Sebastian C 27c8a899ea Replace hsts preload list hashmap with an FST (#37015) ... This reduces the memory used by the preload list to just 1.9MB. The total memory savings in HSTS from pre-103cbed928 is now 62MB, or 96%. And in terms of total resident memory is a 7.5% reduction. The DAFSA/DAWG used by Firefox is 1.1MB so there could be additional gains available but this seems like the best option based on maintained libraries available (I could not find a good maintained library for DAFSAs in Rust). The main trick is this: the FST map API is currently designed to map byte sequences to u64 values. Because we only need to determine if a preloaded domain has the `includeSubdomains` flag set, we encode that into the lowest bit of the ids in the map. This way finding an entry in the map directly provides us with the `includeSubdomains` flag and we don't need to keep another mapping in memory or on disk. Updated the `./mach update-hsts-preload` command to generate the new FST map file. (Not sure if I need to update any dev-dependencies anywhere for this change) This change also replaces the use of "mozilla.org" with "example.com" in the HSTS unit tests to make sure that entries in the preload list do not influence the tests (since example.com should not ever end up on the preload list) Testing: Updated unit tests Fixes: #25929 --------- Signed-off-by: Sebastian C <sebsebmc@gmail.com>		2025-05-20 04:26:55 +00:00
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servoshell	Replace hsts preload list hashmap with an FST (#37015)	2025-05-20 04:26:55 +00:00