本文介绍如何在受版本控制的存储空间(Bucket)中拷贝文件(Object)。您可以通过CopyObject的方法拷贝小于1 GB的文件,通过分片拷贝(UploadPartCopy)的方法拷贝大于1 GB的文件。
拷贝小文件
对于小于1 GB的文件,您可以通过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)。
- x-oss-copy-source默认拷贝Object的当前版本。如果当前版本是删除标记,则返回404表示该Object不存在。您可以在x-oss-copy-source中加入versionId来拷贝指定的Object版本,删除标记不能被拷贝。
- 您可以将Object的早期版本拷贝到同一个Bucket中,拷贝Object的历史版本将会成为一个新的当前版本,达到恢复Object早期版本的目的。
- 如果目标Bucket已开启版本控制,OSS将会为新拷贝出来的Object自动生成唯一的版本ID,此版本ID将会在响应header 的x-oss-version-id中返回。如果目标Bucket未曾开启或者暂停了版本控制,OSS将会为新拷贝的Object自动生成version ID为”null“的版本,且会覆盖原先versionId为”null“的版本。
- 目标Bucket在开启或暂停版本控制状态下,不支持对Appendable类型Object执行拷贝操作。
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);
request.setVersionId("yourSourceObjectVersionId");
/* 拷贝指定版本的文件 */
auto outcome = client.CopyObject(request);
if (outcome.isSuccess()) {
std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
}
else {
/* 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;
}
拷贝小文件的详细说明请参见CopyObject。
拷贝大文件
对于大于1 GB的文件,需要使用分片拷贝(UploadPartCopy)。
UploadPartCopy默认从一个已存在的Object的当前版本中拷贝数据来上传一个Part。允许通过在请求header : x-oss-copy-source中附带versionId的子条件,实现从Object的指定版本进行拷贝,如x-oss-copy-source
: /SourceBucketName/SourceObjectName?versionId=111111。
说明 SourceObjectName要进行URL编码。响应中将会返回被拷贝的Object版本ID:x-oss-copy-source-version-id。
如果未指定versionId且拷贝Object的当前版本为删除标记,OSS将返回404 Not Found。通过指定versionId来拷贝删除标记时,OSS将返回400 Bad Request。
以下代码用于分片拷贝:
#include <alibabacloud/oss/OssClient.h>
#include <sstream>
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);
getObjectMetaReq.setVersionId("yourSourceObjectVersionid");
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(BucketName, ObjectName, metaData);
/* 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 % partSize != 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);
uploadPartCopyReq.setVersionId("yourSourceObjectVersionid");
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()) {
std::cout << "versionid:" << outcome.result().VersionId() << std::endl;
}
else {
/* 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;
}
分片拷贝的详细信息请参见UploadPartCopy。
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