Storage Class

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OBS allows you to set storage classes for buckets. The storage class of an object defaults to be that of its residing bucket. There are three types of storage class for buckets, as described in the following table, catering to various storage performance and cost requirements.

Type	Description	Value in OBS C SDK
OBS Standard	Features low access latency and high throughput and is applicable to storing frequently-accessed (multiple times per month) hotspot or small objects (< 1 MB) requiring quick response.	OBS_STORAGE_CLASS_STANDARD
OBS Infrequent Access	Is applicable to storing semi-frequently accessed (less than 12 times a year) data requiring quick response.	OBS_STORAGE_CLASS_STANDARD_IA
OBS Archive	Is applicable to archiving rarely-accessed (once a year) data.	OBS_STORAGE_CLASS_GLACIER

For more information, see Bucket Storage Classes.

Setting the Storage Class for a Bucket

You can use set_bucket_storage_class_policy to set the bucket storage class. The following table describes the parameters.

Field	Type	Mandatory or Optional	Description
option	The context of the bucket. For details, see Configuring option.	Mandatory	Bucket parameter
storage_class_policy	obs_storage_class	Mandatory	Storage class
handler	obs_response_handler *	Mandatory	Callback function
callback_data	void *	Optional	Callback data

Sample code:

static void test_set_bucket_storage_class(char *bucket_name, 
                 obs_storage_class storage_class_policy)
{
    obs_status ret_status = OBS_STATUS_BUTT;
    // Create and initialize option.
    obs_options option;
    init_obs_options(&option);
    option.bucket_options.host_name = "<your-endpoint>";
    option.bucket_options.bucket_name = "<Your bucketname>";

    // Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY.
    // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
    option.bucket_options.access_key = getenv("ACCESS_KEY_ID");
    option.bucket_options.secret_access_key = getenv("SECRET_ACCESS_KEY");
    // Set response callback function.
    obs_response_handler response_handler =
    { 
        0, &response_complete_callback
    };

    set_bucket_storage_class_policy(&option, storage_class_policy, 
                &response_handler, &ret_status);
    if (ret_status == OBS_STATUS_OK) {
        printf("set bucket storage class successfully. \n");
    }
    else
    {
        printf("set bucket storage class failed(%s).\n", 
                            obs_get_status_name(ret_status));
    }
}

Obtaining the Storage Class of a Bucket

You can use get_bucket_storage_class_policy to obtain the bucket storage class. The following table describes the parameters.

Field	Type	Mandatory or Optional	Description
option	The context of the bucket. For details, see Configuring option.	Mandatory	Bucket parameter
handler	obs_get_bucket_storage_class_handler *	Mandatory	Callback function
callback_data	void *	Optional	Callback data

Sample code:

static void test_get_bucket_storage_class(char *bucket_name)
{
    // Create and initialize option.
    obs_status ret_status = OBS_STATUS_BUTT;
    obs_options option;
    init_obs_options(&option);
    option.bucket_options.host_name = "<your-endpoint>";
    option.bucket_options.bucket_name = "<Your bucketname>";

    // Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY.
    // Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/eu/usermanual-ca/ca_01_0003.html.
    option.bucket_options.access_key = getenv("ACCESS_KEY_ID");
    option.bucket_options.secret_access_key = getenv("SECRET_ACCESS_KEY");
    // Set response callback function.
    obs_get_bucket_storage_class_handler getBucketStorageResponse = 
    {
        {0, &response_complete_callback}, 
        &get_bucket_storageclass_handler
    };
    //Obtain the bucket storage class.
    get_bucket_storage_class_policy(&option, &getBucketStorageResponse, &ret_status);
    if (OBS_STATUS_OK == ret_status) 
    {
        printf("get bucket storage class successfully.\n");
    }
    else
    {
        printf("get bucket storage class failed(%s).\n", obs_get_status_name(ret_status));
    }
}