compact/v0 package

Package compact makes fragmentation a number you can act on.

A soft delete does not free anything. It clears the element and leaves the tree node behind, so the bytes stay locked and every read still walks past them. Compacting drops those nodes and the chain refunds their deposit to whoever signed the transaction. So compaction is paid work, and the only real question is WHEN: too early and you free too few nodes to cover the gas, too late and every read has been paying for the holes in between.

This realm refuses to answer that question, on purpose. It publishes the two integers the answer is made of and lets whoever is watching decide, because the realm cannot see the gas price of the day and the caller can.

• Fragmentation() is live vs allocated, the free read a bot polls.
• Reclaimable() is what a Compact would actually free, right now.
• Quote() prices it at the floor gas price, as an advertisement.

The arithmetic is gno.land/p/moul/x/storagecost and the container is gno.land/p/moul/ulist, whose Compact drops dead nodes without moving a live index, so an index is stable for the life of the realm.

Why this quote is trustworthy where a reaper's is not

A reaper advertises what deleting entries will refund, and to do that it has to guess how much state an entry occupies from its payload length. That guess is bad: a per-entry floor dominates at the small end, and one realm under-advertised by 25x on chain because of it.

Compaction has no such problem. What it frees is a COUNT of dead nodes, and the container already reports that count exactly. Every node costs the same whatever it carried. So the number on this page is a measured constant times an exact integer, not a ratio applied to a guess, which is why this is the half of the mechanism worth showing first.