拷贝文件分为拷贝小文件和拷贝大文件。

拷贝小文件

对于小于 1GB 的文件，您可以通过 client.CopyObject 方法将文件从一个存储空间（源存储空间）复制到同一地域的另一个存储空间（目标存储空间）。此方法参数指定方式如下

参数指定方式 描述
CopyObjectOutcome OssClient::CopyObject(const CopyObjectRequest &request) 允许指定目标文件的元信息和拷贝的限制条件。如果拷贝操作的源文件地址和目标文件地址相同，则直接替换源文件的元信息。
说明 此操作的限制条件如下：
  • 用户有源文件的读写权限。
  • 不支持跨地域拷贝。例如，不支持将杭州存储空间里的文件拷贝到青岛。
  • 文件的大小不能超过1GB。

以下代码用于拷贝小文件：

#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
     /* 初始化OSS账号信息 */
    std::string AccessKeyId = "yourAccessKeyId";
    std::string AccessKeySecret = "yourAccessKeySecret";
    std::string Endpoint = "yourEndpoint";
    std::string SourceBucketName = "yourSourceBucketName";
    std::string CopyBucketName = "yourCopyBucketName";
    std::string SourceObjectName = "yourSourceObjectName";
    std::string CopyObjectName = "yourCopyObjectName";

    /* 初始化网络等资源 */
    InitializeSdk();

    ClientConfiguration conf;
    OssClient client(Endpoint, AccessKeyId, AccessKeySecret, conf);

    CopyObjectRequest request(CopyBucketName, CopyObjectName);
    request.setCopySource(SourceBucketName, SourceObjectName);

    /* 拷贝文件 */
    auto outcome = client.CopyObject(request);

    if (!outcome.isSuccess()) {
        /* 异常处理 */
        std::cout << "CopyObject fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        ShutdownSdk();
        return -1;
    }

    /* 释放网络等资源 */
    ShutdownSdk();
    return 0;
}

拷贝大文件

对于大于1GB的文件，需要使用分片拷贝（UploadPartCopy）。分片拷贝分为三步：

  1. 通过 client.InitiateMultipartUpload 初始化分片拷贝任务。
  2. 通过 client.UploadPartCopy 进行分片拷贝。除最后一个分片外，其它分片都要大于 100KB。
  3. 通过 client.CompleteMultipartUpload 提交分片拷贝任务。
说明 拷贝大文件也不支持跨地域拷贝。例如，不支持将北京存储空间里的文件拷贝到青岛。
以下代码用于拷贝大文件： 
#include <alibabacloud/oss/OssClient.h>
using namespace AlibabaCloud::OSS;

int main(void)
{
    /* 初始化OSS账号信息 */
    std::string AccessKeyId = "yourAccessKeyId";
    std::string AccessKeySecret = "yourAccessKeySecret";
    std::string Endpoint = "yourEndpoint";
    std::string SourceBucketName = "yourSourceBucketName";
    std::string CopyBucketName = "yourCopyBucketName";
    std::string SourceObjectName = "yourSourceObjectName";
    std::string CopyObjectName = "yourCopyObjectName";

    /* 初始化网络等资源 */
    InitializeSdk();

    ClientConfiguration conf;
    OssClient client(Endpoint, AccessKeyId, AccessKeySecret, conf);

    auto getObjectMetaReq = GetObjectMetaRequest(SourceBucketName, SourceObjectName);
    auto getObjectMetaResult = GetObjectMeta(getObjectMetaReq);
    if (!getObjectMetaResult.isSuccess()) {
        std::cout << "GetObjectMeta fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        ShutdownSdk();
        return -1;
    }
    /* 获取被拷贝文件大小 */
    auto objectSize = getObjectMetaResult.result().ContentLength();

    /* 拷贝大文件 */
    InitiateMultipartUploadRequest initUploadRequest(CopyBucketName, CopyObjectName);

    /* 初始化分片拷贝事件 */
    auto uploadIdResult = client.InitiateMultipartUpload(initUploadRequest);
    auto uploadId = uploadIdResult.result().UploadId();
    int64_t partSize = 100 * 1024;
    PartList partETagList;
    int partCount = static_cast<int>(objectSize / partSize);
    /* 计算分片个数*/
    if (objectSize % part Size != 0) {
        partCount++;
    }

    /* 对每一个分片进行拷贝 */
    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 + 1);
        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:" << outcome.error().Code() <<
            ",message:" << outcome.error().Message() <<
            ",requestId:" << outcome.error().RequestId() << std::endl;
        }

    }

    /* 完成分片拷贝 */
    CompleteMultipartUploadRequest request(CopyBucketName, CopyObjectName, partETagList, uploadId);
    auto outcome = client.CompleteMultipartUpload(request);

    if (!outcome.isSuccess()) {
        /* 异常处理 */
        std::cout << "CompleteMultipartUpload fail" <<
        ",code:" << outcome.error().Code() <<
        ",message:" << outcome.error().Message() <<
        ",requestId:" << outcome.error().RequestId() << std::endl;
        ShutdownSdk();
        return -1;
    }

    /* 释放网络等资源 */
    ShutdownSdk();
    return 0;
}

分片拷贝的详细说明请参见UploadPartCopy。