Class S3FileWriter

packages/filesystem/s3/rw.ts:40–77

 * 通过 PUT 请求上传内容到 S3
 */
export class S3FileWriter implements FileWriter {
  client: S3Client;

  bucket: string;

  key: string;

  modifiedDate?: number;

  constructor(client: S3Client, bucket: string, key: string, modifiedDate?: number) {
    this.client = client;
    this.bucket = bucket;
    this.key = key;
    this.modifiedDate = modifiedDate;
  }

  /**
   * 写入文件内容
   * @param content 文件内容（字符串或 Blob）
   * @throws {S3Error} 上传失败
   */
  async write(content: string | Blob): Promise<void> {
    const body = content instanceof Blob ? new Uint8Array(await content.arrayBuffer()) : content;

    const headers: Record<string, string> = {
      "content-type": "application/octet-stream",
    };
    if (this.modifiedDate) {
      // 历史兼容：S3 侧使用 createtime 元数据保存文件时间，实际来源是 FileCreateOptions.modifiedDate。
      headers["x-amz-meta-createtime"] = new Date(this.modifiedDate).toISOString();
    }

    await this.client.request("PUT", this.bucket, this.key, {
      body: typeof body === "string" ? body : body,
      headers,
    });
  }
}