Quelle Pool.js Sprache: JAVA

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

var EventEmitter = require("resource://devtools/shared/event-emitter.js");

/**
* Actor and Front implementations
*/

/**
* A protocol object that can manage the lifetime of other protocol
* objects. Pools are used on both sides of the connection to help coordinate lifetimes.
*
* @param {DevToolsServerConnection|DevToolsClient} [conn]
*   Either a DevToolsServerConnection or a DevToolsClient. Must have
*   addActorPool, removeActorPool, and poolFor.
*   conn can be null if the subclass provides a conn property.
* @param {String} [label]
*   An optional label for the Pool.
* @constructor
*/
class Pool extends EventEmitter {
  constructor(conn, label) {
    super();

    if (conn) {
      this.conn = conn;
    }
    this.label = label;

    // Will be individually flipped to true by Actor/Front classes.
    // Will also only be exposed via Actor/Front::isDestroyed().
    this._isDestroyed = false;
  }

  __poolMap = null;
  parentPool = null;

  /**
   * Return the parent pool for this client.
   */
  getParent() {
    return this.parentPool;
  }

  /**
   * A pool is at the top of its pool hierarchy if it has:
   * - no parent
   * - or it is its own parent
   */
  isTopPool() {
    const parent = this.getParent();
    return !parent || parent === this;
  }

  poolFor(actorID) {
    return this.conn.poolFor(actorID);
  }

  /**
   * Override this if you want actors returned by this actor
   * to belong to a different actor by default.
   */
  marshallPool() {
    return this;
  }

  /**
   * Pool is the base class for all actors, even leaf nodes.
   * If the child map is actually referenced, go ahead and create
   * the stuff needed by the pool.
   */
  get _poolMap() {
    if (this.__poolMap) {
      return this.__poolMap;
    }
    this.__poolMap = new Map();
    this.conn.addActorPool(this);
    return this.__poolMap;
  }

  /**
   * Add an actor as a child of this pool.
   */
  manage(actor) {
    if (!actor.actorID) {
      actor.actorID = this.conn.allocID(actor.typeName);
    } else {
      // If the actor is already registered in a pool, remove it without destroying it.
      // This happens for example when an addon is reloaded. To see this behavior, take a
      // look at devtools/server/tests/xpcshell/test_addon_reload.js

      const parent = actor.getParent();
      if (parent && parent !== this) {
        parent.unmanage(actor);
      }
    }
    // Duplicate the ID into another field as `actorID` will be cleared on destruction
    actor.persistedActorID = actor.actorID;

    this._poolMap.set(actor.actorID, actor);
    actor.parentPool = this;
  }

  unmanageChildren(FrontType) {
    for (const front of this.poolChildren()) {
      if (!FrontType || front instanceof FrontType) {
        this.unmanage(front);
      }
    }
  }

  /**
   * Remove an actor as a child of this pool.
   */
  unmanage(actor) {
    if (this.__poolMap) {
      this.__poolMap.delete(actor.actorID);
    }
    actor.parentPool = null;
  }

  // true if the given actor ID exists in the pool.
  has(actorID) {
    return this.__poolMap && this._poolMap.has(actorID);
  }

  /**
   * Search for an actor in this pool, given an actorID
   * @param {String} actorID
   * @returns {Actor/null} Returns null if the actor wasn't found
   */
  getActorByID(actorID) {
    if (this.__poolMap) {
      return this._poolMap.get(actorID);
    }
    return null;
  }

  // Generator that yields each non-self child of the pool.
  *poolChildren() {
    if (!this.__poolMap) {
      return;
    }
    for (const actor of this.__poolMap.values()) {
      // Self-owned actors are ok, but don't need visiting twice.
      if (actor === this) {
        continue;
      }
      yield actor;
    }
  }

  isDestroyed() {
    // Note: _isDestroyed is only flipped from Actor and Front subclasses for
    // now, so this method should not be called on pure Pool instances.
    // See Bug 1717811.
    return this._isDestroyed;
  }

  /**
   * Pools can override this method in order to opt-out of a destroy sequence.
   *
   * For instance, Fronts are destroyed during the toolbox destroy. However when
   * the toolbox is destroyed, the document holding the toolbox is also
   * destroyed. So it should not be necessary to cleanup Fronts during toolbox
   * destroy.
   *
   * For the time being, Fronts (or Pools in general) which want to opt-out of
   * toolbox destroy can override this method and check the value of
   * `this.conn.isToolboxDestroy`.
   */
  skipDestroy() {
    return false;
  }

  /**
   * Destroy this item, removing it from a parent if it has one,
   * and destroying all children if necessary.
   */
  destroy() {
    const parent = this.getParent();
    if (parent) {
      parent.unmanage(this);
    }
    if (!this.__poolMap) {
      return;
    }
    // Immediately clear the poolmap so that we bail out early if the code is reentrant.
    const poolMap = this.__poolMap;
    this.__poolMap = null;

    for (const actor of poolMap.values()) {
      // Self-owned actors are ok, but don't need destroying twice.
      if (actor === this) {
        continue;
      }

      // Some pool-managed values don't extend Pool and won't have skipDestroy
      // defined. For instance, the root actor and the lazy actors.
      if (typeof actor.skipDestroy === "function" && actor.skipDestroy()) {
        continue;
      }

      const destroy = actor.destroy;
      if (destroy) {
        // Disconnect destroy while we're destroying in case of (misbehaving)
        // circular ownership.
        actor.destroy = null;
        destroy.call(actor);
        actor.destroy = destroy;
      }
    }

    // `conn` might be null for LazyPool in an unexplained way.
    if (this.conn) {
      this.conn.removeActorPool(this);
      this.conn = null;
    }
  }
}

exports.Pool = Pool;

quality94%

¤ Dauer der Verarbeitung: 0.26 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.