Appelez l'opération AppendObject pour ajouter du contenu à des objets existants de type « appendable ».
Remarques
Cette rubrique utilise le point de terminaison public de la région Chine (Hangzhou). Pour accéder à OSS depuis d'autres services Alibaba Cloud situés dans la même région, utilisez un point de terminaison interne. Pour plus d'informations sur les régions et les points de terminaison OSS, consultez Régions et points de terminaison.
Cette rubrique explique comment créer une instance OSSClient avec un point de terminaison OSS. Pour d'autres configurations, telles que l'utilisation d'un domaine personnalisé ou l'authentification via des identifiants du Security Token Service (STS), consultez Initialisation (SDK C).
Si l'objet cible n'existe pas, l'opération AppendObject crée un objet de type « appendable ».
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Si l'objet cible existe déjà :
Si l'objet est de type « appendable » et que la position de départ spécifiée correspond à la taille actuelle de l'objet, les données sont ajoutées à la fin de l'objet.
Si l'objet est de type « appendable » mais que la position de départ spécifiée ne correspond pas à la taille actuelle de l'objet, l'erreur PositionNotEqualToLength est renvoyée.
Si l'objet n'est pas de type « appendable », l'erreur ObjectNotAppendable est renvoyée.
Autorisations
Par défaut, un compte Alibaba Cloud dispose de toutes les autorisations. Les utilisateurs RAM ou les rôles RAM associés à un compte Alibaba Cloud ne disposent d'aucune autorisation par défaut. Le compte Alibaba Cloud ou l'administrateur du compte doit accorder les autorisations d'opération via des politiques RAM ou une Bucket Policy.
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API |
Action |
Description |
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AppendObject |
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Appelez cette opération pour charger un objet en l'ajoutant à un objet existant. |
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Lors du chargement d'un objet par ajout à un objet existant, cette autorisation est requise si vous spécifiez des tags d'objet via x-oss-tagging. |
Ajout de données depuis la mémoire
L'exemple de code suivant montre comment ajouter des données depuis la mémoire à un objet dans un bucket spécifié :
#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, for the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the 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";
const char *object_content = "More than just cloud.";
/* Set yourRegion to the region where the bucket is located. For example, for 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 running 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"));
// Configure the following two parameters.
aos_str_set(&options->config->region, region);
options->config->signature_version = 4;
/* Specifies whether a CNAME is used. 0 indicates that a CNAME is not 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);
}
/* The memory pool for memory management 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 memory 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 to 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_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);
/* Get the starting append position. */
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);
}
/* Append the object. */
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 releases the memory allocated to resources during the request. */
aos_pool_destroy(pool);
/* Release the previously allocated global resources. */
aos_http_io_deinitialize();
return 0;
}Ajout de données depuis un fichier local
L'exemple de code suivant montre comment ajouter des données depuis un fichier local à un objet dans un bucket spécifié :
#include "oss_api.h"
#include "aos_http_io.h"
/* Set yourEndpoint to the Endpoint of the region where the bucket is located. For example, for the China (Hangzhou) region, set the Endpoint to https://oss-cn-hangzhou.aliyuncs.com. */
const char *endpoint = "yourEndpoint";
/* Specify the 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";
/* Set yourRegion to the region where the bucket is located. For example, for 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 running 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"));
// Configure the following two parameters.
aos_str_set(&options->config->region, region);
options->config->signature_version = 4;
/* Specifies whether a CNAME is used. 0 indicates that a CNAME is not 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);
}
/* The memory pool for memory management 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 memory 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 to 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;
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);
/* Get the starting append position. */
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);
}
/* Append the object. */
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 releases the memory allocated to resources during the request. */
aos_pool_destroy(pool);
/* Release the previously allocated global resources. */
aos_http_io_deinitialize();
return 0;
}Références
Pour obtenir l'exemple de code complet relatif au chargement par ajout, consultez GitHub.
Pour plus d'informations sur l'opération API de chargement par ajout, consultez AppendObject.