Obtaining the Download Progress (SDK for Node.js)

// Import the OBS library.
// Use npm to install the client.
const ObsClient = require("esdk-obs-nodejs");
// Use the source code to install the client.
// var ObsClient = require('./lib/obs');

// Create an ObsClient instance.
const obsClient = new ObsClient({
  // Obtain an AK and SK pair using environment variables (recommended) or import it in other ways. Using hard coding may result in leakage.
  // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
  access_key_id: process.env.ACCESS_KEY_ID,
  secret_access_key: process.env.SECRET_ACCESS_KEY,
  // (Optional) If you use a temporary AK/SK pair and a security token to access OBS, you are not advised to use hard coding, which may result in information leakage. You can obtain an AK/SK pair using environment variables or import an AK/SK pair in other ways.
  // security_token: process.env.SECURITY_TOKEN,
  // Enter the endpoint corresponding to the bucket. CN-Hong Kong is used here as an example. Replace it with the one currently in use.
  server: "https://obs.ap-southeast-1.myhuaweicloud.com"
});

async function downloadFile() {
  try {
    const params = {
      // Specify the bucket name.
      Bucket: 'examplebucket',
      // Specify an object. example/objectname is used in this example.
      Key: 'example/objectname',
      // Specify a local absolute path (/tmp/objectname in this example) for download. If the path is left blank, the current working directory is used by default.
      DownloadFile: 'localfile',
      // Specify whether to enable resumable transmission. The value true is used in this example. The default value is false.
      EnableCheckpoint: true,
      // Specify a part size, in bytes. This example sets each part to 9 MB.
      PartSize: 9 * 1024 * 1024,
      // Specify the maximum number of parts that can be concurrently transmitted. 5 is used in this example.
      TaskNum: 5,
      // Progress callback
      ProgressCallback: function(transferredAmount, totalAmount, totalSeconds){
         // Obtain the average download rate (KB/s).
         console.log(transferredAmount * 1.0 / totalSeconds / 1024);
         // Obtain the download progress in percentage.
         console.log(transferredAmount * 100.0 / totalAmount);
      };
    };
    // Download the object using resumable download.
    const result = await obsClient.downloadFile(params);
    if (result.CommonMsg.Status <= 300) {
      console.log("Download file(%s) under the bucket(%s) successful!", params.Key, params.Bucket);
      console.log("RequestId: %s", result.CommonMsg.RequestId);
      console.log("StorageClass:%s, ETag:%s, ContentType:%s, ContentLength:%d, LastModified:%s",
        result.InterfaceResult.StorageClass, result.InterfaceResult.ETag, result.InterfaceResult.ContentType,
        result.InterfaceResult.ContentLength, result.InterfaceResult.LastModified,
      );
      return;
    };
    console.log("An ObsError was found, which means your request sent to OBS was rejected with an error response.");
    console.log("Status: %d", result.CommonMsg.Status);
    console.log("Code: %s", result.CommonMsg.Code);
    console.log("Message: %s", result.CommonMsg.Message);
    console.log("RequestId: %s", result.CommonMsg.RequestId);
  } catch (error) {
    console.log("An Exception was found, which means the client encountered an internal problem when attempting to communicate with OBS, for example, the client was unable to access the network.");
    console.log(error);
  };
};

downloadFile();