// Copyright (c) 2011 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 CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_H_
#define CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_H_
#pragma once

#include <map>
#include <queue>
#include <string>

#include "base/memory/scoped_ptr.h"
#include "base/process.h"
#include "base/timer.h"
#include "content/browser/child_process_launcher.h"
#include "content/browser/renderer_host/render_process_host.h"
#include "ui/gfx/surface/transport_dib.h"

class CommandLine;
class RendererMainThread;
class RenderWidgetHelper;

namespace base {
class SharedMemory;
}

// Implements a concrete RenderProcessHost for the browser process for talking
// to actual renderer processes (as opposed to mocks).
//
// Represents the browser side of the browser <--> renderer communication
// channel. There will be one RenderProcessHost per renderer process.
//
// This object is refcounted so that it can release its resources when all
// hosts using it go away.
//
// This object communicates back and forth with the RenderProcess object
// running in the renderer process. Each RenderProcessHost and RenderProcess
// keeps a list of RenderView (renderer) and TabContents (browser) which
// are correlated with IDs. This way, the Views and the corresponding ViewHosts
// communicate through the two process objects.
class BrowserRenderProcessHost : public RenderProcessHost,
                                 public ChildProcessLauncher::Client {
 public:
  explicit BrowserRenderProcessHost(Profile* profile);
  virtual ~BrowserRenderProcessHost();

  // RenderProcessHost implementation (public portion).
  virtual bool Init(bool is_accessibility_enabled);
  virtual int GetNextRoutingID();
  virtual void CancelResourceRequests(int render_widget_id);
  virtual void CrossSiteSwapOutACK(const ViewMsg_SwapOut_Params& params);
  virtual bool WaitForUpdateMsg(int render_widget_id,
                                const base::TimeDelta& max_delay,
                                IPC::Message* msg);
  virtual void ReceivedBadMessage();
  virtual void WidgetRestored();
  virtual void WidgetHidden();
  virtual int VisibleWidgetCount() const;
  virtual bool FastShutdownIfPossible();
  virtual bool SendWithTimeout(IPC::Message* msg, int timeout_ms);
  virtual base::ProcessHandle GetHandle();
  virtual TransportDIB* GetTransportDIB(TransportDIB::Id dib_id);

  // IPC::Channel::Sender via RenderProcessHost.
  virtual bool Send(IPC::Message* msg);

  // IPC::Channel::Listener via RenderProcessHost.
  virtual bool OnMessageReceived(const IPC::Message& msg);
  virtual void OnChannelConnected(int32 peer_pid);
  virtual void OnChannelError();

  // ChildProcessLauncher::Client implementation.
  virtual void OnProcessLaunched();

 private:
  friend class VisitRelayingRenderProcessHost;

  // Creates and adds the IO thread message filters.
  void CreateMessageFilters();

  // Control message handlers.
  void OnShutdownRequest();
  void SuddenTerminationChanged(bool enabled);
  void OnUserMetricsRecordAction(const std::string& action);
  void OnRevealFolderInOS(const FilePath& path);

  // Generates a command line to be used to spawn a renderer and appends the
  // results to |*command_line|.
  void AppendRendererCommandLine(CommandLine* command_line) const;

  // Copies applicable command line switches from the given |browser_cmd| line
  // flags to the output |renderer_cmd| line flags. Not all switches will be
  // copied over.
  void PropagateBrowserCommandLineToRenderer(const CommandLine& browser_cmd,
                                             CommandLine* renderer_cmd) const;

  // Callers can reduce the RenderProcess' priority.
  void SetBackgrounded(bool backgrounded);

  // The count of currently visible widgets.  Since the host can be a container
  // for multiple widgets, it uses this count to determine when it should be
  // backgrounded.
  int32 visible_widgets_;

  // Does this process have backgrounded priority.
  bool backgrounded_;

  // Used to allow a RenderWidgetHost to intercept various messages on the
  // IO thread.
  scoped_refptr<RenderWidgetHelper> widget_helper_;

  // A map of transport DIB ids to cached TransportDIBs
  std::map<TransportDIB::Id, TransportDIB*> cached_dibs_;
  enum {
    // This is the maximum size of |cached_dibs_|
    MAX_MAPPED_TRANSPORT_DIBS = 3,
  };

  // Map a transport DIB from its Id and return it. Returns NULL on error.
  TransportDIB* MapTransportDIB(TransportDIB::Id dib_id);

  void ClearTransportDIBCache();
  // This is used to clear our cache five seconds after the last use.
  base::DelayTimer<BrowserRenderProcessHost> cached_dibs_cleaner_;

  // Used in single-process mode.
  scoped_ptr<RendererMainThread> in_process_renderer_;

  // True if this prcoess should have accessibility enabled;
  bool accessibility_enabled_;

  // True after Init() has been called. We can't just check channel_ because we
  // also reset that in the case of process termination.
  bool is_initialized_;

  // Used to launch and terminate the process without blocking the UI thread.
  scoped_ptr<ChildProcessLauncher> child_process_launcher_;

  // Messages we queue while waiting for the process handle.  We queue them here
  // instead of in the channel so that we ensure they're sent after init related
  // messages that are sent once the process handle is available.  This is
  // because the queued messages may have dependencies on the init messages.
  std::queue<IPC::Message*> queued_messages_;

  DISALLOW_COPY_AND_ASSIGN(BrowserRenderProcessHost);
};

#endif  // CONTENT_BROWSER_RENDERER_HOST_BROWSER_RENDER_PROCESS_HOST_H_