You must restore an Archive object before you can read it. This topic describes how to restore Archive objects.

The following section describes the status of an Archive object throughout the restoration process:
  • By default, the Archive object is in the frozen state.
  • After you submit a request to restore the object, the object enters the restoring state. It takes about one minute to complete the restoration task.
  • After the Object Storage Service (OSS) server completes the restoration task, the object enters the restored state and can be read. By default, the restored state lasts 24 hours and can be extended by another 24 hours after you call RestoreObject again. During one restoration process, RestoreObject can be called up to seven times on an object. In other words, an object can remain in the restored state for up to seven days.
  • After the restored state expires, the object returns to the frozen state.

The following code provides an example on how to restore an Archive object:

#include "oss_api.h"
#include "aos_http_io.h"
const char *endpoint = "<yourEndpoint>";
const char *access_key_id = "<yourAccessKeyId>";
const char *access_key_secret = "<yourAccessKeySecret>";
const char *bucket_name = "<yourBucketName>";
const char *object_name = "<yourObjectName>";
const char *object_content = "More than just cloud.";
void init_options(oss_request_options_t *options)
    options->config = oss_config_create(options->pool);
    /* Use a char* string to initialize the aos_string_t data type. */
    aos_str_set(&options->config->endpoint, endpoint);
    aos_str_set(&options->config->access_key_id, access_key_id);
    aos_str_set(&options->config->access_key_secret, access_key_secret);
    /* Specify whether to use CNAME. The value of 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Configure network parameters such as the timeout period. */
    options->ctl = aos_http_controller_create(options->pool, 0);
int main(int argc, char *argv[])
    /* Call the aos_http_io_initialize method in main() to initialize global resources such as networks and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code that is used to create a memory pool is included in the APR library. */
    aos_pool_t *pool;
    /* Create a memory pool. The value of the second parameter is NULL. This value specifies that the pool does not inherit other memory pools. */
    aos_pool_create(&pool, NULL);
    /* Create and initialize options. This parameter includes global configuration information such as endpoint, access_key_id, access_key_secret, is_cname, and curl. */
    oss_request_options_t *oss_client_options;
    /* Allocate memory resources in the memory pool to the options. */  
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_string_t object;
    aos_list_t buffer;
    oss_acl_e oss_acl = OSS_ACL_PRIVATE;
    aos_buf_t *content = NULL;
    aos_table_t *headers = NULL;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    aos_str_set(&bucket, bucket_name);
    aos_str_set(&object, object_name);
    headers = aos_table_make(pool, 0);
    /* Create an Archive bucket. */
    resp_status = oss_create_bucket_with_storage_class(oss_client_options, &bucket, oss_acl, OSS_STORAGE_CLASS_ARCHIVE, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("create bucket succeeded\n");
    } else {
        printf("create bucket failed\n");
    content = aos_buf_pack(oss_client_options->pool, object_content, strlen(object_content));
    aos_list_add_tail(&content->node, &buffer);
    /* Upload an object. */
    resp_status = oss_put_object_from_buffer(oss_client_options, &bucket, &object, &buffer, headers, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("put object from buffer succeeded\n");
    } else {
        printf("put object from buffer failed\n");      
    /* Restore the uploaded object. */
    do {
        headers = aos_table_make(pool, 0);
        resp_status = oss_restore_object(oss_client_options, &bucket, &object, headers, &resp_headers);
        printf("restore object resp_status->code: %d \n", resp_status->code);
        if (resp_status->code != 409) {
        } else {
            printf("restore object is already in progress, resp_status->code: %d \n", resp_status->code);
    } while (1);
    /* Release the memory pool. This operation releases memory resources that are allocated for the request. */
    /* Release the allocated global resources. */
    return 0;

For more information about the Archive storage class, see Overview. For more information about related status codes, see RestoreObject in API Reference.