A DestinationStream is a /namespace/id[0]/id[1]/.../id[n] that represents a collection of Activities. Example destinations: -The Profile Stream on http://plus.google.com/+JohnDoe/posts -A Square Stream on http://plus.google.com/squares/123 -A "comment Stream" (Fountain) on http://www.youtube.com/watch?id=123 It's possible for a single Activity to show in each of these destinations - and it might behave/look slightly differently for each one. Destinations can have their own business logic associated with them at both write-time and read-time server-side (these are documented below). Each DestinationStream is indexed and can be retrieved using the GetDestinationStreamRequest. For the repeated ID space indexing happens at all levels, e.g. if you have: /square/123/abc /square/123/efd /square/456 You can fetch /square/123/abc directly or /square/123 (which includes all Activities in both /square/123/abc and /square/123/efd), or even /square which retrieves all Activities in the Square namespace (visible for that user). On the storage layer, we represent DestinationStream as Channel (http://cs/#google3/social/common/channel/channel.proto), since the storage does not have the concept of a Stream. Both terms are used interchangeably within the service layer, but client of Social Infrastructure should use the term DestinationStream. Next ID: 3

Attributes

• id (type: list(String.t), default: nil) - The hierarchy of IDs. Each individual ID is "flat" and the repeated list defines the hierarchy. Namespaces define the "validity" of this hierachy (depth, naming convention, etc) and the server will reject invalid IDs.
• namespace (type: String.t, default: nil) -