13 releases
0.4.7 | Sep 30, 2024 |
---|---|
0.4.6 | May 26, 2024 |
0.4.5 | Dec 23, 2023 |
0.4.4 | Aug 31, 2023 |
0.4.1 | May 8, 2022 |
#42 in Database implementations
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Shmap
A key-value store based on linux shared-memory files (shm) for persisting state across program restarts.
Features
-
Items are stored in the linux shared memory: it uses
shm_open
to create file in the ramdisk (/dev/shm), then they are mapped in memory with mmap. -
Concurrent access to items it provided thanks to
named-lock
mutexes. -
Value serialization can be made transparently with serde (
bincode
), so don't forget to use serde_bytes to enable optimized handling of&[u8]
andVec<u8>
! -
You can protect your data with AES256-GCM encryption.
-
You can add a TTL so that your items won't be available anymore after this timeout.
Example
use shmap::{Shmap, ShmapError};
use std::time::Duration;
fn main() -> Result<(), ShmapError> {
let shmap = Shmap::new();
shmap.insert("key", "value")?;
let value = shmap.get("key")?;
assert_eq!(Some("value".to_string()), value);
// It is strongly advised to use TTL to avoid using too much RAM
shmap.insert_with_ttl("key", "temporary_value", Duration::from_secs(60))?;
Ok(())
}
Supported OS
Any POSIX linux where /dev/shm
is mounted. MacOS and any BSD descendants are therefore not supported.
The POSIX shared memory object implementation on Linux makes use of a dedicated tmpfs(5) filesystem that is normally mounted under /dev/shm.
Dependencies
~3–27MB
~401K SLoC