[SyncFS] Add FileMetadata and FileTracker message

chrome/browser/sync_file_system/drive_backend/metadata_database.proto

 // 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.
 //
 // Protocol buffer definitions for Drive backend of Syncable FileSystem.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package sync_file_system.drive_backend;
 
 enum FileKind {
   KIND_UNSUPPORTED = 0;
   KIND_FILE = 1;
   KIND_FOLDER = 2;
 }
 
 message ServiceMetadata {
   optional int64 largest_change_id = 1;
-  optional string sync_root_folder_id = 2;
+  optional int64 sync_root_tracker_id = 2;
+
+  // Is the sequence number of FileTrackers. Must be positive.

[nhiroki, 2013/08/06 07:50:59]

nit: s/"Is the"/"The"/

[tzik, 2013/08/06 08:33:45]

Done.

+  optional int64 next_tracker_id = 3;
 }
+
+// Holds details of file/folder metadata.
+message FileDetails {
+  repeated string parent_folder_ids = 1;

[nhiroki, 2013/08/06 07:50:59]

super-nit: How about adding extra blank line between l.29 and l.30. for
readability? (repeated vs. optional)

[tzik, 2013/08/06 08:33:45]

Done.

+  optional string title = 2;
+  optional FileKind kind = 3;
+  optional string md5 = 4;
+  optional string etag = 5;
+
+  // Creation time and modification time of the resource.
+  // Serialized by Time::ToInternalValue.
+  optional int64 creation_time = 6;
+  optional int64 modification_time = 7;
+
+  optional bool deleted = 8;
+  optional int64 change_id = 9;
+}
+
+// Represents a server-side file.
+message FileMetadata {
+  // File ID of the remote file/folder which the FileMetadata represents.
+  required string file_id = 1;
+  optional FileDetails details = 2;

[kinuko, 2013/08/06 07:51:00]

nit: can you put an empty line between 47-48

[tzik, 2013/08/06 08:33:45]

Done.

+}
+
+// Represents synced local file.
+message FileTracker {
+  // A unique sequence number to identify the tracker. Must be positive.
+  required int64 tracker_id = 1;
+
+  // Points the parent tracker in the tracker tree.  0 if there's no parent.
+  required int64 parent_tracker_id = 2;
+
+  required string file_id = 3;
+
+  optional string app_id = 4;
+  optional bool is_app_root = 5;
+
+  optional FileDetails synced_details = 6;
+
+  // True if the file is changed since the last update for this file.
+  optional bool dirty = 7;
+
+  // True if the FileTracker is active.
+  // Remote file content modification should only be applied for active
+  // FileTracker.

[kinuko, 2013/08/06 07:51:00]

nit: for -> to
nit: active FileTracker -> active trackers (or active FileTrackers)

'Remote file content modification' can be probably shortened to just 'Remote
modifications' or 'Remote changes'

[tzik, 2013/08/06 08:33:45]

Done.

+  // Active FileTracker must have a unique title under its parent.
+  optional bool active = 8;
+
+  // Valid only for folders.
+  // True indicates the folder contents has not yet been fetched.

[nhiroki, 2013/08/06 07:50:59]

nit: s/indicates/if/ (to make consistent with other lines like l.66)

[kinuko, 2013/08/06 07:51:00]

nit: has -> have

[tzik, 2013/08/06 08:33:45]

Done.

[tzik, 2013/08/06 08:33:45]

Done.

+  optional bool needs_folder_listing = 9;
+}