;;; gudap.el --- Debug Adapter Protocol client for Emacs -*- lexical-binding: t -*-
;; Author: Dominik Martinez <dominikmartinez@pm.me>
;; URL:
;; Version: 0.1.0
;; Package-Requires:
;; Keywords: languages, debug, dap
;;; Commentary:
;; gudap.el is a Debug Adapter Protocol client for Emacs.
;;
;; To use, add the following to your init file:
;;
;; (require 'gudap)
;;
;; Code ~heavily~ adapted from Eglot.
;;; Code:
(require 'eglot)
(require 'jsonrpc)
(defgroup gudap nil
"Interaction with Debug Adapter Protocol servers."
:prefix "gudap-"
:group 'applications)
(defconst dap-buffer-size 200)
(defclass dap-connection ()
((name
:initarg :name)
(process
:initarg :process
:accessor process)
(event-dispatcher
:initform #'ignore
:initarg :event-dispatcher)
(request-dispatcher
:initform #'ignore
:initarg :request-dispatcher)
(response-dispatcher
:initform #'ignore
:initarg :response-dispatcher)
(buffer
:initform '()
:accessor buffer)
(expected-seq
:initform 1
:accessor expected-seq)
(expected-bytes
:accessor expected-bytes)))
(cl-defgeneric connection-live-p (connection))
(cl-defmethod connection-live-p ((connection dap-connection))
(process-live-p (process connection)))
(defvar gudap-server-programs '(((elixir-mode elixir-ts-mode) . ("elixir-ls-debug"))))
(defvar gudap--connections-by-project (make-hash-table :test #'equal)
"Keys are projects. Values are lists of dap connecections.")
(defvar gudap--cached-connection nil)
(defun gudap-reset ()
(interactive)
(clrhash gudap--connections-by-project)
(setq gudap--cached-connection nil))
(defun gudap (managed-major-modes project _class contact language-id &optional interactive)
(interactive (let ((eglot-server-programs gudap-server-programs))
(eglot--guess-contact t)))
(let* ((current-conn (gudap-current-connection))
(live-p (and current-conn (connection-live-p current-conn))))
(if (and live-p
interactive
(y-or-n-p "[gudap] Live process found, reconnect instead? "))
(gudap-reconnect current-conn interactive)
(when live-p (ignore-errors (gudap-shutdown current-conn)))
(gudap--connect managed-major-modes project 'dap-connection contact language-id))))
(defun gudap--connect (managed-modes project class contact language-id)
(let* ((nickname (project-name project))
(readable-name (format "GUDAP (%s/%s)" nickname managed-modes))
(process (make-process :name readable-name
:buffer readable-name
:command contact
:filter 'dap--process-filter
:sentinel 'dap--server-sentinel))
(server (make-instance class
:name readable-name
:process process
:event-dispatcher 'gudap-event-dispatcher)))
(process-put process 'dap-connection server)
(puthash project
(cons server
(gethash project gudap--connections-by-project '()))
gudap--connections-by-project)))
(defun gudap-event-dispatcher (conn message)
(pp message))
(defun gudap-current-connection ()
"Return logical Gudap server for current buffer, nil if none."
(setq gudap--cached-connection
(or gudap--cached-connection
(gethash (eglot--current-project) gudap--connections-by-project))))
(defun dap--server-sentinel (proc event)
(message "gudap sentinel event: %s" event)
(let ((server (process-get proc 'dap-connection)))
(puthash (eglot--current-project)
(remove server (gethash (eglot--current-project) gudap--connections-by-project))
gudap--connections-by-project))
(setq gudap--cached-connection nil))
(defvar dap--in-process-filter nil
"Non-nil if inside `dap--process-filter'.")
(cl-defun dap--process-filter (proc string)
"Called when new data STRING has arrived for PROC."
(when dap--in-process-filter
;; Problematic recursive process filters may happen if
;; `dap--connection-receive', called by us, eventually calls
;; client code which calls `process-send-string' (which see) to,
;; say send a follow-up message. If that happens to writes enough
;; bytes for pending output to be received, we will lose JSONRPC
;; messages. In that case, remove recursiveness by re-scheduling
;; ourselves to run from within a timer as soon as possible
;; (bug#60088)
(run-at-time 0 nil #'dap--process-filter proc string)
(cl-return-from dap--process-filter))
(when (buffer-live-p (process-buffer proc))
(with-current-buffer (process-buffer proc)
(let* ((inhibit-read-only t)
(dap--in-process-filter t)
(connection (process-get proc 'dap-connection))
(expected-bytes (expected-bytes connection)))
;; Insert the text, advancing the process marker.
;;
(save-excursion
(goto-char (process-mark proc))
(insert string)
(set-marker (process-mark proc) (point)))
;; Loop (more than one message might have arrived)
;;
(unwind-protect
(let (done)
(while (not done)
(cond
((not expected-bytes)
;; Starting a new message
;;
(setq expected-bytes
(and (search-forward-regexp
"\\(?:.*: .*\r\n\\)*Content-Length: \
*\\([[:digit:]]+\\)\r\n\\(?:.*: .*\r\n\\)*\r\n"
(+ (point) 100)
t)
(string-to-number (match-string 1))))
(unless expected-bytes
(setq done :waiting-for-new-message)))
(t
;; Attempt to complete a message body
;;
(let ((available-bytes (- (position-bytes (process-mark proc))
(position-bytes (point)))))
(cond
((>= available-bytes
expected-bytes)
(let* ((message-end (byte-to-position
(+ (position-bytes (point))
expected-bytes))))
(unwind-protect
(save-restriction
(narrow-to-region (point) message-end)
(let* ((json-message
(condition-case-unless-debug oops
(jsonrpc--json-read)
(error
(jsonrpc--warn "Invalid JSON: %s %s"
(cdr oops) (buffer-string))
nil))))
(when json-message
;; Process content in another
;; buffer, shielding proc buffer from
;; tamper
(with-temp-buffer
(dap-connection-receive connection
json-message)))))
(goto-char message-end)
(delete-region (point-min) (point))
(setq expected-bytes nil))))
(t
;; Message is still incomplete
;;
(setq done :waiting-for-more-bytes-in-this-message))))))))
;; Saved parsing state for next visit to this filter
;;
(setf (expected-bytes connection) expected-bytes))))))
(defun dap-connection-receive (conn message)
(if (dap-buffer-full (buffer conn))
(dap-connection-process-messages conn t))
(setf (buffer conn) (dap-buffer-insert (buffer conn) message))
(dap-connection-process-messages conn))
(defun dap-buffer-insert (buffer message)
(if (dap-buffer-full-p buffer)
(error "Buffer full."))
(let ((seq (plist-get :seq message))
(next-seq (plist-get :seq (cadr buffer))))
(cond
(
(not next-seq)
(list message))
(
(> seq next-seq)
(cons (car buffer) (dap-message-buffer-insert (cdr buffer) message)))
(
t
(cons message buffer)))))
(defun dap-buffer-full-p (buffer)
(length= buffer dap-buffer-size))
(defun dap-connection-process-messages (conn &optional all)
(let ((next-message (car (buffer conn))))
(while (and next-message
(or all
(= (plist-get next-message :seq) (expected-seq conn))))
(dap-process-message conn (pop (buffer conn)))
(setq next-message (car (buffer conn))))))
(defun dap-process-message (conn message)
(cl-destructuring-bind (&key seq type &allow-other-keys)
message
(setf (expected-seq conn) (1+ seq))
(cond
(;; event
(equal type "event")
(funcall (slot-value conn 'event-dispatcher) conn message))
(;; request
(equal type "request")
(funcall (slot-value conn 'request-dispatcher) conn message))
(;; response
(equal type "response")
(funcall (slot-value conn 'response-dispatcher) conn message)))))
;;;###autoload
(provide 'gudap)
;;; gudap.el ends here