mtp_device_map_service.cc revision effb81e5f8246d0db0270817048dc992db66e9fb 
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#include "chrome/browser/media_galleries/fileapi/mtp_device_map_service.h"
6
7#include <string>
8#include <utility>
9
10#include "base/stl_util.h"
11#include "chrome/browser/media_galleries/fileapi/mtp_device_async_delegate.h"
12#include "content/public/browser/browser_thread.h"
13#include "webkit/browser/fileapi/external_mount_points.h"
14
15namespace {
16
17base::LazyInstance<MTPDeviceMapService> g_mtp_device_map_service =
18    LAZY_INSTANCE_INITIALIZER;
19
20}  // namespace
21
22// static
23MTPDeviceMapService* MTPDeviceMapService::GetInstance() {
24  return g_mtp_device_map_service.Pointer();
25}
26
27void MTPDeviceMapService::RegisterMTPFileSystem(
28    const base::FilePath::StringType& device_location,
29    const std::string& fsid) {
30  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
31
32  if (!ContainsKey(mtp_device_usage_map_, device_location)) {
33    // Note that this initializes the delegate asynchronously, but since
34    // the delegate will only be used from the IO thread, it is guaranteed
35    // to be created before use of it expects it to be there.
36    CreateMTPDeviceAsyncDelegate(device_location,
37        base::Bind(&MTPDeviceMapService::AddAsyncDelegate,
38                   base::Unretained(this), device_location));
39    mtp_device_usage_map_[device_location] = 0;
40  }
41
42  mtp_device_usage_map_[device_location]++;
43  mtp_device_map_[fsid] = device_location;
44}
45
46void MTPDeviceMapService::RevokeMTPFileSystem(const std::string& fsid) {
47  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
48
49  MTPDeviceFileSystemMap::iterator it = mtp_device_map_.find(fsid);
50  if (it != mtp_device_map_.end()) {
51    base::FilePath::StringType device_location = it->second;
52    mtp_device_map_.erase(it);
53    MTPDeviceUsageMap::iterator delegate_it =
54        mtp_device_usage_map_.find(device_location);
55    DCHECK(delegate_it != mtp_device_usage_map_.end());
56    mtp_device_usage_map_[device_location]--;
57    if (mtp_device_usage_map_[device_location] == 0) {
58      mtp_device_usage_map_.erase(delegate_it);
59      RemoveAsyncDelegate(device_location);
60    }
61  }
62}
63
64void MTPDeviceMapService::AddAsyncDelegate(
65    const base::FilePath::StringType& device_location,
66    MTPDeviceAsyncDelegate* delegate) {
67  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
68  DCHECK(delegate);
69  DCHECK(!device_location.empty());
70  if (ContainsKey(async_delegate_map_, device_location))
71    return;
72  async_delegate_map_[device_location] = delegate;
73}
74
75void MTPDeviceMapService::RemoveAsyncDelegate(
76    const base::FilePath::StringType& device_location) {
77  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
78  AsyncDelegateMap::iterator it = async_delegate_map_.find(device_location);
79  DCHECK(it != async_delegate_map_.end());
80  it->second->CancelPendingTasksAndDeleteDelegate();
81  async_delegate_map_.erase(it);
82}
83
84MTPDeviceAsyncDelegate* MTPDeviceMapService::GetMTPDeviceAsyncDelegate(
85    const std::string& filesystem_id) {
86  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
87  base::FilePath device_path;
88  if (!fileapi::ExternalMountPoints::GetSystemInstance()->GetRegisteredPath(
89          filesystem_id, &device_path)) {
90    return NULL;
91  }
92
93  const base::FilePath::StringType& device_location = device_path.value();
94  DCHECK(!device_location.empty());
95  AsyncDelegateMap::const_iterator it =
96      async_delegate_map_.find(device_location);
97  return (it != async_delegate_map_.end()) ? it->second : NULL;
98}
99
100MTPDeviceMapService::MTPDeviceMapService() {
101}
102
103MTPDeviceMapService::~MTPDeviceMapService() {
104  DCHECK(mtp_device_usage_map_.empty());
105}
106