use rayon::prelude::*;

#[no_mangle]  
pub extern "C" fn add_to_array(arr: *const i32, len: usize, num: i32, result: *mut i32) {
    let slice = unsafe { std::slice::from_raw_parts(arr, len) };
    let output = unsafe { std::slice::from_raw_parts_mut(result, len) };

    // 并行操作輸出數(shù)組
    output
        .par_iter_mut()
        .enumerate()
        .for_each(|(i, out)| {
            *out = slice[i] + num;
        });
}

[package]
name = "rust_napi"
version = "0.1.0"
edition = "2021"

[dependencies]
napi = { version = "2.11.0" }
rand = "0.8"
rayon = "1.7"

[lib]
crate-type = ["cdylib"] // mac 打包cdylib， windows 打包dll

// mac 指定架構
cargo build --release --target x86_64-apple-darwin
// window
cargo build --release

// cargo build --release --target x86_64-apple-darwin
const path = require("path");

const ffi = require("ffi-napi");
const ref = require("ref-napi");

// 動態(tài)確定庫文件路徑 "/rust_napi/target/x86_64-apple-darwin/release/librust_napi.dylib"

const libName =
  process.platform === "win32"
    ? "librust_napi.dll"
    : process.platform === "darwin"
    ? "/rust_napi/target/x86_64-apple-darwin/release/librust_napi.dylib"
    : "librust_napi.so";

const libPath = path.join(__dirname, libName);

// 加載 Rust 庫
const rustLib = ffi.Library(libPath, {
  add_to_array: ["void", ["pointer", "size_t", "int", "pointer"]],
});

function addToArray(arr, num) {
  const arrayLength = arr.length;
  const inputBuffer = Buffer.alloc(arrayLength * 4); // 每個 i32 占 4 字節(jié)
  const outputBuffer = Buffer.alloc(arrayLength * 4);

  // 將 JavaScript 數(shù)組寫入輸入緩沖區(qū)
  arr.forEach((value, index) => {
    inputBuffer.writeInt32LE(value, index * 4);
  });

  // 調(diào)用 Rust 函數(shù)
  rustLib.add_to_array(inputBuffer, arrayLength, num, outputBuffer);

  // 從輸出緩沖區(qū)讀取結果數(shù)組
  const result = [];
  for (let i = 0; i < arrayLength; i++) {
    result.push(outputBuffer.readInt32LE(i * 4));
  }
  return result;
}

const generateRandomIntArray = (size, min, max) => {
  return Array.from({ length: size }, () =>
    Math.floor(Math.random() * (max - min) + min)
  );
};

let listy = generateRandomIntArray(4e7, 1, 100);

let start = Date.now();
addToArray(listy, 100);
console.log(Date.now() - start, 4); // rust 974

module.exports = { addToArray };