perf(netstack2): optimize reverse NAT lookup with O(1) map #205
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…tion Replace O(n) linear search through NAT table with O(1) reverse lookup map for reply packet NAT translation. Changes: - Add reverseConnKey type for reverse NAT lookups - Add reverseNatTable map to ProxyHandler for O(1) lookups - Populate both forward and reverse maps when creating NAT entries - Replace iteration-based reverse lookup with direct map access Performance: - O(n) → O(1) complexity for reverse NAT lookups - Eliminates lock-held iteration on every reply packet - Removes string comparisons from hot path - Expected 10-50x improvement for reverse NAT lookups This addresses Critical fosrl#1 from performance analysis where reply path was walking the entire NAT table to find original mapping.
LaurenceJJones
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Description
Replace O(n) linear search through NAT table with O(1) reverse lookup map for reply packet NAT translation.
Changes:
Performance:
This addresses Critical from performance analysis where reply path was walking the entire NAT table to find original mapping.
How to test?
Purely internal optimization, instead of walking the entire natTable every time to find where to reverse too. We create a map that is indexed by the reverse fields which stores the same netState data from the forward natTable.