Implement media path filter

webkit/fileapi/media/native_media_file_util.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 "webkit/fileapi/media/native_media_file_util.h"

[vandebo (ex-Chrome), 2012/08/01 01:11:05]

Maybe I'm wrong, but it seems that in the end, this file is going to be a copy
of native_file_util plus code to apply the media filter?  Would it be easier to
maintain the two classes by having just one copy that knows how to use the
filter but has no filter in the non-media case?

[tzik, 2012/08/01 21:46:06]

NativeFileUtil is no longer a subclass of FileSystemFileUtil, it is just a set
of helper function.
And FileUtil's are directly call file_util:: functions instead of
NativeFileUtil.
So, I'd like not to merge it to NativeFileUtil.

Should we use layering? Hmm....

+
+#include "net/base/mime_util.h"
+#include "webkit/fileapi/file_system_operation_context.h"
+#include "webkit/fileapi/media/media_path_filter.h"
+
+using base::PlatformFileError;
+using base::PlatformFileInfo;
+
+namespace fileapi {
+
+class MediaPathFilter;
+
+namespace {
+
+class FilteringFileEnumerator
+    : public FileSystemFileUtil::AbstractFileEnumerator {
+ public:
+  FilteringFileEnumerator(
+      scoped_ptr<FileSystemFileUtil::AbstractFileEnumerator> base_enumerator,
+      MediaPathFilter* filter)
+      : base_enumerator_(base_enumerator.Pass()),
+        filter_(filter) {
+    DCHECK(base_enumerator_.get());
+    DCHECK(filter);
+  }
+
+  virtual FilePath Next() OVERRIDE {
+    while (true) {
+      FilePath next = base_enumerator_->Next();
+      if (next.empty() ||
+          base_enumerator_->IsDirectory() ||
+          filter_->Match(next))
+        return next;
+    }
+  }
+
+  virtual int64 Size() OVERRIDE {
+    return base_enumerator_->Size();
+  }
+
+  virtual base::Time LastModifiedTime() OVERRIDE {
+    return base_enumerator_->LastModifiedTime();
+  }
+
+  virtual bool IsDirectory() OVERRIDE {
+    return base_enumerator_->IsDirectory();
+  }
+
+ private:
+  scoped_ptr<FileSystemFileUtil::AbstractFileEnumerator> base_enumerator_;
+  MediaPathFilter* filter_;
+};
+
+}  // namespace
+
+NativeMediaFileUtil::NativeMediaFileUtil() {
+}
+
+PlatformFileError NativeMediaFileUtil::CreateOrOpen(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    int file_flags,
+    PlatformFile* file_handle,
+    bool* created) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError NativeMediaFileUtil::EnsureFileExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url, bool* created) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+FileSystemFileUtil::AbstractFileEnumerator*
+NativeMediaFileUtil::CreateFileEnumerator(
+    FileSystemOperationContext* context,
+    const FileSystemURL& root_url,
+    bool recursive) {
+  DCHECK(context);
+
+  AbstractFileEnumerator* base_enumerator =
+      IsolatedFileUtil::CreateFileEnumerator(context, root_url, recursive);
+  return new FilteringFileEnumerator(
+      scoped_ptr<AbstractFileEnumerator>(base_enumerator),
+      context->media_path_filter());
+}
+
+PlatformFileError NativeMediaFileUtil::Touch(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    const base::Time& last_access_time,
+    const base::Time& last_modified_time) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError NativeMediaFileUtil::Truncate(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    int64 length) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+bool NativeMediaFileUtil::PathExists(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  DCHECK(context);
+
+  FilePath path;
+  PlatformFileInfo file_info;
+  PlatformFileError error =
+      GetFileInfo(context, url, &file_info, &path);
+  return error == base::PLATFORM_FILE_OK;
+}
+
+bool NativeMediaFileUtil::IsDirectoryEmpty(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  DCHECK(context);
+  DCHECK(context->media_path_filter());
+
+  scoped_ptr<AbstractFileEnumerator> enumerator(
+      CreateFileEnumerator(context, url, false));
+  FilePath path;
+  while (!(path = enumerator->Next()).empty()) {
+    if (enumerator->IsDirectory() ||
+        context->media_path_filter()->Match(path))
+      return false;
+  }
+  return true;
+}
+
+PlatformFileError NativeMediaFileUtil::CopyOrMoveFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& src_url,
+    const FileSystemURL& dest_url,
+    bool copy) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError NativeMediaFileUtil::CopyInForeignFile(
+    FileSystemOperationContext* context,
+    const FilePath& src_file_path,
+    const FileSystemURL& dest_url) {
+  // TODO(tzik): Apply context()->mime_path_filter() here when we support write
+  // access.
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError NativeMediaFileUtil::DeleteFile(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url) {
+  return base::PLATFORM_FILE_ERROR_SECURITY;
+}
+
+PlatformFileError NativeMediaFileUtil::GetFileInfo(
+    FileSystemOperationContext* context,
+    const FileSystemURL& url,
+    PlatformFileInfo* file_info,
+    FilePath* platform_path) {
+  DCHECK(context);
+  DCHECK(context->media_path_filter());
+  DCHECK(file_info);
+  DCHECK(platform_path);
+
+  base::PlatformFileError error =
+      IsolatedFileUtil::GetFileInfo(context, url, file_info, platform_path);
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+
+  if (file_info->is_directory ||
+      context->media_path_filter()->Match(*platform_path))
+    return base::PLATFORM_FILE_OK;
+  return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+}
+
+}  // namespace fileapi