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android / platform / external / rust / crates / hashlink / a0fc585129071f370635672700170d42be872cbf
commita0fc585129071f370635672700170d42be872cbf[log] [tgz]
authorTreehugger Robot <[email protected]>Tue Dec 13 14:38:54 2022 +0000
committerAutomerger Merge Worker <[email protected]>Tue Dec 13 14:38:54 2022 +0000
tree882a79439473f4b31a0f5fbf01606d798530fdf5
parentcdecca1b98c51b77a8a19ada320e9a70ec33da14 [diff]
parent320ce7d6d50234d3b532bb994638a4ff2ec76f65 [diff]
Merge "Update TEST_MAPPING" am: 86279311bc am: 3d29f3578a am: 320ce7d6d5

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashlink/+/2348243

Change-Id: Iacdd640237b754c9af3f92f49aa2d96e1a9be9b7
Signed-off-by: Automerger Merge Worker <[email protected]>
tree: 882a79439473f4b31a0f5fbf01606d798530fdf5
  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. cargo2android.json
  11. CHANGELOG.md
  12. LICENSE-APACHE
  13. LICENSE-MIT
  14. METADATA
  15. MODULE_LICENSE_APACHE2
  16. OWNERS
  17. README.md
  18. 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.