Google Git
Sign in
android / platform / external / rust / crates / hashlink / eb62f240b959c196f0c218edc526612ae11f6008
commiteb62f240b959c196f0c218edc526612ae11f6008[log] [tgz]
authorJoel Galenson <jgalenson@google.com>Tue May 25 22:59:34 2021 +0000
committerAutomerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>Tue May 25 22:59:34 2021 +0000
tree88390f1a9f0ab00e0ed8b47c06a1b2bf73d448d3
parent25b6e21c78c960133408b16b25378e892ce9f096 [diff]
parente30d42e8fe4b64ad02e14bb18767f26f53fc1f07 [diff]
Upgrade rust/crates/hashlink to 0.7.0 am: e30d42e8fe

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashlink/+/1712276

Change-Id: I198f22387beea5aa298035292fdec93fd1725031
tree: 88390f1a9f0ab00e0ed8b47c06a1b2bf73d448d3
  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
  17. TEST_MAPPING
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.