Crate mhdb

MHdb is a pure Rust embedded key-value store database, based on dbm.

Simple use

use mhdb::{Db, prelude::*};
 
let mut db = Db::open("mydb")?;
let key = "Number".to_owned();
let val = 42i32;
 
db.store(key.clone(), val)?;
 
let num: Option<i32> = db.fetch(42u8)?;
assert_eq!(num, Some(val));
println!("{}", num.unwrap());

Any type implementing Datum can be stored in the database.

Datum

A datum represents a single item in the database. Types used as keys and/or values must therefore implement the Datum trait.

Datum is automatically implemented on any type implementing the Serde traits Serialize and Deserialize.

In-memory database

Any type which implements the Source trait can be used as database sources. This trait is in turn automatically implemented for any type which implements the Read, Write, Seek, Sync, and Send standard library traits. A vector may therefore be used as an in-memory database.

use mhdb::{Db, prelude::*};
use std::io::Cursor;

let dirf = Cursor::new(Vec::<u8>::new());
let pagf = Cursor::new(Vec::<u8>::new());
let mut db: Db = Db::with_sources(Box::new(pagf), Box::new(dirf))?;
 
db.store(42u8, "Hello world".to_owned())?;
let txt: Option<String> = db.fetch(42u8)?;
assert!(txt.is_some());
println!("{}", txt.unwrap());

Limitations

• Key-value pairs can not be larger than 506B
• Db objects are not thread safe

Modules

prelude

The Db prelude.

Structs

Db

The database object. All interraction with mhdb databases is done through this object.

Enums

Error

Errors returned by database operations.

Traits

Datum

A datum represents a single item in the database. Any type used as key or value needs to implement Datum.

Source

Trait required by database sources. Automatically implemented for standard library types such as File and Cursor.