1 files changed, 185 insertions, 0 deletions
diff --git a/toolkit/components/contentprefs/ContentPrefServiceChild.sys.mjs b/toolkit/components/contentprefs/ContentPrefServiceChild.sys.mjs
new file mode 100644
index 0000000000..38d0d3c160
--- /dev/null
+++ b/toolkit/components/contentprefs/ContentPrefServiceChild.sys.mjs
@@ -0,0 +1,185 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* 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/. */
+
+import {
+  ContentPref,
+  _methodsCallableFromChild,
+  cbHandleCompletion,
+  cbHandleError,
+  cbHandleResult,
+  safeCallback,
+} from "resource://gre/modules/ContentPrefUtils.sys.mjs";
+
+// We only need one bit of information out of the context.
+function contextArg(context) {
+  return context && context.usePrivateBrowsing
+    ? { usePrivateBrowsing: true }
+    : null;
+}
+
+function NYI() {
+  throw new Error("Do not add any new users of these functions");
+}
+
+function CallbackCaller(callback) {
+  this._callback = callback;
+}
+
+CallbackCaller.prototype = {
+  handleResult(contentPref) {
+    cbHandleResult(
+      this._callback,
+      new ContentPref(contentPref.domain, contentPref.name, contentPref.value)
+    );
+  },
+
+  handleError(result) {
+    cbHandleError(this._callback, result);
+  },
+
+  handleCompletion(reason) {
+    cbHandleCompletion(this._callback, reason);
+  },
+};
+
+export class ContentPrefsChild extends JSProcessActorChild {
+  constructor() {
+    super();
+
+    // Map from pref name -> set of observers
+    this._observers = new Map();
+
+    // Map from random ID string -> CallbackCaller, per request
+    this._requests = new Map();
+  }
+
+  _getRandomId() {
+    return Services.uuid.generateUUID().toString();
+  }
+
+  receiveMessage(msg) {
+    let data = msg.data;
+    let callback;
+    switch (msg.name) {
+      case "ContentPrefs:HandleResult":
+        callback = this._requests.get(data.requestId);
+        callback.handleResult(data.contentPref);
+        break;
+
+      case "ContentPrefs:HandleError":
+        callback = this._requests.get(data.requestId);
+        callback.handleError(data.error);
+        break;
+
+      case "ContentPrefs:HandleCompletion":
+        callback = this._requests.get(data.requestId);
+        this._requests.delete(data.requestId);
+        callback.handleCompletion(data.reason);
+        break;
+
+      case "ContentPrefs:NotifyObservers": {
+        let observerList = this._observers.get(data.name);
+        if (!observerList) {
+          break;
+        }
+
+        for (let observer of observerList) {
+          safeCallback(observer, data.callback, data.args);
+        }
+
+        break;
+      }
+    }
+  }
+
+  callFunction(call, args, callback) {
+    let requestId = this._getRandomId();
+    let data = { call, args, requestId };
+
+    this._requests.set(requestId, new CallbackCaller(callback));
+    this.sendAsyncMessage("ContentPrefs:FunctionCall", data);
+  }
+
+  addObserverForName(name, observer) {
+    let set = this._observers.get(name);
+    if (!set) {
+      set = new Set();
+
+      // This is the first observer for this name. Start listening for changes
+      // to it.
+      this.sendAsyncMessage("ContentPrefs:AddObserverForName", {
+        name,
+      });
+      this._observers.set(name, set);
+    }
+
+    set.add(observer);
+  }
+
+  removeObserverForName(name, observer) {
+    let set = this._observers.get(name);
+    if (!set) {
+      return;
+    }
+
+    set.delete(observer);
+    if (set.size === 0) {
+      // This was the last observer for this name. Stop listening for changes.
+      this.sendAsyncMessage("ContentPrefs:RemoveObserverForName", {
+        name,
+      });
+
+      this._observers.delete(name);
+    }
+  }
+}
+
+export var ContentPrefServiceChild = {
+  QueryInterface: ChromeUtils.generateQI(["nsIContentPrefService2"]),
+
+  addObserverForName: (name, observer) => {
+    ChromeUtils.domProcessChild
+      .getActor("ContentPrefs")
+      .addObserverForName(name, observer);
+  },
+  removeObserverForName: (name, observer) => {
+    ChromeUtils.domProcessChild
+      .getActor("ContentPrefs")
+      .removeObserverForName(name, observer);
+  },
+
+  getCachedByDomainAndName: NYI,
+  getCachedBySubdomainAndName: NYI,
+  getCachedGlobal: NYI,
+  extractDomain: NYI,
+};
+
+function forwardMethodToParent(method, signature, ...args) {
+  // Ignore superfluous arguments
+  args = args.slice(0, signature.length);
+
+  // Process context argument for forwarding
+  let contextIndex = signature.indexOf("context");
+  if (contextIndex > -1) {
+    args[contextIndex] = contextArg(args[contextIndex]);
+  }
+  // Take out the callback argument, if present.
+  let callbackIndex = signature.indexOf("callback");
+  let callback = null;
+  if (callbackIndex > -1 && args.length > callbackIndex) {
+    callback = args.splice(callbackIndex, 1)[0];
+  }
+
+  let actor = ChromeUtils.domProcessChild.getActor("ContentPrefs");
+  actor.callFunction(method, args, callback);
+}
+
+for (let [method, signature] of _methodsCallableFromChild) {
+  ContentPrefServiceChild[method] = forwardMethodToParent.bind(
+    ContentPrefServiceChild,
+    method,
+    signature
+  );
+}