Configuring Direct Reading for a Bucket (SDK for C)

Function

The direct reading function means that you can directly perform operations on Archive objects without restoring them.

By default, direct reading is disabled for a bucket.

This API is used to enable or disable direct reading for a bucket.

• When direct reading is enabled for a bucket:
  • You can directly perform operations on objects in the bucket regardless of whether they have been restored.
  • If objects are not restored, your operations on them will be charged separately.
• When direct reading is disabled for a bucket:
  • You need to restore objects in the bucket before you can operate them.

Restrictions

• To configure direct reading for a bucket, you must be the bucket owner or have the required permission (obs:bucket:PutDirectColdAccessConfiguration granted using IAM or PutDirectColdAccessConfiguration granted using a bucket policy). For details, see Introduction to OBS Access Control, IAM Custom Policies, and Creating a Custom Bucket Policy.
• The mapping between OBS regions and endpoints must comply with what is listed in Regions and Endpoints.

Method

void set_bucket_direct_cold_access(const obs_options *options, const char *direct_cold_access_status, 
           obs_response_handler *handler, void *callback_data);

Request Parameters

Sample Code

This example configures direct reading for a bucket.

#include "eSDKOBS.h"
#include <stdio.h>
// The response callback function. The content of properties in the callback can be recorded in callback_data (custom callback data).
obs_status response_properties_callback(const obs_response_properties *properties, void *callback_data);
// The callback function for the completed response. The content of obs_status and obs_error_details in the callback can be recorded in callback_data (custom callback data).
void response_complete_callback(obs_status status, const obs_error_details *error, void *callback_data);
int main()
{
    // The following example shows how to use set_bucket_direct_cold_access to configure direct reading for a bucket.
    // Call the obs_initialize method at the program entry to initialize global resources such as the network and memory.
    obs_initialize(OBS_INIT_ALL);
    obs_options options;
    // Create and initialize options, including the access domain name (host_name), access keys (access_key_id and access_key_secret), bucket name (bucket_name), and bucket storage class (storage_class).
    init_obs_options(&options);
    // Enter the endpoint corresponding to the bucket for host_name. CN-Hong Kong is used here as an example. Replace it with the one currently in use.
    options.bucket_options.host_name = "obs.ap-southeast-1.myhuaweicloud.com";
    // Hard-coded or plaintext AK and SK are risky. For security purposes, encrypt your AK and SK and store them in the configuration file or environment variables.
    // In this example, the AK and SK are stored in environment variables for identity authentication. Before running the code in this example, configure local environment variables ACCESS_KEY_ID and SECRET_ACCESS_KEY.
    options.bucket_options.access_key = getenv("ACCESS_KEY_ID");
    options.bucket_options.secret_access_key = getenv("SECRET_ACCESS_KEY");
    // Specify the bucket name, for example, example-bucket-name.
    char * bucketName = "example-bucket-name";
    options.bucket_options.bucket_name = bucketName;
    obs_response_handler response_handler = { &response_properties_callback, &response_complete_callback };
    obs_status ret_status = OBS_STATUS_BUTT;
    // Enable direct reading for the bucket.
    set_bucket_direct_cold_access(&options, "Enabled", &response_handler, &ret_status);
    if (OBS_STATUS_OK == ret_status) {
        printf("set bucket direct cold access successfully. \n");
    }
    else
    {
        printf("set bucket direct cold access failed(%s).\n", obs_get_status_name(ret_status));
    }
    // Release the allocated global resources.
    obs_deinitialize();
}
// The response callback function. The content of properties in the callback can be recorded in callback_data (custom callback data).
obs_status response_properties_callback(const obs_response_properties *properties, void *callback_data)
{
    if (properties == NULL)
    {
        printf("error! obs_response_properties is null!");
        return OBS_STATUS_OK;
    }
    // Print the response.
#define print_nonnull(name, field)                                 \
    do {                                                           \
        if (properties-> field) {                                  \
            printf("%s: %s\n", name, properties->field);          \
        }                                                          \
    } while (0)
    print_nonnull("request_id", request_id);
    print_nonnull("request_id2", request_id2);
    print_nonnull("content_type", content_type);
    if (properties->content_length) {
        printf("content_length: %llu\n", properties->content_length);
    }
    print_nonnull("server", server);
    print_nonnull("ETag", etag);
    print_nonnull("version_id", version_id);
    return OBS_STATUS_OK;
}
// The callback function for the completed response. The content of obs_status and obs_error_details in the callback can be recorded in callback_data (custom callback data).
void response_complete_callback(obs_status status, const obs_error_details *error, void *callback_data)
{
    if (callback_data) {
        obs_status *ret_status = (obs_status *)callback_data;
        *ret_status = status;
    }
    else {
        printf("Callback_data is NULL");
    }
    if (error && error->message) {
        printf("Error Message: \n   %s\n", error->message);
    }
    if (error && error->resource) {
        printf("Error Resource: \n  %s\n", error->resource);
    }
    if (error && error->further_details) {
        printf("Error further_details: \n   %s\n", error->further_details);
    }
    if (error && error->extra_details_count) {
        int i;
        for (i = 0; i < error->extra_details_count; i++) {
            printf("Error Extra Detail(%d):\n   %s:%s\n", i, error->extra_details[i].name,
                error->extra_details[i].value);
        }
    }
    if (error && error->error_headers_count) {
        int i;
        for (i = 0; i < error->error_headers_count; i++) {
            const char *errorHeader = error->error_headers[i];
            printf("Error Headers(%d):\n    %s\n", i, errorHeader == NULL ? "NULL Header" : errorHeader);
        }
    }
}

Helpful Links

• The API for configuring direct reading for a bucket
• OBS Error Codes
• Direct Reading