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A proxy coalesces nearby requested spans into economical origin reads: empty logical selectors must not allocate backend fetches · case 02

A proxy coalesces nearby requested spans into economical origin reads: empty logical selectors must not allocate backend fetches.

Member previewVariant 2 · 3 implementations · 8 checks per implementation

Case contract

x contains request rows [start,stop] with half-open nonnegative bounds, a nonnegative max-gap, and a set of forbidden byte positions. Empty requests contribute no work. Sort requests by start/stop, merge overlapping or nearby reads only if the gap has no forbidden byte. Return fetch spans and, in original request order, [fetch-index,offset-within-fetch,count] mappings. Empty requests map to null. This model plans origin reads only and does not redefine inclusive wire range semantics.

Why this case matters

Range responses combine representation identity, conditional requests, framing, and partial-object state.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
empty-read fixture 4	`[[[0, 0], [3, 3]], [null, null]]`	`[[], [null, null]]`	Failed

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