Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/wsgiref/handlers.pyi

@@ -0,0 +1,93 @@
+import sys
+from abc import abstractmethod
+from types import TracebackType
+from typing import IO, Callable, Dict, List, MutableMapping, Optional, Text, Tuple, Type
+
+from .headers import Headers
+from .types import ErrorStream, InputStream, StartResponse, WSGIApplication, WSGIEnvironment
+from .util import FileWrapper
+
+_exc_info = Tuple[Optional[Type[BaseException]], Optional[BaseException], Optional[TracebackType]]
+
+def format_date_time(timestamp: Optional[float]) -> str: ...  # undocumented
+
+if sys.version_info >= (3, 2):
+    def read_environ() -> Dict[str, str]: ...
+
+class BaseHandler:
+    wsgi_version: Tuple[int, int]  # undocumented
+    wsgi_multithread: bool
+    wsgi_multiprocess: bool
+    wsgi_run_once: bool
+
+    origin_server: bool
+    http_version: str
+    server_software: Optional[str]
+
+    os_environ: MutableMapping[str, str]
+
+    wsgi_file_wrapper: Optional[Type[FileWrapper]]
+    headers_class: Type[Headers]  # undocumented
+
+    traceback_limit: Optional[int]
+    error_status: str
+    error_headers: List[Tuple[Text, Text]]
+    error_body: bytes
+    def run(self, application: WSGIApplication) -> None: ...
+    def setup_environ(self) -> None: ...
+    def finish_response(self) -> None: ...
+    def get_scheme(self) -> str: ...
+    def set_content_length(self) -> None: ...
+    def cleanup_headers(self) -> None: ...
+    def start_response(
+        self, status: Text, headers: List[Tuple[Text, Text]], exc_info: Optional[_exc_info] = ...
+    ) -> Callable[[bytes], None]: ...
+    def send_preamble(self) -> None: ...
+    def write(self, data: bytes) -> None: ...
+    def sendfile(self) -> bool: ...
+    def finish_content(self) -> None: ...
+    def close(self) -> None: ...
+    def send_headers(self) -> None: ...
+    def result_is_file(self) -> bool: ...
+    def client_is_modern(self) -> bool: ...
+    def log_exception(self, exc_info: _exc_info) -> None: ...
+    def handle_error(self) -> None: ...
+    def error_output(self, environ: WSGIEnvironment, start_response: StartResponse) -> List[bytes]: ...
+    @abstractmethod
+    def _write(self, data: bytes) -> None: ...
+    @abstractmethod
+    def _flush(self) -> None: ...
+    @abstractmethod
+    def get_stdin(self) -> InputStream: ...
+    @abstractmethod
+    def get_stderr(self) -> ErrorStream: ...
+    @abstractmethod
+    def add_cgi_vars(self) -> None: ...
+
+class SimpleHandler(BaseHandler):
+    stdin: InputStream
+    stdout: IO[bytes]
+    stderr: ErrorStream
+    base_env: MutableMapping[str, str]
+    def __init__(
+        self,
+        stdin: InputStream,
+        stdout: IO[bytes],
+        stderr: ErrorStream,
+        environ: MutableMapping[str, str],
+        multithread: bool = ...,
+        multiprocess: bool = ...,
+    ) -> None: ...
+    def get_stdin(self) -> InputStream: ...
+    def get_stderr(self) -> ErrorStream: ...
+    def add_cgi_vars(self) -> None: ...
+    def _write(self, data: bytes) -> None: ...
+    def _flush(self) -> None: ...
+
+class BaseCGIHandler(SimpleHandler): ...
+
+class CGIHandler(BaseCGIHandler):
+    def __init__(self) -> None: ...
+
+class IISCGIHandler(BaseCGIHandler):
+    def __init__(self) -> None: ...