add oss for download

src/util/download.ts

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+import { ServerResponse } from 'http';
+import { BucketItemStat } from 'minio';
+import fs from 'fs';
+import path from 'path';
+
+const viewableExtensions = ['jpg', 'jpeg', 'png', 'gif', 'svg', 'webp', 'mp4', 'webm', 'mp3', 'wav', 'ogg', 'pdf', 'doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx'];
+import { OssBase } from '../index.ts';
+/**
+ * 过滤 metaData 中的 key, 去除 password, accesskey, secretkey，
+ * 并返回过滤后的 metaData
+ * @param metaData
+ * @returns
+ */
+export const filterMetaDataKeys = (metaData: Record<string, string>, clearKeys: string[] = []) => {
+  const keys = Object.keys(metaData);
+  // remove X-Amz- meta data
+  const removeKeys = ['password', 'accesskey', 'secretkey', ...clearKeys];
+  const filteredKeys = keys.filter((key) => !removeKeys.includes(key));
+  return filteredKeys.reduce((acc, key) => {
+    acc[key] = metaData[key];
+    return acc;
+  }, {} as Record<string, string>);
+};
+type SendObjectOptions = {
+  res: ServerResponse;
+  client: OssBase;
+  objectName: string;
+  isDownload?: boolean;
+};
+export const NotFoundFile = (res: ServerResponse, msg?: string, code = 404) => {
+  res.writeHead(code, { 'Content-Type': 'text/plain' });
+  res.end(msg || 'Not Found File');
+  return;
+};
+export const sendObject = async ({ res, objectName, client, isDownload = false }: SendObjectOptions) => {
+  let stat: BucketItemStat;
+  try {
+    stat = await client.statObject(objectName);
+  } catch (e) {
+  } finally {
+    if (!stat || stat.size === 0) {
+      return NotFoundFile(res);
+    }
+    const contentLength = stat.size;
+    const etag = stat.etag;
+    const lastModified = stat.lastModified.toISOString();
+    const filename = objectName.split('/').pop() || 'no-file-name-download'; // Extract filename from objectName
+    const fileExtension = filename.split('.').pop()?.toLowerCase() || '';
+    const filteredMetaData = filterMetaDataKeys(stat.metaData, ['size', 'etag', 'last-modified']);
+    const contentDisposition = viewableExtensions.includes(fileExtension) && !isDownload ? 'inline' : `attachment; filename="${filename}"`;
+
+    res.writeHead(200, {
+      'Content-Length': contentLength,
+      etag,
+      'last-modified': lastModified,
+      'Content-Disposition': contentDisposition,
+      'file-name': filename,
+      ...filteredMetaData,
+    });
+    const objectStream = await client.getObject(objectName);
+
+    objectStream.pipe(res, { end: true });
+  }
+};
+
+export const downloadObject = async ({ objectName, client, filePath }: Pick<SendObjectOptions, 'objectName' | 'client'> & { filePath: string }) => {
+  const objectStream = await client.getObject(objectName);
+  const dir = path.dirname(filePath);
+  if (!fs.existsSync(dir)) {
+    fs.mkdirSync(dir, { recursive: true });
+  }
+  objectStream.pipe(fs.createWriteStream(filePath));
+  return objectStream;
+};

src/util/hash.ts

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+import crypto from 'crypto';
+// 582af9ef5cdc53d6628f45cb842f874a
+// const hashStr = '{"a":"a"}';
+// const hash = crypto.createHash('md5').update(hashStr).digest('hex');
+// console.log(hash);
+
+/**
+ * 计算字符串的md5值
+ * @param str
+ * @returns
+ */
+export const hash = (str: string | Buffer | Object) => {
+  let hashStr: string | Buffer;
+  if (typeof str === 'object') {
+    hashStr = JSON.stringify(str, null, 2);
+  } else {
+    hashStr = str;
+  }
+  return crypto.createHash('md5').update(hashStr).digest('hex');
+};
+
+export const hashSringify = (str: Object) => {
+  return JSON.stringify(str, null, 2);
+};

src/util/index.ts

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+export * from './hash.ts';