infernojs / inferno / 37197056946

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optimizations:
1. $EV: per-element handler storage (events/delegation.ts)
V8 gives an empty {} literal four property slots up front, which is 28 B in Chrome. An element almost always has one handler, so three slots go unused. For objects made by a constructor, V8 watches the first few instances and then shrinks the object size to the slots they actually used, which is 1 here, so each object becomes 16 B. Node measured 56 → 32 B without Chrome's pointer compression, the same 4-slot to 1-slot change.

Effect: jfb has two such elements per row, so 2,000 × 12 B per 1k rows. Measured: −27 KiB allocated and retained for create, replace and append

2. Map for the key index (patching.ts, patchKeyedChildrenComplex)
with a plain object, numeric keys such as jfb's row ids are stored as array-style indexes. Ids like 6001–7000 are sparse, so V8 falls back to a dictionary that is reallocated larger each time it fills, and every outgrown copy becomes garbage. That was 74 KiB per replace. A Map grows much more compactly. Measured: −45 to −50 KiB per replace, all of it garbage, so run memory is unaffected.

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