1 files changed, 160 insertions, 0 deletions
diff --git a/toolkit/components/contentprefs/ContentPrefServiceParent.sys.mjs b/toolkit/components/contentprefs/ContentPrefServiceParent.sys.mjs
new file mode 100644
index 0000000000..66b4a02741
--- /dev/null
+++ b/toolkit/components/contentprefs/ContentPrefServiceParent.sys.mjs
@@ -0,0 +1,160 @@
+/* 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 { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  _methodsCallableFromChild: "resource://gre/modules/ContentPrefUtils.sys.mjs",
+});
+
+let loadContext = Cu.createLoadContext();
+let privateLoadContext = Cu.createPrivateLoadContext();
+
+function contextArg(context) {
+  return context && context.usePrivateBrowsing
+    ? privateLoadContext
+    : loadContext;
+}
+
+export class ContentPrefsParent extends JSProcessActorParent {
+  constructor() {
+    super();
+
+    // The names we're using this observer object for, used to keep track
+    // of the number of names we care about as well as for removing this
+    // observer if its associated process goes away.
+    this._prefsToObserve = new Set();
+    this._observer = null;
+  }
+
+  didDestroy() {
+    if (this._observer) {
+      for (let i of this._prefsToObserve) {
+        lazy.cps2.removeObserverForName(i, this._observer);
+      }
+      this._observer = null;
+    }
+  }
+
+  receiveMessage(msg) {
+    switch (msg.name) {
+      case "ContentPrefs:AddObserverForName": {
+        // The child process is responsible for not adding multiple parent
+        // observers for the same name.
+        let actor = this;
+        if (!this._observer) {
+          this._observer = {
+            onContentPrefSet(group, name, value, isPrivate) {
+              actor.onContentPrefSet(group, name, value, isPrivate);
+            },
+            onContentPrefRemoved(group, name, isPrivate) {
+              actor.onContentPrefRemoved(group, name, isPrivate);
+            },
+          };
+        }
+
+        let prefName = msg.data.name;
+        this._prefsToObserve.add(prefName);
+        lazy.cps2.addObserverForName(prefName, this._observer);
+        break;
+      }
+
+      case "ContentPrefs:RemoveObserverForName": {
+        let prefName = msg.data.name;
+        this._prefsToObserve.delete(prefName);
+        if (this._prefsToObserve.size == 0) {
+          lazy.cps2.removeObserverForName(prefName, this._observer);
+          this._observer = null;
+        }
+        break;
+      }
+
+      case "ContentPrefs:FunctionCall":
+        let data = msg.data;
+        let signature;
+
+        if (
+          !lazy._methodsCallableFromChild.some(([method, args]) => {
+            if (method == data.call) {
+              signature = args;
+              return true;
+            }
+            return false;
+          })
+        ) {
+          throw new Error(`Can't call ${data.call} from child!`);
+        }
+
+        let actor = this;
+        let args = data.args;
+
+        return new Promise(resolve => {
+          let listener = {
+            handleResult(pref) {
+              actor.sendAsyncMessage("ContentPrefs:HandleResult", {
+                requestId: data.requestId,
+                contentPref: {
+                  domain: pref.domain,
+                  name: pref.name,
+                  value: pref.value,
+                },
+              });
+            },
+
+            handleError(error) {
+              actor.sendAsyncMessage("ContentPrefs:HandleError", {
+                requestId: data.requestId,
+                error,
+              });
+            },
+            handleCompletion(reason) {
+              actor.sendAsyncMessage("ContentPrefs:HandleCompletion", {
+                requestId: data.requestId,
+                reason,
+              });
+            },
+          };
+          // Push our special listener.
+          args.push(listener);
+
+          // Process context argument for forwarding
+          let contextIndex = signature.indexOf("context");
+          if (contextIndex > -1) {
+            args[contextIndex] = contextArg(args[contextIndex]);
+          }
+
+          // And call the function.
+          lazy.cps2[data.call](...args);
+        });
+    }
+
+    return undefined;
+  }
+
+  onContentPrefSet(group, name, value, isPrivate) {
+    this.sendAsyncMessage("ContentPrefs:NotifyObservers", {
+      name,
+      callback: "onContentPrefSet",
+      args: [group, name, value, isPrivate],
+    });
+  }
+
+  onContentPrefRemoved(group, name, isPrivate) {
+    this.sendAsyncMessage("ContentPrefs:NotifyObservers", {
+      name,
+      callback: "onContentPrefRemoved",
+      args: [group, name, isPrivate],
+    });
+  }
+}
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "cps2",
+  "@mozilla.org/content-pref/service;1",
+  "nsIContentPrefService2"
+);