support client config with tcp_port but without command (#2300)

Co-authored-by: Marek Budik <mbudik@protonmail.com>
Co-authored-by: Rafal Chlodnicki <rchl2k@gmail.com>

docs/src/client_configuration.md

@@ -65,6 +65,8 @@ The vast majority of language servers can communicate over stdio. To use stdio,
 
 Some language servers can also act as a TCP server accepting incoming TCP connections. So: the language server subprocess is started by this package, and the subprocess will then open a TCP listener port. The editor can then connect as a client and initiate the communication. To use this mode, set `tcp_port` to a positive number designating the port to connect to on `localhost`.
 
+Optionally in this case, you can omit the `command` setting if you don't want Sublime LSP to manage the language server process and you'll take care of it yourself. 
+
 ### TCP - localhost - editor acts as a TCP server
 
 Some _LSP servers_ instead expect the _LSP client_ to act as a _TCP server_. The _LSP server_ will then connect as a _TCP client_, after which the _LSP client_ is expected to initiate the communication. To use this mode, set `tcp_port` to a negative number designating the port to bind to for accepting new TCP connections.

docs/src/language_servers.md

@@ -188,6 +188,8 @@ Follow installation instructions on [LSP-gopls](https://github.com/sublimelsp/LS
     }
     ```
 
+If you encounter high cpu load or any other issues you can try omitting the [command] line, and ensure the godot editor is running while you work in sublime.
+
 ## GraphQL
 
 Follow installation instructions on [LSP-graphql](https://github.com/sublimelsp/LSP-graphql).

plugin/core/transports.py

@@ -94,9 +94,9 @@ def _decode(message: bytes) -> Dict[str, Any]:
 
 class ProcessTransport(Transport[T]):
 
-    def __init__(self, name: str, process: subprocess.Popen, socket: Optional[socket.socket], reader: IO[bytes],
-                 writer: IO[bytes], stderr: Optional[IO[bytes]], processor: AbstractProcessor[T],
-                 callback_object: TransportCallbacks[T]) -> None:
+    def __init__(self, name: str, process: Optional[subprocess.Popen], socket: Optional[socket.socket],
+                 reader: IO[bytes], writer: IO[bytes], stderr: Optional[IO[bytes]],
+                 processor: AbstractProcessor[T], callback_object: TransportCallbacks[T]) -> None:
         self._closed = False
         self._process = process
         self._socket = socket
@@ -106,12 +106,13 @@ def __init__(self, name: str, process: subprocess.Popen, socket: Optional[socket
         self._processor = processor
         self._reader_thread = threading.Thread(target=self._read_loop, name='{}-reader'.format(name))
         self._writer_thread = threading.Thread(target=self._write_loop, name='{}-writer'.format(name))
-        self._stderr_thread = threading.Thread(target=self._stderr_loop, name='{}-stderr'.format(name))
         self._callback_object = weakref.ref(callback_object)
         self._send_queue = Queue(0)  # type: Queue[Union[T, None]]
         self._reader_thread.start()
         self._writer_thread.start()
-        self._stderr_thread.start()
+        if stderr:
+            self._stderr_thread = threading.Thread(target=self._stderr_loop, name='{}-stderr'.format(name))
+            self._stderr_thread.start()
 
     def send(self, payload: T) -> None:
         self._send_queue.put_nowait(payload)
@@ -135,7 +136,8 @@ def __del__(self) -> None:
         self.close()
         self._join_thread(self._writer_thread)
         self._join_thread(self._reader_thread)
-        self._join_thread(self._stderr_thread)
+        if self._stderr_thread:
+            self._join_thread(self._stderr_thread)
 
     def _read_loop(self) -> None:
         exception = None
@@ -164,23 +166,24 @@ def invoke(p: T) -> None:
 
     def _end(self, exception: Optional[Exception]) -> None:
         exit_code = 0
-        if not exception:
-            try:
-                # Allow the process to stop itself.
-                exit_code = self._process.wait(1)
-            except (AttributeError, ProcessLookupError, subprocess.TimeoutExpired):
-                pass
-        if self._process.poll() is None:
-            try:
-                # The process didn't stop itself. Terminate!
-                self._process.kill()
-                # still wait for the process to die, or zombie processes might be the result
-                # Ignore the exit code in this case, it's going to be something non-zero because we sent SIGKILL.
-                self._process.wait()
-            except (AttributeError, ProcessLookupError):
-                pass
-            except Exception as ex:
-                exception = ex  # TODO: Old captured exception is overwritten
+        if self._process:
+            if not exception:
+                try:
+                    # Allow the process to stop itself.
+                    exit_code = self._process.wait(1)
+                except (AttributeError, ProcessLookupError, subprocess.TimeoutExpired):
+                    pass
+            if self._process.poll() is None:
+                try:
+                    # The process didn't stop itself. Terminate!
+                    self._process.kill()
+                    # still wait for the process to die, or zombie processes might be the result
+                    # Ignore the exit code in this case, it's going to be something non-zero because we sent SIGKILL.
+                    self._process.wait()
+                except (AttributeError, ProcessLookupError):
+                    pass
+                except Exception as ex:
+                    exception = ex  # TODO: Old captured exception is overwritten
 
         def invoke() -> None:
             callback_object = self._callback_object()
@@ -252,13 +255,12 @@ def start_subprocess() -> subprocess.Popen:
     if config.listener_socket:
         assert isinstance(config.tcp_port, int) and config.tcp_port > 0
         process, sock, reader, writer = _await_tcp_connection(
-            config.name,
-            config.tcp_port,
-            config.listener_socket,
-            start_subprocess
-        )
+            config.name, config.tcp_port, config.listener_socket, start_subprocess)
     else:
-        process = start_subprocess()
+        if config.command:
+            process = start_subprocess()
+        elif not config.tcp_port:
+            raise RuntimeError("Failed to provide command or tcp_port, at least one of them has to be configured")
         if config.tcp_port:
             sock = _connect_tcp(config.tcp_port)
             if sock is None:
@@ -270,8 +272,9 @@ def start_subprocess() -> subprocess.Popen:
             writer = process.stdin  # type: ignore
     if not reader or not writer:
         raise RuntimeError('Failed initializing transport: reader: {}, writer: {}'.format(reader, writer))
+    stderr = process.stderr if process else None
     return ProcessTransport(
-        config.name, process, sock, reader, writer, process.stderr, json_rpc_processor, callback_object)  # type: ignore
+        config.name, process, sock, reader, writer, stderr, json_rpc_processor, callback_object)  # type: ignore
 
 
 _subprocesses = weakref.WeakSet()  # type: weakref.WeakSet[subprocess.Popen]