chrome/renderer/render_thread.h

// Copyright (c) 2009 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_RENDERER_RENDER_THREAD_H_
#define CHROME_RENDERER_RENDER_THREAD_H_

#include <string>
#include <vector>

#include "base/gfx/native_widget_types.h"
#include "base/shared_memory.h"
#include "base/task.h"
#include "build/build_config.h"
#include "chrome/common/child_thread.h"
#include "chrome/common/css_colors.h"
#include "chrome/renderer/renderer_histogram_snapshots.h"
#include "chrome/renderer/visitedlink_slave.h"

class AppCacheDispatcher;
class DBMessageFilter;
class DevToolsAgentFilter;
class FilePath;
class ListValue;
class RenderDnsMaster;
class RendererHistogram;
class RendererWebKitClientImpl;
class SkBitmap;
class UserScriptSlave;
class URLPattern;

struct ModalDialogEvent;
struct RendererPreferences;
struct WebPreferences;

// The RenderThreadBase is the minimal interface that a RenderView/Widget
// expects from a render thread. The interface basically abstracts a way to send
// and receive messages.
class RenderThreadBase {
 public:
  virtual ~RenderThreadBase() {}

  virtual bool Send(IPC::Message* msg) = 0;

  // Called to add or remove a listener for a particular message routing ID.
  // These methods normally get delegated to a MessageRouter.
  virtual void AddRoute(int32 routing_id, IPC::Channel::Listener* listener) = 0;
  virtual void RemoveRoute(int32 routing_id) = 0;

  virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter) = 0;
  virtual void RemoveFilter(IPC::ChannelProxy::MessageFilter* filter) = 0;

  // Called by a RenderWidget when it is hidden or restored.
  virtual void WidgetHidden() = 0;
  virtual void WidgetRestored() = 0;
};

// The RenderThread class represents a background thread where RenderView
// instances live.  The RenderThread supports an API that is used by its
// consumer to talk indirectly to the RenderViews and supporting objects.
// Likewise, it provides an API for the RenderViews to talk back to the main
// process (i.e., their corresponding TabContents).
//
// Most of the communication occurs in the form of IPC messages.  They are
// routed to the RenderThread according to the routing IDs of the messages.
// The routing IDs correspond to RenderView instances.
class RenderThread : public RenderThreadBase,
                     public ChildThread {
 public:
  // Grabs the IPC channel name from the command line.
  RenderThread();
  // Constructor that's used when running in single process mode.
  RenderThread(const std::string& channel_name);
  virtual ~RenderThread();

  // Returns the one render thread for this process.  Note that this should only
  // be accessed when running on the render thread itself
  static RenderThread* current();

  // Overridden from RenderThreadBase.
  virtual bool Send(IPC::Message* msg) {
    return ChildThread::Send(msg);
  }

  virtual void AddRoute(int32 routing_id, IPC::Channel::Listener* listener) {
    widget_count_++;
    return ChildThread::AddRoute(routing_id, listener);
  }
  virtual void RemoveRoute(int32 routing_id) {
    widget_count_--;
    return ChildThread::RemoveRoute(routing_id);
  }

  virtual void AddFilter(IPC::ChannelProxy::MessageFilter* filter);
  virtual void RemoveFilter(IPC::ChannelProxy::MessageFilter* filter);

  virtual void WidgetHidden();
  virtual void WidgetRestored();

  VisitedLinkSlave* visited_link_slave() const {
    return visited_link_slave_.get();
  }

  UserScriptSlave* user_script_slave() const {
    return user_script_slave_.get();
  }

  AppCacheDispatcher* appcache_dispatcher() const {
    return appcache_dispatcher_.get();
  }

  bool plugin_refresh_allowed() const { return plugin_refresh_allowed_; }

  // Do DNS prefetch resolution of a hostname.
  void Resolve(const char* name, size_t length);

  // Send all the Histogram data to browser.
  void SendHistograms(int sequence_number);

  // Invokes InformHostOfCacheStats after a short delay.  Used to move this
  // bookkeeping operation off the critical latency path.
  void InformHostOfCacheStatsLater();

  // Sends a message to the browser to close all idle connections.
  void CloseIdleConnections();

  // Sends a message to the browser to enable or disable the disk cache.
  void SetCacheMode(bool enabled);

 private:
  virtual void OnControlMessageReceived(const IPC::Message& msg);

  void Init();

  void OnUpdateVisitedLinks(base::SharedMemoryHandle table);
  void OnAddVisitedLinks(const VisitedLinkSlave::Fingerprints& fingerprints);
  void OnResetVisitedLinks();

  void OnUpdateUserScripts(base::SharedMemoryHandle table);
  void OnSetExtensionFunctionNames(const std::vector<std::string>& names);
  void OnPageActionsUpdated(const std::string& extension_id,
                            const std::vector<std::string>& page_actions);
  void OnExtensionSetAPIPermissions(const std::string& extension_id,
                                    const std::vector<std::string>& permissions);
  void OnExtensionSetHostPermissions(const GURL& extension_url,
                                     const std::vector<URLPattern>& permissions);
  void OnSetNextPageID(int32 next_page_id);
  void OnSetCSSColors(const std::vector<CSSColors::CSSColorMapping>& colors);
  void OnCreateNewView(gfx::NativeViewId parent_hwnd,
                       ModalDialogEvent modal_dialog_event,
                       const RendererPreferences& renderer_prefs,
                       const WebPreferences& webkit_prefs,
                       int32 view_id);
  void OnTransferBitmap(const SkBitmap& bitmap, int resource_id);
  void OnSetCacheCapacities(size_t min_dead_capacity,
                            size_t max_dead_capacity,
                            size_t capacity);
  void OnGetCacheResourceStats();

  // Send all histograms to browser.
  void OnGetRendererHistograms(int sequence_number);

  void OnExtensionMessageInvoke(const std::string& function_name,
                                const ListValue& args);
  void OnPurgePluginListCache(bool reload_pages);

  // Gather usage statistics from the in-memory cache and inform our host.
  // These functions should be call periodically so that the host can make
  // decisions about how to allocation resources using current information.
  void InformHostOfCacheStats();

  // We initialize WebKit as late as possible.
  void EnsureWebKitInitialized();

  // A task we invoke periodically to assist with idle cleanup.
  void IdleHandler();

  // These objects live solely on the render thread.
  scoped_ptr<ScopedRunnableMethodFactory<RenderThread> > task_factory_;
  scoped_ptr<VisitedLinkSlave> visited_link_slave_;
  scoped_ptr<UserScriptSlave> user_script_slave_;
  scoped_ptr<RenderDnsMaster> dns_master_;
  scoped_ptr<AppCacheDispatcher> appcache_dispatcher_;
  scoped_refptr<DevToolsAgentFilter> devtools_agent_filter_;
  scoped_ptr<RendererHistogramSnapshots> histogram_snapshots_;
  scoped_ptr<RendererWebKitClientImpl> webkit_client_;

  scoped_refptr<DBMessageFilter> db_message_filter_;

#if defined(OS_POSIX)
  scoped_refptr<IPC::ChannelProxy::MessageFilter>
      suicide_on_channel_error_filter_;
#endif

  // If true, then a GetPlugins call is allowed to rescan the disk.
  bool plugin_refresh_allowed_;

  // Is there a pending task for doing CacheStats.
  bool cache_stats_task_pending_;

  // The count of RenderWidgets running through this thread.
  int widget_count_;

  // The count of hidden RenderWidgets running through this thread.
  int hidden_widget_count_;

  // The current value of the idle notification timer delay.
  double idle_notification_delay_in_s_;

  DISALLOW_COPY_AND_ASSIGN(RenderThread);
};

#endif  // CHROME_RENDERER_RENDER_THREAD_H_