commit | 9f363d3451693f98953d8f0cbaa1dbcab006e969 | [log] [tgz] |
---|---|---|
author | Haamed Gheibi <haamed@google.com> | Thu Sep 23 17:28:57 2021 +0000 |
committer | Haamed Gheibi <haamed@google.com> | Thu Sep 23 17:28:57 2021 +0000 |
tree | 14e202d86ff5a3bc6a55cccd1533a1e3863f13e1 | |
parent | 233411f8b3b03e92898b64729d8f7e37a77bd077 [diff] | |
parent | 5f533e026a9a2ebb762cd31802c22d51631b8502 [diff] |
Merge TP1A.210812.002 Bug: 198367246 Change-Id: Ieb691a6c7f5e6944d841d3887311d269666900a7
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.