LedgerMap

Overview

LedgerMap is a key-value store implemented in Rust. The primary feature of this library is its ability to store data in an append-only fashion, effectively forming a ledger. Additionally, it supports data integrity checks using SHA-256 checksums for ledger entries.

This library is designed for use in smart contract environments, capable of compiling for wasm32 targets while also being usable and testable on x86_64 architectures.

Note: This library is still in the development stage. Use it at your own risk.

Installation

Add LedgerMap to your Cargo.toml:

[dependencies]
ledger-map = "0.4.0"

Usage

Here is a basic example to get you started:

 use ledger_map::{LedgerMap};
 use env_logger::Env;

fn main() {
    // Optional: set log level to info by default
    env_logger::try_init_from_env(Env::default().default_filter_or("info")).unwrap();

    // Optional: Use custom file path for the persistent storage
    // let ledger_path = Some(std::path::PathBuf::from("/tmp/ledger_map/test_data.bin"));
    let ledger_path = None;

    // Create a new LedgerMap instance, and index all labels for quick search
    let mut ledger_map = LedgerMap::new_with_path(None, ledger_path).expect("Failed to create LedgerMap");

    // Insert a few new entries, each with a separate label
    ledger_map.upsert("Label1", b"key1".to_vec(), b"value1".to_vec()).unwrap();
    ledger_map.upsert("Label2", b"key2".to_vec(), b"value2".to_vec()).unwrap();
    ledger_map.commit_block().unwrap();

    // Retrieve all entries
    let entries = ledger_map.iter(None).collect::<Vec<_>>();
    println!("All entries: {:?}", entries);

    // Iterate only over entries with the Label1 label
    let entries = ledger_map.iter(Some("Label1")).collect::<Vec<_>>();
    println!("Label1 entries: {:?}", entries);

    // Iterate only over entries with the Label2 label
    let entries = ledger_map.iter(Some("Label2")).collect::<Vec<_>>();
    println!("Label2 entries: {:?}", entries);

    // Delete an entry from Label1
    ledger_map.delete("Label1", b"key1".to_vec()).unwrap();
    ledger_map.commit_block().unwrap();

    // Label1 entries are now empty
    assert_eq!(ledger_map.iter(Some("Label1")).count(), 0);

    // Label2 entries still exist
    assert_eq!(ledger_map.iter(Some("Label2")).count(), 1);
}

Features

• Append-Only Storage: Data is stored in an append-only manner, forming a ledger.
• Data Integrity: Uses SHA-256 checksums for verifying the integrity of ledger entries.
• Platform Support: Designed to work on both wasm32 and x86_64 targets.

Dependencies

This library is implemented in pure Rust.

Contributing

We welcome contributions! Please submit a pull request if you would like to contribute.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.