Explore using a sorted dictionary to store messages in memory

[dlqqq]

Problem

A sorted dictionary is a dictionary which allows O(1) value access by key, and maintains a well-defined ordering of keys.

This data representation is perfect for getting messages, where there are two key operations which ideally should run in O(1) time:

• Get all messages / last K messages in order
• Get 1 message by its ID

Proposed Solution

Explore using a sorted dictionary to store messages in memory. One issue is that I don't think pycrdt has a sorted dictionary shared type, but it may still be possible for each YChat instance to maintain its own sorted dictionary in-memory.