emacs-jupyter/jupyter-server-kernel.el
2023-02-13 20:30:20 -06:00

351 lines
14 KiB
EmacsLisp

;;; jupyter-server-kernel.el --- Working with kernels behind a Jupyter server -*- lexical-binding: t -*-
;; Copyright (C) 2020 Nathaniel Nicandro
;; Author: Nathaniel Nicandro <nathanielnicandro@gmail.com>
;; Created: 23 Apr 2020
;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 3, or (at
;; your option) any later version.
;; This program is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;; Holds the definitions of `jupyter-server', what communicates to the
;; Jupyter server using the REST API, and `jupyter-kernel-server' a
;; representation of a kernel on a server.
;;; Code:
(require 'jupyter-kernel)
(require 'jupyter-rest-api)
(require 'jupyter-monads)
(require 'websocket)
(declare-function jupyter-tramp-server-from-file-name "jupyter-tramp")
(declare-function jupyter-tramp-file-name-p "jupyter-tramp")
(declare-function jupyter-server-kernel-id-from-name "jupyter-server")
(defgroup jupyter-server-kernel nil
"Kernel behind a Jupyter server"
:group 'jupyter)
;;; `jupyter-server'
(defvar-local jupyter-current-server nil
"The `jupyter-server' associated with the current buffer.
Used in, e.g. a `jupyter-server-kernel-list-mode' buffer.")
(put 'jupyter-current-server 'permanent-local t)
(defvar jupyter--servers nil)
;; TODO: We should really rename `jupyter-server' to something like
;; `jupyter-server-client' since it isn't a representation of a server, but a
;; communication channel with one.
(defclass jupyter-server (jupyter-rest-client eieio-instance-tracker)
((tracking-symbol :initform 'jupyter--servers)
(kernelspecs
:type json-plist
:initform nil
:documentation "Kernelspecs for the kernels available behind
this gateway. Access them through `jupyter-kernelspecs'.")))
(cl-defmethod make-instance ((_class (subclass jupyter-server)) &rest slots)
(cl-assert (plist-get slots :url))
(or (cl-loop
with url = (plist-get slots :url)
for server in jupyter--servers
if (equal url (oref server url)) return server)
(cl-call-next-method)))
(defun jupyter-servers ()
"Return a list of all `jupyter-server's."
jupyter--servers)
(defun jupyter-gc-servers ()
"Delete `jupyter-server' instances that are no longer accessible."
(dolist (server (jupyter-servers))
(unless (jupyter-api-server-exists-p server)
(jupyter-api-delete-cookies (oref server url))
(delete-instance server))))
(cl-defmethod jupyter-api-request :around ((server jupyter-server) _method &rest _plist)
(condition-case nil
(cl-call-next-method)
(jupyter-api-unauthenticated
(if (memq jupyter-api-authentication-method '(ask token password))
(oset server auth jupyter-api-authentication-method)
(error "Unauthenticated request, can't attempt re-authentication \
with default `jupyter-api-authentication-method'"))
(prog1 (cl-call-next-method)
(jupyter-reauthenticate-websockets server)))))
(cl-defmethod jupyter-kernelspecs ((client jupyter-rest-client) &optional _refresh)
(or (jupyter-api-get-kernelspec client)
(error "Can't retrieve kernelspecs from server @ %s"
(oref client url))))
(cl-defmethod jupyter-kernelspecs ((server jupyter-server) &optional refresh)
"Return the kernelspecs on SERVER.
By default the available kernelspecs are cached. To force an
update of the cached kernelspecs, give a non-nil value to
REFRESH."
(when (or refresh (null (oref server kernelspecs)))
(let ((specs (cl-call-next-method)))
(plist-put specs :kernelspecs
(cl-loop
for (_ spec) on (plist-get specs :kernelspecs) by #'cddr
for name = (plist-get spec :name)
collect (make-jupyter-kernelspec
:name name
:plist (plist-get spec :spec))))
(oset server kernelspecs specs)))
(plist-get (oref server kernelspecs) :kernelspecs))
(cl-defmethod jupyter-kernelspecs :extra "server" ((host string) &optional refresh)
(if (jupyter-tramp-file-name-p host)
(jupyter-kernelspecs (jupyter-tramp-server-from-file-name host) refresh)
(cl-call-next-method)))
(cl-defmethod jupyter-server-has-kernelspec-p ((server jupyter-server) name)
"Return non-nil if SERVER can launch kernels with kernelspec NAME."
(jupyter-guess-kernelspec name (jupyter-kernelspecs server)))
;;; Kernel definition
(cl-defstruct (jupyter-server-kernel
(:include jupyter-kernel))
(server jupyter-current-server
:read-only t
:documentation "The kernel server.")
;; TODO: Make this read only by only allowing creating
;; representations of kernels that have already been launched and
;; have a connection to the kernel.
(id nil
:type (or null string)
:documentation "The kernel ID."))
(cl-defmethod jupyter-alive-p ((kernel jupyter-server-kernel))
(pcase-let (((cl-struct jupyter-server-kernel server id) kernel))
(and id server
;; TODO: Cache this call
(condition-case err
(jupyter-api-get-kernel server id)
(file-error nil) ; Non-existent server
(jupyter-api-http-error
(unless (= (nth 1 err) 404) ; Not Found
(signal (car err) (cdr err)))))
(cl-call-next-method))))
(defun jupyter-server-kernel (&rest args)
"Return a `jupyter-server-kernel' initialized with ARGS."
(apply #'make-jupyter-server-kernel args))
(cl-defmethod jupyter-kernel :extra "server" (&rest args)
"Return a representation of a kernel on a Jupyter server.
If ARGS has a :server key, return a `jupyter-server-kernel'
initialized using ARGS. If ARGS also has a :spec key, whose
value is the name of a kernelspec, the returned kernel's spec
slot will be the corresponding `jupyter-kernelspec'.
Call the next method if ARGS does not contain :server."
(let ((server (plist-get args :server)))
(if (not server) (cl-call-next-method)
(cl-assert (object-of-class-p server 'jupyter-server))
(let ((spec (plist-get args :spec)))
(when (stringp spec)
(plist-put args :spec
;; TODO: (jupyter-server-kernelspec server "python3")
;; which returns an I/O action and then arrange
;; for that action to be bound by mlet* and set
;; as the spec value. Or better yet, have
;; `jupyter-kernel' return a delayed kernel with
;; the server connection already open and
;; kernelspecs already retrieved.
(or (jupyter-guess-kernelspec
spec (jupyter-kernelspecs server))
;; TODO: Return the error to the I/O context.
(error "No kernelspec matching %s @ %s" spec
(oref server url))))))
(apply #'jupyter-server-kernel args))))
;;; Websocket IO
(defvar jupyter--reauth-subscribers (make-hash-table :weakness 'key :test 'eq))
(defun jupyter-reauthenticate-websockets (server)
"Re-authenticate WebSocket connections of SERVER."
(when-let* ((pub (gethash server jupyter--reauth-subscribers)))
(jupyter-run-with-io pub
(jupyter-publish 'reauthenticate))))
(cl-defmethod jupyter-websocket-io ((kernel jupyter-server-kernel))
"Return a list representing an IO connection to KERNEL.
The list is composed of two elements (IO-PUB ACTION-SUB), IO-PUB
is a publisher used to send/receive messages to/from KERNEL and
ACTION-SUB is a subscriber of kernel actions to perform on
KERNEL.
To send a message to KERNEL, publish a list of the form
(list 'send CHANNEL MSG-TYPE CONTENT MSG-ID)
to IO-PUB, e.g.
(jupyter-run-with-io IO-PUB
(jupyter-publish (list 'send CHANNEL MSG-TYPE CONTENT MSG-ID)))
To receive messages from KERNEL, subscribe to IO-PUB e.g.
(jupyter-run-with-io IO-PUB
(jupyter-subscribe
(jupyter-subscriber
(lambda (msg)
...))))
The value 'interrupt or 'shutdown can be published to ACTION-SUB
to interrupt or shutdown KERNEL. The value (list 'action FN)
where FN is a single argument function can also be published, in
this case FN will be evaluated on KERNEL."
(jupyter-launch kernel)
(let* ((ws nil)
(shutdown nil)
(make-websocket nil)
(kernel-io
(jupyter-publisher
(lambda (event)
(if shutdown (error "Kernel shutdown!")
(pcase event
(`(message . ,rest) (jupyter-content rest))
(`(send ,channel ,msg-type ,content ,msg-id)
(websocket-send-text
ws (let* ((cd (websocket-client-data ws))
(session (plist-get cd :session)))
(jupyter-encode-raw-message session msg-type
:channel channel
:msg-id msg-id
:content content))))
('start
(unless (websocket-openp ws)
(setq ws (funcall make-websocket))))
('stop (websocket-close ws)))))))
(status-pub (jupyter-publisher))
(on-message
(lambda (_ws frame)
(pcase (websocket-frame-opcode frame)
((or 'text 'binary)
(let ((msg (jupyter-read-plist-from-string
(websocket-frame-payload frame))))
(jupyter-run-with-io kernel-io
(jupyter-publish (cons 'message msg)))))
(_
(jupyter-run-with-io status-pub
(jupyter-publish
(list 'error (websocket-frame-opcode frame)))))))))
(pcase-let* (((cl-struct jupyter-server-kernel server id) kernel)
(pub (or (gethash server jupyter--reauth-subscribers)
(setf (gethash server jupyter--reauth-subscribers)
(jupyter-publisher)))))
(setq make-websocket (lambda ()
(jupyter-api-kernel-websocket
server id
:custom-header-alist (jupyter-api-auth-headers server)
;; TODO: on-error publishes to status-pub
:on-message on-message))
ws (funcall make-websocket))
(jupyter-run-with-io pub
(jupyter-subscribe
(jupyter-subscriber
(lambda (_reauth)
(websocket-close ws)
(setq ws (funcall make-websocket))))))
(list kernel-io
(jupyter-subscriber
(lambda (action)
(pcase action
('interrupt
(jupyter-interrupt kernel))
('shutdown
(jupyter-shutdown kernel)
(websocket-close ws)
(setq shutdown t))
('restart
(jupyter-restart kernel))
(`(action ,fn)
(funcall fn kernel)))))))))
(cl-defmethod jupyter-io ((kernel jupyter-server-kernel))
(jupyter-websocket-io kernel))
;;; Kernel management
;; The KERNEL argument is optional here so that `jupyter-launch'
;; does not require more than one argument just to handle this case.
(cl-defmethod jupyter-launch ((server jupyter-server) &optional kernel)
(cl-check-type kernel string)
(let* ((spec (jupyter-guess-kernelspec
kernel (jupyter-kernelspecs server)))
(plist (jupyter-api-start-kernel
server (jupyter-kernelspec-name spec))))
(jupyter-kernel :server server :id (plist-get plist :id) :spec spec)))
;; FIXME: Don't allow creating kernels without them being launched.
(cl-defmethod jupyter-launch ((kernel jupyter-server-kernel))
"Launch KERNEL based on its kernelspec.
When KERNEL does not have an ID yet, launch KERNEL on SERVER
using its SPEC."
(pcase-let (((cl-struct jupyter-server-kernel server id spec session) kernel))
(unless session
(and id (setq id (or (jupyter-server-kernel-id-from-name server id) id)))
(if id
;; When KERNEL already has an ID before it has a session,
;; assume we are connecting to an already launched kernel. In
;; this case, make sure the KERNEL's SPEC is the same as the
;; one being connected to.
;;
;; Note, this also has the side effect of raising an error
;; when the ID does not match one on the server.
(unless spec
(let ((model (jupyter-api-get-kernel server id)))
(setf (jupyter-kernel-spec kernel)
(jupyter-guess-kernelspec
(plist-get model :name)
(jupyter-kernelspecs server)))))
(let ((plist (jupyter-api-start-kernel
server (jupyter-kernelspec-name spec))))
(setf (jupyter-server-kernel-id kernel) (plist-get plist :id))
(sit-for 1)))
;; TODO: Replace with the real session object
(setf (jupyter-kernel-session kernel) (jupyter-session))))
(cl-call-next-method))
(cl-defmethod jupyter-shutdown ((kernel jupyter-server-kernel))
(pcase-let (((cl-struct jupyter-server-kernel server id session) kernel))
(cl-call-next-method)
(when session
(jupyter-api-shutdown-kernel server id))))
(cl-defmethod jupyter-restart ((kernel jupyter-server-kernel))
(pcase-let (((cl-struct jupyter-server-kernel server id session) kernel))
(when session
(jupyter-api-restart-kernel server id))))
(cl-defmethod jupyter-interrupt ((kernel jupyter-server-kernel))
(pcase-let (((cl-struct jupyter-server-kernel server id) kernel))
(jupyter-api-interrupt-kernel server id)))
(provide 'jupyter-server-kernel)
;;; jupyter-server-kernel.el ends here