gdata: Convert public synchronous functions in GDataFileSystem to asynchronous.

chrome/browser/chromeos/gdata/gdata_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 "chrome/browser/chromeos/gdata/gdata_util.h"
 
 #include <string>
 #include <vector>
 #include <utility>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "base/string_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
+#include "chrome/browser/chromeos/gdata/gdata.pb.h"
 #include "chrome/browser/chromeos/gdata/gdata_file_system.h"
 #include "chrome/browser/chromeos/gdata/gdata_system_service.h"
 #include "chrome/browser/chromeos/login/user.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_security_policy.h"
@@ skipping 52 matching lines @@
 }
 
 void OpenEditURLUIThread(Profile* profile, GURL* edit_url) {
   Browser* browser = browser::FindLastActiveWithProfile(profile);
   if (browser) {
     browser->OpenURL(content::OpenURLParams(*edit_url, content::Referrer(),
         CURRENT_TAB, content::PAGE_TRANSITION_TYPED, false));
   }
 }
 
+// Invoked upon completion of GetFileInfoByPathAsync initiated by
+// InsertGDataCachePathPermissions.
+void OnGetFileInfoForInsertGDataCachePathsPermissions(
+    Profile* profile,
+    std::vector<std::pair<FilePath, int> >* cache_paths,
+    const base::Closure& callback,
+    base::PlatformFileError error,
+    scoped_ptr<GDataFileProto> file_info) {
+  DCHECK(profile);
+  DCHECK(cache_paths);
+  DCHECK(!callback.is_null());
+
+  GDataFileSystem* file_system = GetGDataFileSystem(profile);
+  if (!file_system || error != base::PLATFORM_FILE_OK) {
+    callback.Run();
+    return;
+  }
+
+  DCHECK(file_info.get());
+  std::string resource_id = file_info->gdata_entry().resource_id();
+  std::string file_md5 = file_info->file_md5();
+
+  // We check permissions for raw cache file paths only for read-only
+  // operations (when fileEntry.file() is called), so read only permissions
+  // should be sufficient for all cache paths. For the rest of supported
+  // operations the file access check is done for drive/ paths.
+  cache_paths->push_back(std::make_pair(
+      file_system->GetCacheFilePath(resource_id, file_md5,
+          GDataCache::CACHE_TYPE_PERSISTENT,
+          GDataCache::CACHED_FILE_FROM_SERVER),
+      kReadOnlyFilePermissions));
+  // TODO(tbarzic): When we start supporting openFile operation, we may have to
+  // change permission for localy modified files to match handler's permissions.
+  cache_paths->push_back(std::make_pair(
+      file_system->GetCacheFilePath(resource_id, file_md5,
+          GDataCache::CACHE_TYPE_PERSISTENT,
+          GDataCache::CACHED_FILE_LOCALLY_MODIFIED),
+     kReadOnlyFilePermissions));
+  cache_paths->push_back(std::make_pair(
+      file_system->GetCacheFilePath(resource_id, file_md5,
+          GDataCache::CACHE_TYPE_PERSISTENT,
+          GDataCache::CACHED_FILE_MOUNTED),
+     kReadOnlyFilePermissions));
+  cache_paths->push_back(std::make_pair(
+      file_system->GetCacheFilePath(resource_id, file_md5,
+          GDataCache::CACHE_TYPE_TMP,
+          GDataCache::CACHED_FILE_FROM_SERVER),
+      kReadOnlyFilePermissions));
+
+  callback.Run();
+}
+
 }  // namespace
 
 const FilePath& GetGDataMountPointPath() {
   CR_DEFINE_STATIC_LOCAL(FilePath, gdata_mount_path,
       (FilePath::FromUTF8Unsafe(kGDataMountPointPath)));
   return gdata_mount_path;
 }
 
 const std::string& GetGDataMountPointPathAsString() {
   CR_DEFINE_STATIC_LOCAL(std::string, gdata_mount_path_string,
@@ skipping 118 matching lines @@
   FilePath extracted;
   for (size_t i = arraysize(kGDataMountPointPathComponents) - 1;
        i < components.size(); ++i) {
     extracted = extracted.Append(components[i]);
   }
   return extracted;
 }
 
 void InsertGDataCachePathsPermissions(
     Profile* profile,
-    const FilePath& gdata_path,
-    std::vector<std::pair<FilePath, int> >* cache_paths ) {
+    scoped_ptr<std::vector<FilePath> > gdata_paths,
+    std::vector<std::pair<FilePath, int> >* cache_paths,
+    const base::Closure& callback) {
+  DCHECK(profile);
+  DCHECK(gdata_paths.get());
   DCHECK(cache_paths);
+  DCHECK(!callback.is_null());
 
   GDataFileSystem* file_system = GetGDataFileSystem(profile);
-  if (!file_system)
+  if (!file_system || gdata_paths->empty()) {
+    callback.Run();
     return;
+  }
 
-  GDataFileProperties file_properties;
-  if (!file_system->GetFileInfoByPath(gdata_path, &file_properties))
-    return;
+  // Remove one file path entry from the back of the input vector |gdata_paths|.
+  FilePath gdata_path = gdata_paths->back();
+  gdata_paths->pop_back();
 
-  std::string resource_id = file_properties.resource_id;
-  std::string file_md5 = file_properties.file_md5;
-
-  // We check permissions for raw cache file paths only for read-only
-  // operations (when fileEntry.file() is called), so read only permissions
-  // should be sufficient for all cache paths. For the rest of supported
-  // operations the file access check is done for drive/ paths.
-  cache_paths->push_back(std::make_pair(
-      file_system->GetCacheFilePath(resource_id, file_md5,
-                                    GDataCache::CACHE_TYPE_PERSISTENT,
-                                    GDataCache::CACHED_FILE_FROM_SERVER),
-      kReadOnlyFilePermissions));
-  // TODO(tbarzic): When we start supporting openFile operation, we may have to
-  // change permission for localy modified files to match handler's permissions.
-  cache_paths->push_back(std::make_pair(
-      file_system->GetCacheFilePath(resource_id, file_md5,
-                                    GDataCache::CACHE_TYPE_PERSISTENT,
-                                    GDataCache::CACHED_FILE_LOCALLY_MODIFIED),
-     kReadOnlyFilePermissions));
-  cache_paths->push_back(std::make_pair(
-      file_system->GetCacheFilePath(resource_id, file_md5,
-                                    GDataCache::CACHE_TYPE_PERSISTENT,
-                                    GDataCache::CACHED_FILE_MOUNTED),
-     kReadOnlyFilePermissions));
-  cache_paths->push_back(std::make_pair(
-      file_system->GetCacheFilePath(resource_id, file_md5,
-                                    GDataCache::CACHE_TYPE_TMP,
-                                    GDataCache::CACHED_FILE_FROM_SERVER),
-      kReadOnlyFilePermissions));
+  // Call GetFileInfoByPathAsync() to get file info for |gdata_path| then insert
+  // all possible cache paths to the output vector |cache_paths|.
+  // Note that we can only process one file path at a time. Upon completion
+  // of OnGetFileInfoForInsertGDataCachePathsPermissions(), we recursively call
+  // InsertGDataCachePathsPermissions() to process the next file path from the
+  // back of the input vector |gdata_paths| until it is empty.
+  file_system->GetFileInfoByPathAsync(
+      gdata_path,
+      base::Bind(&OnGetFileInfoForInsertGDataCachePathsPermissions,
+                 profile,
+                 cache_paths,
+                 base::Bind(&InsertGDataCachePathsPermissions,
+                             profile,
+                             base::Passed(&gdata_paths),
+                             cache_paths,
+                             callback)));
 }
 
 bool IsGDataAvailable(Profile* profile) {
   if (!chromeos::UserManager::Get()->IsUserLoggedIn() ||
       chromeos::UserManager::Get()->IsLoggedInAsGuest() ||
       chromeos::UserManager::Get()->IsLoggedInAsDemoUser())
     return false;
 
   // Do not allow GData for incognito windows / guest mode.
   if (profile->IsOffTheRecord())
@@ skipping 66 matching lines @@
   // Assign the extracted extensions to md5 and extra_extension.
   int extension_count = extensions.size();
   *md5 = (extension_count > 0) ? extensions[extension_count - 1] :
                                  std::string();
   *extra_extension = (extension_count > 1) ? extensions[extension_count - 2] :
                                              std::string();
 }
 
 }  // namespace util
 }  // namespace gdata