Google Git
Sign in
android / platform / external / rust / crates / hashlink / 4516dc9262aac01857b5f839b0c9d219c20e9481
commit4516dc9262aac01857b5f839b0c9d219c20e9481[log] [tgz]
authorChih-Hung Hsieh <chh@google.com>Tue Nov 24 02:28:14 2020 +0000
committerAutomerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>Tue Nov 24 02:28:14 2020 +0000
tree50069180fea404c5247eb6b933c6836cda6f2857
parentf9571b675554e0cc4c2a37e68df0b78a40f5c027 [diff]
parent1c858da4ae69b422f92107f6fd4a5a784a2a4063 [diff]
Import hashlink-0.6.0 am: e93fbab9e5 am: 0543f0dc8c am: 1c858da4ae

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashlink/+/1493280

Change-Id: Iab9fee96659b72a6045c1dcedde1b42ccafd5268
tree: 50069180fea404c5247eb6b933c6836cda6f2857
  1. .circleci/
  2. src/
  3. tests/
  4. LICENSE ⇨ LICENSE-APACHE
  5. .cargo_vcs_info.json
  6. .gitignore
  7. Android.bp
  8. Cargo.toml
  9. Cargo.toml.orig
  10. CHANGELOG.md
  11. LICENSE-APACHE
  12. LICENSE-MIT
  13. METADATA
  14. MODULE_LICENSE_APACHE2
  15. OWNERS
  16. README.md
README.md

hashlink -- HashMap-like containers that hold their key-value pairs in a user controllable order

Build Status Latest Version API Documentation

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.

Credit

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.

License

This library is licensed the same as linked-hash-map and hashbrown, it is licensed under either of:

at your option.