@jupyterlab/services/lib/kernel/manager.js

"use strict";
// Copyright (c) Jupyter Development Team.
// Distributed under the terms of the Modified BSD License.
Object.defineProperty(exports, "__esModule", { value: true });
exports.KernelManager = void 0;
const polling_1 = require("@lumino/polling");
const signaling_1 = require("@lumino/signaling");
const __1 = require("..");
const basemanager_1 = require("../basemanager");
const restapi_1 = require("./restapi");
const default_1 = require("./default");
/**
 * An implementation of a kernel manager.
 */
class KernelManager extends basemanager_1.BaseManager {
    /**
     * Construct a new kernel manager.
     *
     * @param options - The default options for kernel.
     */
    constructor(options = {}) {
        var _a;
        super(options);
        this._isReady = false;
        this._kernelConnections = new Set();
        this._models = new Map();
        this._runningChanged = new signaling_1.Signal(this);
        this._connectionFailure = new signaling_1.Signal(this);
        // Start model and specs polling with exponential backoff.
        this._pollModels = new polling_1.Poll({
            auto: false,
            factory: () => this.requestRunning(),
            frequency: {
                interval: 10 * 1000,
                backoff: true,
                max: 300 * 1000
            },
            name: `@jupyterlab/services:KernelManager#models`,
            standby: (_a = options.standby) !== null && _a !== void 0 ? _a : 'when-hidden'
        });
        // Initialize internal data.
        this._ready = (async () => {
            await this._pollModels.start();
            await this._pollModels.tick;
            this._isReady = true;
        })();
    }
    /**
     * Test whether the manager is ready.
     */
    get isReady() {
        return this._isReady;
    }
    /**
     * A promise that fulfills when the manager is ready.
     */
    get ready() {
        return this._ready;
    }
    /**
     * A signal emitted when the running kernels change.
     */
    get runningChanged() {
        return this._runningChanged;
    }
    /**
     * A signal emitted when there is a connection failure.
     */
    get connectionFailure() {
        return this._connectionFailure;
    }
    /**
     * Dispose of the resources used by the manager.
     */
    dispose() {
        if (this.isDisposed) {
            return;
        }
        this._models.clear();
        this._kernelConnections.forEach(x => x.dispose());
        this._pollModels.dispose();
        super.dispose();
    }
    /**
     * Connect to an existing kernel.
     *
     * @returns The new kernel connection.
     *
     * #### Notes
     * This will use the manager's server settings and ignore any server
     * settings passed in the options.
     */
    connectTo(options) {
        var _a;
        const { id } = options.model;
        let handleComms = (_a = options.handleComms) !== null && _a !== void 0 ? _a : true;
        // By default, handle comms only if no other kernel connection is.
        if (options.handleComms === undefined) {
            for (const kc of this._kernelConnections) {
                if (kc.id === id && kc.handleComms) {
                    handleComms = false;
                    break;
                }
            }
        }
        const kernelConnection = new default_1.KernelConnection({
            handleComms,
            ...options,
            serverSettings: this.serverSettings
        });
        this._onStarted(kernelConnection);
        if (!this._models.has(id)) {
            // We trust the user to connect to an existing kernel, but we verify
            // asynchronously.
            void this.refreshRunning().catch(() => {
                /* no-op */
            });
        }
        return kernelConnection;
    }
    /**
     * Create an iterator over the most recent running kernels.
     *
     * @returns A new iterator over the running kernels.
     */
    running() {
        return this._models.values();
    }
    /**
     * Force a refresh of the running kernels.
     *
     * @returns A promise that resolves when the running list has been refreshed.
     *
     * #### Notes
     * This is not typically meant to be called by the user, since the
     * manager maintains its own internal state.
     */
    async refreshRunning() {
        await this._pollModels.refresh();
        await this._pollModels.tick;
    }
    /**
     * Start a new kernel.
     *
     * @param createOptions - The kernel creation options
     *
     * @param connectOptions - The kernel connection options
     *
     * @returns A promise that resolves with the kernel connection.
     *
     * #### Notes
     * The manager `serverSettings` will be always be used.
     */
    async startNew(createOptions = {}, connectOptions = {}) {
        const model = await (0, restapi_1.startNew)(createOptions, this.serverSettings);
        return this.connectTo({
            ...connectOptions,
            model
        });
    }
    /**
     * Shut down a kernel by id.
     *
     * @param id - The id of the target kernel.
     *
     * @returns A promise that resolves when the operation is complete.
     */
    async shutdown(id) {
        await (0, restapi_1.shutdownKernel)(id, this.serverSettings);
        await this.refreshRunning();
    }
    /**
     * Shut down all kernels.
     *
     * @returns A promise that resolves when all of the kernels are shut down.
     */
    async shutdownAll() {
        // Update the list of models to make sure our list is current.
        await this.refreshRunning();
        // Shut down all models.
        await Promise.all([...this._models.keys()].map(id => (0, restapi_1.shutdownKernel)(id, this.serverSettings)));
        // Update the list of models to clear out our state.
        await this.refreshRunning();
    }
    /**
     * Find a kernel by id.
     *
     * @param id - The id of the target kernel.
     *
     * @returns A promise that resolves with the kernel's model.
     */
    async findById(id) {
        if (this._models.has(id)) {
            return this._models.get(id);
        }
        await this.refreshRunning();
        return this._models.get(id);
    }
    /**
     * Execute a request to the server to poll running kernels and update state.
     */
    async requestRunning() {
        var _a, _b;
        let models;
        try {
            models = await (0, restapi_1.listRunning)(this.serverSettings);
        }
        catch (err) {
            // Handle network errors, as well as cases where we are on a
            // JupyterHub and the server is not running. JupyterHub returns a
            // 503 (<2.0) or 424 (>2.0) in that case.
            if (err instanceof __1.ServerConnection.NetworkError ||
                ((_a = err.response) === null || _a === void 0 ? void 0 : _a.status) === 503 ||
                ((_b = err.response) === null || _b === void 0 ? void 0 : _b.status) === 424) {
                this._connectionFailure.emit(err);
            }
            throw err;
        }
        if (this.isDisposed) {
            return;
        }
        if (this._models.size === models.length &&
            models.every(model => {
                const existing = this._models.get(model.id);
                if (!existing) {
                    return false;
                }
                return (existing.connections === model.connections &&
                    existing.execution_state === model.execution_state &&
                    existing.last_activity === model.last_activity &&
                    existing.name === model.name &&
                    existing.reason === model.reason &&
                    existing.traceback === model.traceback);
            })) {
            // Identical models list (presuming models does not contain duplicate
            // ids), so just return
            return;
        }
        this._models = new Map(models.map(x => [x.id, x]));
        // For any kernel connection to a kernel that doesn't exist, notify it of
        // the shutdown.
        this._kernelConnections.forEach(kc => {
            if (!this._models.has(kc.id)) {
                kc.handleShutdown();
            }
        });
        this._runningChanged.emit(models);
    }
    /**
     * Handle a kernel starting.
     */
    _onStarted(kernelConnection) {
        this._kernelConnections.add(kernelConnection);
        kernelConnection.statusChanged.connect(this._onStatusChanged, this);
        kernelConnection.disposed.connect(this._onDisposed, this);
    }
    _onDisposed(kernelConnection) {
        this._kernelConnections.delete(kernelConnection);
        // A dispose emission could mean the server session is deleted, or that
        // the kernel JS object is disposed and the kernel still exists on the
        // server, so we refresh from the server to make sure we reflect the
        // server state.
        void this.refreshRunning().catch(() => {
            /* no-op */
        });
    }
    _onStatusChanged(kernelConnection, status) {
        if (status === 'dead') {
            // We asynchronously update our list of kernels, which asynchronously
            // will dispose them. We do not want to immediately dispose them because
            // there may be other signal handlers that want to be called.
            void this.refreshRunning().catch(() => {
                /* no-op */
            });
        }
    }
}
exports.KernelManager = KernelManager;
/**
 * The namespace for `KernelManager` class statics.
 */
(function (KernelManager) {
    /**
     * A no-op kernel manager to be used when starting kernels.
     */
    class NoopManager extends KernelManager {
        constructor() {
            super(...arguments);
            this._readyPromise = new Promise(() => {
                /* no-op */
            });
        }
        /**
         * Whether the manager is active.
         */
        get isActive() {
            return false;
        }
        /**
         * Used for testing.
         */
        get parentReady() {
            return super.ready;
        }
        /**
         * Start a new kernel - throws an error since it is not supported.
         */
        async startNew(createOptions = {}, connectOptions = {}) {
            return Promise.reject(new Error('Not implemented in no-op Kernel Manager'));
        }
        /**
         * Connect to an existing kernel - throws an error since it is not supported.
         */
        connectTo(options) {
            throw new Error('Not implemented in no-op Kernel Manager');
        }
        /**
         * Shut down a kernel by id - throws an error since it is not supported.
         */
        async shutdown(id) {
            return Promise.reject(new Error('Not implemented in no-op Kernel Manager'));
        }
        /**
         * A promise that fulfills when the manager is ready (never).
         */
        get ready() {
            return this.parentReady.then(() => this._readyPromise);
        }
        /**
         * Execute a request to the server to poll running kernels and update state.
         */
        async requestRunning() {
            return Promise.resolve();
        }
    }
    KernelManager.NoopManager = NoopManager;
})(KernelManager || (exports.KernelManager = KernelManager = {}));
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