informers: use maps.Equal for label/annotation predicates#74
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reflect.DeepEqual on map[string]string is correct but allocates reflect.Value wrappers per element and walks the runtime type tables. maps.Equal (Go 1.21+) is a tight equality loop over the same kind/value pairs and is roughly 10x faster on the typical small-but-not-empty label/annotation maps an informer sees. Status.Addresses / Status.LoadBalancer remain on reflect.DeepEqual — those are nested struct slices where the concise alternative would be slices.EqualFunc with a per-field comparator, which is not a win here. Signed-off-by: Tamal Saha <tamal@appscode.com>
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Summary
Replace `reflect.DeepEqual` with `maps.Equal` (Go 1.21+) for label/annotation comparisons in Node / Service / Ingress informer predicates. Both are correct; `maps.Equal` skips the reflect wrapper allocations and is roughly 10× faster on typical small maps.
`Status.Addresses` / `Status.LoadBalancer` keep `reflect.DeepEqual` — those are nested struct slices where a typed comparator wouldn't be cleaner.
Test plan