Object Storage Service:Resumable download (C SDK)

#include "oss_api.h"
#include "aos_http_io.h"
/* Replace yourEndpoint with the Endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";

/* Replace with your bucket name, for example, examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the full path of the object. The full path cannot contain the bucket name. For example, exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Specify the full path of the local file. */
const char *local_filename = "yourLocalFilename";
/* Replace yourRegion with the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou. */
const char *region = "yourRegion";
void init_options(oss_request_options_t *options)
{
    options->config = oss_config_create(options->pool);
    /* Initialize the aos_string_t type with a char* string. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set. */    
    aos_str_set(&options->config->access_key_id, getenv("OSS_ACCESS_KEY_ID"));
    aos_str_set(&options->config->access_key_secret, getenv("OSS_ACCESS_KEY_SECRET"));
    // You must also configure the following two parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether a CNAME is used. A value of 0 indicates that no CNAME is used. */
    options->config->is_cname = 0;
    /* Set 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 at the program entry to initialize global resources such as the network and memory. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* A memory pool (pool) for memory management, which is equivalent to apr_pool_t. The implementation code is in the apr library. */
    aos_pool_t *pool;
    /* Create a new memory pool. The second parameter is NULL, which indicates that the new pool does not inherit from another memory pool. */
    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 for options in the memory pool. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize the client options oss_client_options. */
    init_options(oss_client_options);
    /* Initialize parameters. */
    aos_string_t bucket;
    aos_string_t object;
    aos_string_t file;
    aos_table_t *headers = NULL;
    aos_table_t *resp_headers = NULL; 
    aos_status_t *resp_status = NULL; 
    oss_resumable_clt_params_t *clt_params;
    aos_str_set(&bucket, bucket_name);
    aos_str_set(&object, object_name);
    aos_str_set(&file, local_filename);
    /* Perform a resumable download. */
    clt_params = oss_create_resumable_clt_params_content(pool, 1024 * 100, 3, AOS_TRUE, NULL);
    resp_status = oss_resumable_download_file(oss_client_options, &bucket, &object, &file, headers, NULL, clt_params, NULL, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("download succeeded\n");
    } else {
        printf("download failed\n");
    }
    /* Release the memory pool. This is equivalent to releasing the memory allocated for various resources during the request. */
    aos_pool_destroy(pool);
    /* Release the previously allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}