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      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_USB_USB_SERVICE_H_
      6 #define CHROME_BROWSER_USB_USB_SERVICE_H_
      7 
      8 #include <map>
      9 #include <utility>
     10 #include <vector>
     11 
     12 #include "base/basictypes.h"
     13 #include "base/callback.h"
     14 #include "base/memory/ref_counted.h"
     15 #include "base/memory/singleton.h"
     16 
     17 namespace base {
     18 
     19 template <class T> class DeleteHelper;
     20 
     21 }  // namespace base
     22 
     23 struct InitUsbContextTraits;
     24 template <typename T> struct DefaultSingletonTraits;
     25 
     26 typedef struct libusb_device* PlatformUsbDevice;
     27 typedef struct libusb_context* PlatformUsbContext;
     28 
     29 class UsbContext;
     30 class UsbDevice;
     31 
     32 // The USB service handles creating and managing an event handler thread that is
     33 // used to manage and dispatch USB events. It is also responsible for device
     34 // discovery on the system, which allows it to re-use device handles to prevent
     35 // competition for the same USB device.
     36 class UsbService {
     37  public:
     38   typedef scoped_ptr<std::vector<scoped_refptr<UsbDevice> > >
     39       ScopedDeviceVector;
     40 
     41   // Must be called on FILE thread.
     42   // Returns NULL when failed to initialized.
     43   static UsbService* GetInstance();
     44 
     45   scoped_refptr<UsbDevice> GetDeviceById(uint32 unique_id);
     46 
     47   // Get all of the devices attached to the system, inserting them into
     48   // |devices|. Clears |devices| before use. The result will be sorted by id
     49   // in increasing order. Must be called on FILE thread.
     50   void GetDevices(std::vector<scoped_refptr<UsbDevice> >* devices);
     51 
     52  private:
     53   friend struct InitUsbContextTraits;
     54   friend struct DefaultSingletonTraits<UsbService>;
     55   friend class base::DeleteHelper<UsbService>;
     56 
     57   explicit UsbService(PlatformUsbContext context);
     58   virtual ~UsbService();
     59 
     60   // Return true if |device|'s vendor and product identifiers match |vendor_id|
     61   // and |product_id|.
     62   static bool DeviceMatches(scoped_refptr<UsbDevice> device,
     63                             const uint16 vendor_id,
     64                             const uint16 product_id);
     65 
     66   // Enumerate USB devices from OS and Update devices_ map.
     67   void RefreshDevices();
     68 
     69   scoped_refptr<UsbContext> context_;
     70 
     71   // TODO(ikarienator): Figure out a better solution.
     72   uint32 next_unique_id_;
     73 
     74   // The map from PlatformUsbDevices to UsbDevices.
     75   typedef std::map<PlatformUsbDevice, scoped_refptr<UsbDevice> > DeviceMap;
     76   DeviceMap devices_;
     77 
     78   DISALLOW_COPY_AND_ASSIGN(UsbService);
     79 };
     80 
     81 #endif  // CHROME_BROWSER_USB_USB_SERVICE_H_
     82