Isolated FS for media devices.

webkit/fileapi/media/device_media_file_util.cc

Index: webkit/fileapi/media/device_media_file_util.cc
diff --git a/webkit/fileapi/media/device_media_file_util.cc b/webkit/fileapi/media/device_media_file_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..31a5a0d1989a6491fc1e13990c85c58b031b1211
--- /dev/null
+++ b/webkit/fileapi/media/device_media_file_util.cc
@@ -0,0 +1,205 @@
+// 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 "webkit/fileapi/media/device_media_file_util.h"
+
+#include "base/message_loop_proxy.h"
+#include "base/file_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "webkit/blob/shareable_file_reference.h"
+#include "webkit/fileapi/file_system_operation_context.h"
+#include "webkit/fileapi/file_system_url.h"
+#include "webkit/fileapi/isolated_context.h"
+#include "webkit/fileapi/media/media_device_map_service.h"
+#include "webkit/fileapi/media/media_device_interface_impl.h"
+
+using base::PlatformFileError;
+using base::PlatformFileInfo;
+using webkit_blob::ShareableFileReference;
+
+namespace fileapi {
+
+namespace {
+
+const FilePath::CharType kIsolatedMediaFileSystemDir[] =
+    FILE_PATH_LITERAL("IsolatedMediaFileSystem");

[kinuko, 2012/07/30 23:19:03]

DeviceMediaFileSystem might reflect where the path is used better?

[kmadhusu, 2012/07/31 01:17:48]

Done.

+
+}  // namespace
+
+DeviceMediaFileUtil::DeviceMediaFileUtil(const FilePath& profile_path)
+    : profile_path_(profile_path) {
+}
+
+PlatformFileError DeviceMediaFileUtil::CreateOrOpen(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url, int file_flags,
+    PlatformFile* file_handle, bool* created) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::Close(
+    FileSystemOperationContext* context,
+    PlatformFile file_handle) {
+  // We don't allow open thus Close won't be called.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::EnsureFileExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool* created) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::CreateDirectory(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool exclusive,
+    bool recursive) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::GetFileInfo(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    PlatformFileInfo* file_info,
+    FilePath* platform_path) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return base::PLATFORM_FILE_ERROR_INVALID_URL;
+  *platform_path = url.path();

[kinuko, 2012/07/30 23:19:03]

Returning this url.path() won't be usable outside this FileUtil, maybe we could
just leave it empty.

[kmadhusu, 2012/07/31 01:17:48]

Done.

+  return device->GetFileInfo(*platform_path, file_info);

[kinuko, 2012/07/30 23:19:03]

nit: *platform_path -> url.path()  (though they have the same value)

[kmadhusu, 2012/07/31 01:17:48]

Done.

+}
+
+FileSystemFileUtil::AbstractFileEnumerator*
+DeviceMediaFileUtil::CreateFileEnumerator(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    bool recursive) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return new FileSystemFileUtil::EmptyFileEnumerator();
+  return device->CreateFileEnumerator(url.path(), recursive);
+}
+
+PlatformFileError DeviceMediaFileUtil::GetLocalFilePath(
+    FileSystemOperationContext* context,
+    const FileSystemURL& file_system_url,
+    FilePath* local_file_path) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::Touch(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    const base::Time& last_access_time,
+    const base::Time& last_modified_time) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return base::PLATFORM_FILE_ERROR_INVALID_URL;
+  return device->Touch(url.path(), last_access_time, last_modified_time);
+}
+
+PlatformFileError DeviceMediaFileUtil::Truncate(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    int64 length) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+bool DeviceMediaFileUtil::PathExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return false;
+  return device->PathExists(url.path());
+}
+
+bool DeviceMediaFileUtil::DirectoryExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return false;
+  return device->DirectoryExists(url.path());
+}
+
+bool DeviceMediaFileUtil::IsDirectoryEmpty(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())
+    return false;
+  return device->IsDirectoryEmpty(url.path());
+}
+
+PlatformFileError DeviceMediaFileUtil::CopyOrMoveFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& src_url,
+    const FileSystemURL& dest_url,
+    bool copy) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::CopyInForeignFile(
+    FileSystemOperationContext* context,
+    const FilePath& src_file_path,
+    const FileSystemURL& dest_url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::DeleteFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError DeviceMediaFileUtil::DeleteSingleDirectory(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+scoped_refptr<ShareableFileReference> DeviceMediaFileUtil::CreateSnapshotFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    base::PlatformFileError* result,
+    base::PlatformFileInfo* file_info,
+    FilePath* local_path) {

[kinuko, 2012/07/30 23:19:03]

Can we DCHECK out ptrs before we dereference them?

DCHECK(result);
DCHECK(file_info);
DCHEC(local_path);

[kmadhusu, 2012/07/31 01:17:48]

Done.

+  scoped_refptr<ShareableFileReference> file_ref;
+  *result = base::PLATFORM_FILE_ERROR_INVALID_URL;
+
+  scoped_refptr<MediaDeviceInterfaceImpl> device(context->media_device());
+  if (!device.get())

[kinuko, 2012/07/30 23:19:03]

Maybe we should set a better error code to *result in this case.

[kmadhusu, 2012/07/31 01:17:48]

This is very unlikely to happen. As we discussed, changing this to DCHECK.

+    return file_ref;
+
+  // Create a temp file in "profile_path_/kIsolatedMediaFileSystemDir".
+  FilePath isolated_media_file_system_dir_path =
+      profile_path_.Append(kIsolatedMediaFileSystemDir);
+  bool dir_exists = file_util::DirectoryExists(
+      isolated_media_file_system_dir_path);
+  if (!dir_exists) {
+    if (!file_util::CreateDirectory(isolated_media_file_system_dir_path))

[kinuko, 2012/07/30 23:19:03]

ditto.

[kmadhusu, 2012/07/31 01:17:48]

Done.

+      return file_ref;
+  }
+
+  bool file_created = file_util::CreateTemporaryFileInDir(

[Lei Zhang, 2012/07/30 23:03:25]

kinuko: What do you think of this potential issue?

When you do this, the temporary file will no longer have its original extension.
As a result, the net::GetWellKnownMimeTypeFromExtension() call in
FileAPIMessageFilter::DidCreateSnapshot() will not work correctly. Though this
did not affect my test extension.

[kinuko, 2012/07/30 23:19:03]

I see what you mean.  I think we should rather fix
FileAPIMessageFilter::DidCreateSnapshot() to use the extension of the virtual
path... will fix now.

+      isolated_media_file_system_dir_path, local_path);
+  if (!file_created)

[kinuko, 2012/07/30 23:19:03]

ditto.

[kmadhusu, 2012/07/31 01:17:48]

Done.

+    return file_ref;
+
+  if (device->CreateSnapshotFile(url.path(), *local_path, file_info))
+    *result = base::PLATFORM_FILE_OK;
+
+  if (*result != base::PLATFORM_FILE_ERROR_INVALID_URL) {

[kinuko, 2012/07/30 23:19:03]

if (*result == base::PLATFORM_FILE_OK)

[kmadhusu, 2012/07/31 01:17:48]

Done.

+    file_ref = ShareableFileReference::GetOrCreate(
+                   *local_path,
+                   ShareableFileReference::DELETE_ON_FINAL_RELEASE,
+                   context->file_task_runner());
+  }
+  return file_ref;
+}
+
+}  // namespace fileapi