Allocate batchRequest only on cache miss#123
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pavelnikolov merged 1 commit intoMay 27, 2026
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Loader.Load allocated the batchRequest and its done channel at the top of the function, before the cache lookup. req is only ever used on a cache miss (it is sent to the batcher), so on a cache hit it was allocated and immediately discarded. Move the allocation below the cache-hit early return so cached loads don't pay for it. Benchmark (Load on a primed key, -benchmem): before: 3 allocs/op 160 B/op 45.7 ns/op after: 1 alloc/op 16 B/op 20.5 ns/op Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
Loader.Loadallocated thebatchRequestand itsdonechannel at the top of the function, before the cache lookup.reqis only used on a cache miss (it's sent to the batcher and read by the returned thunk), so on a cache hit it was allocated and immediately discarded — every cached load paid for a struct + channel allocation it never used.This moves the allocation below the cache-hit early-return so cached loads don't pay for it. No behavioural change: nothing between the cache check and the new allocation site references
req.Fixes #122.
Benchmark
Loadon a primed/cached key (-benchmem):Testing
go test .passes. (The pre-existing build failures inexample/lru_cacheandexample/ttl_cacheare unrelated to this change — they fail the same way on unmodifiedmaster.)