Object Storage Service:Copy an object (C# SDK V1)

Observações

• Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços do Alibaba Cloud na mesma região, utilize um endpoint interno. Para obter mais informações sobre regiões e endpoints do OSS, consulte Regiões e endpoints.

• Este tópico demonstra como criar uma instância OSSClient com um endpoint do OSS. Para configurações alternativas, como uso de domínio personalizado ou autenticação com credenciais do Security Token Service (STS), consulte Inicialização (C# SDK V1).

• Você deve ter permissões de leitura no objeto de origem e permissões de leitura/gravação no bucket de destino.

• Os buckets de origem e de destino não devem ter políticas de retenção configuradas. Caso contrário, a cópia falhará e o sistema retornará o erro The object you specified is immutable..

• Não há suporte para cópia entre regiões. Por exemplo, você não pode copiar um objeto de um bucket em China (Hangzhou) para um bucket em China (Qingdao).

Copiar um arquivo pequeno

O código a seguir exemplifica como copiar um objeto pequeno:

using Aliyun.OSS;
using Aliyun.OSS.Common;

// Specify the Endpoint for 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.
var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// 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.
var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
// Specify the name of the source bucket. Example: srcexamplebucket.
var sourceBucket = "srcexamplebucket";
// Specify the full path of the source object. The full path cannot contain the bucket name. Example: srcdir/scrobject.txt.
var sourceObject = "srcdir/scrobject.txt";
// Specify the name of the destination bucket, which must be in the same region as the source bucket. Example: destbucket.
var targetBucket = "destbucket";
// Specify the full path of the destination object. The full path cannot contain the bucket name. Example: destdir/destobject.txt.
var targetObject = "destdir/destobject.txt";
// Specify 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 string region = "cn-hangzhou";

// Create a ClientConfiguration instance and modify the default parameters as needed.
var conf = new ClientConfiguration();

// Use Signature V4.
conf.SignatureVersion = SignatureVersion.V4;

// Create an OssClient instance.
var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
client.SetRegion(region);
try
{
    var metadata = new ObjectMetadata();
    // Set custom metadata. Custom metadata is a key-value pair. For example, set the key to mk1 and the value to mv1.
    metadata.AddHeader("mk1", "mv1");
    metadata.AddHeader("mk2", "mv2");
    var req = new CopyObjectRequest(sourceBucket, sourceObject, targetBucket, targetObject)
    {
        // If NewObjectMetadata is null, the metadata of the source object is copied (COPY mode). If NewObjectMetadata is not null, the metadata of the source object is overwritten (REPLACE mode).
        NewObjectMetadata = metadata 
    };
    // Copy the object.
    client.CopyObject(req);
    Console.WriteLine("Copy object succeeded");
}
catch (OssException ex)
{
    Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID: {2} \tHostID: {3}",
        ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
}
catch (Exception ex)
{
    Console.WriteLine("Failed with error info: {0}", ex.Message);
}

Copiar um arquivo grande

• Cópia multipart

  Para objetos maiores que 1 GB, utilize a cópia multipart (UploadPartCopy). O processo consiste em três etapas:

  1. Use o método InitiateMultipartUploadRequest para inicializar um evento de upload multipart.

  2. Use o método UploadPartCopy para copiar as partes.

  3. Use o método CompleteMultipartUpload para concluir a cópia do objeto.

  O código a seguir mostra como executar uma cópia multipart:

  using Aliyun.OSS;
  using Aliyun.OSS.Common;
  // Specify the Endpoint for 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.
  var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
  // 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.
  var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
  var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
  // Specify the name of the source bucket. Example: srcexamplebucket.
  var sourceBucket = "srcexamplebucket";
  // Specify the full path of the source object. The full path cannot contain the bucket name. Example: srcdir/scrobject.txt.
  var sourceObject = "srcdir/scrobject.txt";
  // Specify the name of the destination bucket, which must be in the same region as the source bucket. Example: destbucket.
  var targetBucket = "destbucket";
  // Specify the full path of the destination object. The full path cannot contain the bucket name. Example: destdir/destobject.txt.
  var targetObject = "destdir/destobject.txt";
  var uploadId = "";
  var partSize = 50 * 1024 * 1024;
  // Specify 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 string region = "cn-hangzhou";
  
  // Create a ClientConfiguration instance and modify the default parameters as needed.
  var conf = new ClientConfiguration();
  
  // Use Signature V4.
  conf.SignatureVersion = SignatureVersion.V4;
  
  // Create an OssClient instance.
  var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
  client.SetRegion(region);
  try
  {
      // Initialize the copy task. You can use InitiateMultipartUploadRequest to specify the metadata of the destination object.
      var request = new InitiateMultipartUploadRequest(targetBucket, targetObject);
      var result = client.InitiateMultipartUpload(request);
      // Print the upload ID.
      uploadId = result.UploadId;
      Console.WriteLine("Init multipart upload succeeded， Upload Id: {0}", result.UploadId);
      // Calculate the number of parts.
      var metadata = client.GetObjectMetadata(sourceBucket, sourceObject);
      var fileSize = metadata.ContentLength;
      var partCount = (int)fileSize / partSize;
      if (fileSize % partSize != 0)
      {
          partCount++;
      }
      // Start the multipart copy.
      var partETags = new List<PartETag>();
      for (var i = 0; i < partCount; i++)
      {
          var skipBytes = (long)partSize * i;
          var size = (partSize < fileSize - skipBytes) ? partSize : (fileSize - skipBytes);
          // Create an UploadPartCopyRequest. You can use UploadPartCopyRequest to specify conditions.
          var uploadPartCopyRequest = new UploadPartCopyRequest(targetBucket, targetObject, sourceBucket, sourceObject, uploadId)
              {
                  PartSize = size,
                  PartNumber = i + 1,
                  // BeginIndex specifies the starting position of the part to be copied.
                  BeginIndex = skipBytes
              };
          // Call the uploadPartCopy method to copy each part.
          var uploadPartCopyResult = client.UploadPartCopy(uploadPartCopyRequest);
          Console.WriteLine("UploadPartCopy : {0}", i);
          partETags.Add(uploadPartCopyResult.PartETag);
      }
      // Complete the multipart copy.
      var completeMultipartUploadRequest =
      new CompleteMultipartUploadRequest(targetBucket, targetObject, uploadId);
      // partETags is a list of PartETags saved during the multipart upload. After OSS receives this list, it verifies each part. If all parts are valid, OSS combines them into a complete object.
      foreach (var partETag in partETags)
      {
          completeMultipartUploadRequest.PartETags.Add(partETag);
      }
      var completeMultipartUploadResult = client.CompleteMultipartUpload(completeMultipartUploadRequest);
      Console.WriteLine("CompleteMultipartUpload succeeded");
  }
  catch (OssException ex)
  {
      Console.WriteLine("Failed with error code: {0}; Error info: {1}. \nRequestID: {2} \tHostID: {3}",
          ex.ErrorCode, ex.Message, ex.RequestId, ex.HostId);
  }
  catch (Exception ex)
  {
      Console.WriteLine("Failed with error info: {0}", ex.Message);
  }

• Cópia retomável

  Se uma tarefa de cópia for interrompida, retome-a a partir do ponto de interrupção.

  O código a seguir mostra como executar uma cópia retomável:

  using Aliyun.OSS;
  // Specify the Endpoint for 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.
  var endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
  // 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.
  var accessKeyId = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_ID");
  var accessKeySecret = Environment.GetEnvironmentVariable("OSS_ACCESS_KEY_SECRET");
  // Specify the name of the source bucket. Example: srcexamplebucket.
  var sourceBucket = "srcexamplebucket";
  // Specify the full path of the source object. The full path cannot contain the bucket name. Example: srcdir/scrobject.txt.
  var sourceObject = "srcdir/scrobject.txt";
  // Specify the name of the destination bucket, which must be in the same region as the source bucket. Example: destbucket.
  var targetBucket = "destbucket";
  // Specify the full path of the destination object. The full path cannot contain the bucket name. Example: destdir/destobject.txt.
  var targetObject = "destdir/destobject.txt";
  // Specify the file that records the copy results. The progress information is saved to this file. If the copy task fails, it resumes from the recorded breakpoint. After the copy is complete, this file is deleted.
  var checkpointDir = @"yourCheckpointDir";
  // Specify 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 string region = "cn-hangzhou";
  
  // Create a ClientConfiguration instance and modify the default parameters as needed.
  var conf = new ClientConfiguration();
  
  // Use Signature V4.
  conf.SignatureVersion = SignatureVersion.V4;
  
  // Create an OssClient instance.
  var client = new OssClient(endpoint, accessKeyId, accessKeySecret, conf);
  client.SetRegion(region);
  try
  {
      var request = new CopyObjectRequest(sourceBucket, sourceObject, targetBucket, targetObject);
      // The checkpointDir directory saves the intermediate state for resumable copy. This allows the task to resume after a failure. If checkpointDir is null, the resumable copy feature is disabled, and the copy task starts over each time.
      client.ResumableCopyObject(request, checkpointDir);
      Console.WriteLine("Resumable copy new object:{0} succeeded", request.DestinationKey);
  }
  catch (Exception ex)
  {
      Console.WriteLine("Resumable copy new object failed, {0}", ex.Message);
  }

Referências

• Copiar um objeto pequeno

  • Para obter o código de exemplo completo usado para copiar um objeto pequeno, consulte GitHub.

  • Para obter mais informações sobre a operação de API usada para copiar um objeto pequeno, consulte CopyObject.

• Copiar um objeto grande

  • Para obter o código de exemplo completo usado para copiar um objeto grande, consulte GitHub.

  • Para obter mais informações sobre a operação de API usada para copiar um objeto grande, consulte UploadPartCopy.

• Cópia retomável

  Para obter o código de exemplo completo usado para cópia retomável, consulte GitHub.