Hermes-agent

agent/lsp/__init__.py

@@ -0,0 +1,106 @@
+"""Language Server Protocol (LSP) integration for Hermes Agent.
+
+Hermes runs full language servers (pyright, gopls, rust-analyzer,
+typescript-language-server, etc.) as subprocesses and pipes their
+``textDocument/publishDiagnostics`` output into the post-write lint
+delta filter used by ``write_file`` and ``patch``.
+
+LSP is **gated on git workspace detection** — if the agent's cwd is
+inside a git repository, LSP runs against that workspace; otherwise the
+file_operations layer falls back to its existing in-process syntax
+checks.  This keeps users on user-home cwd's (e.g. Telegram gateway
+chats) from spawning daemons they don't need.
+
+Public API:
+
+    from agent.lsp import get_service
+
+    svc = get_service()
+    if svc and svc.enabled_for(path):
+        await svc.touch_file(path)
+        diags = svc.diagnostics_for(path)
+
+The bulk of the wiring is internal — most callers only need the layer
+in :func:`tools.file_operations.FileOperations._check_lint_delta`,
+which is already wired (see that module).
+
+Architecture is documented in ``website/docs/user-guide/features/lsp.md``.
+"""
+from __future__ import annotations
+
+import atexit
+import logging
+import threading
+from typing import Optional
+
+from agent.lsp.manager import LSPService
+
+logger = logging.getLogger("agent.lsp")
+
+_service: Optional[LSPService] = None
+_atexit_registered = False
+_service_lock = threading.Lock()
+
+
+def get_service() -> Optional[LSPService]:
+    """Return the process-wide LSP service singleton, or None when disabled.
+
+    The service is created lazily on first call.  ``None`` is returned
+    when LSP is disabled in config, when no workspace can be detected,
+    or when the platform doesn't support subprocess-based LSP servers.
+
+    On first creation, registers an :mod:`atexit` handler that tears
+    down spawned language servers on Python exit so a long-running
+    CLI or gateway session doesn't leak pyright/gopls/etc. processes
+    when it terminates.
+    """
+    global _service, _atexit_registered
+    if _service is not None:
+        return _service if _service.is_active() else None
+    with _service_lock:
+        if _service is not None:
+            return _service if _service.is_active() else None
+        _service = LSPService.create_from_config()
+        if not _atexit_registered:
+            # ``atexit`` handlers run in LIFO order on normal Python
+            # exit and on SystemExit, but NOT on os._exit() or
+            # uncaught signals.  Language servers are stateless
+            # subprocesses — losing them on SIGKILL is fine; they'll
+            # be reaped by the kernel along with their parent.  We
+            # care about clean exits where Python flushes stdio
+            # before terminating; without this hook every
+            # ``hermes chat`` exit would leak pyright processes that
+            # outlive the parent for a few seconds while their
+            # stdout buffers drain.
+            atexit.register(_atexit_shutdown)
+            _atexit_registered = True
+    return _service if (_service is not None and _service.is_active()) else None
+
+
+def shutdown_service() -> None:
+    """Tear down the LSP service if one was started.
+
+    Safe to call multiple times; safe to call when no service was created.
+    """
+    global _service
+    with _service_lock:
+        svc = _service
+        _service = None
+    if svc is not None:
+        try:
+            svc.shutdown()
+        except Exception as e:  # noqa: BLE001
+            logger.debug("LSP shutdown error: %s", e)
+
+
+def _atexit_shutdown() -> None:
+    """atexit-registered wrapper.  Logs at debug because by the time
+    atexit fires the user has already seen the agent's final output —
+    a noisy shutdown line on top of that is just clutter."""
+    try:
+        shutdown_service()
+    except Exception as e:  # noqa: BLE001
+        logger.debug("atexit LSP shutdown failed: %s", e)
+
+
+__all__ = ["get_service", "shutdown_service", "LSPService"]