Listing Object Versions

If you have any questions during the development, post them on the Issues page of GitHub. For details about parameters and usage of each API, see the API Reference.

You can call ObsClient.ListVersions to list objects versions.

The following table describes the parameters involved in this API.

Parameter	Description	Property in OBS .NET SDK
BucketName	Bucket name	ListVersionsRequest.BucketName
Prefix	Name prefix that the objects to be listed must contain	ListVersionsRequest.Prefix
KeyMarker	Object name to start with when listing object versions. All object versions whose names follow the specified value lexicographically are returned.	ListVersionsRequest.KeyMarker
MaxKeys	Maximum number of listed object versions. The value ranges from 1 to 1000. If the specified value exceeds 1000, only 1,000 object versions are returned by default.	ListVersionsRequest.MaxKeys
Delimiter	Character used to group object names. If the object name contains the Delimiter parameter, the character string from the first character to the first delimiter in the object name is grouped under a single result element, CommonPrefix. (If a prefix is specified in the request, the prefix must be removed from the object name.)	ListVersionsRequest.Delimiter
VersionIdMarker	Version ID to start with when listing object versions in a bucket. All object versions following the value specified by this parameter are listed in lexicographical order by object name and version ID. This parameter must be used together with KeyMarker.	ListVersionsRequest.VersionIdMarker

If the value of VersionIdMarker is not a version ID specified by KeyMarker, VersionIdMarker is ineffective.
The returned result of ObsClient.ListVersions includes object versions and delete markers.

Listing Object Versions in Simple Mode

The following sample code shows how to list object versions in simple mode. A maximum of 1,000 object versions can be returned.

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//List object versions.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Information about a maximum of 1,000 object versions can be listed each time. If a bucket contains more than 1,000 objects and ListVersionsResponse.IsTruncated is true in the returned result, not all object versions are listed. In such cases, you can use ListVersionsResponse.NextKeyMarker and ListVersionsResponse.NextVersionIdMarker to obtain the start position for next listing.

Listing Object Versions by Specifying the Number

The sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//List object versions by specifying the number.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing Object Versions by Specifying a Prefix

The sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//List object versions by specifying a prefix.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    request.Prefix = "prefix";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing Object Versions by Specifying the Start Position

The sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//Specify the start position for listing.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    request.Prefix = "prefix";
    request.KeyMarker = "keyMarker";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing All Object Versions in Paging Mode

The sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//List all object versions in paging mode.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    ListVersionsResponse response;
    do
    {
        response = client.ListVersions(request);
        Console.WriteLine("List versions response: {0}", response.StatusCode);
        foreach (ObsObjectVersion objectVersion in response.Versions)
        {
            Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
            Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
        }
        request.KeyMarker = response.NextKeyMarker;
        request.VersionIdMarker = response.NextVersionIdMarker;
    }
    while (response.IsTruncated);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing All Object Versions in a Folder

There is no folder concept in OBS. All elements in buckets are objects. Folders are actually objects whose sizes are 0 and whose names end with a slash (/). When you set a folder name as the prefix, objects in this folder will be listed. The sample code is as follows:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK before storing them in the configuration file or environment variables. In this example, the AK and SK are stored in environment variables. Before running the code in this example, configure environment variables AccessKeyID and SecretAccessKey.
// 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.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//List all object versions in paging mode.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 1000;
    // Set the prefix to dir/.
    request.Prefix = "dir/";
    ListVersionsResponse response;
    do
    {
        response = client.ListVersions(request);
        Console.WriteLine("List versions response: {0}", response.StatusCode);
        foreach (ObsObjectVersion objectVersion in response.Versions)
        {
            Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
            Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
        }
        request.KeyMarker = response.NextKeyMarker;
        request.VersionIdMarker = response.NextVersionIdMarker;
    }
    while (response.IsTruncated);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Parent topic: Versioning

Previous topic: Restoring a Specific Archive Object Version

Next topic: Setting or Obtaining an Object Version ACL

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