chrome/browser/renderer_host/pepper/pepper_flash_device_id_host.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_RENDERER_HOST_PEPPER_PEPPER_FLASH_DEVICE_ID_HOST_H_
   6 #define CHROME_BROWSER_RENDERER_HOST_PEPPER_PEPPER_FLASH_DEVICE_ID_HOST_H_
   7
   8 #include "base/memory/weak_ptr.h"
   9 #include "content/public/browser/browser_thread.h"
  10 #include "ppapi/host/host_message_context.h"
  11 #include "ppapi/host/resource_host.h"
  12 #include "ppapi/proxy/resource_message_params.h"
  13
  14 namespace base {
  15 class FilePath;
  16 }
  17
  18 namespace content {
  19 class BrowserPpapiHost;
  20 }
  21
  22 namespace chrome {
  23
  24 class PepperFlashDeviceIDHost : public ppapi::host::ResourceHost {
  25  public:
  26   PepperFlashDeviceIDHost(content::BrowserPpapiHost* host,
  27                           PP_Instance instance,
  28                           PP_Resource resource);
  29   virtual ~PepperFlashDeviceIDHost();
  30
  31   // ResourceHost override.
  32   virtual int32_t OnResourceMessageReceived(
  33       const IPC::Message& msg,
  34       ppapi::host::HostMessageContext* context) OVERRIDE;
  35
  36  private:
  37   // Helper class to manage the unfortunate number of thread transitions
  38   // required for this operation. We must first get the profile info from the
  39   // UI thread, and then actually read the file from the FILE thread before
  40   // returning to the IO thread to forward the result to the plugin.
  41   class Fetcher
  42       : public base::RefCountedThreadSafe<
  43             Fetcher,
  44             content::BrowserThread::DeleteOnIOThread> {
  45    public:
  46     explicit Fetcher(const base::WeakPtr<PepperFlashDeviceIDHost>& host);
  47
  48     // Schedules the request operation. The host will be called back with
  49     // GotDRMContents. On failure, the contents will be empty.
  50     void Start(content::BrowserPpapiHost* browser_host);
  51
  52    private:
  53     friend struct content::BrowserThread::DeleteOnThread<
  54         content::BrowserThread::IO>;
  55     friend class base::DeleteHelper<Fetcher>;
  56
  57     ~Fetcher();
  58
  59     // Called on the UI thread to get the file path corresponding to the
  60     // given render view. It will schedule the resulting file to be read on the
  61     // file thread. On error, it will pass the empty path to the file thread.
  62     void GetFilePathOnUIThread(int render_process_id,
  63                                int render_view_id);
  64
  65     // Called on the file thread to read the contents of the file and to
  66     // forward it to the IO thread. The path will be empty on error (in
  67     // which case it will forward the empty string to the IO thread).
  68     void ReadDRMFileOnFileThread(const base::FilePath& path);
  69
  70     // Called on the IO thread to call back into the device ID host with the
  71     // file contents, or the empty string on failure.
  72     void ReplyOnIOThread(const std::string& contents);
  73
  74     // Access only on IO thread (this class is destroyed on the IO thread
  75     // to ensure that this is deleted properly, since weak ptrs aren't
  76     // threadsafe).
  77     base::WeakPtr<PepperFlashDeviceIDHost> host_;
  78
  79     DISALLOW_COPY_AND_ASSIGN(Fetcher);
  80   };
  81   friend class Fetcher;
  82
  83   // IPC message handler.
  84   int32_t OnHostMsgGetDeviceID(const ppapi::host::HostMessageContext* context);
  85
  86   // Called by the fetcher when the DRM ID was retrieved, or the empty string
  87   // on error.
  88   void GotDRMContents(const std::string& contents);
  89
  90   base::WeakPtrFactory<PepperFlashDeviceIDHost> factory_;
  91
  92   content::BrowserPpapiHost* browser_ppapi_host_;
  93
  94   // When a request is pending, the fetcher will be non-null, and the reply
  95   // context will have the appropriate routing info set for the reply.
  96   scoped_refptr<Fetcher> fetcher_;
  97   ppapi::host::ReplyMessageContext reply_context_;
  98
  99   DISALLOW_COPY_AND_ASSIGN(PepperFlashDeviceIDHost);
 100 };
 101
 102 }  // namespace chrome
 103
 104 #endif  // CHROME_BROWSER_RENDERER_HOST_PEPPER_PEPPER_FLASH_DEVICE_ID_HOST_H_