device/media_transfer_protocol/media_transfer_protocol

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This source file includes following definitions.
AddObserver
RemoveObserver
GetStorages
GetStorageInfo
OpenStorage
CloseStorage
ReadDirectoryByPath
ReadDirectoryById
ReadFileChunkByPath
ReadFileChunkById
GetFileInfoByPath
GetFileInfoById
OnStorageAttached
OnStorageDetached
OnStorageChanged
OnEnumerateStorages
OnGetStorageInfo
OnOpenStorage
OnOpenStorageError
OnCloseStorage
OnCloseStorageError
OnReadDirectory
OnReadDirectoryError
OnReadFile
OnReadFileError
OnGetFileInfo
OnGetFileInfoError
GetBus
FinishSetupOnOriginThread
Initialize
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "device/media_transfer_protocol/media_transfer_protocol_manager.h"

#include <map>
#include <queue>
#include <set>
#include <utility>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/location.h"
#include "base/memory/weak_ptr.h"
#include "base/observer_list.h"
#include "base/sequenced_task_runner.h"
#include "base/stl_util.h"
#include "base/threading/thread_checker.h"
#include "dbus/bus.h"
#include "device/media_transfer_protocol/media_transfer_protocol_daemon_client.h"
#include "device/media_transfer_protocol/mtp_file_entry.pb.h"
#include "device/media_transfer_protocol/mtp_storage_info.pb.h"
#include "third_party/cros_system_api/dbus/service_constants.h"

#if defined(OS_CHROMEOS)
#include "chromeos/dbus/dbus_thread_manager.h"
#endif

namespace device {

namespace {

MediaTransferProtocolManager* g_media_transfer_protocol_manager = NULL;

// The MediaTransferProtocolManager implementation.
class MediaTransferProtocolManagerImpl : public MediaTransferProtocolManager {
 public:
  explicit MediaTransferProtocolManagerImpl(
      scoped_refptr<base::SequencedTaskRunner> task_runner)
      : weak_ptr_factory_(this) {
#if defined(OS_CHROMEOS)
    DCHECK(!task_runner.get());
#else
    DCHECK(task_runner.get());
    dbus::Bus::Options options;
    options.bus_type = dbus::Bus::SYSTEM;
    options.connection_type = dbus::Bus::PRIVATE;
    options.dbus_task_runner = task_runner;
    session_bus_ = new dbus::Bus(options);
#endif

    if (GetBus()) {
      // Listen for future mtpd service owner changes, in case it is not
      // available right now. There is no guarantee on Linux or ChromeOS that
      // mtpd is running already.
      mtpd_owner_changed_callback_ = base::Bind(
          &MediaTransferProtocolManagerImpl::FinishSetupOnOriginThread,
          weak_ptr_factory_.GetWeakPtr());
      GetBus()->ListenForServiceOwnerChange(mtpd::kMtpdServiceName,
                                            mtpd_owner_changed_callback_);
      GetBus()->GetServiceOwner(mtpd::kMtpdServiceName,
                                mtpd_owner_changed_callback_);
    }
  }

  virtual ~MediaTransferProtocolManagerImpl() {
    DCHECK(g_media_transfer_protocol_manager);
    g_media_transfer_protocol_manager = NULL;
    if (GetBus()) {
      GetBus()->UnlistenForServiceOwnerChange(mtpd::kMtpdServiceName,
                                              mtpd_owner_changed_callback_);
    }

#if !defined(OS_CHROMEOS)
    session_bus_->GetDBusTaskRunner()->PostTask(
        FROM_HERE, base::Bind(&dbus::Bus::ShutdownAndBlock, session_bus_));
#endif

    VLOG(1) << "MediaTransferProtocolManager Shutdown completed";
  }

  // MediaTransferProtocolManager override.
  virtual void AddObserver(Observer* observer) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    observers_.AddObserver(observer);
  }

  // MediaTransferProtocolManager override.
  virtual void RemoveObserver(Observer* observer) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    observers_.RemoveObserver(observer);
  }

  // MediaTransferProtocolManager override.
  virtual const std::vector<std::string> GetStorages() const OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    std::vector<std::string> storages;
    for (StorageInfoMap::const_iterator it = storage_info_map_.begin();
         it != storage_info_map_.end();
         ++it) {
      storages.push_back(it->first);
    }
    return storages;
  }

  // MediaTransferProtocolManager override.
  virtual const MtpStorageInfo* GetStorageInfo(
      const std::string& storage_name) const OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    StorageInfoMap::const_iterator it = storage_info_map_.find(storage_name);
    return it != storage_info_map_.end() ? &it->second : NULL;
  }

  // MediaTransferProtocolManager override.
  virtual void OpenStorage(const std::string& storage_name,
                           const std::string& mode,
                           const OpenStorageCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(storage_info_map_, storage_name) || !mtp_client_) {
      callback.Run(std::string(), true);
      return;
    }
    open_storage_callbacks_.push(callback);
    mtp_client_->OpenStorage(
        storage_name,
        mode,
        base::Bind(&MediaTransferProtocolManagerImpl::OnOpenStorage,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnOpenStorageError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  // MediaTransferProtocolManager override.
  virtual void CloseStorage(const std::string& storage_handle,
                            const CloseStorageCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(true);
      return;
    }
    close_storage_callbacks_.push(std::make_pair(callback, storage_handle));
    mtp_client_->CloseStorage(
        storage_handle,
        base::Bind(&MediaTransferProtocolManagerImpl::OnCloseStorage,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnCloseStorageError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  // MediaTransferProtocolManager override.
  virtual void ReadDirectoryByPath(
      const std::string& storage_handle,
      const std::string& path,
      const ReadDirectoryCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(std::vector<MtpFileEntry>(), true);
      return;
    }
    read_directory_callbacks_.push(callback);
    mtp_client_->ReadDirectoryByPath(
        storage_handle,
        path,
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadDirectory,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadDirectoryError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  // MediaTransferProtocolManager override.
  virtual void ReadDirectoryById(
      const std::string& storage_handle,
      uint32 file_id,
      const ReadDirectoryCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(std::vector<MtpFileEntry>(), true);
      return;
    }
    read_directory_callbacks_.push(callback);
    mtp_client_->ReadDirectoryById(
        storage_handle,
        file_id,
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadDirectory,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadDirectoryError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  // MediaTransferProtocolManager override.
  virtual void ReadFileChunkByPath(const std::string& storage_handle,
                                   const std::string& path,
                                   uint32 offset,
                                   uint32 count,
                                   const ReadFileCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(std::string(), true);
      return;
    }
    read_file_callbacks_.push(callback);
    mtp_client_->ReadFileChunkByPath(
        storage_handle, path, offset, count,
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadFile,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadFileError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  // MediaTransferProtocolManager override.
  virtual void ReadFileChunkById(const std::string& storage_handle,
                                 uint32 file_id,
                                 uint32 offset,
                                 uint32 count,
                                 const ReadFileCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(std::string(), true);
      return;
    }
    read_file_callbacks_.push(callback);
    mtp_client_->ReadFileChunkById(
        storage_handle, file_id, offset, count,
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadFile,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnReadFileError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual void GetFileInfoByPath(const std::string& storage_handle,
                                 const std::string& path,
                                 const GetFileInfoCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(MtpFileEntry(), true);
      return;
    }
    get_file_info_callbacks_.push(callback);
    mtp_client_->GetFileInfoByPath(
        storage_handle,
        path,
        base::Bind(&MediaTransferProtocolManagerImpl::OnGetFileInfo,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnGetFileInfoError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual void GetFileInfoById(const std::string& storage_handle,
                               uint32 file_id,
                               const GetFileInfoCallback& callback) OVERRIDE {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, storage_handle) || !mtp_client_) {
      callback.Run(MtpFileEntry(), true);
      return;
    }
    get_file_info_callbacks_.push(callback);
    mtp_client_->GetFileInfoById(
        storage_handle,
        file_id,
        base::Bind(&MediaTransferProtocolManagerImpl::OnGetFileInfo,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&MediaTransferProtocolManagerImpl::OnGetFileInfoError,
                   weak_ptr_factory_.GetWeakPtr()));
  }

 private:
  // Map of storage names to storage info.
  typedef std::map<std::string, MtpStorageInfo> StorageInfoMap;
  // Callback queues - DBus communication is in-order, thus callbacks are
  // received in the same order as the requests.
  typedef std::queue<OpenStorageCallback> OpenStorageCallbackQueue;
  // (callback, handle)
  typedef std::queue<std::pair<CloseStorageCallback, std::string>
                    > CloseStorageCallbackQueue;
  typedef std::queue<ReadDirectoryCallback> ReadDirectoryCallbackQueue;
  typedef std::queue<ReadFileCallback> ReadFileCallbackQueue;
  typedef std::queue<GetFileInfoCallback> GetFileInfoCallbackQueue;

  void OnStorageAttached(const std::string& storage_name) {
    DCHECK(thread_checker_.CalledOnValidThread());
    mtp_client_->GetStorageInfo(
        storage_name,
        base::Bind(&MediaTransferProtocolManagerImpl::OnGetStorageInfo,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&base::DoNothing));
  }

  void OnStorageDetached(const std::string& storage_name) {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (storage_info_map_.erase(storage_name) == 0) {
      // This can happen for a storage where
      // MediaTransferProtocolDaemonClient::GetStorageInfo() failed.
      // Return to avoid giving observers phantom detach events.
      return;
    }
    FOR_EACH_OBSERVER(Observer,
                      observers_,
                      StorageChanged(false /* detach */, storage_name));
  }

  void OnStorageChanged(bool is_attach, const std::string& storage_name) {
    DCHECK(thread_checker_.CalledOnValidThread());
    DCHECK(mtp_client_);
    if (is_attach)
      OnStorageAttached(storage_name);
    else
      OnStorageDetached(storage_name);
  }

  void OnEnumerateStorages(const std::vector<std::string>& storage_names) {
    DCHECK(thread_checker_.CalledOnValidThread());
    DCHECK(mtp_client_);
    for (size_t i = 0; i < storage_names.size(); ++i) {
      if (ContainsKey(storage_info_map_, storage_names[i])) {
        // OnStorageChanged() might have gotten called first.
        continue;
      }
      OnStorageAttached(storage_names[i]);
    }
  }

  void OnGetStorageInfo(const MtpStorageInfo& storage_info) {
    DCHECK(thread_checker_.CalledOnValidThread());
    const std::string& storage_name = storage_info.storage_name();
    if (ContainsKey(storage_info_map_, storage_name)) {
      // This should not happen, since MediaTransferProtocolManagerImpl should
      // only call EnumerateStorages() once, which populates |storage_info_map_|
      // with the already-attached devices.
      // After that, all incoming signals are either for new storage
      // attachments, which should not be in |storage_info_map_|, or for
      // storage detachments, which do not add to |storage_info_map_|.
      // Return to avoid giving observers phantom detach events.
      NOTREACHED();
      return;
    }

    // New storage. Add it and let the observers know.
    storage_info_map_.insert(std::make_pair(storage_name, storage_info));
    FOR_EACH_OBSERVER(Observer,
                      observers_,
                      StorageChanged(true /* is attach */, storage_name));
  }

  void OnOpenStorage(const std::string& handle) {
    DCHECK(thread_checker_.CalledOnValidThread());
    if (!ContainsKey(handles_, handle)) {
      handles_.insert(handle);
      open_storage_callbacks_.front().Run(handle, false);
    } else {
      NOTREACHED();
      open_storage_callbacks_.front().Run(std::string(), true);
    }
    open_storage_callbacks_.pop();
  }

  void OnOpenStorageError() {
    open_storage_callbacks_.front().Run(std::string(), true);
    open_storage_callbacks_.pop();
  }

  void OnCloseStorage() {
    DCHECK(thread_checker_.CalledOnValidThread());
    const std::string& handle = close_storage_callbacks_.front().second;
    if (ContainsKey(handles_, handle)) {
      handles_.erase(handle);
      close_storage_callbacks_.front().first.Run(false);
    } else {
      NOTREACHED();
      close_storage_callbacks_.front().first.Run(true);
    }
    close_storage_callbacks_.pop();
  }

  void OnCloseStorageError() {
    DCHECK(thread_checker_.CalledOnValidThread());
    close_storage_callbacks_.front().first.Run(true);
    close_storage_callbacks_.pop();
  }

  void OnReadDirectory(const std::vector<MtpFileEntry>& file_entries) {
    DCHECK(thread_checker_.CalledOnValidThread());
    read_directory_callbacks_.front().Run(file_entries, false);
    read_directory_callbacks_.pop();
  }

  void OnReadDirectoryError() {
    DCHECK(thread_checker_.CalledOnValidThread());
    read_directory_callbacks_.front().Run(std::vector<MtpFileEntry>(), true);
    read_directory_callbacks_.pop();
  }

  void OnReadFile(const std::string& data) {
    DCHECK(thread_checker_.CalledOnValidThread());
    read_file_callbacks_.front().Run(data, false);
    read_file_callbacks_.pop();
  }

  void OnReadFileError() {
    DCHECK(thread_checker_.CalledOnValidThread());
    read_file_callbacks_.front().Run(std::string(), true);
    read_file_callbacks_.pop();
  }

  void OnGetFileInfo(const MtpFileEntry& entry) {
    DCHECK(thread_checker_.CalledOnValidThread());
    get_file_info_callbacks_.front().Run(entry, false);
    get_file_info_callbacks_.pop();
  }

  void OnGetFileInfoError() {
    DCHECK(thread_checker_.CalledOnValidThread());
    get_file_info_callbacks_.front().Run(MtpFileEntry(), true);
    get_file_info_callbacks_.pop();
  }

  // Get the Bus object used to communicate with mtpd.
  dbus::Bus* GetBus() {
    DCHECK(thread_checker_.CalledOnValidThread());
#if defined(OS_CHROMEOS)
    return chromeos::DBusThreadManager::Get()->GetSystemBus();
#else
    return session_bus_.get();
#endif
  }

  // Callback to finish initialization after figuring out if the mtpd service
  // has an owner, or if the service owner has changed.
  // |mtpd_service_owner| contains the name of the current owner, if any.
  void FinishSetupOnOriginThread(const std::string& mtpd_service_owner) {
    DCHECK(thread_checker_.CalledOnValidThread());

    if (mtpd_service_owner == current_mtpd_owner_)
      return;

    // In the case of a new service owner, clear |storage_info_map_|.
    // Assume all storages have been disconnected. If there is a new service
    // owner, reconnecting to it will reconnect all the storages as well.

    // Save a copy of |storage_info_map_| keys as |storage_info_map_| can
    // change in OnStorageDetached().
    std::vector<std::string> storage_names;
    for (StorageInfoMap::const_iterator it = storage_info_map_.begin();
         it != storage_info_map_.end();
         ++it) {
      storage_names.push_back(it->first);
    }
    for (size_t i = 0; i != storage_names.size(); ++i)
      OnStorageDetached(storage_names[i]);

    if (mtpd_service_owner.empty()) {
      current_mtpd_owner_.clear();
      mtp_client_.reset();
      return;
    }

    current_mtpd_owner_ = mtpd_service_owner;

    mtp_client_.reset(MediaTransferProtocolDaemonClient::Create(GetBus()));

    // Set up signals and start initializing |storage_info_map_|.
    mtp_client_->ListenForChanges(
        base::Bind(&MediaTransferProtocolManagerImpl::OnStorageChanged,
                   weak_ptr_factory_.GetWeakPtr()));
    mtp_client_->EnumerateStorages(
        base::Bind(&MediaTransferProtocolManagerImpl::OnEnumerateStorages,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&base::DoNothing));
  }

  // Mtpd DBus client.
  scoped_ptr<MediaTransferProtocolDaemonClient> mtp_client_;

#if !defined(OS_CHROMEOS)
  // And a D-Bus session for talking to mtpd.
  scoped_refptr<dbus::Bus> session_bus_;
#endif

  // Device attachment / detachment observers.
  ObserverList<Observer> observers_;

  // Map to keep track of attached storages by name.
  StorageInfoMap storage_info_map_;

  // Set of open storage handles.
  std::set<std::string> handles_;

  dbus::Bus::GetServiceOwnerCallback mtpd_owner_changed_callback_;

  std::string current_mtpd_owner_;

  // Queued callbacks.
  OpenStorageCallbackQueue open_storage_callbacks_;
  CloseStorageCallbackQueue close_storage_callbacks_;
  ReadDirectoryCallbackQueue read_directory_callbacks_;
  ReadFileCallbackQueue read_file_callbacks_;
  GetFileInfoCallbackQueue get_file_info_callbacks_;

  base::ThreadChecker thread_checker_;

  base::WeakPtrFactory<MediaTransferProtocolManagerImpl> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(MediaTransferProtocolManagerImpl);
};

}  // namespace

// static
MediaTransferProtocolManager* MediaTransferProtocolManager::Initialize(
    scoped_refptr<base::SequencedTaskRunner> task_runner) {
  DCHECK(!g_media_transfer_protocol_manager);

  g_media_transfer_protocol_manager =
      new MediaTransferProtocolManagerImpl(task_runner);
  VLOG(1) << "MediaTransferProtocolManager initialized";

  return g_media_transfer_protocol_manager;
}

}  // namespace device
/* [<][>][^][v][top][bottom][index][help] */
root/device/media_transfer_protocol/media_transfer_protocol_manager.cc

DEFINITIONS
