Object Storage Service:Progress bar

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS by using other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about the regions and endpoints supported by OSS, see Regions and endpoints.

• In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.

Sample code

The following sample code provides an example on how to query the download progress:

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

void ProgressCallback(size_t increment, int64_t transfered, int64_t total, void* userData)
{
    // increment specifies the size of the data received from this callback. 
    // transferred specifies the size of the downloaded data. 
    // total specifies the total size of the object that you want to download. 
    std::cout << "ProgressCallback[" << userData << "] => " <<
                 increment <<" ," << transfered << "," << total << std::endl;
}

int main(void )
{
    /* Initialize information about the account that is used to access OSS. */
            
    /* Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
    std::string Endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
    /* Specify the name of the bucket. Example: examplebucket. */
    std::string BucketName = "examplebucket";
    /* Specify the full path of the object. Do not include the bucket name in the full path of the object. Example: exampledir/exampleobject.txt. */
    std::string ObjectName = "exampledir/exampleobject.txt";

    /* Initialize resources such as network resources. */
    InitializeSdk();

    ClientConfiguration conf;
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */
    auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
    OssClient client(Endpoint, credentialsProvider, conf);
  
    /* Query the object. */
    GetObjectRequest request(BucketName, ObjectName);
    TransferProgress progressCallback = { ProgressCallback , nullptr };
    request.setTransferProgress(progressCallback);

    auto outcome = client.GetObject(request);

    if (!outcome.isSuccess()) {    
        /* Handle exceptions. */
        std::cout << "getObject fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
         return -1;  
    }

    /* Release resources such as network resources. */
    ShutdownSdk();
    return 0;
}

References

For the complete sample code on how to use the progress bar during object download, visit GitHub.