commit | 40b52e5b2635f978b2f090a3fc636379f57dbb8f | [log] [tgz] |
---|---|---|
author | Bob Badour <bbadour@google.com> | Tue Feb 16 22:29:57 2021 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Tue Feb 16 22:29:57 2021 +0000 |
tree | 69609eba0194af44d59844c6df753b5c412889ee | |
parent | 4516dc9262aac01857b5f839b0c9d219c20e9481 [diff] | |
parent | 60882280850f9f9e5483c4e468e71a90b8e03079 [diff] |
[LSC] Add LOCAL_LICENSE_KINDS to external/rust/crates/hashlink am: 44ad0963dd am: 5b314e0d60 am: 0c49e6f05e am: 6088228085 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashlink/+/1588766 MUST ONLY BE SUBMITTED BY AUTOMERGER Change-Id: I1de168edf419131cb1159d71abf12d5283becde6
This crate is a fork of linked-hash-map that builds on top of hashbrown to implement more up to date versions of LinkedHashMap
LinkedHashSet
, and LruCache
.
One important API change is that when a LinkedHashMap
is used as a LRU cache, it allows you to easily retrieve an entry and move it to the back OR produce a new entry at the back without needlessly repeating key hashing and lookups:
let mut lru_cache = LinkedHashMap::new(); let key = "key".to_owned(); // Try to find my expensive to construct and hash key let _cached_val = match lru_cache.raw_entry_mut().from_key(&key) { RawEntryMut::Occupied(mut occupied) => { // Cache hit, move entry to the back. occupied.to_back(); occupied.into_mut() } RawEntryMut::Vacant(vacant) => { // Insert expensive to construct key and expensive to compute value, // automatically inserted at the back. vacant.insert(key.clone(), 42).1 } };
Or, a simpler way to do the same thing:
let mut lru_cache = LinkedHashMap::new(); let key = "key".to_owned(); let _cached_val = lru_cache .raw_entry_mut() .from_key(&key) .or_insert_with(|| (key.clone(), 42));
This crate contains a decent amount of unsafe code from handling its internal linked list, and the unsafe code has diverged quite a lot from the original linked-hash-map
implementation. It currently passes tests under miri and sanitizers, but it should probably still receive more review and testing, and check for test code coverage.
There is a huge amount of code in this crate that is copied verbatim from linked-hash-map
and hashbrown
, especially tests, associated types like iterators, and things like Debug
impls.
This library is licensed the same as linked-hash-map and hashbrown, it is licensed under either of:
at your option.