7 stable releases
1.1.1 | Jan 31, 2024 |
---|---|
1.1.0 | Jan 27, 2024 |
1.0.3 | Oct 26, 2023 |
1.0.2 | Sep 25, 2023 |
1.0.0 | Jul 30, 2023 |
#60 in Caching
Used in 3 crates
(via lmfu)
90KB
748 lines
String Pools / Strings Interning
Features
- quick
Deref<str>
implementation - one pointer resolution, one comparison, and one pointer increment - thin
PoolStr
type - a pointer - The pool is deallocated only when every object referencing it have been dropped.
- no_std, but
alloc
is required - thread-safe
Pool
'sDebug
implementation allows you to see all of its strings- simple O(n /
P
) insertion/search, whereP
isPool
's const generic parameter
Example
# use {strpool::{Pool, PoolStr}, core::ops::Deref};
// you can reduce insertion/search complexity by raising this number,
// at the expense of more frequent allocations for small strings.
// strings are spread evenly into these subpools based on their hash.
// => must be a non-zero power of two.
const SUB_POOLS: usize = 1;
// no need for mutability, the pool uses atomic operations
let pool: Pool<SUB_POOLS> = Pool::new();
// use Pool::intern(&self, &str) to insert a string slice into the pool
// if the string was already present, that PoolStr will be reused.
let pool_string = pool.intern("Hello world!");
// you can obtain a &str with the Deref implementation
assert_eq!(pool_string.deref(), "Hello world!");
// Hash, Eq, Debug, Display are implemented as well.
// you can use Pool::find(&self, &str) to check if the pool contains a string
assert_eq!(pool.find("oh hi mark"), None);
// the empty string doesn't rely on a pool, it's always there
assert_eq!(pool.find(""), Some(PoolStr::empty()));
// See all interned strings via the Debug implementation
println!("{:#?}", pool);
Internal Memory Structure (Example)
Dependencies
~165–360KB
~10K SLoC