Object Storage Service:追加アップロード

使用上の注意

• このトピックでは、中国 (杭州) リージョンのパブリックエンドポイントを使用します。 OSSと同じリージョンにある他のAlibaba Cloudサービスを使用してObject Storage Service (OSS) にアクセスする場合は、内部エンドポイントを使用します。 OSSでサポートされているリージョンとエンドポイントの詳細については、「リージョンとエンドポイント」をご参照ください。

• このトピックでは、OSSエンドポイントを使用してOSSClientインスタンスを作成します。 カスタムドメイン名またはSTS (Security Token Service) を使用してOSSClientインスタンスを作成する場合は、「初期化」をご参照ください。

• 追加アップロードを使用するには、oss:PutObject権限が必要です。 詳細については、「RAMユーザーへのカスタムポリシーのアタッチ」をご参照ください。

• コンテンツを追加するオブジェクトが存在しない場合、AppendObject操作によって追加可能なオブジェクトが作成されます。

• コンテンツを追加するオブジェクトが存在する場合:

  • オブジェクトが追加可能なオブジェクトであり、追加操作が開始される指定された位置が現在のオブジェクトサイズに等しい場合、データはオブジェクトの最後に追加されます。

  • オブジェクトが追加可能オブジェクトであり、追加操作の開始位置が現在のオブジェクトサイズと等しくない場合、PositionNotEqualToLengthエラーが返されます。

  • オブジェクトが追加可能オブジェクトでない場合、ObjectNotAppendableエラーが返されます。

追加アップロードを使用してローカルメモリからデータをアップロードする

次のサンプルコードは、追加アップロードを使用してローカルメモリから特定のバケットにデータをアップロードする方法の例を示しています。

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

/* Specify the name of the bucket. Example: examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the full path of the object. Do not include the bucket name in the full path of the object. Example: exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
const char *object_content = "More than just cloud.";
/* Specify the region in which the bucket is located. For example, if the bucket is located 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);
    /* Use a char* string to initialize data of the aos_string_t type. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */    
    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"));
    // Specify two additional parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use CNAME. The value 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Specify 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 network resources and memory resources. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code 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 indicates 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 the memory resources in the memory pool to the options. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_string_t object;
    aos_list_t buffer;
    int64_t position = 0;
    char *next_append_position = NULL;
    aos_buf_t *content = NULL;
    aos_table_t *headers1 = NULL;
    aos_table_t *headers2 = 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);
    headers1 = aos_table_make(pool, 0);
    /* Obtain the position from which the first append operation starts. */
    resp_status = oss_head_object(oss_client_options, &bucket, &object, headers1, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        next_append_position = (char*)(apr_table_get(resp_headers, "x-oss-next-append-position"));
        position = atoi(next_append_position);
    }
    /* Perform the append operation. */
    headers2 = aos_table_make(pool, 0);
    aos_list_init(&buffer);
    content = aos_buf_pack(pool, object_content, strlen(object_content));
    aos_list_add_tail(&content->node, &buffer);
    resp_status = oss_append_object_from_buffer(oss_client_options, &bucket, &object, position, &buffer, headers2, &resp_headers);
    if (aos_status_is_ok(resp_status)) {
        printf("append object from buffer succeeded\n");
    } else {
        printf("append object from buffer failed\n");
    }
    /* Release the memory pool. This operation releases the memory resources allocated for the request. */
    aos_pool_destroy(pool);
    /* Release the allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

追加アップロードを使用してローカルファイルをアップロードする

次のサンプルコードは、追加アップロードを使用してローカルファイルを特定のバケットにアップロードする方法の例を示しています。

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

/* Specify the name of the bucket. Example: examplebucket. */
const char *bucket_name = "examplebucket";
/* Specify the full path of the object. Do not include the bucket name in the full path of the object. Example: exampledir/exampleobject.txt. */
const char *object_name = "exampledir/exampleobject.txt";
/* Specify the full path of the local file. */
const char *local_filename = "yourLocalFilename";
/* Specify the region in which the bucket is located. For example, if the bucket is located 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);
    /* Use a char* string to initialize data of the aos_string_t type. */
    aos_str_set(&options->config->endpoint, endpoint);
    /* Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. */    
    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"));
    // Specify two additional parameters.
    aos_str_set(&options->config->region, region);
    options->config->signature_version = 4;
    /* Specify whether to use CNAME. The value 0 indicates that CNAME is not used. */
    options->config->is_cname = 0;
    /* Specify 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 network resources and memory resources. */
    if (aos_http_io_initialize(NULL, 0) != AOSE_OK) {
        exit(1);
    }
    /* Create a memory pool to manage memory. aos_pool_t is equivalent to apr_pool_t. The code 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 indicates 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 the memory resources in the memory pool to the options. */
    oss_client_options = oss_request_options_create(pool);
    /* Initialize oss_client_options. */
    init_options(oss_client_options);
    /* Initialize the parameters. */
    aos_string_t bucket;
    aos_string_t object;
    aos_string_t file;
    int64_t position = 0;
    char *next_append_position = NULL;
    aos_table_t *headers1 = NULL;
    aos_table_t *headers2 = 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);
    aos_str_set(&file, local_filename);
    /* Obtain the position from which the first append operation starts. */
    resp_status = oss_head_object(oss_client_options, &bucket, &object, headers1, &resp_headers);
    if(aos_status_is_ok(resp_status)) {
        next_append_position = (char*)(apr_table_get(resp_headers, "x-oss-next-append-position"));
        position = atoi(next_append_position);
    }
    /* Perform the append operation. */
    resp_status = oss_append_object_from_file(oss_client_options, &bucket, &object, position, &file, headers2, &resp_headers);
    /* Check whether the append operation is successful. */
    if (aos_status_is_ok(resp_status)) {
        printf("append object from file succeeded\n");
    } else {
        printf("append object from file failed\n");
    }
    /* Release the memory pool. This operation releases the memory resources allocated for the request. */
    aos_pool_destroy(pool);
    /* Release the allocated global resources. */
    aos_http_io_deinitialize();
    return 0;
}

関連ドキュメント

• 追加アップロードの実行に使用される完全なサンプルコードについては、『GitHub』をご参照ください。

• 追加アップロードを実行するために呼び出すことができるAPI操作の詳細については、「AppendObject」をご参照ください。