Copie objetos dentro de un mismo bucket o entre buckets de la misma región.
Notas de uso
En este tema se utiliza el endpoint público de la región China (Hangzhou). Si necesita acceder a OSS desde otros servicios de Alibaba Cloud ubicados en la misma región, utilice un endpoint interno. Para obtener más información sobre las regiones y los endpoints de OSS, consulte Regions and endpoints.
Este tema muestra cómo crear una instancia de OSSClient con un endpoint de OSS. Para conocer configuraciones alternativas, como usar un dominio personalizado o autenticarse con credenciales de Security Token Service (STS), consulte Create an OssClient instance.
Para copiar un objeto, debe contar con permisos de lectura sobre el objeto de origen, así como permisos de lectura y escritura en el bucket de destino.
Compruebe que no haya políticas de retención configuradas en el bucket de origen ni en el de destino. De lo contrario, se devuelve el mensaje de error The object you specified is immutable..
El bucket de origen y el de destino deben estar en la misma región. Por ejemplo, no es posible copiar objetos de un bucket ubicado en la región China (Hangzhou) hacia otro situado en la región China (Qingdao).
Copiar un objeto pequeño
Llame al método client.CopyObject para copiar un objeto de menos de 1 GB desde un bucket de origen hacia uno de destino dentro de la misma región. A continuación se describe cómo configurar los parámetros al llamar a client.CopyObject.
|
Método de configuración |
Descripción |
|
CopyObjectOutcome OssClient::CopyObject(const CopyObjectRequest &request) |
Permite especificar los metadatos del objeto de destino y las condiciones de copia. Si las URL del objeto de origen y del objeto de destino son iguales, los metadatos indicados en la solicitud reemplazan a los del objeto de origen. |
A continuación se muestra un ejemplo de código para copiar un objeto pequeño:
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize information about the account that is used to access OSS. */
/* 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. */
std::string Endpoint = "yourEndpoint";
/* 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. */
std::string Region = "yourRegion";
/* Specify the name of the source bucket. Example: srcexamplebucket. */
std::string SourceBucketName = "srcexamplebucket";
/* Specify the name of the destination bucket. The destination bucket must be located in the same region as the source bucket. Example: destbucket. */
std::string CopyBucketName = "destbucket";
/* Specify the full path of the source object. Do not include the bucket name in the full path. Example: srcdir/scrobject.txt. */
std::string SourceObjectName = "srcdir/scrobject.txt";
/* Specify the full path of the destination object. Do not include the bucket name in the full path. Example: destdir/destobject.txt. */
std::string CopyObjectName = "destdir/destobject.txt";
/* Initialize resources such as network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* 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. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
CopyObjectRequest request(CopyBucketName, CopyObjectName);
request.setCopySource(SourceBucketName, SourceObjectName);
/* Copy the object. */
auto outcome = client.CopyObject(request);
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "CopyObject fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release resources such as network resources. */
ShutdownSdk();
return 0;
}Copiar un objeto grande
Para objetos mayores a 1 GB, utilice la copia por partes (UploadPartCopy). Este proceso consta de tres pasos:
Utilice client.InitiateMultipartUpload para iniciar una tarea de copia por partes.
Utilice client.UploadPartCopy para copiar las partes. Todas deben superar los 100 KB, excepto la última.
Utilice client.CompleteMultipartUpload para finalizar la tarea de copia por partes.
A continuación se muestra un ejemplo de código para copiar un objeto grande:
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;
int main(void)
{
/* Initialize information about the account that is used to access OSS. */
/* 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. */
std::string Endpoint = "yourEndpoint";
/* 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. */
std::string Region = "yourRegion";
/* Specify the name of the source bucket. Example: srcexamplebucket. */
std::string SourceBucketName = "srcexamplebucket";
/* Specify the name of the destination bucket. The destination bucket must be located in the same region as the source bucket. Example: destbucket. */
std::string CopyBucketName = "destbucket";
/* Specify the full path of the source object. Do not include the bucket name in the full path. Example: srcdir/scrobject.txt. */
std::string SourceObjectName = "srcdir/scrobject.txt";
/* Specify the full path of the destination object. Do not include the bucket name in the full path. Example: destdir/destobject.txt. */
std::string CopyObjectName = "destdir/destobject.txt";
/* Initialize resources such as network resources. */
InitializeSdk();
ClientConfiguration conf;
conf.signatureVersion = SignatureVersionType::V4;
/* 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. */
auto credentialsProvider = std::make_shared<EnvironmentVariableCredentialsProvider>();
OssClient client(Endpoint, credentialsProvider, conf);
client.SetRegion(Region);
auto getObjectMetaReq = GetObjectMetaRequest(SourceBucketName, SourceObjectName);
auto getObjectMetaResult = client.GetObjectMeta(getObjectMetaReq);
if (!getObjectMetaResult.isSuccess()) {
std::cout << "GetObjectMeta fail" <<
",code:" << getObjectMetaResult.error().Code() <<
",message:" << getObjectMetaResult.error().Message() <<
",requestId:" << getObjectMetaResult.error().RequestId() << std::endl;
return -1;
}
/* Query the size of the source object. */
auto objectSize = getObjectMetaResult.result().ContentLength();
/* Copy the large object. */
InitiateMultipartUploadRequest initUploadRequest(CopyBucketName, CopyObjectName);
/* Initiate a multipart copy task. */
auto uploadIdResult = client.InitiateMultipartUpload(initUploadRequest);
auto uploadId = uploadIdResult.result().UploadId();
int64_t partSize = 100 * 1024;
PartList partETagList;
int partCount = static_cast<int>(objectSize / partSize);
/* Calculate the number of parts. */
if (objectSize % partSize != 0) {
partCount++;
}
/* Copy each part. */
for (int i = 1; i <= partCount; i++) {
auto skipBytes = partSize * (i - 1);
auto size = (partSize < objectSize - skipBytes) ? partSize : (objectSize - skipBytes);
auto uploadPartCopyReq = UploadPartCopyRequest(CopyBucketName, CopyObjectName, SourceBucketName, SourceObjectName,uploadId, i);
uploadPartCopyReq.setCopySourceRange(skipBytes, skipBytes + size -1);
auto uploadPartOutcome = client.UploadPartCopy(uploadPartCopyReq);
if (uploadPartOutcome.isSuccess()) {
Part part(i, uploadPartOutcome.result().ETag());
partETagList.push_back(part);
}
else {
std::cout << "UploadPartCopy fail" <<
",code:" << uploadPartOutcome.error().Code() <<
",message:" << uploadPartOutcome.error().Message() <<
",requestId:" << uploadPartOutcome.error().RequestId() << std::endl;
}
}
/* Complete the multipart copy task. */
CompleteMultipartUploadRequest request(CopyBucketName, CopyObjectName, partETagList, uploadId);
auto outcome = client.CompleteMultipartUpload(request);
if (!outcome.isSuccess()) {
/* Handle exceptions. */
std::cout << "CompleteMultipartUpload fail" <<
",code:" << outcome.error().Code() <<
",message:" << outcome.error().Message() <<
",requestId:" << outcome.error().RequestId() << std::endl;
return -1;
}
/* Release resources such as network resources. */
ShutdownSdk();
return 0;
}Referencias
Para consultar el código de ejemplo completo que permite copiar objetos grandes y pequeños, visite GitHub.
Para obtener más información sobre la operación de API que permite copiar un objeto pequeño, consulte CopyObject.
Para obtener más información sobre la operación de API que permite copiar un objeto grande, consulte UploadPartCopy.