[PPF] Model caches with stale < MIN_SHELL_STALE as prefetch-only data - #98339
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[PPF] Model caches with stale < MIN_SHELL_STALE as prefetch-only data#98339lubieowoce wants to merge 3 commits into
stale < MIN_SHELL_STALE as prefetch-only data#98339lubieowoce wants to merge 3 commits into
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Tests PassedCommit: d5f8ee9 |
Note that in practice, the usage of `makeStageHangingPromise` was fine, because `stagedRendering.finalStage < stage` was never true in static prerenders, so we never actually tracked it as a runtime data access. However semantically it should never be tracked as runtime data, because a runtime shell would not provide it either.
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stale < MIN_SHELL_STALE as prefetch-only data (not runtime data)stale < MIN_SHELL_STALE as prefetch-only data
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Caches that have
stale < MIN_SHELL_STALEwere usingmakeStageHangingPromisein prerenders, which (in theory) was meant to track a runtime data access during a static prerender, which in turn would make the page use runtime shells. This is semantically incorrect, because both static and runtime shells would exclude the cache, and both static and runtime prefetches would include it, so it does not actually signal runtimeness, only prefetchness. The only thing we should be doing for these caches is excluding the content, same asunstable_prefetch().This PR replaces
makeStageHangingPromisewithmakePrefetchHangingPromise, which is not tracked as runtime data at all. We also use it forunstable_prefetch()to signal the correspondence.Note that in practice, the usage of
makeStageHangingPromiseinuse-cache-wrapperwas technically fine, because its runtime data tracking was effectively dead code. We only returned it ifstagedRendering.finalStage < stage, but for static prerendersstage = staticLinkDataStage = PrefetchStaticandfinalStage = Static, so the condition was never actually true, and we never actually tracked it as a runtime data access. However semantically it should still not be tracked as runtime data.(The condition can be true in a runtime prerender that only prerenders the shell. We don't do any tracking in runtime prerenders, so it was also a no-op).
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