[BUG-234158] Add an additional byte to ObjectUpdate message with number of children

[sl-service-account]

How would you like the feature to work?

Inside ObjectData include a byte representing the number of child nodes below this.

In the case of Avatars, this could be the number of worn attachments; and in the case of standard primitives/linksets, it would be the number of child nodes linked into the linkset (excluding the parent).

If data is missing, a way to prompt the resend of the descendants would be nice too; although I think an Object Properties Request will do this already.

Why is this feature important to you? How would it benefit the community?

There's no way to tell if a linkset has fully been received by a client; this has two problems:

1) we cannot tell if any data is missing, and 2) we cannot tell when an object is finished and ready to render (e.g. avatars)

A single byte, containing the number of child primitives (e.g. for avatars, child primitives would be # of attachments; for a more conventional linkset, it'd the number of child primitives in the linkset) would allow us to determine this

Original Jira Fields

| Field | Value | | ------------- | ------------- | | Issue | BUG-234158 | | Summary | Add an additional byte to ObjectUpdate message with number of children | | Type | New Feature Request | | Priority | Unset | | Status | Accepted | | Resolution | Accepted | | Created at | 2023-07-21T07:57:28Z | | Updated at | 2023-09-21T15:47:33Z | ``` { 'Build Id': 'unset', 'Business Unit': ['Platform'], 'Date of First Response': '2023-07-26T13:29:34.629-0500', 'How would you like the feature to work?': 'Inside ObjectData include a byte representing the number of child nodes below this.\r\n\r\nIn the case of Avatars, this could be the number of worn attachments; and in the case of standard primitives/linksets, it would be the number of child nodes linked into the linkset (excluding the parent).\r\n\r\nIf data is missing, a way to prompt the resend of the descendants would be nice too; although I _think_ an Object Properties Request will do this already.', 'ReOpened Count': 0.0, 'Severity': 'Unset', 'Target Viewer Version': 'viewer-development', 'Why is this feature important to you? How would it benefit the community?': "There's no way to tell if a linkset has fully been received by a client; this has two problems:\r\n\r\n1) we cannot tell if any data is missing, and \r\n2) we cannot tell when an object is finished and ready to render (e.g. avatars)\r\n\r\nA single byte, containing the number of child primitives (e.g. for avatars, child primitives would be # of attachments; for a more conventional linkset, it'd the number of child primitives in the linkset) would allow us to determine this", } ```

[sl-service-account]

Simon Linden commented at 2023-07-26T18:29:35Z

Let's add more than a byte - 16 or 32 bits we might use in the future