perf: reuse manifest json visitors#839
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Motivation: Reduce container visitor allocation in manifestJsonEx-heavy workloads. Modification: Reuse stateless MaterializeJsonRenderer array and object visitors instead of allocating a new visitor for each container. Result: JSON manifestation keeps the same output while reducing allocation pressure in nested arrays and objects.
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Motivation:
Reduce allocation pressure in
std.manifestJson*paths that repeatedly materialize nested arrays and objects.Key Design Decision:
The reused visitors are stateless with respect to the current container; container state remains in the renderer/materializer traversal, so reuse does not leak values between nested containers.
Modification:
MaterializeJsonRendererreuses shared array and object visitors instead of allocating a new visitor instance per container.Benchmark Results:
bench/resources/go_suite/manifestJsonEx.jsonnet5.452 +/- 0.670 ms5.330 +/- 0.590 ms-2.24%235.971 +/- 12.925 ms224.975 +/- 11.550 ms-4.66%88.576 +/- 0.915 ms.manifestJsonEx 0.052 ms/op,realistic2 40.068 ms/op,large_string_template 1.137 ms/opAnalysis:
This targets allocation overhead in manifestation without changing rendered JSON semantics.
References:
Source exploration commit: He-Pin/sjsonnet
aac92b03.Result:
Local
./mill --no-server -j 1 __.reformatand./mill --no-server -j 1 __.testpassed on this split branch (2066/2066).