Show remaing space of MTP device in File Manager.

chrome/browser/chromeos/extensions/file_manager/private_api_file_system.cc

 // Copyright 2013 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 "chrome/browser/chromeos/extensions/file_manager/private_api_file_system.h"
 
 #include <sys/statvfs.h>
 #include <set>
 
 #include "base/memory/weak_ptr.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/task_runner_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
 #include "chrome/browser/chromeos/drive/file_system_interface.h"
 #include "chrome/browser/chromeos/drive/file_system_util.h"
 #include "chrome/browser/chromeos/extensions/file_manager/event_router.h"
 #include "chrome/browser/chromeos/extensions/file_manager/event_router_factory.h"
 #include "chrome/browser/chromeos/extensions/file_manager/private_api_util.h"
 #include "chrome/browser/chromeos/file_manager/fileapi_util.h"
 #include "chrome/browser/chromeos/file_manager/path_util.h"
 #include "chrome/browser/chromeos/file_manager/volume_manager.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend.h"
 #include "chrome/browser/drive/drive_api_util.h"
 #include "chrome/browser/drive/event_logger.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/common/extensions/api/file_manager_private.h"
 #include "chrome/common/extensions/api/file_manager_private_internal.h"
 #include "chromeos/disks/disk_mount_manager.h"
+#include "components/storage_monitor/storage_info.h"
+#include "components/storage_monitor/storage_monitor.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/common/url_constants.h"
+#include "device/media_transfer_protocol/media_transfer_protocol_manager.h"
+#include "device/media_transfer_protocol/mtp_storage_info.pb.h"
 #include "net/base/escape.h"
 #include "storage/browser/fileapi/file_stream_reader.h"
 #include "storage/browser/fileapi/file_system_context.h"
 #include "storage/browser/fileapi/file_system_file_util.h"
 #include "storage/browser/fileapi/file_system_operation_context.h"
 #include "storage/browser/fileapi/file_system_operation_runner.h"
 #include "storage/common/fileapi/file_system_info.h"
 #include "storage/common/fileapi/file_system_types.h"
 #include "storage/common/fileapi/file_system_util.h"
 #include "third_party/cros_system_api/constants/cryptohome.h"
 
 using chromeos::disks::DiskMountManager;
 using content::BrowserThread;
 using content::ChildProcessSecurityPolicy;
 using file_manager::util::EntryDefinition;
 using file_manager::util::FileDefinition;
 using storage::FileSystemURL;
 
 namespace extensions {
 namespace {
 
+const char kRootPath[] = "/";
+
 // Retrieves total and remaining available size on |mount_path|.
 void GetSizeStatsOnBlockingPool(const std::string& mount_path,
                                 uint64* total_size,
                                 uint64* remaining_size) {
   struct statvfs stat = {};  // Zero-clear
   if (HANDLE_EINTR(statvfs(mount_path.c_str(), &stat)) == 0) {
     *total_size = static_cast<uint64>(stat.f_blocks) * stat.f_frsize;
     *remaining_size = static_cast<uint64>(stat.f_bavail) * stat.f_frsize;
   }
 }
@@ skipping 330 matching lines @@
       // If stats couldn't be gotten for drive, result should be left
       // undefined. See comments in GetDriveAvailableSpaceCallback().
       SendResponse(true);
       return true;
     }
 
     file_system->GetAvailableSpace(
         base::Bind(&FileManagerPrivateGetSizeStatsFunction::
                        GetDriveAvailableSpaceCallback,
                    this));
+  } else if (volume->type() == file_manager::VOLUME_TYPE_MTP) {
+    // Resolve storage_name.
+    storage_monitor::StorageMonitor* storage_monitor =
+        storage_monitor::StorageMonitor::GetInstance();
+    storage_monitor::StorageInfo info;
+    storage_monitor->GetStorageInfoForPath(volume->mount_path(), &info);
+    std::string storage_name;
+    base::RemoveChars(info.location(), kRootPath, &storage_name);
+    DCHECK(!storage_name.empty());
+
+    // Get MTP StorageInfo.
+    // TODO(yawano) Implement GetStorageInfoFromDevice on chrome side. Currently
+    //     it returns stale storage info at the mount time.
+    device::MediaTransferProtocolManager* manager =
+        storage_monitor->media_transfer_protocol_manager();
+    const MtpStorageInfo* mtp_storage_info =
+        manager->GetStorageInfo(storage_name);
+    if (mtp_storage_info) {
+      const uint64 max_capacity = mtp_storage_info->max_capacity();
+      const uint64 free_space_in_bytes =
+          mtp_storage_info->free_space_in_bytes();
+      GetSizeStatsCallback(&max_capacity, &free_space_in_bytes);
+    }

[kinaba, 2015/05/19 09:37:31]

I guess it's safer to return false when it is unavailable.

[yawano, 2015/05/19 12:08:12]

Done.

   } else {
     uint64* total_size = new uint64(0);
     uint64* remaining_size = new uint64(0);
     BrowserThread::PostBlockingPoolTaskAndReply(
         FROM_HERE,
         base::Bind(&GetSizeStatsOnBlockingPool, volume->mount_path().value(),
                    total_size, remaining_size),
         base::Bind(
             &FileManagerPrivateGetSizeStatsFunction::GetSizeStatsCallback, this,
             base::Owned(total_size), base::Owned(remaining_size)));
@@ skipping 475 matching lines @@
   return RespondLater();
 }
 
 void FileManagerPrivateSetEntryTagFunction::OnSetEntryPropertyCompleted(
     drive::FileError result) {
   Respond(result == drive::FILE_ERROR_OK ? NoArguments()
                                          : Error("Failed to set a tag."));
 }
 
 }  // namespace extensions