// Copyright (c) Jupyter Development Team.
// Distributed under the terms of the Modified BSD License.
define([
'jquery',
'base/js/utils',
'./comm',
'./serialize',
'base/js/events'
], function($, utils, comm, serialize, events) {
"use strict";
/**
* A Kernel class to communicate with the Python kernel. This
* should generally not be constructed directly, but be created
* by. the `Session` object. Once created, this object should be
* used to communicate with the kernel.
*
* Preliminary documentation for the REST API is at
* https://github.com/ipython/ipython/wiki/IPEP-16%3A-Notebook-multi-directory-dashboard-and-URL-mapping#kernels-api
*
* Documentation for the messaging specifications is at
* https://jupyter-client.readthedocs.io/en/stable/messaging.html
*
* @class Kernel
* @param {string} kernel_service_url - the URL to access the kernel REST api
* @param {string} ws_url - the websockets URL
* @param {string} name - the kernel type (e.g. python3)
*/
var Kernel = function (kernel_service_url, ws_url, name) {
this.events = events;
this.id = null;
this.name = name;
this.ws = null;
this._stopping = false;
this.kernel_service_url = kernel_service_url;
this.kernel_url = null;
this.ws_url = ws_url || utils.get_body_data("wsUrl");
if (!this.ws_url) {
// trailing 's' in https will become wss for secure web sockets
this.ws_url = location.protocol.replace('http', 'ws') + "//" + location.host;
}
this.username = "username";
this.session_id = utils.uuid();
this._msg_callbacks = {};
this._msg_callbacks_overrides = {};
this._display_id_to_parent_ids = {};
this._msg_queue = Promise.resolve();
this.info_reply = {}; // kernel_info_reply stored here after starting
if (typeof(WebSocket) !== 'undefined') {
this.WebSocket = WebSocket;
} else if (typeof(MozWebSocket) !== 'undefined') {
this.WebSocket = MozWebSocket;
} else {
alert('Your browser does not have WebSocket support, please try Chrome, Safari or Firefox ≥ 6. Firefox 4 and 5 are also supported by you have to enable WebSockets in about:config.');
}
this.bind_events();
this.init_iopub_handlers();
this.comm_manager = new comm.CommManager(this);
this.last_msg_id = null;
this.last_msg_callbacks = {};
this._autorestart_attempt = 0;
this._reconnect_attempt = 0;
this.reconnect_limit = 7;
this._pending_messages = [];
};
/**
* @function _get_msg
*/
Kernel.prototype._get_msg = function (msg_type, content, metadata, buffers) {
var msg = {
header : {
msg_id : utils.uuid(),
username : this.username,
session : this.session_id,
msg_type : msg_type,
version : "5.2",
},
metadata : metadata || {},
content : content,
buffers : buffers || [],
parent_header : {}
};
return msg;
};
/**
* @function bind_events
*/
Kernel.prototype.bind_events = function () {
var that = this;
this.events.on('send_input_reply.Kernel', function(evt, data) {
that.send_input_reply(data);
});
var record_status = function (evt, info) {
console.log('Kernel: ' + evt.type + ' (' + info.kernel.id + ')');
};
this.events.on('kernel_created.Kernel', record_status);
this.events.on('kernel_reconnecting.Kernel', record_status);
this.events.on('kernel_connected.Kernel', record_status);
this.events.on('kernel_starting.Kernel', record_status);
this.events.on('kernel_restarting.Kernel', record_status);
this.events.on('kernel_autorestarting.Kernel', record_status);
this.events.on('kernel_interrupting.Kernel', record_status);
this.events.on('kernel_disconnected.Kernel', record_status);
// these are commented out because they are triggered a lot, but can
// be uncommented for debugging purposes
//this.events.on('kernel_idle.Kernel', record_status);
//this.events.on('kernel_busy.Kernel', record_status);
this.events.on('kernel_ready.Kernel', record_status);
this.events.on('kernel_killed.Kernel', record_status);
this.events.on('kernel_dead.Kernel', record_status);
this.events.on('kernel_ready.Kernel', function () {
that._autorestart_attempt = 0;
});
this.events.on('kernel_connected.Kernel', function () {
that._reconnect_attempt = 0;
});
};
/**
* Initialize the iopub handlers.
*
* @function init_iopub_handlers
*/
Kernel.prototype.init_iopub_handlers = function () {
var output_msg_types = ['stream', 'display_data', 'execute_result', 'error', 'update_display_data'];
this._iopub_handlers = {};
this.register_iopub_handler('status', $.proxy(this._handle_status_message, this));
this.register_iopub_handler('clear_output', $.proxy(this._handle_clear_output, this));
this.register_iopub_handler('execute_input', $.proxy(this._handle_input_message, this));
this.register_iopub_handler('shutdown_reply', $.proxy(this._handle_shutdown_message, this));
for (var i=0; i < output_msg_types.length; i++) {
this.register_iopub_handler(output_msg_types[i], $.proxy(this._handle_output_message, this));
}
};
/**
* GET /api/kernels
*
* Get the list of running kernels.
*
* @function list
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
Kernel.prototype.list = function (success, error) {
utils.ajax(this.kernel_service_url, {
processData: false,
cache: false,
type: "GET",
dataType: "json",
success: success,
error: this._on_error(error)
});
};
/**
* POST /api/kernels
*
* Start a new kernel.
*
* In general this shouldn't be used -- the kernel should be
* started through the session API. If you use this function and
* are also using the session API then your session and kernel
* WILL be out of sync!
*
* @function start
* @param {params} [Object] - parameters to include in the query string
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
Kernel.prototype.start = function (params, success, error) {
var url = this.kernel_service_url;
var qs = $.param(params || {}); // query string for sage math stuff
if (qs !== "") {
url = url + "?" + qs;
}
this.events.trigger('kernel_starting.Kernel', {kernel: this});
var that = this;
var on_success = function (data, status, xhr) {
that.events.trigger('kernel_created.Kernel', {kernel: that});
that._kernel_created(data);
if (success) {
success(data, status, xhr);
}
};
utils.ajax(url, {
processData: false,
cache: false,
type: "POST",
data: JSON.stringify({name: this.name}),
contentType: 'application/json',
dataType: "json",
success: this._on_success(on_success),
error: this._on_error(error)
});
return url;
};
/**
* GET /api/kernels/[:kernel_id]
*
* Get information about the kernel.
*
* @function get_info
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
Kernel.prototype.get_info = function (success, error) {
utils.ajax(this.kernel_url, {
processData: false,
cache: false,
type: "GET",
dataType: "json",
success: this._on_success(success),
error: this._on_error(error)
});
};
/**
* DELETE /api/kernels/[:kernel_id]
*
* Shutdown the kernel.
*
* If you are also using sessions, then this function should NOT be
* used. Instead, use Session.delete. Otherwise, the session and
* kernel WILL be out of sync.
*
* @function kill
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
Kernel.prototype.kill = function (success, error) {
this.events.trigger('kernel_killed.Kernel', {kernel: this});
this._kernel_dead();
utils.ajax(this.kernel_url, {
processData: false,
cache: false,
type: "DELETE",
dataType: "json",
success: this._on_success(success),
error: this._on_error(error)
});
};
/**
* POST /api/kernels/[:kernel_id]/interrupt
*
* Interrupt the kernel.
*
* @function interrupt
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
Kernel.prototype.interrupt = function (success, error) {
this.events.trigger('kernel_interrupting.Kernel', {kernel: this});
var that = this;
var on_success = function (data, status, xhr) {
/**
* get kernel info so we know what state the kernel is in
*/
that.kernel_info();
if (success) {
success(data, status, xhr);
}
};
var url = utils.url_path_join(this.kernel_url, 'interrupt');
utils.ajax(url, {
processData: false,
cache: false,
type: "POST",
contentType: false, // there's no data with this
dataType: "json",
success: this._on_success(on_success),
error: this._on_error(error)
});
};
Kernel.prototype.restart = function (success, error) {
/**
* POST /api/kernels/[:kernel_id]/restart
*
* Restart the kernel.
*
* @function interrupt
* @param {function} [success] - function executed on ajax success
* @param {function} [error] - function executed on ajax error
*/
this.events.trigger('kernel_restarting.Kernel', {kernel: this});
this.stop_channels();
this._msg_callbacks = {};
this._msg_callbacks_overrides = {};
this._display_id_to_parent_ids = {};
var that = this;
var on_success = function (data, status, xhr) {
that.events.trigger('kernel_created.Kernel', {kernel: that});
that._kernel_created(data);
if (success) {
success(data, status, xhr);
}
};
var on_error = function (xhr, status, err) {
that.events.trigger('kernel_failed_restart.Kernel', {kernel: that});
that._kernel_dead();
if (error) {
error(xhr, status, err);
}
};
var url = utils.url_path_join(this.kernel_url, 'restart');
utils.ajax(url, {
processData: false,
cache: false,
type: "POST",
contentType: false, // there's no data with this
dataType: "json",
success: this._on_success(on_success),
error: this._on_error(on_error)
});
};
Kernel.prototype.reconnect = function () {
/**
* Reconnect to a disconnected kernel. This is not actually a
* standard HTTP request, but useful function nonetheless for
* reconnecting to the kernel if the connection is somehow lost.
*
* @function reconnect
*/
if (this.is_connected()) {
this.stop_channels();
}
this._reconnect_attempt = this._reconnect_attempt + 1;
this.events.trigger('kernel_reconnecting.Kernel', {
kernel: this,
attempt: this._reconnect_attempt,
});
this.start_channels();
};
Kernel.prototype._on_success = function (success) {
/**
* Handle a successful AJAX request by updating the kernel id and
* name from the response, and then optionally calling a provided
* callback.
*
* @function _on_success
* @param {function} success - callback
*/
var that = this;
return function (data, status, xhr) {
if (data) {
that.id = data.id;
that.name = data.name;
}
that.kernel_url = utils.url_path_join(that.kernel_service_url,
encodeURIComponent(that.id));
if (success) {
success(data, status, xhr);
}
};
};
Kernel.prototype._on_error = function (error) {
/**
* Handle a failed AJAX request by logging the error message, and
* then optionally calling a provided callback.
*
* @function _on_error
* @param {function} error - callback
*/
return function (xhr, status, err) {
utils.log_ajax_error(xhr, status, err);
if (error) {
error(xhr, status, err);
}
};
};
Kernel.prototype._kernel_created = function (data) {
/**
* Perform necessary tasks once the kernel has been started,
* including actually connecting to the kernel.
*
* @function _kernel_created
* @param {Object} data - information about the kernel including id
*/
this.id = data.id;
this.kernel_url = utils.url_path_join(this.kernel_service_url,
encodeURIComponent(this.id));
this.start_channels();
};
Kernel.prototype._kernel_connected = function () {
/**
* Perform necessary tasks once the connection to the kernel has
* been established. This includes requesting information about
* the kernel.
*
* @function _kernel_connected
*/
this.events.trigger('kernel_connected.Kernel', {kernel: this});
// Send pending messages. We shift the message off the queue
// after the message is sent so that if there is an exception,
// the message is still pending.
while (this._pending_messages.length > 0) {
this.ws.send(this._pending_messages[0]);
this._pending_messages.shift();
}
// get kernel info so we know what state the kernel is in
var that = this;
this.kernel_info(function (reply) {
that.info_reply = reply.content;
that.events.trigger('kernel_ready.Kernel', {kernel: that});
});
};
Kernel.prototype._kernel_dead = function () {
/**
* Perform necessary tasks after the kernel has died. This closing
* communication channels to the kernel if they are still somehow
* open.
*
* @function _kernel_dead
*/
this.stop_channels();
};
Kernel.prototype.start_channels = function () {
/**
* Start the websocket channels.
* Will stop and restart them if they already exist.
*
* @function start_channels
*/
var that = this;
this.stop_channels();
var ws_host_url = this.ws_url + this.kernel_url;
console.log("Starting WebSockets:", ws_host_url);
this.ws = new this.WebSocket([
that.ws_url,
utils.url_path_join(that.kernel_url, 'channels'),
"?session_id=" + that.session_id
].join('')
);
var already_called_onclose = false; // only alert once
var ws_closed_early = function(evt){
console.log("WebSocket closed early", evt);
if (already_called_onclose){
return;
}
already_called_onclose = true;
// If the websocket was closed early, that could mean
// that the kernel is actually dead. Try getting
// information about the kernel from the API call --
// if that fails, then assume the kernel is dead,
// otherwise just follow the typical websocket closed
// protocol.
that.get_info(function () {
that._ws_closed(ws_host_url, false);
}, function () {
that.events.trigger('kernel_dead.Kernel', {kernel: that});
that._kernel_dead();
});
};
var ws_closed_late = function(evt){
console.log("WebSocket closed unexpectedly", evt);
if (already_called_onclose){
return;
}
already_called_onclose = true;
that._ws_closed(ws_host_url, false);
};
var ws_error = function(evt){
if (already_called_onclose){
return;
}
already_called_onclose = true;
that._ws_closed(ws_host_url, true);
};
this.ws.onopen = $.proxy(this._ws_opened, this);
this.ws.onclose = ws_closed_early;
this.ws.onerror = ws_error;
// switch from early-close to late-close message after 1s
setTimeout(function() {
if (that.ws !== null && !that._stopping) {
that.ws.onclose = ws_closed_late;
}
}, 1000);
this.ws.onmessage = $.proxy(this._handle_ws_message, this);
};
Kernel.prototype._ws_opened = function (evt) {
/**
* Handle a websocket entering the open state,
* signaling that the kernel is connected when websocket is open.
*
* @function _ws_opened
*/
if (this.is_connected()) {
// all events ready, trigger started event.
this._kernel_connected();
}
};
Kernel.prototype._ws_closed = function(ws_url, error) {
/**
* Handle a websocket entering the closed state. If the websocket
* was not closed due to an error, try to reconnect to the kernel.
*
* @function _ws_closed
* @param {string} ws_url - the websocket url
* @param {bool} error - whether the connection was closed due to an error
*/
this.stop_channels();
this.events.trigger('kernel_disconnected.Kernel', {kernel: this});
if (error) {
console.log('WebSocket connection failed: ', ws_url, error);
this.events.trigger('kernel_connection_failed.Kernel', {
kernel: this,
ws_url: ws_url,
attempt: this._reconnect_attempt,
error: error,
});
}
this._schedule_reconnect();
};
Kernel.prototype._schedule_reconnect = function () {
/**
* function to call when kernel connection is lost
* schedules reconnect, or fires 'connection_dead' if reconnect limit is hit
*/
if (this._reconnect_attempt < this.reconnect_limit) {
var timeout = Math.pow(2, this._reconnect_attempt);
console.log("Connection lost, reconnecting in " + timeout + " seconds.");
setTimeout($.proxy(this.reconnect, this), 1e3 * timeout);
} else {
this.events.trigger('kernel_connection_dead.Kernel', {
kernel: this,
reconnect_attempt: this._reconnect_attempt,
});
console.log("Failed to reconnect, giving up.");
}
};
Kernel.prototype.stop_channels = function () {
/**
* Close the websocket. After successful close, the value
* in `this.ws` will be null.
*
* @function stop_channels
*/
var that = this;
var close = function () {
that._stopping = false;
if (that.ws && that.ws.readyState === WebSocket.CLOSED) {
that.ws = null;
}
};
if (this.ws !== null) {
// flag to avoid races with on_close_late
this._stopping = true;
if (this.ws.readyState === WebSocket.OPEN) {
this.ws.onclose = close;
this.ws.close();
} else {
close();
}
}
};
Kernel.prototype.is_connected = function () {
/**
* Check whether there is a connection to the kernel. This
* function only returns true if websocket has been
* created and has a state of WebSocket.OPEN.
*
* @function is_connected
* @returns {bool} - whether there is a connection
*/
// if any channel is not ready, then we're not connected
if (this.ws === null) {
return false;
}
if (this.ws.readyState !== WebSocket.OPEN) {
return false;
}
return true;
};
Kernel.prototype.is_fully_disconnected = function () {
/**
* Check whether the connection to the kernel has been completely
* severed. This function only returns true if all channel objects
* are null.
*
* @function is_fully_disconnected
* @returns {bool} - whether the kernel is fully disconnected
*/
return (this.ws === null);
};
Kernel.prototype._send = function(msg) {
/**
* Send a message (if the kernel is connected) or queue the message for future delivery
*
* Pending messages will automatically be sent when a kernel becomes connected.
*
* @function _send
* @param msg
*/
if (this.is_connected()) {
this.ws.send(msg);
} else {
this._pending_messages.push(msg);
}
};
Kernel.prototype.send_shell_message = function (msg_type, content, callbacks, metadata, buffers) {
/**
* Send a message on the Kernel's shell channel
*
* If the kernel is not connected, the message will be buffered.
*
* @function send_shell_message
*/
var msg = this._get_msg(msg_type, content, metadata, buffers);
msg.channel = 'shell';
this.set_callbacks_for_msg(msg.header.msg_id, callbacks);
this._send(serialize.serialize(msg));
return msg.header.msg_id;
};
Kernel.prototype.kernel_info = function (callback) {
/**
* Get kernel info
*
* @function kernel_info
* @param callback {function}
*
* When calling this method, pass a callback function that expects one argument.
* The callback will be passed the complete `kernel_info_reply` message documented
* [here](https://jupyter-client.readthedocs.io/en/latest/messaging.html#kernel-info)
*/
var callbacks;
if (callback) {
callbacks = { shell : { reply : callback } };
}
return this.send_shell_message("kernel_info_request", {}, callbacks);
};
Kernel.prototype.comm_info = function (target_name, callback) {
/**
* Get comm info
*
* @function comm_info
* @param callback {function}
*
* When calling this method, pass a callback function that expects one argument.
* The callback will be passed the complete `comm_info_reply` message documented
* [here](https://jupyter-client.readthedocs.io/en/latest/messaging.html#comm_info)
*/
var callbacks;
if (callback) {
callbacks = { shell : { reply : callback } };
}
var content = {
target_name : target_name,
};
return this.send_shell_message("comm_info_request", content, callbacks);
};
Kernel.prototype.inspect = function (code, cursor_pos, callback) {
/**
* Get info on an object
*
* When calling this method, pass a callback function that expects one argument.
* The callback will be passed the complete `inspect_reply` message documented
* [here](https://jupyter-client.readthedocs.io/en/latest/messaging.html#object-information)
*
* @function inspect
* @param code {string}
* @param cursor_pos {integer}
* @param callback {function}
*/
var callbacks;
if (callback) {
callbacks = { shell : { reply : callback } };
}
var content = {
code : code,
cursor_pos : cursor_pos,
detail_level : 0
};
return this.send_shell_message("inspect_request", content, callbacks);
};
Kernel.prototype.execute = function (code, callbacks, options) {
/**
* Execute given code into kernel, and pass result to callback.
*
* @async
* @function execute
* @param {string} code
* @param [callbacks] {Object} With the following keys (all optional)
* @param callbacks.shell.reply {function}
* @param callbacks.shell.payload.[payload_name] {function}
* @param callbacks.iopub.output {function}
* @param callbacks.iopub.clear_output {function}
* @param callbacks.input {function}
* @param callbacks.clear_on_done=true {Boolean}
* @param {object} [options]
* @param [options.silent=false] {Boolean}
* @param [options.user_expressions=empty_dict] {Dict}
* @param [options.allow_stdin=false] {Boolean} true|false
*
* @example
*
* The options object should contain the options for the execute
* call. Its default values are:
*
* options = {
* silent : true,
* user_expressions : {},
* allow_stdin : false
* }
*
* When calling this method pass a callbacks structure of the
* form:
*
* callbacks = {
* shell : {
* reply : execute_reply_callback,
* payload : {
* set_next_input : set_next_input_callback,
* }
* },
* iopub : {
* output : output_callback,
* clear_output : clear_output_callback,
* },
* input : raw_input_callback
* }
*
* Each callback will be passed the entire message as a single
* argument. Payload handlers will be passed the corresponding
* payload and the execute_reply message.
*/
var content = {
code : code,
silent : true,
store_history : false,
user_expressions : {},
allow_stdin : false
};
callbacks = callbacks || {};
if (callbacks.input !== undefined) {
content.allow_stdin = true;
}
$.extend(true, content, options);
this.events.trigger('execution_request.Kernel', {kernel: this, content: content});
return this.send_shell_message("execute_request", content, callbacks);
};
/**
* When calling this method, pass a function to be called with the
* `complete_reply` message as its only argument when it arrives.
*
* `complete_reply` is documented
* [here](https://jupyter-client.readthedocs.io/en/latest/messaging.html#complete)
*
* @function complete
* @param code {string}
* @param cursor_pos {integer}
* @param callback {function}
*/
Kernel.prototype.complete = function (code, cursor_pos, callback) {
var callbacks;
if (callback) {
callbacks = { shell : { reply : callback } };
}
var content = {
code : code,
cursor_pos : cursor_pos
};
return this.send_shell_message("complete_request", content, callbacks);
};
/**
* @function send_input_reply
*/
Kernel.prototype.send_input_reply = function (input) {
var content = {
value : input
};
this.events.trigger('input_reply.Kernel', {kernel: this, content: content});
var msg = this._get_msg("input_reply", content);
msg.channel = 'stdin';
this._send(serialize.serialize(msg));
return msg.header.msg_id;
};
/**
* @function register_iopub_handler
*/
Kernel.prototype.register_iopub_handler = function (msg_type, callback) {
this._iopub_handlers[msg_type] = callback;
};
/**
* Get the iopub handler for a specific message type.
*
* @function get_iopub_handler
*/
Kernel.prototype.get_iopub_handler = function (msg_type) {
return this._iopub_handlers[msg_type];
};
/**
* Get callbacks for a specific message.
*
* @function get_callbacks_for_msg
*/
Kernel.prototype.get_callbacks_for_msg = function (msg_id) {
if (msg_id == this.last_msg_id) {
return this.last_msg_callbacks;
} else {
return this._msg_callbacks[msg_id];
}
};
/**
* Get output callbacks for a specific message.
*
* @function get_output_callbacks_for_msg
*
* Since output callbacks can be overridden, we first check the override stack.
*/
Kernel.prototype.get_output_callbacks_for_msg = function (msg_id) {
return this.get_callbacks_for_msg(this.get_output_callback_id(msg_id));
};
/**
* Get the output callback id for a message
*
* Since output callbacks can be redirected, this may not be the same as
* the msg_id.
*
* @function get_output_callback_id
*/
Kernel.prototype.get_output_callback_id = function (msg_id) {
var callback_id = msg_id;
var overrides = this._msg_callbacks_overrides[msg_id];
if (overrides && overrides.length > 0) {
callback_id = overrides[overrides.length-1];
}
return callback_id
}
/**
* Clear callbacks for a specific message.
*
* @function clear_callbacks_for_msg
*/
Kernel.prototype.clear_callbacks_for_msg = function (msg_id) {
if (this._msg_callbacks[msg_id] !== undefined ) {
var callbacks = this._msg_callbacks[msg_id];
var kernel = this;
// clear display_id:msg_id map for display_ids associated with this msg_id
if (!callbacks) return;
callbacks.display_ids.map(function (display_id) {
var msg_ids = kernel._display_id_to_parent_ids[display_id];
if (msg_ids) {
var idx = msg_ids.indexOf(msg_id);
if (idx === -1) {
return;
}
if (msg_ids.length === 1) {
delete kernel._display_id_to_parent_ids[display_id];
} else {
msg_ids.splice(idx, 1);
kernel._display_id_to_parent_ids[display_id] = msg_ids;
}
}
});
delete this._msg_callbacks[msg_id];
}
};
/**
* @function _finish_shell
*/
Kernel.prototype._finish_shell = function (msg_id) {
var callbacks = this._msg_callbacks[msg_id];
if (callbacks !== undefined) {
callbacks.shell_done = true;
if (callbacks.clear_on_done && callbacks.iopub_done) {
this.clear_callbacks_for_msg(msg_id);
}
}
};
/**
* @function _finish_iopub
*/
Kernel.prototype._finish_iopub = function (msg_id) {
var callbacks = this._msg_callbacks[msg_id];
if (callbacks !== undefined) {
callbacks.iopub_done = true;
if (callbacks.clear_on_done && callbacks.shell_done) {
this.clear_callbacks_for_msg(msg_id);
}
}
this.events.trigger('finished_iopub.Kernel', {kernel: this, msg_id: msg_id});
};
/**
* Set callbacks for a particular message.
* Callbacks should be a struct of the following form:
* shell : {
*
* }
*
* If the third parameter is truthy, the callback is set as the last
* callback registered.
*
* @function set_callbacks_for_msg
*/
Kernel.prototype.set_callbacks_for_msg = function (msg_id, callbacks, save) {
var remember = save || true;
if (remember) {
this.last_msg_id = msg_id;
}
if (callbacks) {
// shallow-copy mapping, because we will modify it at the top level
var cbcopy = this._msg_callbacks[msg_id] = this.last_msg_callbacks = {};
cbcopy.shell = callbacks.shell;
cbcopy.iopub = callbacks.iopub;
cbcopy.input = callbacks.input;
cbcopy.clear_on_done = callbacks.clear_on_done;
cbcopy.shell_done = (!callbacks.shell);
cbcopy.iopub_done = (!callbacks.iopub);
cbcopy.display_ids = [];
if (callbacks.clear_on_done === undefined) {
// default to clear-on-done
cbcopy.clear_on_done = true;
}
} else if (remember) {
this.last_msg_callbacks = {};
}
};
/**
* Override output callbacks for a particular msg_id
*/
Kernel.prototype.output_callback_overrides_push = function(msg_id, callback_id) {
var output_callbacks = this._msg_callbacks_overrides[msg_id];
if (!output_callbacks) {
this._msg_callbacks_overrides[msg_id] = output_callbacks = [];
}
output_callbacks.push(callback_id);
}
Kernel.prototype.output_callback_overrides_pop = function(msg_id) {
var callback_ids = this._msg_callbacks_overrides[msg_id];
if (!callback_ids) {
console.error("Popping callback overrides, but none registered", msg_id);
return;
}
return callback_ids.pop();
}
Kernel.prototype._handle_ws_message = function (e) {
var that = this;
this._msg_queue = this._msg_queue.then(function() {
return serialize.deserialize(e.data);
}).then(function(msg) {return that._finish_ws_message(msg);})
.catch(function(error) { console.error("Couldn't process kernel message", error); });
};
Kernel.prototype._finish_ws_message = function (msg) {
switch (msg.channel) {
case 'shell':
return this._handle_shell_reply(msg);
case 'iopub':
return this._handle_iopub_message(msg);
case 'stdin':
return this._handle_input_request(msg);
default:
console.error("unrecognized message channel", msg.channel, msg);
}
};
Kernel.prototype._handle_shell_reply = function (reply) {
this.events.trigger('shell_reply.Kernel', {kernel: this, reply:reply});
var that = this;
var content = reply.content;
var metadata = reply.metadata;
var parent_id = reply.parent_header.msg_id;
var callbacks = this.get_callbacks_for_msg(parent_id);
var promise = Promise.resolve();
if (!callbacks || !callbacks.shell) {
return;
}
var shell_callbacks = callbacks.shell;
// signal that shell callbacks are done
this._finish_shell(parent_id);
if (shell_callbacks.reply !== undefined) {
promise = promise.then(function() {return shell_callbacks.reply(reply);});
}
if (content.payload && shell_callbacks.payload) {
promise = promise.then(function() {
return that._handle_payloads(content.payload, shell_callbacks.payload, reply);
});
}
return promise;
};
/**
* @function _handle_payloads
*/
Kernel.prototype._handle_payloads = function (payloads, payload_callbacks, msg) {
var promise = [];
var l = payloads.length;
// Payloads are handled by triggering events because we don't want the Kernel
// to depend on the Notebook or Pager classes.
for (var i=0; i<l; i++) {
var payload = payloads[i];
var callback = payload_callbacks[payload.source];
if (callback) {
promise.push(callback(payload, msg));
}
}
return Promise.all(promise);
};
/**
* @function _handle_status_message
*/
Kernel.prototype._handle_status_message = function (msg) {
var execution_state = msg.content.execution_state;
var parent_id = msg.parent_header.msg_id;
// dispatch status msg callbacks, if any
var callbacks = this.get_callbacks_for_msg(parent_id);
if (callbacks && callbacks.iopub && callbacks.iopub.status) {
try {
callbacks.iopub.status(msg);
} catch (e) {
console.log("Exception in status msg handler", e, e.stack);
}
}
if (execution_state === 'busy') {
this.events.trigger('kernel_busy.Kernel', {kernel: this});
} else if (execution_state === 'idle') {
// signal that iopub callbacks are (probably) done
// async output may still arrive,
// but only for the most recent request
this._finish_iopub(parent_id);
// trigger status_idle event
this.events.trigger('kernel_idle.Kernel', {kernel: this});
} else if (execution_state === 'starting') {
this.events.trigger('kernel_starting.Kernel', {kernel: this});
var that = this;
this.kernel_info(function (reply) {
that.info_reply = reply.content;
that.events.trigger('kernel_ready.Kernel', {kernel: that});
});
} else if (execution_state === 'restarting') {
// autorestarting is distinct from restarting,
// in that it means the kernel died and the server is restarting it.
// kernel_restarting sets the notification widget,
// autorestart shows the more prominent dialog.
this._autorestart_attempt = this._autorestart_attempt + 1;
this.events.trigger('kernel_restarting.Kernel', {kernel: this});
this.events.trigger('kernel_autorestarting.Kernel', {kernel: this, attempt: this._autorestart_attempt});
} else if (execution_state === 'dead') {
this.events.trigger('kernel_dead.Kernel', {kernel: this});
this._kernel_dead();
}
};
/**
* Handle clear_output message
*
* @function _handle_clear_output
*/
Kernel.prototype._handle_clear_output = function (msg) {
var callbacks = this.get_output_callbacks_for_msg(msg.parent_header.msg_id);
if (!callbacks || !callbacks.iopub) {
return;
}
var callback = callbacks.iopub.clear_output;
if (callback) {
callback(msg);
}
};
/**
* handle an output message (execute_result, display_data, etc.)
*
* @function _handle_output_message
*/
Kernel.prototype._handle_output_message = function (msg) {
var that = this;
var msg_id = msg.parent_header.msg_id;
var callbacks = this.get_output_callbacks_for_msg(msg_id);
if (['display_data', 'update_display_data', 'execute_result'].indexOf(msg.header.msg_type) > -1) {
// display_data messages may re-route based on their display_id
var display_id = (msg.content.transient || {}).display_id;
if (display_id) {
// it has a display_id
var parent_ids = this._display_id_to_parent_ids[display_id];
if (parent_ids) {
// we've seen it before, update existing outputs with same display_id
// by handling display_data as update_display_data
var update_msg = $.extend(true, {}, msg);
update_msg.header.msg_type = 'update_display_data';
parent_ids.map(function (parent_id) {
var callbacks = that.get_callbacks_for_msg(parent_id);
if (!callbacks) return;
var callback = callbacks.iopub.output;
if (callback) {
callback(update_msg);
}
});
}
// we're done here if it's update_display
if (msg.header.msg_type === 'update_display_data') {
// it's an update, don't proceed to the normal display
return;
}
// regular display_data with id, record it for future updating
// in _display_id_to_parent_ids for future lookup
if (this._display_id_to_parent_ids[display_id] === undefined) {
this._display_id_to_parent_ids[display_id] = [];
}
var callback_id = this.get_output_callback_id(msg_id);
if (this._display_id_to_parent_ids[display_id].indexOf(callback_id) === -1) {
this._display_id_to_parent_ids[display_id].push(callback_id);
}
// and in callbacks for cleanup on clear_callbacks_for_msg
if (callbacks && callbacks.display_ids.indexOf(display_id) === -1) {
callbacks.display_ids.push(display_id);
}
}
}
if (!callbacks || !callbacks.iopub) {
// The message came from another client. Let the UI decide what to
// do with it.
this.events.trigger('received_unsolicited_message.Kernel', msg);
return;
}
var callback = callbacks.iopub.output;
if (callback) {
callback(msg);
}
};
/**
* Handle an input message (execute_input).
*
* @function _handle_input message
*/
Kernel.prototype._handle_input_message = function (msg) {
var callbacks = this.get_callbacks_for_msg(msg.parent_header.msg_id);
if (!callbacks) {
// The message came from another client. Let the UI decide what to
// do with it.
this.events.trigger('received_unsolicited_message.Kernel', msg);
}
};
/**
* Handle a kernel shutdown message
* @function _handle_shutdown_message
*/
Kernel.prototype._handle_shutdown_message = function (msg) {
if (!msg.content.restart) {
this.events.trigger('kernel_dead.Kernel', {kernel: this});
this._kernel_dead();
}
}
/**
* Dispatch IOPub messages to respective handlers. Each message
* type should have a handler.
*
* @function _handle_iopub_message
*/
Kernel.prototype._handle_iopub_message = function (msg) {
var handler = this.get_iopub_handler(msg.header.msg_type);
if (handler !== undefined) {
return handler(msg);
}
};
/**
* @function _handle_input_request
*/
Kernel.prototype._handle_input_request = function (request) {
var header = request.header;
var content = request.content;
var metadata = request.metadata;
var msg_type = header.msg_type;
if (msg_type !== 'input_request') {
console.log("Invalid input request!", request);
return;
}
var callbacks = this.get_callbacks_for_msg(request.parent_header.msg_id);
if (callbacks) {
if (callbacks.input) {
callbacks.input(request);
}
}
};
return {'Kernel': Kernel};
});