This refactor implements a new class hierarchy to manage the lifetime of a
Jupyter kernel. The first node in this hierarchy is the
`jupyter-kernel-lifetime` class which defines a set of methods to manage the
lifetime of a kernel. An object that inherits from `jupyter-kernel-lifetime` is
stating that it has an association with a kernel and can be used to manage the
lifetime of the associated kernel.
The `jupyter-meta-kernel` class inherits from `jupyter-kernel-lifetime` and
mainly defines a `spec` slot used to hold the `kernelspec` from which a command
can be constructed to start a kernel and a `session` slot used to hold the
`jupyter-session` object that clients can use to establish communication with a
kernel once its live. Concrete classes that actually launch kernels are
intended to inherit from this class and use its slots.
`jupyter-kernel-process` manages the lifetime of a kernel started as a process
using the function `start-file-process`, `jupyter-command-kernel` calls the
`jupyter kernel` shell command to start a kernel, finally `jupyter-spec-kernel`
uses the `spec` slot to construct a shell command to start a kernel.
A `jupyter-kernel-manager` now consists of a `kernel` slot that holds a
`jupyter-meta-kernel` and a `control-channel` slot and inherits from
`jupyter-kernel-lifetime`. The `jupyter-kernel-lifetime` methods of the manager
just defer to those of `kernel` while also taking into account the
`control-channel`.
* jupyter-base.el (jupyter-write-connection-file): New function.
* jupyter-channel-ioloop.el
(jupyter-channel-ioloop-add-start-channel-event): Remove `sleep-for` call.
The startup message is not so important anymore.
* jupyter-client.el (jupyter-wait-until-startup: New function.
* jupyter-kernel-manager.el (jupyter-kernel-lifetime)
(jupyter-kernel, jupyter-kernel-process, jupyter-command-kernel)
(jupyter-spec-kernel): New classes.
(jupyter-kernel-manager): Inherit from jupyter-kernel-lifetime only and
implement its methods.
(jupyter-kernel-manager--cleanup, jupyter-kernel-managers)
(jupyter-delete-all-kernels, jupyter--kernel-sentinel)
(jupyter--start-kernel): Remove and remove related, their functionality has
been generalized in the new classes.
(jupyter-interrupt-kernel, jupyter-shutdown-kernel)
(jupyter-start-channels, jupyter-start-kernel, jupyter-kernel-alive-p)
(jupyter-kill-kernel): Refactor and implement to use the new class hierarchy.
* test/jupyter-test.el: Refactor tests to account for changes.
(jupyter-write-connect-file, jupyter-command-kernel): New tests.
* jupyter-kernelspec.el (jupyter-guess-kernelspec): New function.
Also fix misuse of `alist-get`. `alist-get` uses `assq` for comparison by
default, but we are comparing strings. This caused issues when caching REPL
buffers and the subsequent re-use of them during testing.
The previous mechanism to communicate with a kernel was too low level from the
perspective of a client. The client interfaced directly with the subprocess
abstraction, `jupyter-ioloop`, and had to handle all "events" that occurred in
the `jupyter-ioloop`, e.g. when a channel was started or stopped. But in
reality such events should not be the concern of a client.
A client should only care about events that are directly related to kernel
messages and not events related to the implementation details of *how*
communication occurs.
This commit abstracts out the way in which a client communicates with its
kernel by introducing a new `jupyter-comm-layer` class. The
`jupyter-comm-layer` class takes care of managing the communication channel
between a kernel and its clients as well as sending events to all registered
clients. This way, clients operate solely at the level of events on the
communication layer. All a client does is register itself to receive events on
the communication layer and send events on the layer.
* jupyter-base.el (jupyter-session-endpoints): New function.
* jupyter-client.el (jupyter-kernel-client): Remove ioloop and channels slots.
Add kcomm slot.
(initialize-instance): Unconditionally stop channels.
(jupyter-initialize-connection): Change into a method call.
Call `jupyter-initialize-connection` on the `kcomm` slot.
(jupyter-with-client-buffer): Remove stale comment.
(jupyter-send): Call `jupyter-send` on the `kcomm` slot.
(jupyter-ioloop-handler): Remove all method definitions, replace `sent` and
`message` methods with their `jupyter-event-handler` equivalents.
(jupyter-hb-pause, jupyter-hb-unpause, jupyter-hb-beating):
(jupyter-channel-alive-p, jupyter-start-channel, jupyter-stop-channel):
(jupyter-start-channels, jupyter-stop-channels):
Replace with calls to their equivalents using the `kcomm` slot.
* jupyter-comm-layer.el: New file.
* jupyter-kernel-manager (jupyter-make-client): Set a client's `kcomm` slot to
`jupyter-channel-ioloop-comm`.
* jupyter-messages.el (jupyter-decode-message): Use `list` directly. There
seemed to be issues when using the new `jupyter-sync-channel-comm` due to
using quoted lists.
* test/jupyter-test.el: Add `jupyter-comm-layer` test. Update other tests.
* test/test-helper.el: Add `jupyter-comm-layer` mock objects. Update
`jupyter-echo-client`.
Mainly variable re-naming and in preparation for adding in auto-restart
support.
* `jupyter-hb-consider-dead-periods` -> `jupyter-hb-max-failures`
* Also convert to a customizable variable
* `kernel-died-cb` -> `dead-cb`
This handles an edge case where `field-end` would return the position at the
beginning of a cell even though there was text that was part of the cell code
after that position. The issue had to do with the interaction between the
sticky text properties at field boundaries. See #38.
Whenever a prompt string exceeds `jupyter-repl-prompt-margin-width`, increase
`jupyter-repl-prompt-margin-width` so that is can accommodate the string and
redisplay all prompts.
