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
17namespace base {
18
19template <class T> class DeleteHelper;
20
21}  // namespace base
22
23struct InitUsbContextTraits;
24template <typename T> struct DefaultSingletonTraits;
25
26typedef struct libusb_device* PlatformUsbDevice;
27typedef struct libusb_context* PlatformUsbContext;
28
29class UsbContext;
30class 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.
36class 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