tag | c7aac39d4284aaf90d4205c0f7450e546aaeca68 | |
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tagger | The Android Open Source Project <initial-contribution@android.com> | Thu Feb 18 09:58:21 2021 -0800 |
object | 44ad0963ddc7577f1ddbea0fee1beaf1e250e0d9 |
Android S Preview 1
commit | 44ad0963ddc7577f1ddbea0fee1beaf1e250e0d9 | [log] [tgz] |
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author | Bob Badour <bbadour@google.com> | Fri Feb 12 15:07:28 2021 -0800 |
committer | Bob Badour <bbadour@google.com> | Fri Feb 12 15:07:28 2021 -0800 |
tree | 69609eba0194af44d59844c6df753b5c412889ee | |
parent | 0543f0dc8c49e4fdeb57e3c5f4ba921f8c5a1b9a [diff] |
[LSC] Add LOCAL_LICENSE_KINDS to external/rust/crates/hashlink Added SPDX-license-identifier-Apache-2.0 SPDX-license-identifier-MIT to: Android.bp Bug: 68860345 Bug: 151177513 Bug: 151953481 Test: m all Exempt-From-Owner-Approval: janitorial work Change-Id: I2d478253fe0d999700ea2d6816e8bb5202bcb1d6
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.