device/usb/usb_service.h

   1 // Copyright 2014 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 DEVICE_USB_USB_SERVICE_H_
   6 #define DEVICE_USB_USB_SERVICE_H_
   7
   8 #include <vector>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/threading/non_thread_safe.h"
  13
  14 namespace base {
  15 class SingleThreadTaskRunner;
  16 }
  17
  18 namespace device {
  19
  20 class UsbDevice;
  21
  22 // The USB service handles creating and managing an event handler thread that is
  23 // used to manage and dispatch USB events. It is also responsible for device
  24 // discovery on the system, which allows it to re-use device handles to prevent
  25 // competition for the same USB device.
  26 class UsbService : public base::NonThreadSafe {
  27  public:
  28   // Must be called on a thread with a MessageLoopForIO (for example
  29   // BrowserThread::FILE). The UI task runner reference is used to talk to the
  30   // PermissionBrokerClient on ChromeOS (UI thread). Returns NULL when
  31   // initialization fails.
  32   static UsbService* GetInstance(
  33       scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
  34
  35   static void SetInstanceForTest(UsbService* instance);
  36
  37   virtual scoped_refptr<UsbDevice> GetDeviceById(uint32 unique_id) = 0;
  38
  39   // Get all of the devices attached to the system, inserting them into
  40   // |devices|. Clears |devices| before use. The result will be sorted by id
  41   // in increasing order. Must be called on FILE thread.
  42   virtual void GetDevices(std::vector<scoped_refptr<UsbDevice> >* devices) = 0;
  43
  44  protected:
  45   friend struct base::DefaultDeleter<UsbService>;
  46   UsbService() {}
  47   virtual ~UsbService() {}
  48   DISALLOW_COPY_AND_ASSIGN(UsbService);
  49 };
  50
  51 }  // namespace device
  52
  53 #endif  // DEVICE_USB_USB_SERVICE_H_