Bug 1315044 - Cache ContentActor forms to prevent creating new one when calling RootActor.getProcess multiple times. r=jryans

MozReview-Commit-ID: 3YyShRXQhel

--HG--
extra : rebase_source : 670ce6dc1b4c451bdb59dcebfa859d6089ed2624

devtools/server/actors/root.js

@@ -103,6 +103,7 @@ function RootActor(aConnection, aParameters) {
   this.conn.addActorPool(this._globalActorPool);
 
   this._chromeActor = null;
+  this._processActors = new Map();
 }
 
 RootActor.prototype = {
@@ -230,6 +231,7 @@ RootActor.prototype = {
     this._globalActorPool = null;
     this._parameters = null;
     this._chromeActor = null;
+    this._processActors.clear();
   },
 
   /* The 'listTabs' request and the 'tabListChanged' notification. */
@@ -471,13 +473,24 @@ RootActor.prototype = {
 
       return { form: this._chromeActor.form() };
     } else {
-      let mm = ppmm.getChildAt(aRequest.id);
+      let { id } = aRequest;
+      let mm = ppmm.getChildAt(id);
       if (!mm) {
         return { error: "noProcess",
-                 message: "There is no process with id '" + aRequest.id + "'." };
+                 message: "There is no process with id '" + id + "'." };
       }
-      return DebuggerServer.connectToContent(this.conn, mm)
-                           .then(form => ({ form }));
+      let form = this._processActors.get(id);
+      if (form) {
+        return { form };
+      }
+      let onDestroy = () => {
+        this._processActors.delete(id);
+      };
+      return DebuggerServer.connectToContent(this.conn, mm, onDestroy)
+        .then(form => {
+          this._processActors.set(id, form);
+          return { form };
+        });
     }
   },
 

devtools/server/main.js

@@ -715,7 +715,7 @@ var DebuggerServer = {
     return this._onConnection(transport, prefix, true);
   },
 
-  connectToContent(connection, mm) {
+  connectToContent(connection, mm, onDestroy) {
     let deferred = SyncPromise.defer();
 
     let prefix = connection.allocID("content-process");
@@ -764,6 +764,10 @@ var DebuggerServer = {
           // Nothing to do
         }
       }
+
+      if (onDestroy) {
+        onDestroy(mm);
+      }
     }
 
     let onMessageManagerClose = DevToolsUtils.makeInfallible((subject, topic, data) => {

devtools/server/tests/mochitest/test_getProcess.html

@@ -97,12 +97,24 @@ function runTests() {
           text: "var a = 42; a"
         }, function (response) {
           ok(response.result, 42, "console.eval worked");
-          cleanup();
+
+          getProcessAgain(actor, content.id);
         });
       });
     });
   }
 
+  // Assert that calling client.getProcess against the same process id is
+  // returning the same actor.
+  function getProcessAgain(firstActor, id) {
+    client.getProcess(id).then(response => {
+      let actor = response.form;
+      is(actor, firstActor,
+         "Second call to getProcess with the same id returns the same form");
+      cleanup();
+    });
+  }
+
   function cleanup() {
     client.close().then(function () {
       DebuggerServer.destroy();