diff --git a/README.md b/README.md
index cad0c1dc..d2dcd5fc 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,21 @@ As an example, to change the list of errors that pycodestyle will ignore, assumi
3. Same as 1, but add to `setup.cfg` file in the root of the project.
+Python LSP Server can communicate over WebSockets when configured as follows:
+
+```
+pylsp --ws --port [port]
+```
+
+The following libraries are required for Web Sockets support:
+- [websockets](https://websockets.readthedocs.io/en/stable/) for Python LSP Server Web sockets using websockets library. refer [Websockets installation](https://websockets.readthedocs.io/en/stable/intro/index.html#installation) for more details
+
+You can install this dependency with command below:
+
+```
+pip install 'python-lsp-server[websockets]'
+```
+
## LSP Server Features
* Auto Completion
diff --git a/pylsp/__main__.py b/pylsp/__main__.py
index 4698d5c9..50950a30 100644
--- a/pylsp/__main__.py
+++ b/pylsp/__main__.py
@@ -13,7 +13,7 @@
import json
from .python_lsp import (PythonLSPServer, start_io_lang_server,
- start_tcp_lang_server)
+ start_tcp_lang_server, start_ws_lang_server)
from ._version import __version__
LOG_FORMAT = "%(asctime)s {0} - %(levelname)s - %(name)s - %(message)s".format(
@@ -27,6 +27,10 @@ def add_arguments(parser):
"--tcp", action="store_true",
help="Use TCP server instead of stdio"
)
+ parser.add_argument(
+ "--ws", action="store_true",
+ help="Use Web Sockets server instead of stdio"
+ )
parser.add_argument(
"--host", default="127.0.0.1",
help="Bind to this address"
@@ -72,6 +76,9 @@ def main():
if args.tcp:
start_tcp_lang_server(args.host, args.port, args.check_parent_process,
PythonLSPServer)
+ elif args.ws:
+ start_ws_lang_server(args.port, args.check_parent_process,
+ PythonLSPServer)
else:
stdin, stdout = _binary_stdio()
start_io_lang_server(stdin, stdout, args.check_parent_process,
diff --git a/pylsp/python_lsp.py b/pylsp/python_lsp.py
index 81e93bdc..8cac63d5 100644
--- a/pylsp/python_lsp.py
+++ b/pylsp/python_lsp.py
@@ -6,6 +6,7 @@
import os
import socketserver
import threading
+import ujson as json
from pylsp_jsonrpc.dispatchers import MethodDispatcher
from pylsp_jsonrpc.endpoint import Endpoint
@@ -91,6 +92,57 @@ def start_io_lang_server(rfile, wfile, check_parent_process, handler_class):
server.start()
+def start_ws_lang_server(port, check_parent_process, handler_class):
+ if not issubclass(handler_class, PythonLSPServer):
+ raise ValueError('Handler class must be an instance of PythonLSPServer')
+
+ # pylint: disable=import-outside-toplevel
+
+ # imports needed only for websockets based server
+ try:
+ import asyncio
+ from concurrent.futures import ThreadPoolExecutor
+ import websockets
+ except ImportError as e:
+ raise ImportError("websocket modules missing. Please run pip install 'python-lsp-server[websockets]") from e
+
+ with ThreadPoolExecutor(max_workers=10) as tpool:
+ async def pylsp_ws(websocket):
+ log.debug("Creating LSP object")
+
+ # creating a partial function and suppling the websocket connection
+ response_handler = partial(send_message, websocket=websocket)
+
+ # Not using default stream reader and writer.
+ # Instead using a consumer based approach to handle processed requests
+ pylsp_handler = handler_class(rx=None, tx=None, consumer=response_handler,
+ check_parent_process=check_parent_process)
+
+ async for message in websocket:
+ try:
+ log.debug("consuming payload and feeding it to LSP handler")
+ request = json.loads(message)
+ loop = asyncio.get_running_loop()
+ await loop.run_in_executor(tpool, pylsp_handler.consume, request)
+ except Exception as e: # pylint: disable=broad-except
+ log.exception("Failed to process request %s, %s", message, str(e))
+
+ def send_message(message, websocket):
+ """Handler to send responses of processed requests to respective web socket clients"""
+ try:
+ payload = json.dumps(message, ensure_ascii=False)
+ asyncio.run(websocket.send(payload))
+ except Exception as e: # pylint: disable=broad-except
+ log.exception("Failed to write message %s, %s", message, str(e))
+
+ async def run_server():
+ async with websockets.serve(pylsp_ws, port=port):
+ # runs forever
+ await asyncio.Future()
+
+ asyncio.run(run_server())
+
+
class PythonLSPServer(MethodDispatcher):
""" Implementation of the Microsoft VSCode Language Server Protocol
https://github.com/Microsoft/language-server-protocol/blob/master/versions/protocol-1-x.md
@@ -98,7 +150,7 @@ class PythonLSPServer(MethodDispatcher):
# pylint: disable=too-many-public-methods,redefined-builtin
- def __init__(self, rx, tx, check_parent_process=False):
+ def __init__(self, rx, tx, check_parent_process=False, consumer=None):
self.workspace = None
self.config = None
self.root_uri = None
@@ -106,10 +158,24 @@ def __init__(self, rx, tx, check_parent_process=False):
self.workspaces = {}
self.uri_workspace_mapper = {}
- self._jsonrpc_stream_reader = JsonRpcStreamReader(rx)
- self._jsonrpc_stream_writer = JsonRpcStreamWriter(tx)
self._check_parent_process = check_parent_process
- self._endpoint = Endpoint(self, self._jsonrpc_stream_writer.write, max_workers=MAX_WORKERS)
+
+ if rx is not None:
+ self._jsonrpc_stream_reader = JsonRpcStreamReader(rx)
+ else:
+ self._jsonrpc_stream_reader = None
+
+ if tx is not None:
+ self._jsonrpc_stream_writer = JsonRpcStreamWriter(tx)
+ else:
+ self._jsonrpc_stream_writer = None
+
+ # if consumer is None, it is assumed that the default streams-based approach is being used
+ if consumer is None:
+ self._endpoint = Endpoint(self, self._jsonrpc_stream_writer.write, max_workers=MAX_WORKERS)
+ else:
+ self._endpoint = Endpoint(self, consumer, max_workers=MAX_WORKERS)
+
self._dispatchers = []
self._shutdown = False
@@ -117,6 +183,11 @@ def start(self):
"""Entry point for the server."""
self._jsonrpc_stream_reader.listen(self._endpoint.consume)
+ def consume(self, message):
+ """Entry point for consumer based server. Alternative to stream listeners."""
+ # assuming message will be JSON
+ self._endpoint.consume(message)
+
def __getitem__(self, item):
"""Override getitem to fallback through multiple dispatchers."""
if self._shutdown and item != 'exit':
@@ -141,8 +212,10 @@ def m_shutdown(self, **_kwargs):
def m_exit(self, **_kwargs):
self._endpoint.shutdown()
- self._jsonrpc_stream_reader.close()
- self._jsonrpc_stream_writer.close()
+ if self._jsonrpc_stream_reader is not None:
+ self._jsonrpc_stream_reader.close()
+ if self._jsonrpc_stream_writer is not None:
+ self._jsonrpc_stream_writer.close()
def _match_uri_to_workspace(self, uri):
workspace_uri = _utils.match_uri_to_workspace(uri, self.workspaces)
diff --git a/pyproject.toml b/pyproject.toml
index 3923ecf4..708df34b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -45,6 +45,7 @@ pyflakes = ["pyflakes>=2.4.0,<2.5.0"]
pylint = ["pylint>=2.5.0"]
rope = ["rope>0.10.5"]
yapf = ["yapf"]
+websockets = ["websockets>=10.3"]
test = [
"pylint>=2.5.0",
"pytest",