chrome/browser/media_galleries/fileapi/mtp_device_map_service.cc

   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/isolated_context.h"
  14
  15 namespace {
  16
  17 base::LazyInstance<MTPDeviceMapService> g_mtp_device_map_service =
  18     LAZY_INSTANCE_INITIALIZER;
  19
  20 }  // namespace
  21
  22 // static
  23 MTPDeviceMapService* MTPDeviceMapService::GetInstance() {
  24   return g_mtp_device_map_service.Pointer();
  25 }
  26
  27 void 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
  46 void 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
  64 void 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
  75 void 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
  84 MTPDeviceAsyncDelegate* MTPDeviceMapService::GetMTPDeviceAsyncDelegate(
  85     const std::string& filesystem_id) {
  86   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
  87   base::FilePath device_path;
  88   if (!fileapi::IsolatedContext::GetInstance()->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
 100 MTPDeviceMapService::MTPDeviceMapService() {
 101 }
 102
 103 MTPDeviceMapService::~MTPDeviceMapService() {
 104   DCHECK(mtp_device_usage_map_.empty());
 105 }