chromeos: Add dbus MTPDClient.

chromeos/dbus/mtpd_client.cc

+// 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 "chromeos/dbus/mtpd_client.h"
+
+#include <map>
+
+#include "base/bind.h"
+#include "base/stl_util.h"
+#include "base/stringprintf.h"
+#include "dbus/bus.h"
+#include "dbus/message.h"
+#include "dbus/object_path.h"
+#include "dbus/object_proxy.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+namespace chromeos {
+
+namespace {
+
+// Pops a string value when |reader| is not NULL.
+// Returns true when a value is popped, false otherwise.
+bool MaybePopString(dbus::MessageReader* reader, std::string* value) {
+  if (!reader)
+    return false;
+  return reader->PopString(value);
+}
+
+// Pops a uint16 value when |reader| is not NULL.
+// Returns true when a value is popped, false otherwise.
+bool MaybePopUint16(dbus::MessageReader* reader, uint16* value) {
+  if (!reader)
+    return false;
+  return reader->PopUint16(value);
+}
+
+// Pops a uint32 value when |reader| is not NULL.
+// Returns true when a value is popped, false otherwise.
+bool MaybePopUint32(dbus::MessageReader* reader, uint32* value) {
+  if (!reader)
+    return false;
+  return reader->PopUint32(value);
+}
+
+// Pops a uint64 value when |reader| is not NULL.
+// Returns true when a value is popped, false otherwise.
+bool MaybePopUint64(dbus::MessageReader* reader, uint64* value) {
+  if (!reader)
+    return false;
+  return reader->PopUint64(value);
+}
+
+// Pops a int64 value when |reader| is not NULL.
+// Returns true when a value is popped, false otherwise.
+bool MaybePopInt64(dbus::MessageReader* reader, int64* value) {
+  if (!reader)
+    return false;
+  return reader->PopInt64(value);
+}
+
+// The MTPDClient implementation.
+class MTPDClientImpl : public MTPDClient {
+ public:
+  // TODO(thestig) Use mtpd::kMTPDServiceName and mtpd::kMTPDServicePath below.
+  explicit MTPDClientImpl(dbus::Bus* bus)
+      : proxy_(bus->GetObjectProxy(
+          "org.chromium.MTPD",
+          dbus::ObjectPath("/org/chromium/MTPD"))),
+        weak_ptr_factory_(this) {
+  }
+
+  // MTPDClient override.
+  virtual void EnumerateStorage(const EnumerateStorageCallback& callback,
+                                const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "EnumerateStorage");
+    proxy_->CallMethod(
+        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&MTPDClientImpl::OnEnumerateStorage,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   callback,
+                   error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void GetStorageInfo(const std::string& storage_name,
+                              const GetStorageInfoCallback& callback,
+                              const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "GetStorageInfo");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(storage_name);
+    proxy_->CallMethod(&method_call,
+                       dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnGetStorageInfo,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  storage_name,
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void OpenStorage(const std::string& storage_name,
+                           OpenStorageMode mode,
+                           const OpenStorageCallback& callback,
+                           const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "OpenStorage");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(storage_name);
+    DCHECK_EQ(OPEN_STORAGE_MODE_READ_ONLY, mode);
+    // TODO(thestig) Use constants here.
+    writer.AppendString("readonly");
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnOpenStorage,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void CloseStorage(const std::string& handle,
+                            const CloseStorageCallback& callback,
+                            const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "CloseStorage");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(handle);
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnCloseStorage,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void ReadDirectoryByPath(
+      const std::string& handle,
+      const std::string& path,
+      const ReadDirectoryCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "ReadDirectoryByPath");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(handle);
+    writer.AppendString(path);
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnReadDirectory,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void ReadDirectoryById(
+      const std::string& handle,
+      uint32 file_id,
+      const ReadDirectoryCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "ReadDirectoryById");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(handle);
+    writer.AppendUint32(file_id);
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnReadDirectory,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void ReadFileByPath(const std::string& handle,
+                              const std::string& path,
+                              const ReadFileCallback& callback,
+                              const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "ReadFileByPath");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(handle);
+    writer.AppendString(path);
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnReadFile,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void ReadFileById(const std::string& handle,
+                            uint32 file_id,
+                            const ReadFileCallback& callback,
+                            const ErrorCallback& error_callback) OVERRIDE {
+    // TODO(thestig) Use constants here.
+    dbus::MethodCall method_call("org.chromium.MTPD", "ReadFileById");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(handle);
+    writer.AppendUint32(file_id);
+    proxy_->CallMethod(&method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+                       base::Bind(&MTPDClientImpl::OnReadFile,
+                                  weak_ptr_factory_.GetWeakPtr(),
+                                  callback,
+                                  error_callback));
+  }
+
+  // MTPDClient override.
+  virtual void SetUpConnections(
+      const MTPStorageEventHandler& handler) OVERRIDE {
+    static const SignalEventTuple kSignalEventTuples[] = {
+      // TODO(thestig) Use constants.
+      { "MTPStorageAttached", true },
+      { "MTPStorageDetached", false },
+    };
+    const size_t kNumSignalEventTuples = arraysize(kSignalEventTuples);
+
+    for (size_t i = 0; i < kNumSignalEventTuples; ++i) {
+      // TODO(thestig) Use mtpd::kMTPDInterface here.
+      proxy_->ConnectToSignal(
+          "org.chromium.MTPD",
+          kSignalEventTuples[i].signal_name,
+          base::Bind(&MTPDClientImpl::OnMTPStorageSignal,
+                     weak_ptr_factory_.GetWeakPtr(),
+                     handler,
+                     kSignalEventTuples[i].is_attach),
+          base::Bind(&MTPDClientImpl::OnSignalConnected,
+                     weak_ptr_factory_.GetWeakPtr()));
+    }
+  }
+
+ private:
+  // A struct to contain a pair of signal name and attachment event type.
+  // Used by SetUpConnections.
+  struct SignalEventTuple {
+    const char *signal_name;
+    bool is_attach;
+  };
+
+  // Handles the result of EnumerateStorage and calls |callback| or
+  // |error_callback|.
+  void OnEnumerateStorage(const EnumerateStorageCallback& callback,
+                          const ErrorCallback& error_callback,
+                          dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+    dbus::MessageReader reader(response);
+    std::vector<std::string> storage_names;
+    if (!reader.PopArrayOfStrings(&storage_names)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      error_callback.Run();
+      return;
+    }
+    callback.Run(storage_names);
+  }
+
+  // Handles the result of GetStorageInfo and calls |callback| or
+  // |error_callback|.
+  void OnGetStorageInfo(const std::string& storage_name,
+                        const GetStorageInfoCallback& callback,
+                        const ErrorCallback& error_callback,
+                        dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+    StorageInfo storage_info(storage_name, response);
+    callback.Run(storage_info);
+  }
+
+  // Handles the result of OpenStorage and calls |callback| or |error_callback|.
+  void OnOpenStorage(const OpenStorageCallback& callback,
+                     const ErrorCallback& error_callback,
+                     dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+    dbus::MessageReader reader(response);
+    std::string handle;
+    if (!reader.PopString(&handle)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      error_callback.Run();
+      return;
+    }
+    callback.Run(handle);
+  }
+
+  // Handles the result of CloseStorage and calls |callback| or
+  // |error_callback|.
+  void OnCloseStorage(const CloseStorageCallback& callback,
+                      const ErrorCallback& error_callback,
+                      dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+    callback.Run();
+  }
+
+  // Handles the result of ReadDirectoryByPath/Id and calls |callback| or
+  // |error_callback|.
+  void OnReadDirectory(const ReadDirectoryCallback& callback,
+                       const ErrorCallback& error_callback,
+                       dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+
+    std::vector<FileEntry> file_entries;
+    dbus::MessageReader response_reader(response);
+    dbus::MessageReader array_reader(response);
+    if (!response_reader.PopArray(&array_reader)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      error_callback.Run();
+      return;
+    }
+    while (array_reader.HasMoreData()) {
+      FileEntry entry(response);
+      file_entries.push_back(entry);
+    }
+    callback.Run(file_entries);
+  }
+
+  // Handles the result of ReadFileByPath/Id and calls |callback| or
+  // |error_callback|.
+  void OnReadFile(const ReadFileCallback& callback,
+                  const ErrorCallback& error_callback,
+                  dbus::Response* response) {
+    if (!response) {
+      error_callback.Run();
+      return;
+    }
+
+    uint8* data_bytes = NULL;
+    size_t data_length = 0;
+    dbus::MessageReader reader(response);
+    if (!reader.PopArrayOfBytes(&data_bytes, &data_length)) {
+      error_callback.Run();
+      return;
+    }
+    std::string data(reinterpret_cast<const char*>(data_bytes), data_length);
+    callback.Run(data);
+  }
+
+  // Handles MTPStorageAttached/Dettached signals and calls |handler|.
+  void OnMTPStorageSignal(MTPStorageEventHandler handler,
+                          bool is_attach,
+                          dbus::Signal* signal) {
+    dbus::MessageReader reader(signal);
+    std::string storage_name;
+    if (!reader.PopString(&storage_name)) {
+      LOG(ERROR) << "Invalid signal: " << signal->ToString();
+      return;
+    }
+    DCHECK(!storage_name.empty());
+    handler.Run(is_attach, storage_name);
+  }
+
+
+  // Handles the result of signal connection setup.
+  void OnSignalConnected(const std::string& interface,
+                         const std::string& signal,
+                         bool successed) {
+    LOG_IF(ERROR, !successed) << "Connect to " << interface << " "
+                              << signal << " failed.";
+  }
+
+  dbus::ObjectProxy* proxy_;
+  base::WeakPtrFactory<MTPDClientImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(MTPDClientImpl);
+};
+
+// A stub implementaion of MTPDClient.
+class MTPDClientStubImpl : public MTPDClient {
+ public:
+  MTPDClientStubImpl() {}
+  virtual ~MTPDClientStubImpl() {}
+
+  virtual void EnumerateStorage(
+      const EnumerateStorageCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void GetStorageInfo(
+      const std::string& storage_name,
+      const GetStorageInfoCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void OpenStorage(const std::string& storage_name,
+                           OpenStorageMode mode,
+                           const OpenStorageCallback& callback,
+                           const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void CloseStorage(const std::string& handle,
+                            const CloseStorageCallback& callback,
+                            const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void ReadDirectoryByPath(
+      const std::string& handle,
+      const std::string& path,
+      const ReadDirectoryCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void ReadDirectoryById(
+      const std::string& handle,
+      uint32 file_id,
+      const ReadDirectoryCallback& callback,
+      const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void ReadFileByPath(const std::string& handle,
+                              const std::string& path,
+                              const ReadFileCallback& callback,
+                              const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void ReadFileById(const std::string& handle,
+                            uint32 file_id,
+                            const ReadFileCallback& callback,
+                            const ErrorCallback& error_callback) OVERRIDE {}
+  virtual void SetUpConnections(
+      const MTPStorageEventHandler& handler) OVERRIDE {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MTPDClientStubImpl);
+};
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// StorageInfo
+
+StorageInfo::StorageInfo(const std::string& storage_name,
+                         dbus::Response* response)
+    : vendor_id_(0),
+      product_id_(0),
+      device_flags_(0),
+      storage_name_(storage_name),
+      storage_type_(0),
+      filesystem_type_(0),
+      access_capability_(0),
+      max_capacity_(0),
+      free_space_in_bytes_(0),
+      free_space_in_objects_(0) {
+  InitializeFromResponse(response);
+}
+
+StorageInfo::~StorageInfo() {
+}
+
+// Initializes |this| from |response| given by the mtpd service.
+void StorageInfo::InitializeFromResponse(dbus::Response* response) {
+  dbus::MessageReader response_reader(response);
+  dbus::MessageReader array_reader(response);
+  if (!response_reader.PopArray(&array_reader)) {
+    LOG(ERROR) << "Invalid response: " << response->ToString();
+    return;
+  }
+  // TODO(satorux): Rework this code using Protocol Buffers. crosbug.com/22626
+  typedef std::map<std::string, dbus::MessageReader*> PropertiesMap;
+  PropertiesMap properties;
+  STLValueDeleter<PropertiesMap> properties_value_deleter(&properties);
+  while (array_reader.HasMoreData()) {
+    dbus::MessageReader* value_reader = new dbus::MessageReader(response);
+    dbus::MessageReader dict_entry_reader(response);
+    std::string key;
+    if (!array_reader.PopDictEntry(&dict_entry_reader) ||
+        !dict_entry_reader.PopString(&key) ||
+        !dict_entry_reader.PopVariant(value_reader)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      return;
+    }
+    properties[key] = value_reader;
+  }
+  // TODO(thestig) Add enums for fields below as appropriate.
+  MaybePopString(properties["Vendor"], &vendor_);
+  MaybePopString(properties["Product"], &product_);
+  MaybePopString(properties["StorageDescription"], &storage_description_);
+  MaybePopString(properties["VolumeIdentifier"], &volume_identifier_);
+  MaybePopUint16(properties["VendorId"], &vendor_id_);
+  MaybePopUint16(properties["ProductId"], &product_id_);
+  MaybePopUint16(properties["StorageType"], &storage_type_);
+  MaybePopUint16(properties["FilesystemType"], &filesystem_type_);
+  MaybePopUint16(properties["AccessCapability"], &access_capability_);
+  MaybePopUint32(properties["DeviceFlags"], &device_flags_);
+  MaybePopUint64(properties["MaxCapacity"], &max_capacity_);
+  MaybePopUint64(properties["FreeSpaceInBytes"], &free_space_in_bytes_);
+  MaybePopUint64(properties["FreeSpaceInObjects"], &free_space_in_objects_);

[satorux1, 2012/08/03 17:38:42]

Here's an idea. As you've already learned, exchanging structured data as D-Bus
message is painful and results in crappy code.

What about using protocol buffers instead? It'd be much cleaner. 
PowerManagerClient does this, and I think this is the way to go.

[Lei Zhang, 2012/08/03 18:44:15]

Maybe in a later CL? I added a TODO.

+}
+
+////////////////////////////////////////////////////////////////////////////////
+// FileEntry
+
+FileEntry::FileEntry(dbus::Response* response)
+    : item_id_(0),
+      parent_id_(0),
+      file_size_(0),
+      file_type_(FILE_TYPE_UNKNOWN) {
+  InitializeFromResponse(response);
+}
+
+FileEntry::~FileEntry() {
+}
+
+// Initializes |this| from |response| given by the mtpd service.
+void FileEntry::InitializeFromResponse(dbus::Response* response) {
+  dbus::MessageReader response_reader(response);
+  dbus::MessageReader array_reader(response);
+  if (!response_reader.PopArray(&array_reader)) {
+    LOG(ERROR) << "Invalid response: " << response->ToString();
+    return;
+  }
+  // TODO(satorux): Rework this code using Protocol Buffers. crosbug.com/22626
+  typedef std::map<std::string, dbus::MessageReader*> PropertiesMap;
+  PropertiesMap properties;
+  STLValueDeleter<PropertiesMap> properties_value_deleter(&properties);
+  while (array_reader.HasMoreData()) {
+    dbus::MessageReader* value_reader = new dbus::MessageReader(response);
+    dbus::MessageReader dict_entry_reader(response);
+    std::string key;
+    if (!array_reader.PopDictEntry(&dict_entry_reader) ||
+        !dict_entry_reader.PopString(&key) ||
+        !dict_entry_reader.PopVariant(value_reader)) {
+      LOG(ERROR) << "Invalid response: " << response->ToString();
+      return;
+    }
+    properties[key] = value_reader;
+  }
+
+  // TODO(thestig) Use constants here.
+  MaybePopString(properties["FileName"], &file_name_);
+  MaybePopUint32(properties["ItemId"], &item_id_);
+  MaybePopUint32(properties["ParentId"], &parent_id_);
+  MaybePopUint64(properties["FileSize"], &file_size_);
+
+  int64 modification_date = -1;
+  if (MaybePopInt64(properties["ModificationDate"], &modification_date))
+    modification_date_ = base::Time::FromTimeT(modification_date);
+
+  uint16 file_type = FILE_TYPE_OTHER;
+  if (MaybePopUint16(properties["FileType"], &file_type)) {
+    switch (file_type) {
+      case FILE_TYPE_FOLDER:
+      case FILE_TYPE_JPEG:
+      case FILE_TYPE_JFIF:
+      case FILE_TYPE_TIFF:
+      case FILE_TYPE_BMP:
+      case FILE_TYPE_GIF:
+      case FILE_TYPE_PICT:
+      case FILE_TYPE_PNG:
+      case FILE_TYPE_WINDOWSIMAGEFORMAT:
+      case FILE_TYPE_JP2:
+      case FILE_TYPE_JPX:
+      case FILE_TYPE_UNKNOWN:
+        file_type_ = static_cast<FileType>(file_type);
+      default:
+        file_type_ = FILE_TYPE_OTHER;
+        break;
+    }
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// MTPDClient
+
+MTPDClient::MTPDClient() {}
+
+MTPDClient::~MTPDClient() {}
+
+// static
+MTPDClient* MTPDClient::Create(DBusClientImplementationType type,
+                               dbus::Bus* bus) {
+  if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
+    return new MTPDClientImpl(bus);
+  DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
+  return new MTPDClientStubImpl();
+}
+
+}  // namespace chromeos