Lib.rs

bitcoinleveldb-hash

This Rust crate is a direct translation of the hash.h and hash.cc files from the Bitcoin Core codebase. The code provides a simple hash function that is used for internal data structures in LevelDB, which is used as the database backend for Bitcoin Core.

Notice

This crate is part of a direct translation from C++ to Rust of the Bitcoin Core. As such, some of the function bodies may still be in the process of translation. Please note that this system will become testable once the translation process is complete.

Tokens

• HASH: A dummy struct used in a test function.

• hash_signed_unsigned_issue(): A test function that tests the hash() function with various inputs.

• hash(data: *const u8, n: usize, seed: u32) -> u32: A simple hash function that is used for internal data structures in LevelDB. The function takes a pointer to an array of bytes (data), the number of bytes to hash (n), and an initial seed value (seed) as inputs, and returns a 32-bit hash value. The hash function is similar to MurmurHash, with a fixed m and r value. The hash function picks up four bytes at a time until the last remaining bytes are less than four, and then switches to handle the remaining bytes using a switch-case statement.

Usage

This crate is primarily intended to be used as a dependency in other crates that require the hash function for internal data structures in LevelDB. To use the crate in your Rust project, add the following line to your Cargo.toml file:

[dependencies]
bitcoinleveldb-hash = "0.1.0"

And then import the crate in your Rust code with:

extern crate bitcoinleveldb_hash;

Once the crate is imported, you can use the hash() function as follows:

use bitcoinleveldb_hash::hash;

fn main() {
    let data: [u8; 3] = [0xe2, 0x99, 0xa5];
    let seed: u32 = 0xbc9f1d34;
    let n: usize = data.len();
    let h = hash(data.as_ptr(), n, seed);
    println!("Hash value: {}", h);
}