When copying an object, you can either preserve all metadata (the default) or specify new metadata. However, the ACL is not preserved, but is set to private.

Sharding copy steps

Initialize the sharding copy task with createMultipartUpload.

Sharding the copy via uploadPartCopy.

Merge sharding by completeMultipartUpload.

Sample code

// Import SDK, if the TOS Node.JS SDK version is less than 2.5.2, please change "TosClient" to "TOS" in the code below.​
import { TosClient, TosClientError, TosServerError } from '@volcengine/tos-sdk';​
​
// Create a client.​
const client = new TosClient({​
  accessKeyId: process.env['TOS_ACCESS_KEY'],​
  accessKeySecret: process.env['TOS_SECRET_KEY'],​
  region: "Provide your region", // Fill in the region where the Bucket is located. For example, if it is in China North 2 (Beijing), fill in "Provide your region" as cn-beijing.​
  endpoint: "Provide your endpoint", // Enter the domain address.​
});​
​
function handleError(error) {​
  if (error instanceof TosClientError) {​
    console.log('Client Err Name:', error.name);​
    console.log('Client Err Msg:', error.message);​
    console.log('Client Err Stack:', error.stack);​
  } else if (error instanceof TosServerError) {​
    console.log('Request ID:', error.requestId);​
    console.log('Response Status Code:', error.statusCode);​
    console.log('Response Status Code:', error.statusCode);​
    console.log('Response Header:', error.headers);​
    console.log('Response Err Code:', error.code);​
    console.log('Response Err Msg:', error.message);​
  } else {​
    console.log('unexpected exception, message: ', error);​
  }​
}​
​
async function main() {​
  try {​
    const srcBucket = 'node-sdk-test-bucket'; // Source bucket​
    const srcObject = 'source-test'; // Source object​
    const dstBucket = 'node-sdk-copy-bucket'; // Target bucket​
    const dstObject = 'copy-test'; // Target object​
​
    // Get upload task ID.​
    const {​
      data: { UploadId },​
    } = await client.createMultipartUpload({​
      bucket: dstBucket,​
      key: dstObject,​
    });​
    console.log('UploadId', UploadId);​
​
    // Get the size of existing objects in the source bucket.​
    const {​
      data: { 'content-length': contentLength },​
    } = await client.headObject({​
      bucket: srcBucket,​
      key: srcObject,​
    });​
    console.log('srcObject content-length', contentLength);​
    // Total file size​
    const totalSize = contentLength;​
    const partSize = 5 * 1024 * 1024;​
    let offset = 0;​
    let partNumber = 1;​
    const partsInfo = [];​
​
    while (offset < totalSize) {​
      // Upload chunk copy​
      const uploadResult = await client.uploadPartCopy({​
        bucket: dstBucket,​
        key: dstObject,​
        partNumber,​
        uploadId: UploadId,​
        srcBucket,​
        srcKey: srcObject,​
        copySourceRangeStart: offset,​
        copySourceRangeEnd: offset + partSize - 1,​
      });​
      const eTag = uploadResult.data.ETag;​
      console.log(`partNumber${partNumber} Etag:`, eTag);​
      partsInfo.push({​
        partNumber,​
        eTag,​
      });​
      partNumber++;​
      offset += partSize;​
    }​
    console.log('parts information', partsInfo);​
​
    // Complete chunked upload.​
    const { data } = await client.completeMultipartUpload({​
      bucket: dstBucket,​
      key: dstObject,​
      uploadId: UploadId,​
      parts: partsInfo,​
    });​
    console.log('result data:', data);​
​
    // Query copy object information​
    const headResult = await client.headObject({​
      bucket: dstBucket,​
      key: dstObject,​
    });​
    console.log('headResult', headResult);​
  } catch (error) {​
    handleError(error);​
  }​
}​
​
main();​