Media Gallery: Implement a basic version of GetMediaFileSystems().

chrome/browser/media_gallery/media_file_system_registry.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.
+
+// MediaFileSystemRegistry implementation.
+
+#include "chrome/browser/media_gallery/media_file_system_registry.h"
+
+#include <set>
+
+#include "base/path_service.h"
+#include "base/sys_string_conversions.h"
+#include "chrome/common/chrome_paths.h"
+#include "content/public/browser/browser_thread.h"
+#include "webkit/fileapi/isolated_context.h"
+
+namespace chrome {
+
+static base::LazyInstance<MediaFileSystemRegistry>::Leaky
+    g_media_file_system_registry = LAZY_INSTANCE_INITIALIZER;
+
+using content::BrowserThread;
+using fileapi::IsolatedContext;
+
+// static
+MediaFileSystemRegistry* MediaFileSystemRegistry::GetInstance() {
+  return g_media_file_system_registry.Pointer();
+}
+
+std::vector<MediaFileSystemRegistry::MediaFSIDAndPath>
+MediaFileSystemRegistry::GetMediaFileSystems() const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  std::vector<MediaFSIDAndPath> results;
+  for (MediaPathToFSIDMap::const_iterator it = media_fs_map_.begin();
+       it != media_fs_map_.end();
+       ++it) {
+    const FilePath path = it->first;
+    const std::string fsid = it->second;
+    results.push_back(std::make_pair(fsid, path));
+  }
+  return results;
+}
+
+MediaFileSystemRegistry::MediaFileSystemRegistry() {
+  FilePath pictures_path;
+  if (PathService::Get(chrome::DIR_USER_PICTURES, &pictures_path)) {
+    RegisterPathAsFileSystem(pictures_path);
+  }
+}
+
+MediaFileSystemRegistry::~MediaFileSystemRegistry() {
+}
+
+void MediaFileSystemRegistry::RegisterPathAsFileSystem(const FilePath& path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // Sanity checks for |path|.
+  CHECK(path.IsAbsolute());
+  CHECK(!path.ReferencesParent());
+  // Make sure |path| does not refer to '/' on Unix.
+  // TODO(thestig) Check how BaseName() works for say, 'C:\' on Windows.
+  CHECK(!path.BaseName().IsAbsolute());
+  CHECK(!path.BaseName().empty());
+
+  std::set<FilePath> fileset;
+  fileset.insert(path);
+  const std::string fsid =
+      IsolatedContext::GetInstance()->RegisterIsolatedFileSystem(fileset);
+  CHECK(!fsid.empty());
+  media_fs_map_.insert(std::make_pair(path, fsid));
+}
+
+}  // namespace chrome