请使用rust帮我写一个类似bspatch的程序

以下是一个基本的Rust程序，类似于bspatch，用于将一个旧版本的二进制文件与一个差分文件合并为一个新版本的二进制文件：

use std::fs::File;
use std::io::{Read, Write};

fn main() {
    let old_file_path = "old.bin";
    let patch_file_path = "patch.bin";
    let new_file_path = "new.bin";

    // Open the old binary file for reading
    let mut old_file = File::open(old_file_path).unwrap();

    // Read the old binary file into a vector
    let mut old_data = Vec::new();
    old_file.read_to_end(&mut old_data).unwrap();

    // Open the patch file for reading
    let mut patch_file = File::open(patch_file_path).unwrap();

    // Read the patch file into a vector
    let mut patch_data = Vec::new();
    patch_file.read_to_end(&mut patch_data).unwrap();

    // Apply the patch to the old binary data
    let new_data = bsdiff_rs::patch(&old_data, &patch_data).unwrap();

    // Open the new binary file for writing
    let mut new_file = File::create(new_file_path).unwrap();

    // Write the new binary data to the new file
    new_file.write_all(&new_data).unwrap();
}

这个程序使用了bsdiff_rs库来实现差分文件的合并。要使用这个程序，你需要将旧版本的二进制文件和差分文件放在同一个目录下，并将它们的文件名分别设置为"old.bin"和"patch.bin"。程序将会生成一个新的二进制文件，并将其保存为"new.bin"