commit | 86898edaca2ebd5a8a93b827ef961e6077781890 | [log] [tgz] |
---|---|---|
author | Joel Galenson <jgalenson@google.com> | Mon Nov 29 14:03:57 2021 -0800 |
committer | Joel Galenson <jgalenson@google.com> | Fri Dec 10 15:32:49 2021 -0800 |
tree | 3c2abb16a61cdcb6c665836da86505adbc9db9e0 | |
parent | 0d4ddeb31266076d40eb9fe248ffa5b97729dce9 [diff] |
Refresh Android.bp, cargo2android.json, TEST_MAPPING. Test: None Change-Id: I24d99bdb22e05344ead547d19d3a851ad66ba608
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.