perf: skip ETag generation for no-store responses #7010
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When Cache-Control header contains 'no-store', skip ETag generation since clients will ignore it anyway. This avoids unnecessary hashing operations for responses that explicitly don't want caching. Fixes expressjs#2472
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Thanks for your contribution. We know you’re using AI, and that’s not really an issue, but please don’t duplicate work that already exists. duplicated of #6994 |
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Summary
When
Cache-Control: no-storeis set, the client is required to ignore any ETag header. Generating ETags for these responses wastes CPU cycles on CRC/hash computation that the client will never use.Solution
Check the
Cache-Controlheader forno-storedirective before generating ETags. If present, skip the ETag generation entirely.Changes
lib/response.jsto check forno-storein Cache-Controlno-storeas a standalone directiveCache-Control: no-storeand combined directives likeprivate, no-store, max-age=0Performance
Eliminates unnecessary hash computation for responses that explicitly don't want caching.
Fixes #2472