perf: cache sorted visible key names on Val.Obj#784
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stephenamar-db merged 1 commit intodatabricks:masterfrom Apr 24, 2026
Merged
perf: cache sorted visible key names on Val.Obj#784stephenamar-db merged 1 commit intodatabricks:masterfrom
stephenamar-db merged 1 commit intodatabricks:masterfrom
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stephenamar-db
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Apr 21, 2026
Motivation: Non-inline objects (>8 fields, super chains, excludedKeys) call .sorted(CodepointStringOrdering) on visibleKeyNames at every materialization. This re-sorts and allocates a new array each time. Modification: Add _sortedVisibleKeyNames cache on Val.Obj with lazy initialization. Replace all 5 call sites (Materializer recursive/stackless, Renderer, ByteRenderer, Val.Obj.foreachElement) with the cached accessor. Result: Objects with stable schemas sort their key names once and reuse the result on subsequent materializations.
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stephenamar-db
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Apr 24, 2026
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Summary
visibleKeyNames.sorted(Util.CodepointStringOrdering)onVal.Objto avoid re-sorting on every materialization.sorted()every time they were materialized viastd.manifestJsonor the default output path@volatilefor safe publication (benign race: worst case is a redundant sort)Changes
Val.scala: Add_sortedVisibleKeyNamesfield andsortedVisibleKeyNamesaccessor methodMaterializer.scala: Useobj.sortedVisibleKeyNamesinstead ofobj.visibleKeyNames.sorted(...)in both visitor-based and fused materializer pathsByteRenderer.scala: Useobj.sortedVisibleKeyNamesin fused materializer generic object pathTest plan
./mill 'sjsonnet.jvm[3.3.7]'.test— all tests pass./mill 'sjsonnet.jvm[3.3.7]'.compile— compiles cleancanDirectIteratealready use_sortedInlineOrdercache; this extends caching to the generic (non-inline) path