient.pyi

@@ -0,0 +1,57 @@
+from typing import Any
+
+from tornado import httputil
+from tornado.tcpserver import TCPServer
+from tornado.util import Configurable
+
+class HTTPServer(TCPServer, Configurable, httputil.HTTPServerConnectionDelegate):
+    def __init__(self, *args, **kwargs) -> None: ...
+    request_callback: Any
+    no_keep_alive: Any
+    xheaders: Any
+    protocol: Any
+    conn_params: Any
+    def initialize(
+        self,
+        request_callback,
+        no_keep_alive=...,
+        io_loop=...,
+        xheaders=...,
+        ssl_options=...,
+        protocol=...,
+        decompress_request=...,
+        chunk_size=...,
+        max_header_size=...,
+        idle_connection_timeout=...,
+        body_timeout=...,
+        max_body_size=...,
+        max_buffer_size=...,
+    ): ...
+    @classmethod
+    def configurable_base(cls): ...
+    @classmethod
+    def configurable_default(cls): ...
+    def close_all_connections(self): ...
+    def handle_stream(self, stream, address): ...
+    def start_request(self, server_conn, request_conn): ...
+    def on_close(self, server_conn): ...
+
+class _HTTPRequestContext:
+    address: Any
+    protocol: Any
+    address_family: Any
+    remote_ip: Any
+    def __init__(self, stream, address, protocol) -> None: ...
+
+class _ServerRequestAdapter(httputil.HTTPMessageDelegate):
+    server: Any
+    connection: Any
+    request: Any
+    delegate: Any
+    def __init__(self, server, server_conn, request_conn) -> None: ...
+    def headers_received(self, start_line, headers): ...
+    def data_received(self, chunk): ...
+    def finish(self): ...
+    def on_connection_close(self): ...
+
+HTTPRequest: Any