F4. Read Reciepts

[jazzz]

FURPS: logos-messaging/pm#316

To achieve this, PrivateV1 needs a metaframe to pass along this information. Additionally a mechanism is required to differentiate which payloads require a receipt. Naively If receipts are sent as a PrivateV1Frame, they would invoke a new receipt.

Tasks

• Add Receipt frame type
• Determine how to surface this information effectively to clients - update API if needed.

[jazzz]

Read receipt is an inaccurate term in this case. A more accurate term would be "Delivery Acknowledgement".

Read Receipt -> Event triggered when message processed by the reader
DeliveryAck -> Event triggered when message processed by the client

This implementation uses SDS to track messages which are missing. This does not guarentee that a reader has seen the message, just that the client has received it.