1 files changed, 580 insertions, 0 deletions
diff --git a/devtools/server/actors/resources/utils/parent-process-storage.js b/devtools/server/actors/resources/utils/parent-process-storage.js
new file mode 100644
index 0000000000..423d13b6b5
--- /dev/null
+++ b/devtools/server/actors/resources/utils/parent-process-storage.js
@@ -0,0 +1,580 @@
+/* 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";
+
+const EventEmitter = require("resource://devtools/shared/event-emitter.js");
+const { isWindowGlobalPartOfContext } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/browsing-context-helpers.sys.mjs"
+);
+
+// ms of delay to throttle updates
+const BATCH_DELAY = 200;
+
+// Filters "stores-update" response to only include events for
+// the storage type we desire
+function getFilteredStorageEvents(updates, storageType) {
+  const filteredUpdate = Object.create(null);
+
+  // updateType will be "added", "changed", or "deleted"
+  for (const updateType in updates) {
+    if (updates[updateType][storageType]) {
+      if (!filteredUpdate[updateType]) {
+        filteredUpdate[updateType] = {};
+      }
+      filteredUpdate[updateType][storageType] =
+        updates[updateType][storageType];
+    }
+  }
+
+  return Object.keys(filteredUpdate).length ? filteredUpdate : null;
+}
+
+class ParentProcessStorage {
+  constructor(ActorConstructor, storageKey, storageType) {
+    this.ActorConstructor = ActorConstructor;
+    this.storageKey = storageKey;
+    this.storageType = storageType;
+
+    this.onStoresUpdate = this.onStoresUpdate.bind(this);
+    this.onStoresCleared = this.onStoresCleared.bind(this);
+
+    this.observe = this.observe.bind(this);
+    // Notifications that help us keep track of newly added windows and windows
+    // that got removed
+    Services.obs.addObserver(this, "window-global-created");
+    Services.obs.addObserver(this, "window-global-destroyed");
+
+    // bfcacheInParent is only enabled when fission is enabled
+    // and when Session History In Parent is enabled. (all three modes should now enabled all together)
+    loader.lazyGetter(
+      this,
+      "isBfcacheInParentEnabled",
+      () =>
+        Services.appinfo.sessionHistoryInParent &&
+        Services.prefs.getBoolPref("fission.bfcacheInParent", false)
+    );
+  }
+
+  async watch(watcherActor, { onAvailable }) {
+    this.watcherActor = watcherActor;
+    this.onAvailable = onAvailable;
+
+    // When doing a bfcache navigation with Fission disabled or with Fission + bfCacheInParent enabled,
+    // we're not getting a the window-global-created events.
+    // In such case, the watcher emits specific events that we can use instead.
+    this._offPageShow = watcherActor.on(
+      "bf-cache-navigation-pageshow",
+      ({ windowGlobal }) => this._onNewWindowGlobal(windowGlobal, true)
+    );
+
+    if (watcherActor.sessionContext.type == "browser-element") {
+      const { browsingContext, innerWindowID: innerWindowId } =
+        watcherActor.browserElement;
+      await this._spawnActor(browsingContext.id, innerWindowId);
+    } else if (watcherActor.sessionContext.type == "webextension") {
+      const { addonBrowsingContextID, addonInnerWindowId } =
+        watcherActor.sessionContext;
+      await this._spawnActor(addonBrowsingContextID, addonInnerWindowId);
+    } else if (watcherActor.sessionContext.type == "all") {
+      const parentProcessTargetActor =
+        this.watcherActor.getTargetActorInParentProcess();
+      const { browsingContextID, innerWindowId } =
+        parentProcessTargetActor.form();
+      await this._spawnActor(browsingContextID, innerWindowId);
+    } else {
+      throw new Error(
+        "Unsupported session context type=" + watcherActor.sessionContext.type
+      );
+    }
+  }
+
+  onStoresUpdate(response) {
+    response = getFilteredStorageEvents(response, this.storageKey);
+    if (!response) {
+      return;
+    }
+    this.actor.emit("single-store-update", {
+      changed: response.changed,
+      added: response.added,
+      deleted: response.deleted,
+    });
+  }
+
+  onStoresCleared(response) {
+    const cleared = response[this.storageKey];
+
+    if (!cleared) {
+      return;
+    }
+
+    this.actor.emit("single-store-cleared", {
+      clearedHostsOrPaths: cleared,
+    });
+  }
+
+  destroy() {
+    // Remove observers
+    Services.obs.removeObserver(this, "window-global-created");
+    Services.obs.removeObserver(this, "window-global-destroyed");
+    this._offPageShow();
+    this._cleanActor();
+  }
+
+  async _spawnActor(browsingContextID, innerWindowId) {
+    const storageActor = new StorageActorMock(this.watcherActor);
+    this.storageActor = storageActor;
+    this.actor = new this.ActorConstructor(storageActor);
+
+    // Some storage types require to prelist their stores
+    try {
+      await this.actor.populateStoresForHosts();
+    } catch (e) {
+      // It can happen that the actor gets destroyed while populateStoresForHosts is being
+      // executed.
+      if (this.actor) {
+        throw e;
+      }
+    }
+
+    // If the actor was destroyed, we don't need to go further.
+    if (!this.actor) {
+      return;
+    }
+
+    // We have to manage the actor manually, because ResourceCommand doesn't
+    // use the protocol.js specification.
+    // resource-available-form is typed as "json"
+    // So that we have to manually handle stuff that would normally be
+    // automagically done by procotol.js
+    // 1) Manage the actor in order to have an actorID on it
+    this.watcherActor.manage(this.actor);
+    // 2) Convert to JSON "form"
+    const storage = this.actor.form();
+
+    // All resources should have a resourceType, resourceId and resourceKey
+    // attributes, so available/updated/destroyed callbacks work properly.
+    storage.resourceType = this.storageType;
+    storage.resourceId = `${this.storageType}-${innerWindowId}`;
+    storage.resourceKey = this.storageKey;
+    // NOTE: the resource command needs this attribute
+    storage.browsingContextID = browsingContextID;
+
+    this.onAvailable([storage]);
+
+    // Maps global events from `storageActor` shared for all storage-types,
+    // down to storage-type's specific actor `storage`.
+    storageActor.on("stores-update", this.onStoresUpdate);
+
+    // When a store gets cleared
+    storageActor.on("stores-cleared", this.onStoresCleared);
+  }
+
+  _cleanActor() {
+    this.actor?.destroy();
+    this.actor = null;
+    if (this.storageActor) {
+      this.storageActor.off("stores-update", this.onStoresUpdate);
+      this.storageActor.off("stores-cleared", this.onStoresCleared);
+      this.storageActor.destroy();
+      this.storageActor = null;
+    }
+  }
+
+  /**
+   * Event handler for any docshell update. This lets us figure out whenever
+   * any new window is added, or an existing window is removed.
+   */
+  observe(subject, topic) {
+    if (topic === "window-global-created") {
+      this._onNewWindowGlobal(subject);
+    }
+  }
+
+  /**
+   * Handle WindowGlobal received via:
+   * - <window-global-created> (to cover regular navigations, with brand new documents)
+   * - <bf-cache-navigation-pageshow> (to cover history navications)
+   *
+   * @param {WindowGlobal} windowGlobal
+   * @param {Boolean} isBfCacheNavigation
+   */
+  async _onNewWindowGlobal(windowGlobal, isBfCacheNavigation) {
+    // Only process WindowGlobals which are related to the debugged scope.
+    if (
+      !isWindowGlobalPartOfContext(
+        windowGlobal,
+        this.watcherActor.sessionContext,
+        { acceptNoWindowGlobal: true, acceptSameProcessIframes: true }
+      )
+    ) {
+      return;
+    }
+
+    // Ignore about:blank
+    if (windowGlobal.documentURI.displaySpec === "about:blank") {
+      return;
+    }
+
+    // Only process top BrowsingContext (ignore same-process iframe ones)
+    const isTopContext =
+      windowGlobal.browsingContext.top == windowGlobal.browsingContext;
+    if (!isTopContext) {
+      return;
+    }
+
+    // We only want to spawn a new StorageActor if a new target is being created, i.e.
+    // - target switching is enabled and we're notified about a new top-level window global,
+    //   via window-global-created
+    // - target switching is enabled OR bfCacheInParent is enabled, and a bfcache navigation
+    //   is performed (See handling of "pageshow" event in DevToolsFrameChild)
+    const isNewTargetBeingCreated =
+      this.watcherActor.sessionContext.isServerTargetSwitchingEnabled ||
+      (isBfCacheNavigation && this.isBfcacheInParentEnabled);
+
+    if (!isNewTargetBeingCreated) {
+      return;
+    }
+
+    // When server side target switching is enabled, we replace the StorageActor
+    // with a new one.
+    // On the frontend, the navigation will destroy the previous target, which
+    // will destroy the previous storage front, so we must notify about a new one.
+
+    // When we are target switching we keep the storage watcher, so we need
+    // to send a new resource to the client.
+    // However, we must ensure that we do this when the new target is
+    // already available, so we check innerWindowId to do it.
+    await new Promise(resolve => {
+      const listener = targetActorForm => {
+        if (targetActorForm.innerWindowId != windowGlobal.innerWindowId) {
+          return;
+        }
+        this.watcherActor.off("target-available-form", listener);
+        resolve();
+      };
+      this.watcherActor.on("target-available-form", listener);
+    });
+
+    this._cleanActor();
+    this._spawnActor(
+      windowGlobal.browsingContext.id,
+      windowGlobal.innerWindowId
+    );
+  }
+}
+
+module.exports = ParentProcessStorage;
+
+class StorageActorMock extends EventEmitter {
+  constructor(watcherActor) {
+    super();
+
+    this.conn = watcherActor.conn;
+    this.watcherActor = watcherActor;
+
+    this.boundUpdate = {};
+
+    // Notifications that help us keep track of newly added windows and windows
+    // that got removed
+    this.observe = this.observe.bind(this);
+    Services.obs.addObserver(this, "window-global-created");
+    Services.obs.addObserver(this, "window-global-destroyed");
+
+    // When doing a bfcache navigation with Fission disabled or with Fission + bfCacheInParent enabled,
+    // we're not getting a the window-global-created/window-global-destroyed events.
+    // In such case, the watcher emits specific events that we can use as equivalent to
+    // window-global-created/window-global-destroyed.
+    // We only need to react to those events here if target switching is not enabled; when
+    // it is enabled, ParentProcessStorage will spawn a whole new actor which will allow
+    // the client to get the information it needs.
+    if (!this.watcherActor.sessionContext.isServerTargetSwitchingEnabled) {
+      this._offPageShow = watcherActor.on(
+        "bf-cache-navigation-pageshow",
+        ({ windowGlobal }) => {
+          // if a new target is created in the content process as a result of the bfcache
+          // navigation, we don't need to emit window-ready as a new StorageActorMock will
+          // be created by ParentProcessStorage.
+          // When server targets are disabled, this only happens when bfcache in parent is enabled.
+          if (this.isBfcacheInParentEnabled) {
+            return;
+          }
+          const windowMock = { location: windowGlobal.documentURI };
+          this.emit("window-ready", windowMock);
+        }
+      );
+
+      this._offPageHide = watcherActor.on(
+        "bf-cache-navigation-pagehide",
+        ({ windowGlobal }) => {
+          const windowMock = { location: windowGlobal.documentURI };
+          // The listener of this events usually check that there are no other windows
+          // with the same host before notifying the client that it can remove it from
+          // the UI. The windows are retrieved from the `windows` getter, and in this case
+          // we still have a reference to the window we're navigating away from.
+          // We pass a `dontCheckHost` parameter alongside the window-destroyed event to
+          // always notify the client.
+          this.emit("window-destroyed", windowMock, { dontCheckHost: true });
+        }
+      );
+    }
+  }
+
+  destroy() {
+    // clear update throttle timeout
+    clearTimeout(this.batchTimer);
+    this.batchTimer = null;
+    // Remove observers
+    Services.obs.removeObserver(this, "window-global-created");
+    Services.obs.removeObserver(this, "window-global-destroyed");
+    if (this._offPageShow) {
+      this._offPageShow();
+    }
+    if (this._offPageHide) {
+      this._offPageHide();
+    }
+  }
+
+  get windows() {
+    return (
+      this.watcherActor
+        .getAllBrowsingContexts({
+          acceptSameProcessIframes: true,
+        })
+        .map(x => {
+          const uri = x.currentWindowGlobal.documentURI;
+          return { location: uri };
+        })
+        // NOTE: we are removing about:blank because we might get them for iframes
+        // whose src attribute has not been set yet.
+        .filter(x => x.location.displaySpec !== "about:blank")
+    );
+  }
+
+  // NOTE: this uri argument is not a real window.Location, but the
+  // `currentWindowGlobal.documentURI` object passed from `windows` getter.
+  getHostName(uri) {
+    switch (uri.scheme) {
+      case "about":
+      case "file":
+      case "javascript":
+      case "resource":
+        return uri.displaySpec;
+      case "moz-extension":
+      case "http":
+      case "https":
+        return uri.prePath;
+      default:
+        // chrome: and data: do not support storage
+        return null;
+    }
+  }
+
+  getWindowFromHost(host) {
+    const hostBrowsingContext = this.watcherActor
+      .getAllBrowsingContexts({ acceptSameProcessIframes: true })
+      .find(x => {
+        const hostName = this.getHostName(x.currentWindowGlobal.documentURI);
+        return hostName === host;
+      });
+    // In case of WebExtension or BrowserToolbox, we may pass privileged hosts
+    // which don't relate to any particular window.
+    // Like "indexeddb+++fx-devtools" or "chrome".
+    // (callsites of this method are used to handle null returned values)
+    if (!hostBrowsingContext) {
+      return null;
+    }
+
+    const principal =
+      hostBrowsingContext.currentWindowGlobal.documentStoragePrincipal;
+
+    return { document: { effectiveStoragePrincipal: principal } };
+  }
+
+  get parentActor() {
+    return {
+      isRootActor: this.watcherActor.sessionContext.type == "all",
+      addonId: this.watcherActor.sessionContext.addonId,
+    };
+  }
+
+  /**
+   * Event handler for any docshell update. This lets us figure out whenever
+   * any new window is added, or an existing window is removed.
+   */
+  async observe(windowGlobal, topic) {
+    // Only process WindowGlobals which are related to the debugged scope.
+    if (
+      !isWindowGlobalPartOfContext(
+        windowGlobal,
+        this.watcherActor.sessionContext,
+        { acceptNoWindowGlobal: true, acceptSameProcessIframes: true }
+      )
+    ) {
+      return;
+    }
+
+    // Ignore about:blank
+    if (windowGlobal.documentURI.displaySpec === "about:blank") {
+      return;
+    }
+
+    // Only notify about remote iframe windows when JSWindowActor based targets are enabled
+    // We will create a new StorageActor for the top level tab documents when server side target
+    // switching is enabled
+    const isTopContext =
+      windowGlobal.browsingContext.top == windowGlobal.browsingContext;
+    if (
+      isTopContext &&
+      this.watcherActor.sessionContext.isServerTargetSwitchingEnabled
+    ) {
+      return;
+    }
+
+    // emit window-wready and window-destroyed events when needed
+    const windowMock = { location: windowGlobal.documentURI };
+    if (topic === "window-global-created") {
+      this.emit("window-ready", windowMock);
+    } else if (topic === "window-global-destroyed") {
+      this.emit("window-destroyed", windowMock);
+    }
+  }
+
+  /**
+   * This method is called by the registered storage types so as to tell the
+   * Storage Actor that there are some changes in the stores. Storage Actor then
+   * notifies the client front about these changes at regular (BATCH_DELAY)
+   * interval.
+   *
+   * @param {string} action
+   *        The type of change. One of "added", "changed" or "deleted"
+   * @param {string} storeType
+   *        The storage actor in which this change has occurred.
+   * @param {object} data
+   *        The update object. This object is of the following format:
+   *         - {
+   *             <host1>: [<store_names1>, <store_name2>...],
+   *             <host2>: [<store_names34>...],
+   *           }
+   *           Where host1, host2 are the host in which this change happened and
+   *           [<store_namesX] is an array of the names of the changed store objects.
+   *           Pass an empty array if the host itself was affected: either completely
+   *           removed or cleared.
+   */
+  // eslint-disable-next-line complexity
+  update(action, storeType, data) {
+    if (action == "cleared") {
+      this.emit("stores-cleared", { [storeType]: data });
+      return null;
+    }
+
+    if (this.batchTimer) {
+      clearTimeout(this.batchTimer);
+    }
+    if (!this.boundUpdate[action]) {
+      this.boundUpdate[action] = {};
+    }
+    if (!this.boundUpdate[action][storeType]) {
+      this.boundUpdate[action][storeType] = {};
+    }
+    for (const host in data) {
+      if (!this.boundUpdate[action][storeType][host]) {
+        this.boundUpdate[action][storeType][host] = [];
+      }
+      for (const name of data[host]) {
+        if (!this.boundUpdate[action][storeType][host].includes(name)) {
+          this.boundUpdate[action][storeType][host].push(name);
+        }
+      }
+    }
+    if (action == "added") {
+      // If the same store name was previously deleted or changed, but now is
+      // added somehow, dont send the deleted or changed update.
+      this.removeNamesFromUpdateList("deleted", storeType, data);
+      this.removeNamesFromUpdateList("changed", storeType, data);
+    } else if (
+      action == "changed" &&
+      this.boundUpdate.added &&
+      this.boundUpdate.added[storeType]
+    ) {
+      // If something got added and changed at the same time, then remove those
+      // items from changed instead.
+      this.removeNamesFromUpdateList(
+        "changed",
+        storeType,
+        this.boundUpdate.added[storeType]
+      );
+    } else if (action == "deleted") {
+      // If any item got delete, or a host got delete, no point in sending
+      // added or changed update
+      this.removeNamesFromUpdateList("added", storeType, data);
+      this.removeNamesFromUpdateList("changed", storeType, data);
+
+      for (const host in data) {
+        if (
+          !data[host].length &&
+          this.boundUpdate.added &&
+          this.boundUpdate.added[storeType] &&
+          this.boundUpdate.added[storeType][host]
+        ) {
+          delete this.boundUpdate.added[storeType][host];
+        }
+        if (
+          !data[host].length &&
+          this.boundUpdate.changed &&
+          this.boundUpdate.changed[storeType] &&
+          this.boundUpdate.changed[storeType][host]
+        ) {
+          delete this.boundUpdate.changed[storeType][host];
+        }
+      }
+    }
+
+    this.batchTimer = setTimeout(() => {
+      clearTimeout(this.batchTimer);
+      this.emit("stores-update", this.boundUpdate);
+      this.boundUpdate = {};
+    }, BATCH_DELAY);
+
+    return null;
+  }
+
+  /**
+   * This method removes data from the this.boundUpdate object in the same
+   * manner like this.update() adds data to it.
+   *
+   * @param {string} action
+   *        The type of change. One of "added", "changed" or "deleted"
+   * @param {string} storeType
+   *        The storage actor for which you want to remove the updates data.
+   * @param {object} data
+   *        The update object. This object is of the following format:
+   *         - {
+   *             <host1>: [<store_names1>, <store_name2>...],
+   *             <host2>: [<store_names34>...],
+   *           }
+   *           Where host1, host2 are the hosts which you want to remove and
+   *           [<store_namesX] is an array of the names of the store objects.
+   */
+  removeNamesFromUpdateList(action, storeType, data) {
+    for (const host in data) {
+      if (
+        this.boundUpdate[action] &&
+        this.boundUpdate[action][storeType] &&
+        this.boundUpdate[action][storeType][host]
+      ) {
+        for (const name of data[host]) {
+          const index = this.boundUpdate[action][storeType][host].indexOf(name);
+          if (index > -1) {
+            this.boundUpdate[action][storeType][host].splice(index, 1);
+          }
+        }
+        if (!this.boundUpdate[action][storeType][host].length) {
+          delete this.boundUpdate[action][storeType][host];
+        }
+      }
+    }
+    return null;
+  }
+}