To prevent the exposure of your Volcano Engine account credentials (namely, AccessKey ID and AccessKey Secret) in browser environments, it is strongly recommended that you perform TOS-related operations using temporary access credentials. For detailed instructions, please refer to Using STS Temporary AK/SK+Token to Access Volcano Engine TOS.

Endpoint is the access domain name for TOS external services. For information on endpoints supported by TOS, please refer to Access Domain Endpoint.

Object copy does not support cross-region bucket-to-bucket copying.

When copying an object, the account must have read permission for the source object and write permission for the destination bucket.

When copying an object, you may retain all metadata (default) or specify new metadata. However, the ACL was not retained; instead, it was set to private.

Shard Copy Procedure

Initialize the multipart copy task using createMultipartUpload.

Multipart copy is performed using uploadPartCopy.

Merge parts using completeMultipartUpload.

Sample Code

The following code is used for multipart copying of objects.

<!DOCTYPE html>​
<html lang="en">​
  <head>​
    <meta charset="UTF-8" />​
    <title>Document</title>​
  </head>​
  <body>​
    <button id="upload">Upload</button>​
    <button id="copy">Copy</button>​
    <input id="file" type="file" />​
    <script src="https://tos-public.volccdn.com/obj/volc-tos-public/@volcengine/tos-sdk@latest/browser/tos.umd.production.min.js"></script>​
    <script type="text/javascript">​
      const client = new TOS({​
        region: yourRegion,​
        endpoint: yourEndpoint,​
        accessKeyId: yourAccessKey,​
        accessKeySecret: yourSecretKey,​
        stsToken: yourSecurityToken,​
        bucket: examplebucket,​
      });​
​
      const srcBucket = yourSrcBucket; ​
      const srcObject = 'exampledir/putObject-test'; ​
      const dstBucket = yourDstBucket; ​
      const dstObject = 'exampledir/part-copy-test'; ​
​
      const upload = document.getElementById('upload');​
      upload.addEventListener('click', async () => {​
        const data = document.getElementById('file').files[0];​
        try {​
          await client.uploadFile({​
            bucket: srcBucket,​
            key: srcObject,​
            file: data,​
          });​
        } catch (e) {​
          console.log(e);​
        }​
      });​
​
      const copy = document.getElementById('copy');​
      copy.addEventListener('click', async () => {​
        try {​
          const {​
            data: { UploadId },​
          } = await client.createMultipartUpload({​
            bucket: dstBucket,​
            key: dstObject,​
          });​
          console.log('UploadId', UploadId);​
​
          const {​
            data: { 'content-length': contentLength },​
          } = await client.headObject({​
            bucket: srcBucket,​
            key: srcObject,​
          });​
          console.log('srcObject content-length', contentLength);​
​
          const totalSize = contentLength;​
          const partSize = 5 * 1024 * 1024;​
​
          let offset = 0;​
          let partNumber = 1;​
          const partsInfo = [];​
​
          while (offset < totalSize) {​
            const uploadResult = await client.uploadPartCopy({​
              bucket: dstBucket,​
              key: dstObject,​
              partNumber,​
              uploadId: UploadId,​
              headers: {​
                'x-tos-copy-source': `/${srcBucket}/${srcObject}`,​
                'x-tos-copy-source-range': `bytes=${offset}-${offset + partSize}`,​
              },​
            });​
            const eTag = uploadResult.data.ETag;​
            console.log(`partNumber${partNumber} Etag:`, eTag);​
            partsInfo.push({​
              partNumber,​
              eTag,​
            });​
            partNumber++;​
            offset += partSize;​
          }​
          console.log('parts information', partsInfo);​
​
          const { data } = await client.completeMultipartUpload({​
            bucket: dstBucket,​
            key: dstObject,​
            uploadId: UploadId,​
            parts: partsInfo,​
          });​
​
          console.log('result data:', data);​
        } catch (e) {​
          console.log(e);​
        }​
      });​
    </script>​
  </body>​
</html>​

Last updated: 2025.09.22 18:55:46

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