// worker.js import {Sha256} from "@aws-crypto/sha256-js"; import SparkMD5 from "spark-md5"; onmessage = async function (event) { const data = event.data; // chunk方式读取文件 const chunkSize = 1024 * 1024; // 每次读取1MB const fileSize = data.size; let offset = 0; const hash = new Sha256(); const spark = new SparkMD5.ArrayBuffer(); while (offset < fileSize) { const chunk = data.slice(offset, offset + chunkSize); const buffer = await chunk.arrayBuffer(); hash.update(buffer); spark.append(buffer); offset += chunkSize; console.log(offset / fileSize * 100 , '%'); } const sha256Value = await hash.digest(); const buffer = Array.from(new Int8Array(sha256Value)); const md5Value = spark.end(); const md5Buffer = Array.from(new Int8Array(md5Value)); console.log(sha256Value, buffer); // 输出文件的sha256值 console.log(md5Value, md5Buffer); // 输出文件的MD5值 postMessage(buffer); };优化代码计算sah256

可以考虑使用 Web Crypto API 中的 SubtleCrypto.digest() 方法来计算 SHA-256 值，这样可以避免引入第三方库。修改后的代码如下所示：

onmessage = async function (event) {
  const data = event.data;
  const chunkSize = 1024 * 1024; // 每次读取1MB
  const fileSize = data.size;
  let offset = 0;
  const hash = await crypto.subtle.digest('SHA-256');
  while (offset < fileSize) {
    const chunk = data.slice(offset, offset + chunkSize);
    const buffer = await chunk.arrayBuffer();
    await crypto.subtle.digest('SHA-256', buffer);
    offset += chunkSize;
    console.log(offset / fileSize * 100 , '%');
  }
  const sha256Value = new Uint8Array(hash);
  const buffer = Array.from(sha256Value);
  console.log(sha256Value, buffer); // 输出文件的sha256值
  postMessage(buffer);
};

其中，`crypto.subtle.digest()` 方法返回一个 Promise，该 Promise 会 resolve 为一个 ArrayBuffer，包含计算好的 SHA-256 值。可以通过将其转换为 Uint8Array 来得到最终的值。