Improving the process model extension API

chrome/browser/task_manager/task_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_H_
 #define CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_H_
 #pragma once
 
 #include <map>
 #include <utility>
@@ skipping 237 matching lines @@
 
   // Invoked when a range of items has changed.
   virtual void OnItemsChanged(int start, int length) = 0;
 
   // Invoked when new items are added.
   virtual void OnItemsAdded(int start, int length) = 0;
 
   // Invoked when a range of items has been removed.
   virtual void OnItemsRemoved(int start, int length) = 0;
 
+  // Invoked when a range of items is to be immediately removed. It differs
+  // from OnItemsRemoved by the fact that the item is still in the task manager,
+  // so it can be queried for and found.
+  virtual void OnItemsToBeRemoved(int start, int length) {}
+
   // Invoked when the initialization of the model has been finished and
   // periodical updates is started. The first periodical update will be done
   // in a few seconds. (depending on platform)
   virtual void OnReadyPeriodicalUpdate() {}
 };
 
 // The model that the TaskManager is using.
 class TaskManagerModel : public base::RefCountedThreadSafe<TaskManagerModel> {
  public:
   // (start, length)
   typedef std::pair<int, int> GroupRange;
 
   explicit TaskManagerModel(TaskManager* task_manager);
 
   void AddObserver(TaskManagerModelObserver* observer);
   void RemoveObserver(TaskManagerModelObserver* observer);
 
   // Returns number of registered resources.
   int ResourceCount() const;
   // Returns number of registered groups.
   int GroupCount() const;
 
   // Methods to return raw resource information.
   int64 GetNetworkUsage(int index) const;
   double GetCPUUsage(int index) const;
   int GetProcessId(int index) const;
+  base::ProcessHandle GetProcess(int index) const;
   int GetResourceUniqueId(int index) const;
   // Returns the index of resource that has the given |unique_id|. Returns -1 if
   // no resouce has the |unique_id|.
   int GetResourceIndexByUniqueId(const int unique_id) const;
 
   // Methods to return formatted resource information.
   string16 GetResourceTitle(int index) const;
   string16 GetResourceProfileName(int index) const;
   string16 GetResourceNetworkUsage(int index) const;
   string16 GetResourceCPUUsage(int index) const;
@@ skipping 33 matching lines @@
   bool GetFPS(int index, float* result) const;
 
   // Gets the sqlite memory (in byte). Return false if the resource for the
   // given row doesn't report information.
   bool GetSqliteMemoryUsedBytes(int index, size_t* result) const;
 
   // Gets the amount of memory allocated for javascript. Returns false if the
   // resource for the given row isn't a renderer.
   bool GetV8Memory(int index, size_t* result) const;
 
+  // Gets the amount of memory used for javascript. Returns false if the
+  // resource for the given row isn't a renderer.
+  bool GetV8MemoryUsed(int index, size_t* result) const;
+
   // Returns true if resource for the given row can be activated.
   bool CanActivate(int index) const;
 
   // Returns true if resource for the given row can be inspected using developer
   // tools.
   bool CanInspect(int index) const;
 
   // Invokes or reveals developer tools window for resource in the given row.
   void Inspect(int index) const;
 
@@ skipping 43 matching lines @@
 
   // Returns Extension of given resource or NULL if not applicable.
   const Extension* GetResourceExtension(int index) const;
 
   void AddResource(TaskManager::Resource* resource);
   void RemoveResource(TaskManager::Resource* resource);
 
   void StartUpdating();
   void StopUpdating();
 
+  void StartListening();

[Charlie Reis, 2012/04/27 22:01:56]

These should have comments to explain what they're for and how they're different
from Start/StopUpdating.

[nasko, 2012/04/30 18:05:19]

Done.

+  void StopListening();
+
   void Clear();  // Removes all items.
 
   // Sends OnModelChanged() to all observers to inform them of significant
   // changes to the model.
   void ModelChanged();
 
   void NotifyResourceTypeStats(
         base::ProcessId renderer_id,
         const WebKit::WebCache::ResourceTypeStats& stats);
 
@@ skipping 13 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(ExtensionApiTest, ProcessesVsTaskManager);
 
   ~TaskManagerModel();
 
   enum UpdateState {
     IDLE = 0,      // Currently not updating.
     TASK_PENDING,  // An update task is pending.
     STOPPING       // A update task is pending and it should stop the update.
   };
 
+  enum ListenState {

[Charlie Reis, 2012/04/27 22:01:56]

Why not a is_listeneing_ boolean?  With UpdateState, they needed 3 values.

[nasko, 2012/04/30 18:05:19]

I initially started with different states. You are right that we can do it with
a boolean. Changed.

+    LISTEN_OFF = 0,
+    LISTEN_ON
+  };
+
   // This struct is used to exchange information between the io and ui threads.
   struct BytesReadParam {
     BytesReadParam(int origin_pid,
                    int render_process_host_child_id,
                    int routing_id,
                    int byte_count)
         : origin_pid(origin_pid),
           render_process_host_child_id(render_process_host_child_id),
           routing_id(routing_id),
           byte_count(byte_count) {}
@@ skipping 92 matching lines @@
   // because the linux call takes >10ms to complete. This cache is cleared on
   // every Refresh().
   mutable MemoryUsageMap memory_usage_map_;
 
   ObserverList<TaskManagerModelObserver> observer_list_;
 
   // How many calls to StartUpdating have been made without matching calls to
   // StopUpdating.
   int update_requests_;
 
+  // How many calls to StartListening have been made without matching calls to
+  // StopListening.
+  int listen_requests_;
+
   // Whether we are currently in the process of updating.
   UpdateState update_state_;
 
+  // Whether we have resource managers listening for events and maintaining
+  // the TaskManagerModel resources.
+  ListenState listen_state_;
+
   // A salt lick for the goats.
   uint64 goat_salt_;
 
   // Resource identifier that is unique within single session.
   int last_unique_id_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskManagerModel);
 };
 
 #endif  // CHROME_BROWSER_TASK_MANAGER_TASK_MANAGER_H_