Timeline

math.MaxUint32 overflows int on TinyGo's wasm target. check-in: 53338a5536 user: [email protected] tags: main, perf/memo-tree-encoding, trunk

Count the decoded file set a tree index keeps as the next difference's base toward memoTreeBytes, check a decoded id's gap without wrapping in uint64, and say what cloning the index on publish costs (about 0.5ms for fossil-scm.org's whole history, BenchmarkTreeIndexClone).

TestMemoWideTreesMatchFresh classifies every cone over wide trees that rename, delete and add files, in all three manifest forms, with chains of differences 15 long and with a limit that starts the index again, before and after the store gains check-ins; a branch heads the chains trunk trees continue, so a trunk horizon decodes trees whose chain starts outside its held set. check-in: 7ba1eb6915 user: [email protected] tags: main, perf/memo-tree-encoding, trunk

# Conflicts: # CHANGELOG.md check-in: a90035689e user: [email protected] tags: main, perf/memo-tree-encoding, trunk

A full read of every tree with the graph made a cold classification on fossil-scm.org's clone three to four times slower, which an origin that starts cold often cannot afford. Walks read a tree when they first need it, as before, and the memo keeps what they read as a treeIndex (interned ids, delta-varint sets, full manifests as differences), replaced on each publish so views read it without the lock. memoTreeBytes now bounds that encoding, which holds the whole history of fossil-scm.org in about 11 MiB; past it the index starts again. HZ-6.2-10 stays partial: trees are still read on first use, not with the graph. check-in: b53551c192 user: [email protected] tags: main, perf/memo-tree-encoding, trunk

The origin classification memo now reads the F cards of every tree in the store once, with its references, and extends them by appended check-ins (draft-fossil-horizon-00 §6.2, HZ-6.2-10). Blob names are interned to uint32 ids, each tree's file set is a sorted delta-varint id list, and a full manifest is kept as its symmetric difference from the previous full manifest read, at most 15 links from a piece kept whole, decoded through a 16-entry LRU per view. A store whose index would pass memoTreeBytes keeps none and falls back to the bounded cache of walked trees.

On a clone of fossil-scm.org the trees take 11 MiB (the walked-tree cache held 50 MiB for two horizons), the memo's retained heap halves and peak in-use heap drops from 345-524 MiB to about 170 MiB. Tracked in #463. check-in: 1cb9e11a65 user: [email protected] tags: main, perf/memo-tree-encoding, trunk