// Copyright (c) 2009 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.
//
// Sync protocol for communication between sync client and server.

syntax = "proto2";

option optimize_for = LITE_RUNTIME;

package sync_pb;

// Used to store and send extended attributes, which are arbitrary
// key value pairs.
message ExtendedAttributes {
  repeated group ExtendedAttribute = 1 {
    required string key = 2;
    required bytes value = 3;
  }
}

// Used for inspecting how long we spent performing operations in different
// backends. All times must be in millis.
message ProfilingData {
  optional int64 meta_data_write_time = 1;
  optional int64 file_data_write_time = 2;
  optional int64 user_lookup_time = 3;
  optional int64 meta_data_read_time = 4;
  optional int64 file_data_read_time = 5;
  optional int64 total_request_time = 6;
}

message EntitySpecifics {
  // To add new datatype-specific fields to the protocol, extend
  // EntitySpecifics.  First, pick a non-colliding tag number by
  // picking a revision number of one of your past commits
  // to src.chromium.org.  Then, in a different protocol buffer
  // definition that includes this, do the following:
  //
  //   extend EntitySpecifics {
  //     MyDatatypeSpecifics my_datatype = 32222;
  //   }
  //
  // where:
  //   - 32222 is the non-colliding tag number you picked earlier.
  //   - MyDatatypeSpecifics is the type (probably a message type defined
  //     in your new .proto file) that you want to associate with each
  //     object of the new datatype.
  //   - my_datatype is the field identifier you'll use to access the
  //     datatype specifics from the code.
  //
  // Server implementations are obligated to preserve the contents of
  // EntitySpecifics when it contains unrecognized extensions.  In this
  // way, it is possible to add new datatype fields without having
  // to update the server.
  extensions 30000 to max;
}

message SyncEntity {
  // This item's identifier.  In a commit of a new item, this will be a
  // client-generated ID.  If the commit succeeds, the server will generate
  // a globally unique ID and return it to the committing client in the
  // CommitResponse.EntryResponse.  In the context of a GetUpdatesResponse,
  // |id_string| is always the server generated ID.  The original
  // client-generated ID is preserved in the |originator_client_id| field.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional string id_string = 1;

  // An id referencing this item's parent in the hierarchy.  In a
  // CommitMessage, it is accepted for this to be a client-generated temporary
  // ID if there was a new created item with that ID appearing earlier
  // in the message.  In all other situations, it is a server ID.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional string parent_id_string = 2;

  // old_parent_id is only set in commits and indicates the old server
  // parent(s) to remove. When omitted, the old parent is the same as
  // the new.
  // Present only in CommitMessage.
  optional string old_parent_id = 3;

  // The version of this item -- a monotonically increasing value that is
  // maintained by for each item.  If zero in a CommitMessage, the server
  // will interpret this entity as a newly-created item and generate a
  // new server ID and an initial version number.  If nonzero in a
  // CommitMessage, this item is treated as an update to an existing item, and
  // the server will use |id_string| to locate the item.  Then, if the item's
  // current version on the server does not match |version|, the commit will
  // fail for that item.  The server will not update it, and will return
  // a result code of CONFLICT.  In a GetUpdatesResponse, |version| is
  // always positive and indentifies the revision of the item data being sent
  // to the client.
  // Present in both GetUpdatesResponse and CommitMessage.
  required int64 version = 4;

  // Last modification time (in java time milliseconds)
  // Present in both GetUpdatesResponse and CommitMessage.
  optional int64 mtime = 5;

  // Creation time.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional int64 ctime = 6;

  // A unique-in-the parent name for this item.
  // Present in both GetUpdatesResponse and CommitMessage.
  required string name = 7;

  // non_unique_name holds the base name stored serverside, which is different
  // from |name| when |name| has been suffixed in a way to make it unique
  // among its siblings.  In a GetUpdatesResponse, |non_unique_name| will
  // be supplied in addition to |name|, and the client may choose which
  // field to use depending on its needs.  In a CommitMessage,
  // |non_unique_name| takes precedence over the |name| value if both are
  // supplied.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional string non_unique_name = 8;

  // A value from a monotonically increasing sequence that indicates when
  // this item was last updated on the server. This is now equivalent
  // to version. This is now deprecated in favor of version.
  // Present only in GetUpdatesResponse.
  optional int64 sync_timestamp = 9;

  // If present, singleton_tag identifies this item as being a uniquely
  // instanced item.  The server ensures that there is never more
  // than one entity in a user's store with the same singleton_tag value.
  // This value is used to identify and find e.g. the "Google Chrome" settings
  // folder without relying on it existing at a particular path, or having
  // a particular name, in the data store.
  // Present only in GetUpdatesResponse.
  optional string singleton_tag = 10;

  // If this group is present, it implies that this SyncEntity corresponds to
  // a bookmark or a bookmark folder.
  //
  // TODO(idana): for now, we put the bookmarks related information explicitly
  // in the protocol definition. When we start syncing more data types, it is
  // probably going to be better if we represent the different types as
  // extended attributes.
  optional group BookmarkData = 11 {
    // We use a required field to differentiate between a bookmark and a
    // bookmark folder.
    // Present in both GetUpdatesMessage and CommitMessage.
    required bool bookmark_folder = 12;

    // For bookmark objects, contains the bookmark's URL.
    // Present in both GetUpdatesResponse and CommitMessage.
    optional string bookmark_url = 13;

    // For bookmark objects, contains the bookmark's favicon. The favicon is
    // represented as a 16X16 PNG image.
    // Present in both GetUpdatesResponse and CommitMessage.
    optional bytes bookmark_favicon = 14;
  }

  // Supplies a numeric position for this item, relative to other items with
  // the same parent.  This value is only meaningful in server-to-client
  // contexts; to specify a position in a client-to-server commit context,
  // use |insert_after_item_id|.
  // Present only in GetUpdatesResponse.
  optional int64 position_in_parent = 15;

  // Contains the ID of the element (under the same parent) after which this
  // element resides. An empty string indicates that the element is the first
  // element in the parent.  This value is used during commits to specify
  // a relative position for a position change.  In the context of
  // a GetUpdatesMessage, |position_in_parent| is used instead to
  // communicate position.
  // Present only in CommitMessage.
  optional string insert_after_item_id = 16;

  // Arbitrary key/value pairs associated with this item.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional ExtendedAttributes extended_attributes = 17;

  // If true, indicates that this item has been (or should be) deleted.
  // Present in both GetUpdatesResponse and CommitMessage.
  optional bool deleted = 18 [default = false];

  // A GUID that identifies the the sync client who initially committed
  // this entity.  This value corresponds to |cache_guid| in CommitMessage.
  // This field, along with |originator_client_item_id|, can be used to
  // reunite the original with its official committed version in the case
  // where a client does not receive or process the commit response for
  // some reason.
  // Present only in GetUpdatesResponse.
  optional string originator_cache_guid = 19;

  // The local item id of this entry from the client that initially
  // committed this entity. Typically a negative integer.
  // Present only in GetUpdatesResponse.
  optional string originator_client_item_id = 20;

  // Extensible container for datatype-specific data.
  // This became available in version 23 of the protocol.
  optional EntitySpecifics specifics = 21;

  // Indicate whether this is a folder or not. Available in version 23+.
  optional bool folder = 22 [default = false];
};

message CommitMessage {
  repeated SyncEntity entries = 1;

  // A GUID that identifies the committing sync client.  This value will be
  // returned as originator_cache_guid for any new items.
  optional string cache_guid = 2;

  // This message contains diagnostic information used to correlate
  // commit-related traffic with extensions-related mutations to the
  // data models in chromium.  It plays no functional role in
  // processing this CommitMessage.
  message ChromiumExtensionsActivity {
    // The human-readable ID identifying the extension responsible
    // for the traffic reported in this ChromiumExtensionsActivity.
    optional string extension_id = 1;

    // How many times the extension successfully invoked a write
    // operation through the bookmarks API since the last CommitMessage.
    optional uint32 bookmark_writes_since_last_commit = 2;
  }

  repeated ChromiumExtensionsActivity extensions_activity = 3;
};

message GetUpdatesCallerInfo {
  enum GetUpdatesSource {
    UNKNOWN = 0;  // The source was not set by the caller.
    FIRST_UPDATE = 1;  // First update from an instance of Chrome.
    LOCAL = 2;  // The source of the update was a local change.
    NOTIFICATION = 3;  // The source of the update was a p2p notification.
    PERIODIC = 4;  // The source of the update was periodic polling.
    SYNC_CYCLE_CONTINUATION = 5;  // The source of the update was a
  }                               // continuation of a previous update.

  required GetUpdatesSource source = 1;

  // True only if notifications were enabled for this GetUpdateMessage.
  optional bool notifications_enabled = 2;
};

message GetUpdatesMessage {
  required int64 from_timestamp = 1;

  // Indicates the reason for the GetUpdatesMessage.
  optional GetUpdatesCallerInfo caller_info = 2;
};

message AuthenticateMessage {
  required string auth_token = 1;
};

message ClientToServerMessage {
  required string share = 1;
  optional int32 protocol_version = 2 [default = 23];
  enum Contents {
    COMMIT = 1;
    GET_UPDATES = 2;
    AUTHENTICATE = 3;
  }

  required Contents message_contents = 3;
  optional CommitMessage commit = 4;
  optional GetUpdatesMessage get_updates = 5;
  optional AuthenticateMessage authenticate = 6;

  optional string store_birthday = 7; // Opaque store ID; if it changes, duck!
  // The client sets this if it detects a sync issue. The server will tell it
  // if it should perform a refresh.
  optional bool sync_problem_detected = 8 [default = false];
};

message CommitResponse {
  enum ResponseType {
    SUCCESS = 1;
    CONFLICT = 2; // You're out of date; update and check your data
    // TODO(ncarter): What's the difference between RETRY and TRANSIENT_ERROR?
    RETRY = 3; // Someone has a conflicting, non-expired session open
    INVALID_MESSAGE = 4; // What the client sent was invalid, and trying again
                         // won't help.
    OVER_QUOTA = 5; // This operation would put you, or you are, over quota
    TRANSIENT_ERROR = 6; // Something went wrong; try again in a bit
  }
  repeated group EntryResponse = 1 {
    required ResponseType response_type = 2;

    // Sync servers may also return a new ID for an existing item, indicating
    // a new entry's been created to hold the data the client's sending up.
    optional string id_string = 3;

    // should be filled if our parent was assigned a new ID.
    optional string parent_id_string = 4;

    // This value is the same as the position_in_parent value returned within
    // the SyncEntity message in GetUpdatesResponse.
    optional int64 position_in_parent = 5;

    // The item's current version.
    optional int64 version = 6;

    // Allows the server to move-aside an entry as it's being committed.
    // This name is the same as the name field returned within the SyncEntity
    // message in GetUpdatesResponse.
    optional string name = 7;

    // This name is the same as the non_unique_name field returned within the
    // SyncEntity message in GetUpdatesResponse.
    optional string non_unique_name = 8;

    optional string error_message = 9;

  }
};

message GetUpdatesResponse {
  repeated SyncEntity entries = 1;
  // If there are more changes on the server that weren't processed during this
  // GetUpdates request, the client should send another GetUpdates request and
  // use new_timestamp as the from_timestamp value within GetUpdatesMessage.
  optional int64 new_timestamp = 2;
  // DEPRECATED FIELD - server does not set this anymore.
  optional int64 deprecated_newest_timestamp = 3;
  // Estimated number of changes remaining - use this for UI feedback.
  optional int64 changes_remaining = 4;
};

// A user-identifying struct.  For a given Google account the email and display
// name can change, but obfuscated_id should be constant.
// The obfuscated id is optional because at least one planned use of the proto
// (sharing) does not require it.
message UserIdentification {
  required string email = 1;  // the user's full primary email address.
  optional string display_name = 2;  // the user's display name.
  optional string obfuscated_id = 3;  // an obfuscated, opaque user id.
};

message AuthenticateResponse {
  // Optional only for backward compatibility.
  optional UserIdentification user = 1;
};

message ThrottleParameters {
  // Deprecated. Remove this from the server side.
  required int32 min_measure_payload_size = 1;
  required double target_utilization = 2;
  required double measure_interval_max = 3;
  required double measure_interval_min = 4;
  required double observation_window = 5;
};

// A command from the server instructing the client to update settings or
// perform some operation.
message ClientCommand {
  // Time to wait before sending any requests to the server.
  optional int32 set_sync_poll_interval = 1;  // in seconds
  optional int32 set_sync_long_poll_interval = 2;  // in seconds

  optional int32 max_commit_batch_size = 3;
};

message ClientToServerResponse {
  optional CommitResponse commit = 1;
  optional GetUpdatesResponse get_updates = 2;
  optional AuthenticateResponse authenticate = 3;

  enum ErrorType {
    SUCCESS            = 0;
    ACCESS_DENIED      = 1; // Returned when the user doesn't have access to
                            // store (instead of HTTP 401).
    NOT_MY_BIRTHDAY    = 2; // Returned when the server and client disagree on
                            // the store birthday.
    THROTTLED          = 3; // Returned when the store has exceeded the allowed
                            // bandwidth utilization.
    AUTH_EXPIRED       = 4; // Auth token or cookie has expired.
    USER_NOT_ACTIVATED = 5; // User doesn't have the Chrome bit set on that
                            // Google Account.
    AUTH_INVALID       = 6; // Auth token or cookie is otherwise invalid.
  }
  optional ErrorType error_code = 4 [default = SUCCESS];
  optional string error_message = 5;

  // Opaque store ID; if it changes, the contents of the client's cache
  // is meaningless to this server.  This happens most typically when
  // you switch from one storage backend instance (say, a test instance)
  // to another (say, the official instance).
  optional string store_birthday = 6;

  optional ClientCommand client_command = 7;
  optional ProfilingData profiling_data = 8;
};