New: Limits and priorities in LXMF

[markqvist]

While I know some of you are still waiting patiently for the full API documentation for LXMF, I just wanted to drop a quick note about an important upgrade in the latest LXMF release.

LXMF now manages the message store according to a max size, and a set of prioritisation rules. By default, the max message store size is set to 2 gigabytes, but this can be configured by the client or daemon. Until I have the API docs ready, you will have to read the implementation (which I also just cleaned up significantly) for the full details, but the gist is:

• Messages are weighted based on their size and age according to weight = priority_weight x age_weight x msg_size
• The heaviest messages will get dropped until the message store size is under the limit
• The LXM Router automatically checks the message store periodically and prunes it if necessary