Object Operations

Last updated: 2021-08-16 10:38:09

    Overview

    This document provides an overview of APIs and SDK code samples related to simple operations, multipart operations, and other object operations.

    Simple operations

    API Operation Description
    GET Bucket (List Objects) Querying objects Queries some or all the objects in a bucket.
    PUT Object Uploading an object in whole Uploads an object in whole to a bucket.
    HEAD Object Querying object metadata Queries the metadata of an object.
    GET Object Downloading an object Downloads an object to the local file system.
    PUT Object - Copy Copying an object Copies a file to the destination path.
    DELETE Object Deleting an object Deletes a specified object from a bucket.
    DELETE Multiple Objects Deleting multiple objects Deletes multiple objects from a bucket.
    POST Object restore Restoring an archived object Restores an archived object for access.
    GET Object URL Get the URL of an object Gets the unsigned URL of an object.

    Multipart operations

    API Operation Description
    List Multipart Uploads Querying multipart uploads Queries in-progress multipart uploads.
    Initiate Multipart Upload Initializing a multipart upload Initializes a multipart upload.
    Upload Part Uploading parts Uploads a file in parts.
    Upload Part - Copy Copying an object part Copies a part of an object.
    List Parts Querying uploaded parts Queries the uploaded parts of a multipart upload.
    Complete Multipart Upload Completing a multipart upload Completes the multipart upload of a file.
    Abort Multipart Upload Aborting a multipart upload Aborts a multipart upload and deletes the uploaded parts.

    Simple Operations

    Querying objects

    API description

    This API is used to query some or all the objects in a bucket.

    Method prototype

    CosResult GetBucket(const GetBucketReq& req, GetBucketResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    // The bucket_name is required in the constructor of GetBucketReq.
    qcloud_cos::GetBucketReq req(bucket_name);
    qcloud_cos::GetBucketResp resp;
    qcloud_cos::CosResult result = cos.GetBucket(req, &resp);
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      std::cout << "Name=" << resp.GetName() << std::endl;
      std::cout << "Prefix=" << resp.GetPrefix() << std::endl;
      std::cout << "Marker=" << resp.GetMarker() << std::endl;
      std::cout << "MaxKeys=" << resp.GetMaxKeys() << std::endl;
    } else {
      std::cout << "ErrorInfo=" << result.GetErrorInfo() << 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;
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the GetBucket operation GetBucketReq Yes
    resp Response of the GetBucket operation GetBucketResp Yes

    GetBucketResp provides the following member functions to get the specific content (in XML format) returned by Get Bucket.

    std::vector<Content> GetContents();
    std::string GetName();
    std::string GetPrefix();
    std::string GetMarker();
    uint64_t GetMaxKeys();
    bool IsTruncated();
    std::vector<std::string> GetCommonPrefixes();
    

    Content is defined as follows:

    struct Content {
      std::string m_key; // Key of the object
      std::string m_last_modified; // Time when the object was last modified
      std::string m_etag; // MD5 checksum of the file
      std::string m_size; // File size, in bytes
      std::vector<std::string> m_owner_ids; // Information about the bucket owner
      std::string m_storage_class; // Storage class of the object. Enumerated values: STANDARD, STANDARD_IA
    };
    

    Uploading an object in whole

    API description

    This API is used to upload an object to a specified bucket.

    Method prototype

    /// Upload using a stream.
    CosResult PutObject(const PutObjectByStreamReq& req, PutObjectByStreamResp* resp)
    /// Upload a local file.
    CosResult PutObject(const PutObjectByFileReq& req, PutObjectByFileResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "object_name";
    // Upload in whole (stream)
    {
      std::istringstream iss("put object");
      // istream is required in the request constructor.
      qcloud_cos::PutObjectByStreamReq req(bucket_name, object_name, iss);
      // Call the Set method to set metadata, ACL, etc.
      req.SetXCosStorageClass("STANDARD_IA");
      // Disable MD5 checksum. To enable it, use "req.TurnOnComputeConentMd5()". MD5 checksum is enabled by default.
      req.TurnOffComputeConentMd5();
      qcloud_cos::PutObjectByStreamResp resp;
      qcloud_cos::CosResult result = cos.PutObject(req, &resp);
    
      if (result.IsSucc()) {
          // The call is successful. You can call the resp member functions to get the return content.
          do sth
      } else {
          // The call failed. You can call the result member functions to get the error information.
          std::cout << "ErrorInfo=" << result.GetErrorInfo() << 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;
       }
    }
    // Upload a file in whole
    {
      // The local file path is required in the request constructor.
      qcloud_cos::PutObjectByFileReq req(bucket_name, object_name, "/path/to/local/file");
      // Call the Set method to set metadata, ACL, etc.
      req.SetXCosStorageClass("STANDARD_IA");
      // Disable MD5 checksum. To enable it, use "req.TurnOnComputeConentMd5()". MD5 checksum is enabled by default.
      req.TurnOffComputeConentMd5();
      qcloud_cos::PutObjectByFileResp resp;
      qcloud_cos::CosResult result = cos.PutObject(req, &resp);
          if (result.IsSucc()) {
          // The call is successful. You can call the resp member functions to get the return content.
          do sth
      } else {
          // The call failed. You can call the result member functions to get the error information.
          std::cout << "ErrorInfo=" << result.GetErrorInfo() << 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;
       }
    }
    

    Parameter description

    Parameter Description Type Required
    req Request of the PutObject operation PutObjectByStreamReq/PutObjectByFileReq Yes
    resp Response of the PutObject operation PutObjectByStreamResp/PutObjectByFileResp Yes

    The req parameter contains the following member functions:

    // Cache-Control: cache policy defined in RFC 2616, which is saved as object metadata
    void SetCacheControl(const std::string& str);
    // Content-Disposition: filename defined in RFC 2616, which is stored as object metadata
    void SetContentDisposition(const std::string& str);
    // Content-Encoding: encoding format defined in RFC 2616, which is stored as object metadata
    void SetContentEncoding(const std::string& str);
    // Content-Type: content type (MIME) defined in RFC 2616, which is stored as object metadata
    void SetContentType(const std::string& str);
    // Expect: If `Expect: 100-continue` is used, the requested content will be sent only after confirmation from the server is received.
    void SetExpect(const std::string& str);
    // Expires: expiration time defined in RFC 2616, which is stored as object metadata
    void SetExpires(const std::string& str);
    // Customizable headers, which will be returned as object metadata of up to 2 KB
    void SetXCosMeta(const std::string& key, const std::string& value);
    // x-cos-storage-class: the storage class of an object. Enumerated values: STANDARD, STANDARD_IA, ARCHIVE
    // Default: STANDARD
    void SetXCosStorageClass(const std::string& storage_class);
    // Define the ACL attribute of the object. Valid values: private, public-read
    // Default: private
    void SetXcosAcl(const std::string& str);
    // Grant read permission in the format of x-cos-grant-read: id=" ",id=" ".
    // To authorize a sub-account, use id="qcs::cam::uin/<OwnerUin>:uin/<SubUin>".
    // To authorize the root account, use id="qcs::cam::uin/<OwnerUin>:uin/<OwnerUin>".
    void SetXcosGrantRead(const std::string& str);
    // Grant read-write permission in the format of x-cos-grant-full-control: id=" ",id=" ".
    // To authorize a sub-account, use id="qcs::cam::uin/<OwnerUin>:uin/<SubUin>".
    // To authorize the root account, use id="qcs::cam::uin/<OwnerUin>:uin/<OwnerUin>".
    void SetXcosGrantFullControl(const std::string& str);
    /// Set the algorithm for server-side encryption. Currently, AES-256 is supported.
    void SetXCosServerSideEncryption(const std::string& str);
    

    The resp parameter contains the following member functions:

    /// Get the object’s version number. If versioning is not enabled for the bucket, an empty string will be returned.
    std::string GetVersionId();
    /// Get the algorithm for server-side encryption.
    std::string GetXCosServerSideEncryption();
    

    Querying object metadata

    API description

    This API is used to query the metadata of an object.

    Method prototype

    CosResult HeadObject(const HeadObjectReq& req, HeadObjectResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "object_name";
    qcloud_cos::HeadObjectReq req(bucket_name, object_name);
    qcloud_cos::HeadObjectResp resp;
    qcloud_cos::CosResult result = cos.HeadObject(req, &resp);
    if (result.IsSucc()) {
      // The query is successful. You can call the HeadObjectResp member functions.
    } else {
      // The query failed. You can call the CosResult member functions to get the error information, such as requestID.
    }
    

    Parameter description

    Parameter Description Type Required
    req Request of the HeadObject operation HeadObjectReq Yes
    resp Response of the HeadObject operation HeadObjectResp Yes

    In addition to member functions that read common headers, HeadObjectResp provides the following member functions:

    std::string GetXCosObjectType();
    std::string GetXCosStorageClass();
    // Get the custom metadata. The parameter can be the asterisk (*) in "x-cos-meta-*".
    std::string GetXCosMeta(const std::string& key);
    // Return all custom meta in the form of a map. The key of a map does not contain the "x-cos-meta-" prefix.
    std::map<std::string, std::string> GetXCosMetas();
    // Get the server-side encryption algorithm
    std::string GetXCosServerSideEncryption(); 
    

    Downloading an object

    API description

    This API (Get Object) is used to download an object to the local file system.

    Method prototype

    // Download the object to a local file.
    CosResult GetObject(const GetObjectByFileReq& req, GetObjectByFileResp* resp)
    // Download the object to a stream.
    CosResult GetObject(const GetObjectByStreamReq& req, GetObjectByStreamResp* resp)
    // Download the object to a local file (multi-threaded).
    CosResult GetObject(const MultiGetObjectReq& req, MultiGetObjectResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "object_name";
    std::string local_path = "/tmp/object_name";
    // Download to a local file
    {
      // appid, bucketname, object, and a local path (including filename) are required for the request.
      qcloud_cos::GetObjectByFileReq req(bucket_name, object_name, local_path);
      qcloud_cos::GetObjectByFileResp resp;
      qcloud_cos::CosResult result = cos.GetObject(req, &resp);
      if (result.IsSucc()) {
          // The download is successful. You can call the GetObjectByFileResp member functions.
      } else {
          // You can call the CosResult member functions to get the error information, such as requestID.
      }
    }
    // Download to a stream
    {
      // appid, bucketname, object, and output stream are required for the request.
      std::ostringstream os;
      qcloud_cos::GetObjectByStreamReq req(bucket_name, object_name, os);
      qcloud_cos::GetObjectByStreamResp resp;
      qcloud_cos::CosResult result = cos.GetObject(req, &resp);
      if (result.IsSucc()) {
          // The download is successful. You can call the GetObjectByStreamResp member functions.
      } else {
          // The download failed. You can call the CosResult member functions to get the error information, such as requestID.
      }
    }
    // Multi-threaded download to local
    {
      // appid, bucketname, object, and local path (including the filename) are required for the request
      qcloud_cos::MultiGetObjectReq req(bucket_name, object_name, local_path);
      qcloud_cos::MultiGetObjectResp resp;
      qcloud_cos::CosResult result = cos.GetObject(req, &resp);
      if (result.IsSucc()) {
          // The download is successful. You can call the MultiGetObjectResp member functions.
      } else {
          // The download failed. You can call the CosResult member functions to get the error information, such as requestID.
      }
    }
    

    Parameter description

    Parameter Description Type Required
    req Request of the GetObject operation GetObjectByFileReq/GetObjectByStreamReq/MultiGetObjectReq Yes
    resp Response of the GetObject operation GetObjectByFileResp/GetObjectByStreamResp/MultiGetObjectResp Yes

    The member functions are as follows:

    // Set the Content-Type parameter in the response header.
    void SetResponseContentType(const std::string& str);
    // Set the Content-Language parameter in the response header.
    void SetResponseContentLang(const std::string& str);
    // Set the Content-Expires parameter in the response header.
    void SetResponseExpires(const std::string& str);
    // Set the Cache-Control parameter in the response header.
    void SetResponseCacheControl(const std::string& str);
    // Set the Content-Disposition parameter in the response header.
    void SetResponseContentDisposition(const std::string& str);
    // Set the Content-Encoding parameter in the response header.
    void SetResponseContentEncoding(const std::string& str);
    

    In addition to member functions that read common headers, GetObjectResp provides the following member functions:

    // Get the time an object was last modified, a date in string format, such as "Wed, 28 Oct 2014 20:30:00 GMT"
    std::string GetLastModified();
    // Obtain the object type, which indicates whether the object is appendable. Enumerated values: normal, appendable
    std::string GetXCosObjectType();
    // Obtain the storage class of the object. Enumerated values: STANDARD, STANDARD_IA
    std::string GetXCosStorageClass();
    // Return all custom meta in the form of a map. The key of a map does not contain the "x-cos-meta-" prefix.
    std::map<std::string, std::string> GetXCosMetas();
    // Get the custom metadata. The parameter can be the asterisk (*) in "x-cos-meta-*".
    std::string GetXCosMeta(const std::string& key);
    // Get the server-side encryption algorithm.
    std::string GetXCosServerSideEncryption(); 
    

    Copying an object

    This API (PUT Object - Copy) is used to copy a file to the destination path.

    Method prototype

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

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "sevenyou";
    qcloud_cos::PutObjectCopyReq req(bucket_name, object_name);                                                                                                                       
    req.SetXCosCopySource("sevenyousouthtest-12345656.cn-south.myqcloud.com/sevenyou_source_obj");
    qcloud_cos::PutObjectCopyResp resp;
    qcloud_cos::CosResult result = cos.PutObjectCopy(req, &resp);
    

    Parameter description

    Parameter Description Type Required
    req Request of the PutObjectCopy operation PutObjectCopyReq Yes
    resp Response of the PutObjectCopy operation PutObjectCopyResp Yes

    PutObjectCopyReq contains the following member functions:

    // URL path of the source file. A previous version can be specified by using the `versionid` subresource.
    void SetXCosCopySource(const std::string& str);
    // Whether to copy the metadata. Enumerated values: Copy (default), Replaced
    // If this field is set to "Copy", the user-defined metadata in the header will be ignored and the metadata will be copied directly.
    // If this field is set to "Replaced", the metadata will be modified based on the header information.
    // If the destination path and the source path are the same (that is, the user attempts to modify the metadata), set this field to "Replaced".
    void SetXCosMetadataDirective(const std::string& str);
    // If the object has been modified after the specified time, the operation is performed; otherwise, error code 412 is returned.
    // It can be used together with "x-cos-copy-source-If-None-Match". Using it together with other conditions can cause a conflict.
    void SetXCosCopySourceIfModifiedSince(const std::string& str);
    // If the object has not been modified after the specified time, the operation is performed; otherwise, error code 412 is returned.
    // It can be used together with "x-cos-copy-source-If-Match". Using it together with other conditions can cause a conflict.
    void SetXCosCopySourceIfUnmodifiedSince(const std::string& str);
    // If the Etag of the object is the same as the specified one, the operation is performed; otherwise, error code 412 is returned.
    // It can be used together with "x-cos-copy-source-If-Unmodified-Since". Using it together with other conditions can cause a conflict.
    void SetXCosCopySourceIfMatch(const std::string& str);
    // If the Etag of the object is different from the specified one, the operation is performed; otherwise, error code 412 is returned.
    // It can be used together with "x-cos-copy-source-If-Modified-Since". Using it together with other conditions can cause a conflict.
    void SetXCosCopySourceIfNoneMatch(const std::string& str);
    // x-cos-storage-class: the storage class of an object. Enumerated values: STANDARD, STANDARD_IA
    // Default: STANDARD
    void SetXCosStorageClass(const std::string& storage_class);
    // Define the ACL attribute of the object. Valid values: private, public-read
    // Default: private
    void SetXCosAcl(const std::string& str);
    // Grant read permission in the format of id="[OwnerUin]".  
    void SetXCosGrantRead(const std::string& str);
    // Grant full permission in the format of id="[OwnerUin]".
    void SetXCosGrantFullControl(const std::string& str);
    // Customizable headers, which will be returned as object metadata of up to 2 KB
    void SetXCosMeta(const std::string& key, const std::string& value);
    // Set the algorithm for server-side encryption. Currently, AES-256 is supported.
    void SetXCosServerSideEncryption(const std::string& str);
    

    PutObjectCopyResp contains the following member functions:

    // Return the MD5 checksum of the file. The value of ETag can be used to check whether the object content has changed.
    std::string GetEtag();
    // Return the time the file was last modified, in GMT.
    std::string GetLastModified();
    // Return the version ID.
    std::string GetVersionId();
    /// Return the algorithm for server-side encryption.
    std::string GetXCosServerSideEncryption();
    

    Deleting an object

    API description

    This API is used to delete a specified object from a bucket.

    Method prototype

    CosResult DeleteObject(const DeleteObjectReq& req, DeleteObjectResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "test_object";
    qcloud_cos::DeleteObjectReq req(bucket_name, object_name);
    qcloud_cos::DeleteObjectResp resp;
    qcloud_cos::CosResult result = cos.DeleteObject(req, &resp);
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the DeleteObject operation DeleteObjectReq Yes
    resp Response of the DeleteObject operation DeletObjectResp Yes

    Deleting multiple objects

    API description

    This API is used to delete multiple objects from a bucket.

    Method prototype

    CosResult DeleteObjects(const DeleteObjectsReq& req, DeleteObjectsResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::vector<std::string> objects;
    std::vector<ObjectVersionPair> to_be_deleted;
    objects.push_back("batch_delete_test_00");
    objects.push_back("batch_delete_test_01");
    objects.push_back("batch_delete_test_02");
    objects.push_back("batch_delete_test_03");
    for (size_t idx = 0; idx < objects.size(); ++idx) {
      ObjectVersionPair pair;
      pair.m_object_name = objects[idx];
      to_be_deleted.push_back(pair);
    }
    qcloud_cos::DeleteObjectsReq req(bucket_name, to_be_deleted);  
    qcloud_cos::DeleteObjectsResp resp;                 
    qcloud_cos::CosResult result = cos.DeleteObjects(req, &resp);
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the DeleteObjects operation DeleteObjectsReq Yes
    resp Response of the DeleteObjects operation DeletObjectsResp Yes

    DeleteObjectsReq contains the following member functions:

    // Add an object and specify the version.
    void AddObjectVersion(const std::string& object, const std::string& version)
    // Add an object with no versioning information.
    void AddObject(const std::string& object)
    

    DeleteObjectsResp contains the following member functions:

    // Get the information of successfully deleted objects.
    std::vector<DeletedInfo> GetDeletedInfos() const
    // Get the information of objects that failed to be deleted.
    std::vector<ErrorInfo> GetErrorinfos() const
    

    The structures of DeletedInfo and ErrorInfo are as follows:

    struct DeletedInfo{
      std::string m_key; // object key
    }
    struct ErrorInfo{
      std::string m_key; // object key
      std::string m_code; // error code
      std::string m_message; // error message
    }
    

    Restoring an archived object

    API description

    This API is used to restore an archived object for access.

    Method prototype

    CosResult PostObjectRestore(const PostObjectRestoreReq& req, PostObjectRestoreResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "sevenyou";
    {   
      qcloud_cos::PostObjectRestoreReq req(bucket_name, object_name);
      req.SetExiryDays(30);
      req.SetTier("Standard");
      qcloud_cos::PostObjectRestoreResp resp;
      qcloud_cos::CosResult result = cos.PostObjectRestore(req, &resp);
      // The call is successful. You can call the resp member functions to get the return content.
      if (result.IsSucc()) {
          // ...
      } else {
          // You can call the CosResult member functions to get the error information, such as requestID.
      } 
    }   
    

    Parameter description

    Parameter Description Type Required
    req Request of the PostObjectRestore operation PostObjectRestoreReq Yes
    resp Response of the PostObjectRestore operation PostObjectRestoreResp Yes

    PostObjectRestoreReq contains the following member functions:

    // Set the expiration time of the temporary copy.
    void SetExiryDays(uint64_t days);
    // Enumerated values: Expedited, Standard (default), Bulk
    void SetTier(const std::string& tier);
    

    Getting an object’s URL

    API description

    This API is used to get the unsigned URL of an object.

    Method prototype

    std::string GetObjectUrl(const std::string& bucket, const std::string& object, bool https = true, const std::string& region = "");
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "sevenyou";
    //Get the HTTPS URL of the object. The region is the one configured in config.json.
    cos.GetObjectUrl(bucket_name, object_name);
    //Get the HTTP URL of the object. The region is the one configured in config.json.
    cos.GetObjectUrl(bucket_name, object_name, false);
    //Get the HTTPS URL of the object. The region is ap-shanghai.
    cos.GetObjectUrl(bucket_name, object_name, true, "ap-shanghai");  
    

    Parameter description

    Parameter Description Type Required
    bucket Bucket name String Yes
    object Object name String Yes
    https Whether to use HTTPS Bool No
    region Region String No

    Multipart Operations

    Multipart operations include:

    • Uploading an object in parts: initializing a multipart upload, uploading parts, and completing a multipart upload
    • Deleting uploaded parts

    Querying multipart uploads

    API description

    This API (List Multipart Uploads) is used to query in-progress multipart uploads in a specified bucket.

    Method prototype

    CosResult CosAPI::ListMultipartUpload(const ListMultipartUploadReq& request, ListMultipartUploadResp* response)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "test_object";
    qcloud_cos::ListMultipartUploadReq req(bucket_name, object_name);
    qcloud_cos::ListMultipartUploadResp resp;
    qcloud_cos::CosResult result = cos.ListMultipartUpload(req, &resp);
    for (std::vector<qcloud_cos::Upload>::const_iterator itr = rst.begin(); itr != rst.end(); ++itr) {
      const qcloud_cos::Upload& upload = *itr;
      std::cout << "key = " << upload.m_key << ", uploadid= " << upload.m_uploadid << ", storagen class = " << upload.m_storage_class << ", m_initiated= " << upload.m_initiated << std::endl;
    }   
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the ListMultipartUpload operation ListMultipartUploadReq Yes
    resp Response of the ListMultipartUpload operation ListMultipartUploadResp Yes

    ListMultipartUploadReq contains the following member functions:

    // Specify the prefix that the returned object keys must have. Note that when you query by prefix, the returned keys will contain the prefix.
    void SetPrefix(const std::string& prefix);
    // Set the delimiter. Objects with identical strings between the specified prefix and the first occurrence of the delimiter are grouped together and defined as common prefixes. If there is no prefix, the string between the start of the path and the first delimiter is compared.
    void SetDelimiter(const std::string& delimiter);
    // Specify the encoding format for the returned value. Valid value: url
    void SetEncodingType(const std::string& encoding_type);
    // This field is used together with "upload-id-marker". If "upload-id-marker" is not specified, multipart uploads whose "ObjectName" is lexicographically greater than "key-marker" will be listed. If "upload-id-marker" is specified, multipart uploads whose "ObjectName" is lexicographically greater than "key-marker" will be listed, and multipart uploads whose "ObjectName" is lexicographically equal to "key-marker" with "UploadID" greater than "upload-id-marker" will be listed.
    void SetKeyMarker(const std::string& marker);
    // Set the maximum number of parts to return. Value range: 1-1000 (default)
    void SetMaxUploads(const std::string& max_uploads);
    // This field is used together with "key-marker". If "key-marker" is not specified, "upload-id-marker" will be ignored. If "key-marker" is specified, multipart uploads whose "ObjectName" is lexicographically greater than "key-marker" will be listed, and multipart uploads whose "ObjectName" is lexicographically equal to "key-marker" with "UploadID" greater than "upload-id-marker" will be listed.
    void SetUploadIdMarker(const std::string& upload_id_marker);
    

    ListMultipartUploadResp contains the following member functions:

    // Get the metadata of an object in a bucket.
    std::vector<Upload> GetUpload();
    // Bucket name
    std::string GetName();
    // Encoding format
    std::string GetEncodingType() const// By default, entries are listed in UTF-8 binary order. The list starts after the marker.
    std::string GetMarker() const// The entry list starts after UploadId.
    std::string GetUploadIdMarker() const// If the returned list is truncated, "NextKeyMarker" represents the key after which the next returned list begins.
    std::string GetNextKeyMarker() const// If the returned list is truncated, "UploadId" represents the upload ID after which the next returned list begins.
    std::string GetNextUploadIdMarker() const// The maximum number of returned parts allowed. Value range: 1-1000
    std::string GetMaxUploads () const// Whether the returned list is truncated. The parameter is a boolean (true or false).
    bool IsTruncated();
    // The prefix of returned objects
    std::string GetPrefix() const// The delimiter 
    std::string GetDelimiter() const// Objects with identical paths between the specified prefix and the delimiter are grouped together and defined as common prefixes.
    std::vector<std::string> GetCommonPrefixes() const
    

    Initializing a multipart upload

    API description

    This API (Initiate Multipart Upload) is used to initialize a multipart upload and obtain its uploadId.

    Method prototype

    CosResult InitMultiUpload(const InitMultiUploadReq& req, InitMultiUploadResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "object_name";
    qcloud_cos::InitMultiUploadReq req(bucket_name, object_name);
    qcloud_cos::InitMultiUploadResp resp;
    qcloud_cos::CosResult result = cos.InitMultiUpload(req, &resp);
    std::string upload_id = "";
    if (result.IsSucc()) {
      upload_id = resp.GetUploadId();
    }
    

    Parameter description

    Parameter Description Type Required
    req Request of the InitMultiUpload operation InitMultiUploadReq Yes
    resp Response of the InitMultiUpload operation InitMultiUploadResp Yes

    The InitMultiUploadReq member functions are as follows:

    // Cache-Control: cache policy defined in RFC 2616, which is saved as object metadata
    void SetCacheControl(const std::string& str);
    // Content-Disposition: filename defined in RFC 2616, which is stored as object metadata
    void SetContentDisposition(const std::string& str);
    // Content-Encoding: encoding format defined in RFC 2616, which is stored as object metadata
    void SetContentEncoding(const std::string& str);
    // Content-Type: content type (MIME) defined in RFC 2616, which is stored as object metadata
    void SetContentType(const std::string& str);
    // Expires: expiration time defined in RFC 2616, which is stored as object metadata
    void SetExpires(const std::string& str);
    // Customizable headers, which will be returned as object metadata of up to 2 KB
    void SetXCosMeta(const std::string& key, const std::string& value);
    // x-cos-storage-class: the storage class of an object. Enumerated values: STANDARD, STANDARD_IA, ARCHIVE
    // Default: STANDARD
    void SetXCosStorageClass(const std::string& storage_class);
    // Define the ACL attribute of the object. Valid values: private, public-read
    // Default: private
    void SetXcosAcl(const std::string& str);
    // Grant read permission in the format of x-cos-grant-read: id=" ",id=" ".
    // To authorize a sub-account, use id="qcs::cam::uin/<OwnerUin>:uin/<SubUin>".
    // To authorize the root account, use id="qcs::cam::uin/<OwnerUin>:uin/<OwnerUin>".
    void SetXcosGrantRead(const std::string& str);
    // Grant read-write permission in the format of x-cos-grant-full-control: id=" ",id=" ".
    // To authorize a sub-account, use id="qcs::cam::uin/<OwnerUin>:uin/<SubUin>".
    // To authorize the root account, use id="qcs::cam::uin/<OwnerUin>:uin/<OwnerUin>".
    void SetXcosGrantFullControl(const std::string& str);
    // Set the algorithm for server-side encryption. Currently, AES-256 is supported.
    void SetXCosServerSideEncryption(const std::string& str);
    

    After the request is successfully executed, the returned response will include bucket, key, and uploadId, which represent the destination bucket of the multipart upload, the object name, and the upload ID (required for the subsequent multipart upload) respectively.

    The InitMultiUploadResp member functions are as follows:

    std::string GetBucket();
    std::string GetKey();
    std::string GetUploadId();
    // Algorithm for server-side encryption
    std::string GetXCosServerSideEncryption();
    

    Uploading parts

    This API (Upload Part) is used to upload parts.

    Method prototype

    CosResult UploadPartData(const UploadPartDataReq& request, UploadPartDataResp* response)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "test_object";
    // Upload the first part.
    {
      std::fstream is("demo_5M.part1");
      qcloud_cos::UploadPartDataReq req(bucket_name, object_name, upload_id, is);
      req.SetPartNumber(1);
      // Disable MD5 checksum. To enable it, use "req.TurnOnComputeConentMd5()". MD5 checksum is enabled by default.
      req.TurnOffComputeConentMd5();
      qcloud_cos::UploadPartDataResp resp;
      qcloud_cos::CosResult result = cos.UploadPartData(req, &resp);
       // After the upload is successful, you should record the part number and the returned ETag
      if (result.IsSucc()) {
          etags.push_back(resp.GetEtag());
          part_numbers.push_back(1);
      }
      is.close();
    }
    // Upload the second part.
    {
      std::fstream is("demo_5M.part2");
      qcloud_cos::UploadPartDataReq req(bucket_name, object_name,
                                        upload_id, is);
      req.SetPartNumber(2);
      qcloud_cos::UploadPartDataResp resp;
      qcloud_cos::CosResult result = cos.UploadPartData(req, &resp);
       // After the upload is successful, you should record the part number and the returned ETag 
      if (result.IsSucc()) {
          etags.push_back(resp.GetEtag());
          part_numbers.push_back(2);
      }
      is.close();
    }
    

    Parameter description

    Parameter Description Type Required
    req Request of the UploadPartData operation UploadPartDataReq Yes
    resp Response of the UploadPartData operation UploadPartDataResp Yes

    When you construct UploadPartDataReq, you need to specify the APPID, bucket, object, UploadId, which you can get from the response of initialization, as well as the data stream to upload (which you should close after the call is completed).

    UploadPartDataReq(const std::string& bucket_name,
                      const std::string& object_name, const std::string& upload_id,
                      std::istream& in_stream);
    

    In addition, the part number, which is required to complete the multipart upload, needs to be set in the request.

    void SetPartNumber(uint64_t part_number);
    

    UploadPartDataResp contains the following member function:

    /// Algorithm for server-side encryption
    std::string GetXCosServerSideEncryption();
    

    Copying an object part

    This API is used to copy a part of an object.

    Method prototype

    CosResult UploadPartCopyData(const UploadPartCopyDataReq& request,UploadPartCopyDataResp* response)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "test_object";
    std::string upload_id;
    std::vector<uint64_t> numbers;
    std::vector<std::string> etags;
    std::string etag1 = "", etag2 = "";
    InitMultiUpload(cos, bucket_name, object_name, &upload_id);
    // First part
    qcloud_cos::UploadPartCopyDataReq req(bucket_name, object_name, upload_id, 1);
    req.SetXCosCopySource("sevenyousouth-1251668577.cos.ap-guangzhou.myqcloud.com/seven_10G.tmp");
    req.SetXCosCopySourceRange("bytes=0-1048576000");
    qcloud_cos::UploadPartCopyDataResp resp;
    qcloud_cos::CosResult result = cos.UploadPartCopyData(req, &resp);
    if(result.IsSucc()) {
      etag1 = resp.GetEtag();
    }
    numbers.push_back(1);
    etags.push_back(etag1);
    // Second part
    qcloud_cos::UploadPartCopyDataReq req2(bucket_name, object_name, upload_id, 2);                                                       
    req2.SetXCosCopySource("sevenyoutest-7319456.cos.cn-north.myqcloud.com/sevenyou_2G_part");
    req2.SetXCosCopySourceRange("bytes=1048576000-2097152000");
    qcloud_cos::UploadPartCopyDataResp resp2;
    qcloud_cos::CosResult result = cos.UploadPartCopyData(req2, &resp2);
    if(result.IsSucc()) {
      etag2 = resp2.GetEtag();
    }
    numbers.push_back(2);
    etags.push_back(etag2);
    CompleteMultiUpload(cos, bucket_name, object_name, upload_id, etags, numbers);
    

    Parameter description

    Parameter Description Type Required
    req Request of the UploadPartCopyData operation UploadPartCopyDataReq Yes
    resp Response of the UploadPartCopyData operation UploadPartCopyDataResp Yes
    /// Set the ID of the multipart copy.
    void SetUploadId(const std::string& upload_id)
    /// Set the part number.
    void SetPartNumber(uint64_t part_number)
    /// Set the source file URL for the multipart copy. A previous version can be specified using the versionid sub-resource.
    void SetXCosCopySource(const std::string& src)
    /// Set the byte range of the source file to copy in the format of bytes=first-last.
    void SetXCosCopySourceRange(const std::string& range)
    /// If the object has been modified after the specified time, the operation is performed; otherwise, error code 412 is returned
    void SetXCosCopySourceIfModifiedSince(const std::string& date)
    /// If the object has not been modified after the specified time, the operation is performed; otherwise, error code 412 is returned
    void SetXCosCopySourceIfUnmodifiedSince(const std::string& date)
    /// If the Etag of the object is the same as the specified one, the operation is performed; otherwise, error code 412 is returned 
    void SetXCosCopySourceIfMatch(const std::string& etag)
    /// If the Etag of the object is different from the specified one, the operation is performed; otherwise, error code 412 is returned
    void SetXCosCopySourceIfNoneMatch(const std::string& etag)
    
    /// Get the MD5 checksum of the returned file.
    std::string GetEtag() const
    /// Get the time the file was last modified, in GMT.
    std::string GetLastModified() const
    /// Get the algorithm for server-side encryption.
    std::string GetXCosServerSideEncryption() const
    

    Querying uploaded parts

    API description

    This API is used to query the uploaded parts of a specified multipart upload.

    Method prototype

    CosResult ListParts(const ListPartsReq& req, ListPartsResp* resp)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "test_object";
    // uploadId is obtained by calling InitMultiUpload.
    qcloud_cos::ListPartsReq req(bucket_name, object_name, upload_id);
    req.SetMaxParts(1);                                                                                                                                                               
    req.SetPartNumberMarker("1");
    qcloud_cos::ListPartsResp resp;
    qcloud_cos::CosResult result = cos.ListParts(req, &resp);
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the ListParts operation ListPartsReq Yes
    resp Response of the ListParts operation ListPartsResp Yes

    ListPartsReq contains the following member functions:

    // Constructor: bucket name, object name, and multipart upload ID
    ListPartsReq(const std::string& bucket_name,                                                                                                                                      
               const std::string& object_name,
               const std::string& upload_id); 
    // \brief The encoding format of the returned value
    void SetEncodingType(const std::string& encoding_type);
    // \brief Maximum number of entries returned at a time. Default: 1000
    void SetMaxParts(uint64_t max_parts);
    // \brief By default, entries are listed in UTF-8 binary order. The list starts after the marker.
    void SetPartNumberMarker(const std::string& part_number_marker);
    

    ListPartsResp contains the following member functions:

    // Destination bucket for the multipart upload
    std::string GetBucket();
    // Encoding format for the returned value
    std::string GetEncodingType();
    // Object name
    std::string GetKey();
    // ID of the multipart upload
    std::string GetUploadId();
    // The upload initiator
    Initiator GetInitiator();
    // Part owner
    Owner GetOwner();
    // By default, entries are listed in UTF-8 binary order. The list starts after the marker.
    uint64_t GetPartNumberMarker();
    // Get the information of each part.
    std::vector<Part> GetParts();
    // If the returned list is truncated, "NextMarker" represents the object after which the next returned list begins.
    uint64_t GetNextPartNumberMarker();
    // Storage class of the parts. Enumerated values: Standard, Standard_IA, Archive
    std::string GetStorageClass();
    // Maximum number of entries that can be returned at a time
    uint64_t GetMaxParts();
    // Whether the returned list is truncated. It is a boolean (TRUE or FALSE).
    bool IsTruncated();
    

    Initiator, Owner, and Part are defined as follows:

    struct Initiator {
      std::string m_id; // Initiator’s unique ID
      std::string m_display_name; // Initiator name
    };
    struct Owner {
      std::string m_id; // Owner’s unique ID
      std::string m_display_name; // Owner name
    };
    struct Part {
      uint64_t m_part_num; // Part number
      uint64_t m_size; // Part size, in bytes
      std::string m_etag; // MD5 checksum of the part
      std::string m_last_modified; // Time the part was last modified
    };
    

    Completing a multipart upload

    API description

    This API is used to complete the multipart upload of a file.

    Method prototype

    CosResult CompleteMultiUpload(const CompleteMultiUploadReq& request, CompleteMultiUploadResp* response)
    

    Sample request

    qcloud_cos::CompleteMultiUploadReq req(bucket_name, object_name, upload_id);
    qcloud_cos::CompleteMultiUploadResp resp;
    req.SetEtags(etags);
    req.SetPartNumbers(part_numbers);
    qcloud_cos::CosResult result = cos.CompleteMultiUpload(req, &resp);
    

    Parameter description

    Parameter Description Type Required
    req Request of the CompleteMultiUpload operation CompleteMultiUploadReq Yes
    resp Response of the CompleteMultiUpload operation CompleteMultiUploadResp Yes

    When constructing CompleteMultiUploadReq, you need to specify APPID, bucket, object, and UploadId, which can be obtained from the response of initialization.

    CompleteMultiUploadReq(const std::string& bucket_name,
                         const std::string& object_name, const std::string& upload_id)
    

    In addition, the numbers and ETag values of all the uploaded parts are required for the request.

    // When calling the following methods, make sure that the part numbers and ETag are listed in the same order.
    void SetPartNumbers(const std::vector<uint64_t>& part_numbers);
    void SetEtags(const std::vector<std::string>& etags) ;
    // Add a part number and ETag.
    void AddPartEtagPair(uint64_t part_number, const std::string& etag);
    // Set the algorithm for server-side encryption. Currently, AES-256 is supported.
    void SetXCosServerSideEncryption(const std::string& str);
    

    The response of CompleteMultiUploadResp includes Location, Bucket, Key, and ETag, which represent the public network access domain name of the created object, the destination bucket for the multipart upload, the name of the object, and the MD5 checksum of the merged file respectively. You can call the following member functions to access the response.

    std::string GetLocation();
    std::string GetKey();
    std::string GetBucket();
    std::string GetEtag();
    // Algorithm for server-side encryption
    std::string GetXCosServerSideEncryption();
    

    Aborting a multipart upload

    API description

    This API is used to abort a multipart upload and delete the uploaded parts.

    Method prototype

    CosResult AbortMultiUpload(const AbortMultiUploadReq& request, AbortMultiUploadResp* response)
    

    Sample request

    qcloud_cos::AbortMultiUploadReq req(bucket_name, object_name, upload_id);
    qcloud_cos::AbortMultiUploadResp resp;
    qcloud_cos::CosResult result = cos.AbortMultiUpload(req, &resp);
    

    Parameter description

    Parameter Description Type Required
    req Request of the AbortMultiUpload operation AbortMultiUploadReq Yes
    resp Response of the AbortMultiUpload operation AbortMultiUploadResp Yes

    When constructing AbortMultiUploadReq, you need to specify Bucket, Object, and Upload_id.

    AbortMultiUploadReq(const std::string& bucket_name,
                      const std::string& object_name, const std::string& upload_id);
    

    No specific methods provided. You can call the BaseResp member functions to get the common header.

    Advanced APIs (Recommended)

    Composite upload

    API description

    This API is used to upload multiple parts concurrently using the multipart upload APIs.

    Method prototype

    CosResult MultiUploadObject(const MultiUploadObjectReq& request, MultiUploadObjectResp* response)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "exampleobject";
    std::string local_file = "./test"
    qcloud_cos::MultiUploadObjectReq req(bucket_name, object_name, local_file);
    // To keep the chunks alive inside the completion API, we recommend setting a longer timeout period.
    req.SetRecvTimeoutInms(1000 * 60);
    qcloud_cos::MultiUploadObjectResp resp;
    qcloud_cos::CosResult result = cos.MultiUploadObject(req, &resp);
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the MultiUploadObject operation MultiUploadObjectReq Yes
    resp Response of the MultiUploadObject operation MultiUploadObjectResp Yes

    MultiUploadObjectReq contains the following member functions:

    // Set the part size. If it is set to less than 1 MB, 1 MB will be used. If it is set to greater than 5 GB, 5 GB will be used.
    void SetPartSize(uint64_t bytes)
    // Customizable headers, which will be returned as object metadata of up to 2 KB 
    void SetXCosMeta(const std::string& key, const std::string& value)
    // Set the algorithm for server-side encryption. Currently, AES-256 is supported.
    void SetXCosServerSideEncryption(const std::string& str)
    // Set the internal thread pool size.
    void SetThreadPoolSize(int size)
    

    MultiUploadObjectResp contains the following member functions:

    std::string GetRespTag()
    /// Algorithm for server-side encryption 
    std::string GetXCosServerSideEncryption() const
    

    Composite download

    API description

    This API is used to download multiple byte ranges concurrently.

    Method prototype

    CosResult GetObject(const MultiGetObjectReq& request, 
    MultiGetObjectResp* response)
    

    Sample request

    qcloud_cos::CosConfig config("./config.json");
    qcloud_cos::CosAPI cos(config);
    std::string bucket_name = "examplebucket-1250000000";
    std::string object_name = "exampleobject";
    std::string file_path = "./test";
    qcloud_cos::MultiGetObjectReq req(bucket_name, object_name, file_path);  
    qcloud_cos::MultiGetObjectResp resp;                                    
    qcloud_cos::CosResult result = cos.GetObject(req, &resp); 
    // The call is successful. You can call the resp member functions to get the return content.
    if (result.IsSucc()) {
      // ...
    } else {
      // You can call the CosResult member functions to get the error information, such as requestID.
    } 
    

    Parameter description

    Parameter Description Type Required
    req Request of the MultiGetObject operation MultiGetObjectReq Yes
    resp Response of the MultiGetObject operation MultiGetObjectResp Yes

    MultiGetObjectReq contains the following member functions:

    // Set the part size.
    void SetSliceSize(uint64_t bytes)
    // Set the thread pool size.
    void SetThreadPoolSize(int size)
    

    MultiGetObjectResp contains the following member functions:

    /// Algorithm for server-side encryption
    std::string GetXCosServerSideEncryption() const