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DocumentaçãoCloud Object StorageSDK DocumentationC++ SDKObject operationsCopy and Move Objects

Copy and Move Objects

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Última atualização: 2026-03-12 10:28:19

Introduction

This article introduces example code and descriptions for implementing the object copy and move features in COS using the C++ SDK, including three parts: Advanced Copy API, Simple Copy API, and Moving objects.

Must-Knows

If you use the Simple API to copy objects, you need to have read permissions for the source object and write permissions for the destination object. When you configure the authorization policy, the authorization action for the destination object needs to be set to cos:PutObject, and the authorization action for the source object needs to be set to cos:GetObject. For more authorization, see CAM-supported business APIs.
If you use the Advanced API for automatic multipart copy or use the Simple API's multipart operations to implement multipart copy, you need to have read permissions for the source object and permissions for the destination object to initiate multipart upload, upload object, and complete multipart upload. When you configure the authorization policy, the authorization action for the destination object needs to be set to cos:InitiateMultipartUpload, cos:PutObject, cos:CompleteMultipartUpload, and the authorization action for the source object needs to be set to cos:GetObject. For more authorization, see CAM-supported business APIs.
If you use the move object API, you need to have read and delete permissions for the source object, and write permissions for the destination object. When you configure the authorization policy, the authorization action for the destination object needs to be set to cos:PutObject, and the authorization actions for the source object need to be set to cos:GetObject and cos:DeleteObject. For more authorization, see CAM-supported business APIs.

Related Examples

Function Name
Description
Example code
Advanced Copy
The Advanced Copy API encapsulates the Simple Copy and Multipart Copy APIs, intelligently selecting the method to copy objects based on file size.
Simple Copy
The Simple Copy API can copy an object to a specified bucket and does not support automatic multipart copy. It supports copying objects up to 5GB in size. For objects larger than 5GB, please use the Advanced API to copy.
Move Object
The Move Object API encapsulates copy and delete operations. It only supports moving objects within the current bucket. For cross-bucket movement, you can use the Advanced Copy API and Delete Object API to achieve this.

Advanced Copy (Recommended)

Note:
Automatically determines whether to use simple copy or multipart copy. If the source file is less than 5G, use simple copy; otherwise, use multipart copy.
The chunk size can be configured by users and defaults to 20MB.
The copy thread pool size allows users to configure it, defaulting to 5.

Preliminary Preparation: Create CosAPI

Before calling the COS API, you must first create an instance of CosAPI to make subsequent call requests.
qcloud_cos::CosAPI InitCosAPI() {
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";// Region of the bucket, see https://www.tencentcloud.com/document/product/436/62?from_cn_redirect=1
    std::string secret_id = "************************************"; // User's SecretId. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
    std::string secret_key = "************************************"; // User's SecretKey. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
        
    qcloud_cos::CosConfig config(appid, secret_id, secret_key, region);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Preparations: Using Temporary Keys to Create CosAPI

To access COS with a temporary key, you need to create a CosAPI instance using the temporary key.
qcloud_cos::CosAPI InitCosAPI() {
    // You need to have obtained the temporary key results: tmp_secret_id, tmp_secret_key,
    // For generating temporary keys, see https://www.tencentcloud.com/document/product/436/14048?from_cn_redirect=1#cos-sts-sdk
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";
    std::string tmp_secret_id = "************************************";
    std::string tmp_secret_key = "************************************";
    std::string tmp_token = "token";
    
    qcloud_cos::CosConfig config(appid, tmp_secret_id, tmp_secret_key, region);
    config.SetTmpToken(tmp_token);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Use Case: Copy Object

Note:
This Demo demonstrates how to use the advanced copying API to copy objects.
The thread pool size and chunk size can be set globally. This thread pool is dedicated to each download and shares the same configuration with advanced uploads.

Method Prototype

CosResult CosAPI::Copy(const CopyReq& req, CopyResp* resp)

Request Example

void CopyDemo(qcloud_cos::CosAPI& cos) {
    std::string object_name = "test_dst.txt";                                        // Object name after copying
    std::string source = bucket_name + ".cos." + region + ".myqcloud.com/test_src.txt"; ;  // Source object for copying

    // The part size for multipart copy is set to 20MB by default, with a maximum supported size of 5GB and a minimum of 1MB
    // This configuration is global. Once explicitly set, all subsequently initialized CopyReq instances will use this configuration.
    CosSysConfig::SetUploadCopyPartSize(20 * 1024 * 1024); 
    
    qcloud_cos::CopyReq req(bucket_name, object_name);// Target bucket name and object name
    qcloud_cos::CopyResp resp;


    req.SetXCosCopySource(source);
    qcloud_cos::CosResult result = cos.Copy(req, &resp);



    std::cout << "===========================Copy=============================" << std::endl;
    PrintResult(result, resp);
    std::cout << "============================================================" << std::endl;
}

Parameter Description

Parameter Name
Description
Type
req
Copy file request
CopyReq
resp
Copy file response
CopyResp
CopyReq Member or Function Description:
Member or Function
Description
Parameter Type
bucket_name
Target bucket name, which can be set via the constructor or set method.
The naming format for buckets is BucketName-APPID. For details, see Naming Conventions
string
object_name
Target object key (Key), which can be set via the constructor or set method.
is the unique identifier of the object in the bucket. For example, in the object access domain name examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/doc/picture.jpg, the object key is doc/picture.jpg. For details, see Object Key
string
SetXCosCopySource
Used to set the source object location for copying.
string
CopyResp Member Function Description:
Member functions
Description
Return Type
GetVersionId
Get the version number of the Object. If versioning is not enabled for the Bucket, an empty string is returned.
string
GetXCosServerSideEncryption
Obtain the server-side encryption algorithm used
string
GetEtag
Obtain the Etag of the stored object.
string
GetXCosRequestId
Obtain the request ID.
string

The CosSysConfig class is used for related configurations. In this sample, the main member functions are as follows:
Member functions
Description
Parameter Type
SetUploadCopyPartSize
Set the part size for multipart copy, unit: byte (Byte), default: 20MB.
The setting method is CosSysConfig::SetUploadCopyPartSize(20 * 1024 * 1024).
uint64_t
SetUploadThreadPoolSize
Set the download thread pool size, defaulting to 5.
The setting method is CosSysConfig::SetUploadThreadPoolSize(5).
unsigned

Returning Description

CosResult main member functions are as follows:
Member functions
Description
Return Type
IsSucc
Indicates whether the operation is successful; returns true for success, false for failure.
bool
GetHttpStatus
Obtain the http status code.
int
GetErrorCode
Obtain the error code when the request fails.
string
GetErrorMsg
Obtain the error message when the request fails.
string
GetXCosRequestId
Obtain the request ID.
string
Usage examples for CosResult are as follows. Users may choose to utilize them based on their needs:
void PrintResult(const qcloud_cos::CosResult& result, const qcloud_cos::BaseResp& resp) {
    if (result.IsSucc()) {
        std::cout << "Request Succ." << std::endl;
        std::cout << resp.DebugString() << std::endl;
    } else {
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "HttpStatus=" << result.GetHttpStatus() << std::endl;
        std::cout << "ErrorCode=" << result.GetErrorCode() << std::endl;
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "ResourceAddr=" << result.GetResourceAddr() << std::endl;
        std::cout << "XCosRequestId=" << result.GetXCosRequestId() << std::endl;
        std::cout << "XCosTraceId=" << result.GetXCosTraceId() << std::endl;
    }
}

Simple Copy

Preliminary Preparation: Create CosAPI

Before calling the COS API, you must first create an instance of CosAPI to make subsequent call requests.
qcloud_cos::CosAPI InitCosAPI() {
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";// Region of the bucket, see https://www.tencentcloud.com/document/product/436/62?from_cn_redirect=1
    std::string secret_id = "************************************"; // User's SecretId. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
    std::string secret_key = "************************************"; // User's SecretKey. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
        
    qcloud_cos::CosConfig config(appid, secret_id, secret_key, region);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Preparations: Using Temporary Keys to Create CosAPI

To access COS with a temporary key, you need to create a CosAPI instance using the temporary key.
qcloud_cos::CosAPI InitCosAPI() {
    // You need to have obtained the temporary key results: tmp_secret_id, tmp_secret_key,
    // For generating temporary keys, see https://www.tencentcloud.com/document/product/436/14048?from_cn_redirect=1#cos-sts-sdk
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";
    std::string tmp_secret_id = "************************************";
    std::string tmp_secret_key = "************************************";
    std::string tmp_token = "token";
    
    qcloud_cos::CosConfig config(appid, tmp_secret_id, tmp_secret_key, region);
    config.SetTmpToken(tmp_token);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Use Case:Simple Copy Object

Note:
This Demo demonstrates how to perform simple copy operations using the COS C++ SDK.
supports copying objects up to 5GB in size

Method Prototype

CosResult CosAPI::PutObjectCopy(const PutObjectCopyReq& req, PutObjectCopyResp* resp)

Request Example

void PutObjectCopyDemo(qcloud_cos::CosAPI& cos) {
    std::string object_name = "test_dst.txt";                                        // Target object name for copying
    std::string source = bucket_name + ".cos." + region + ".myqcloud.com/test.txt";  // Source object for copying
    qcloud_cos::PutObjectCopyReq req(bucket_name, object_name);// Target bucket name and object name
    req.SetXCosCopySource(source);
    qcloud_cos::PutObjectCopyResp resp;
    qcloud_cos::CosResult result = cos.PutObjectCopy(req, &resp);


    std::cout << "===================PutObjectCopyResponse====================" << std::endl;
    PrintResult(result, resp);
    std::cout << "============================================================" << std::endl;
}

Parameter Description

Parameter Name
Description
Type
req
Copy file request
PutObjectCopyReq
resp
Copy file response
PutObjectCopyResp
PutObjectCopyReq Member or Function Description:
Member or Function
Description
Parameter Type
bucket_name
Target bucket name, which can be set via the constructor or set method.
The naming format for buckets is BucketName-APPID. For details, see Naming Conventions
string
object_name
Target object key (Key), which can be set via the constructor or set method.
is the unique identifier of the object in the bucket. For example, in the object access domain name examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/doc/picture.jpg, the object key is doc/picture.jpg. For details, see Object Key
string
SetXCosCopySource
Used to set the source object location for copying.
string
PutObjectCopyResp Member Function Description:
Member functions
Description
Return Type
GetVersionId
Get the version number of the Object. If versioning is not enabled for the Bucket, an empty string is returned.
string
GetXCosServerSideEncryption
Obtain the server-side encryption algorithm used
string
GetEtag
Obtain the Etag of the stored object.
string
GetXCosRequestId
Obtain the request ID.
string

Returning Description

CosResult main member functions are as follows:
Member functions
Description
Return Type
IsSucc
Indicates whether the operation is successful; returns true for success, false for failure.
bool
GetHttpStatus
Obtain the http status code.
int
GetErrorCode
The error code can be obtained when the request fails.
string
GetErrorMsg
Obtain the error message when the request fails.
string
GetXCosRequestId
Obtain the request ID.
string
Usage examples for CosResult are as follows. Users may choose to utilize them based on their needs:
void PrintResult(const qcloud_cos::CosResult& result, const qcloud_cos::BaseResp& resp) {
    if (result.IsSucc()) {
        std::cout << "Request Succ." << std::endl;
        std::cout << resp.DebugString() << std::endl;
    } else {
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "HttpStatus=" << result.GetHttpStatus() << std::endl;
        std::cout << "ErrorCode=" << result.GetErrorCode() << std::endl;
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "ResourceAddr=" << result.GetResourceAddr() << std::endl;
        std::cout << "XCosRequestId=" << result.GetXCosRequestId() << std::endl;
        std::cout << "XCosTraceId=" << result.GetXCosTraceId() << std::endl;
    }
}

Move Object

Preliminary Preparation: Create CosAPI

Before calling the COS API, you must first create an instance of CosAPI to make subsequent call requests.
qcloud_cos::CosAPI InitCosAPI() {
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";// Region of the bucket, see https://www.tencentcloud.com/document/product/436/62?from_cn_redirect=1
    std::string secret_id = "************************************"; // User's SecretId. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
    std::string secret_key = "************************************"; // User's SecretKey. It is recommended to use sub-account keys, with authorization following the least privilege principle to mitigate usage risks. For information on how to obtain sub-account keys, see https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1
        
    qcloud_cos::CosConfig config(appid, secret_id, secret_key, region);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Preparations: Using Temporary Keys to Create CosAPI

To access COS with a temporary key, you need to create a CosAPI instance using the temporary key.
qcloud_cos::CosAPI InitCosAPI() {
    // You need to have obtained the temporary key results: tmp_secret_id, tmp_secret_key,
    // For generating temporary keys, see https://www.tencentcloud.com/document/product/436/14048?from_cn_redirect=1#cos-sts-sdk
    uint64_t appid = 12500000000;
    std::string region = "ap-guangzhou";
    std::string tmp_secret_id = "************************************";
    std::string tmp_secret_key = "************************************";
    std::string tmp_token = "token";
    
    qcloud_cos::CosConfig config(appid, tmp_secret_id, tmp_secret_key, region);
    config.SetTmpToken(tmp_token);
    qcloud_cos::CosAPI cos_tmp(config);
    return cos_tmp;
}

Use Case: Moving Objects

Note:
This Demo demonstrates how to use the COS C++ SDK for object relocation.
Moving objects is only supported within the current bucket. For cross-bucket movement, you can achieve this using the Advanced Copy API and Delete Object API.

Method Prototype

CosResult CosAPI::MoveObject(const MoveObjectReq& req)

Request Example

void MoveObjectDemo(qcloud_cos::CosAPI& cos) {
    std::string src_object = "test_src.txt";
    std::string dst_object = "test_dst.txt";
    qcloud_cos::MoveObjectReq req(bucket_name, src_object, dst_object);

    qcloud_cos::CosResult result = cos.MoveObject(req);

    std::cout << "========================MoveObject==========================" << std::endl;
    if (result.IsSucc()) {
        std::cout << "MoveObject Succ." << std::endl;
    } else {
        std::cout << "MoveObject Fail, ErrorMsg: " << result.GetErrorMsg() << std::endl;
    }
    std::cout << "============================================================" << std::endl;
}

Parameter Description

Parameter Name
Description
Type
req
Move Object Request
MoveObjectReq
MoveObjectReq Member or Function Description:
Member or Function
Description
Parameter Type
bucket_name
Target and source bucket names, which can be set via the constructor or set method.
The naming format for buckets is BucketName-APPID. For details, see Naming Conventions
string
src_object
Source object key (Key), which can be set via the constructor or set method.
is the unique identifier of the object in the bucket. For example, in the object access domain name examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/doc/picture.jpg, the object key is doc/picture.jpg. For details, see Object Key
string
dst_object
Target Object Key
string

Returning Description

CosResult main member functions are as follows:
Member functions
Description
Return Type
IsSucc
Indicates whether the operation is successful; returns true for success, false for failure.
bool
GetHttpStatus
Obtain the http status code.
int
GetErrorCode
The error code can be obtained when the request fails.
string
GetErrorMsg
Obtain the error message when the request fails.
string
GetXCosRequestId
Obtain the request ID.
string
Usage examples for CosResult are as follows. Users may choose to utilize them based on their needs:
void PrintResult(const qcloud_cos::CosResult& result, const qcloud_cos::BaseResp& resp) {
    if (result.IsSucc()) {
        std::cout << "Request Succ." << std::endl;
        std::cout << resp.DebugString() << std::endl;
    } else {
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "HttpStatus=" << result.GetHttpStatus() << std::endl;
        std::cout << "ErrorCode=" << result.GetErrorCode() << std::endl;
        std::cout << "ErrorMsg=" << result.GetErrorMsg() << std::endl;
        std::cout << "ResourceAddr=" << result.GetResourceAddr() << std::endl;
        std::cout << "XCosRequestId=" << result.GetXCosRequestId() << std::endl;
        std::cout << "XCosTraceId=" << result.GetXCosTraceId() << std::endl;
    }
}

API Operations

For the API documentation on simple operations, see the PUT Object - Copy document.

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