createMultipartUpload method

Future<CreateMultipartUploadOutput> createMultipartUpload({

required String bucket,
required String key,
ObjectCannedACL? acl,
bool? bucketKeyEnabled,
String? cacheControl,
String? contentDisposition,
String? contentEncoding,
String? contentLanguage,
String? contentType,
String? expectedBucketOwner,
DateTime? expires,
String? grantFullControl,
String? grantRead,
String? grantReadACP,
String? grantWriteACP,
Map<String, String>? metadata,
ObjectLockLegalHoldStatus? objectLockLegalHoldStatus,
ObjectLockMode? objectLockMode,
DateTime? objectLockRetainUntilDate,
RequestPayer? requestPayer,
String? sSECustomerAlgorithm,
Uint8List? sSECustomerKey,
String? sSECustomerKeyMD5,
String? sSEKMSEncryptionContext,
String? sSEKMSKeyId,
ServerSideEncryption? serverSideEncryption,
StorageClass? storageClass,
String? tagging,
String? websiteRedirectLocation,

})

This operation initiates a multipart upload and returns an upload ID. This upload ID is used to associate all of the parts in the specific multipart upload. You specify this upload ID in each of your subsequent upload part requests (see UploadPart). You also include this upload ID in the final request to either complete or abort the multipart upload request.

For more information about multipart uploads, see Multipart Upload Overview.

If you have configured a lifecycle rule to abort incomplete multipart uploads, the upload must complete within the number of days specified in the bucket lifecycle configuration. Otherwise, the incomplete multipart upload becomes eligible for an abort operation and Amazon S3 aborts the multipart upload. For more information, see Aborting Incomplete Multipart Uploads Using a Bucket Lifecycle Policy.

For information about the permissions required to use the multipart upload API, see Multipart Upload API and Permissions.

For request signing, multipart upload is just a series of regular requests. You initiate a multipart upload, send one or more requests to upload parts, and then complete the multipart upload process. You sign each request individually. There is nothing special about signing multipart upload requests. For more information about signing, see Authenticating Requests (AWS Signature Version 4). You can optionally request server-side encryption. For server-side encryption, Amazon S3 encrypts your data as it writes it to disks in its data centers and decrypts it when you access it. You can provide your own encryption key, or use AWS Key Management Service (AWS KMS) customer master keys (CMKs) or Amazon S3-managed encryption keys. If you choose to provide your own encryption key, the request headers you provide in UploadPart and UploadPartCopy requests must match the headers you used in the request to initiate the upload by using CreateMultipartUpload.

To perform a multipart upload with encryption using an AWS KMS CMK, the requester must have permission to the kms:Encrypt, kms:Decrypt, kms:ReEncrypt*, kms:GenerateDataKey*, and kms:DescribeKey actions on the key. These permissions are required because Amazon S3 must decrypt and read data from the encrypted file parts before it completes the multipart upload.

If your AWS Identity and Access Management (IAM) user or role is in the same AWS account as the AWS KMS CMK, then you must have these permissions on the key policy. If your IAM user or role belongs to a different account than the key, then you must have the permissions on both the key policy and your IAM user or role.

For more information, see Protecting Data Using Server-Side Encryption.

Access Permissions

When copying an object, you can optionally specify the accounts or groups that should be granted specific permissions on the new object. There are two ways to grant the permissions using the request headers:

Specify a canned ACL with the x-amz-acl request header. For more information, see Canned ACL.
Specify access permissions explicitly with the x-amz-grant-read, x-amz-grant-read-acp, x-amz-grant-write-acp, and x-amz-grant-full-control headers. These parameters map to the set of permissions that Amazon S3 supports in an ACL. For more information, see Access Control List (ACL) Overview.

You can use either a canned ACL or specify access permissions explicitly. You cannot do both.

Server-Side- Encryption-Specific Request Headers

You can optionally tell Amazon S3 to encrypt data at rest using server-side encryption. Server-side encryption is for data encryption at rest. Amazon S3 encrypts your data as it writes it to disks in its data centers and decrypts it when you access it. The option you use depends on whether you want to use AWS managed encryption keys or provide your own encryption key.

Use encryption keys managed by Amazon S3 or customer master keys (CMKs) stored in AWS Key Management Service (AWS KMS) – If you want AWS to manage the keys used to encrypt data, specify the following headers in the request.
- x-amz-server-side-encryption
- x-amz-server-side-encryption-aws-kms-key-id
- x-amz-server-side-encryption-context
For more information about server-side encryption with CMKs stored in AWS KMS (SSE-KMS), see Protecting Data Using Server-Side Encryption with CMKs stored in AWS KMS.
Use customer-provided encryption keys – If you want to manage your own encryption keys, provide all the following headers in the request.
- x-amz-server-side-encryption-customer-algorithm
- x-amz-server-side-encryption-customer-key
- x-amz-server-side-encryption-customer-key-MD5
For more information about server-side encryption with CMKs stored in AWS KMS (SSE-KMS), see Protecting Data Using Server-Side Encryption with CMKs stored in AWS KMS.

Access-Control-List (ACL)-Specific Request Headers

You also can use the following access control–related headers with this operation. By default, all objects are private. Only the owner has full access control. When adding a new object, you can grant permissions to individual AWS accounts or to predefined groups defined by Amazon S3. These permissions are then added to the access control list (ACL) on the object. For more information, see Using ACLs. With this operation, you can grant access permissions using one of the following two methods:

Specify a canned ACL (x-amz-acl) — Amazon S3 supports a set of predefined ACLs, known as canned ACLs. Each canned ACL has a predefined set of grantees and permissions. For more information, see Canned ACL.
Specify access permissions explicitly — To explicitly grant access permissions to specific AWS accounts or groups, use the following headers. Each header maps to specific permissions that Amazon S3 supports in an ACL. For more information, see Access Control List (ACL) Overview. In the header, you specify a list of grantees who get the specific permission. To grant permissions explicitly, use:
- x-amz-grant-read
- x-amz-grant-write
- x-amz-grant-read-acp
- x-amz-grant-write-acp
- x-amz-grant-full-control
You specify each grantee as a type=value pair, where the type is one of the following:
- id – if the value specified is the canonical user ID of an AWS account
- uri – if you are granting permissions to a predefined group
- emailAddress – if the value specified is the email address of an AWS account
For example, the following x-amz-grant-read header grants the AWS accounts identified by account IDs permissions to read object data and its metadata:
x-amz-grant-read: id="11112222333", id="444455556666"

The following operations are related to CreateMultipartUpload:

Parameter bucket : The name of the bucket to which to initiate the upload

When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation with an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

When using this API with Amazon S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When using this operation using S3 on Outposts through the AWS SDKs, you provide the Outposts bucket ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see Using S3 on Outposts in the Amazon Simple Storage Service Developer Guide.

Parameter key : Object key for which the multipart upload is to be initiated.

Parameter acl : The canned ACL to apply to the object.

This action is not supported by Amazon S3 on Outposts.

Parameter bucketKeyEnabled : Specifies whether Amazon S3 should use an S3 Bucket Key for object encryption with server-side encryption using AWS KMS (SSE-KMS). Setting this header to true causes Amazon S3 to use an S3 Bucket Key for object encryption with SSE-KMS.

Specifying this header with an object operation doesn’t affect bucket-level settings for S3 Bucket Key.

Parameter cacheControl : Specifies caching behavior along the request/reply chain.

Parameter contentDisposition : Specifies presentational information for the object.

Parameter contentEncoding : Specifies what content encodings have been applied to the object and thus what decoding mechanisms must be applied to obtain the media-type referenced by the Content-Type header field.

Parameter contentLanguage : The language the content is in.

Parameter contentType : A standard MIME type describing the format of the object data.

Parameter expectedBucketOwner : The account id of the expected bucket owner. If the bucket is owned by a different account, the request will fail with an HTTP 403 (Access Denied) error.

Parameter expires : The date and time at which the object is no longer cacheable.

Parameter grantFullControl : Gives the grantee READ, READ_ACP, and WRITE_ACP permissions on the object.

This action is not supported by Amazon S3 on Outposts.

Parameter grantRead : Allows grantee to read the object data and its metadata.

This action is not supported by Amazon S3 on Outposts.

Parameter grantReadACP : Allows grantee to read the object ACL.

This action is not supported by Amazon S3 on Outposts.

Parameter grantWriteACP : Allows grantee to write the ACL for the applicable object.

This action is not supported by Amazon S3 on Outposts.

Parameter metadata : A map of metadata to store with the object in S3.

Parameter objectLockLegalHoldStatus : Specifies whether you want to apply a Legal Hold to the uploaded object.

Parameter objectLockMode : Specifies the Object Lock mode that you want to apply to the uploaded object.

Parameter objectLockRetainUntilDate : Specifies the date and time when you want the Object Lock to expire.

Parameter sSECustomerAlgorithm : Specifies the algorithm to use to when encrypting the object (for example, AES256).

Parameter sSECustomerKey : Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data. This value is used to store the object and then it is discarded; Amazon S3 does not store the encryption key. The key must be appropriate for use with the algorithm specified in the x-amz-server-side-encryption-customer-algorithm header.

Parameter sSECustomerKeyMD5 : Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.

Parameter sSEKMSEncryptionContext : Specifies the AWS KMS Encryption Context to use for object encryption. The value of this header is a base64-encoded UTF-8 string holding JSON with the encryption context key-value pairs.

Parameter sSEKMSKeyId : Specifies the ID of the symmetric customer managed AWS KMS CMK to use for object encryption. All GET and PUT requests for an object protected by AWS KMS will fail if not made via SSL or using SigV4. For information about configuring using any of the officially supported AWS SDKs and AWS CLI, see Specifying the Signature Version in Request Authentication in the Amazon S3 Developer Guide.

Parameter serverSideEncryption : The server-side encryption algorithm used when storing this object in Amazon S3 (for example, AES256, aws:kms).

Parameter storageClass : By default, Amazon S3 uses the STANDARD Storage Class to store newly created objects. The STANDARD storage class provides high durability and high availability. Depending on performance needs, you can specify a different Storage Class. Amazon S3 on Outposts only uses the OUTPOSTS Storage Class. For more information, see Storage Classes in the Amazon S3 Service Developer Guide.

Parameter tagging : The tag-set for the object. The tag-set must be encoded as URL Query parameters.

Parameter websiteRedirectLocation : If the bucket is configured as a website, redirects requests for this object to another object in the same bucket or to an external URL. Amazon S3 stores the value of this header in the object metadata.

Implementation

Future<CreateMultipartUploadOutput> createMultipartUpload({
  required String bucket,
  required String key,
  ObjectCannedACL? acl,
  bool? bucketKeyEnabled,
  String? cacheControl,
  String? contentDisposition,
  String? contentEncoding,
  String? contentLanguage,
  String? contentType,
  String? expectedBucketOwner,
  DateTime? expires,
  String? grantFullControl,
  String? grantRead,
  String? grantReadACP,
  String? grantWriteACP,
  Map<String, String>? metadata,
  ObjectLockLegalHoldStatus? objectLockLegalHoldStatus,
  ObjectLockMode? objectLockMode,
  DateTime? objectLockRetainUntilDate,
  RequestPayer? requestPayer,
  String? sSECustomerAlgorithm,
  Uint8List? sSECustomerKey,
  String? sSECustomerKeyMD5,
  String? sSEKMSEncryptionContext,
  String? sSEKMSKeyId,
  ServerSideEncryption? serverSideEncryption,
  StorageClass? storageClass,
  String? tagging,
  String? websiteRedirectLocation,
}) async {
  ArgumentError.checkNotNull(bucket, 'bucket');
  ArgumentError.checkNotNull(key, 'key');
  _s.validateStringLength(
    'key',
    key,
    1,
    1152921504606846976,
    isRequired: true,
  );
  final headers = <String, String>{
    if (acl != null) 'x-amz-acl': acl.toValue(),
    if (bucketKeyEnabled != null)
      'x-amz-server-side-encryption-bucket-key-enabled':
          bucketKeyEnabled.toString(),
    if (cacheControl != null) 'Cache-Control': cacheControl.toString(),
    if (contentDisposition != null)
      'Content-Disposition': contentDisposition.toString(),
    if (contentEncoding != null)
      'Content-Encoding': contentEncoding.toString(),
    if (contentLanguage != null)
      'Content-Language': contentLanguage.toString(),
    if (contentType != null) 'Content-Type': contentType.toString(),
    if (expectedBucketOwner != null)
      'x-amz-expected-bucket-owner': expectedBucketOwner.toString(),
    if (expires != null) 'Expires': _s.rfc822ToJson(expires),
    if (grantFullControl != null)
      'x-amz-grant-full-control': grantFullControl.toString(),
    if (grantRead != null) 'x-amz-grant-read': grantRead.toString(),
    if (grantReadACP != null) 'x-amz-grant-read-acp': grantReadACP.toString(),
    if (grantWriteACP != null)
      'x-amz-grant-write-acp': grantWriteACP.toString(),
    if (metadata != null)
      ...metadata.map((key, value) => MapEntry('x-amz-meta-$key', value)),
    if (objectLockLegalHoldStatus != null)
      'x-amz-object-lock-legal-hold': objectLockLegalHoldStatus.toValue(),
    if (objectLockMode != null)
      'x-amz-object-lock-mode': objectLockMode.toValue(),
    if (objectLockRetainUntilDate != null)
      'x-amz-object-lock-retain-until-date':
          _s.iso8601ToJson(objectLockRetainUntilDate),
    if (requestPayer != null) 'x-amz-request-payer': requestPayer.toValue(),
    if (sSECustomerAlgorithm != null)
      'x-amz-server-side-encryption-customer-algorithm':
          sSECustomerAlgorithm.toString(),
    if (sSECustomerKey != null)
      'x-amz-server-side-encryption-customer-key': sSECustomerKey.toString(),
    if (sSECustomerKeyMD5 != null)
      'x-amz-server-side-encryption-customer-key-MD5':
          sSECustomerKeyMD5.toString(),
    if (sSEKMSEncryptionContext != null)
      'x-amz-server-side-encryption-context':
          sSEKMSEncryptionContext.toString(),
    if (sSEKMSKeyId != null)
      'x-amz-server-side-encryption-aws-kms-key-id': sSEKMSKeyId.toString(),
    if (serverSideEncryption != null)
      'x-amz-server-side-encryption': serverSideEncryption.toValue(),
    if (storageClass != null) 'x-amz-storage-class': storageClass.toValue(),
    if (tagging != null) 'x-amz-tagging': tagging.toString(),
    if (websiteRedirectLocation != null)
      'x-amz-website-redirect-location': websiteRedirectLocation.toString(),
  };
  final $result = await _protocol.sendRaw(
    method: 'POST',
    requestUri:
        '/${Uri.encodeComponent(bucket)}/${key.split('/').map(Uri.encodeComponent).join('/')}?uploads',
    headers: headers,
    exceptionFnMap: _exceptionFns,
  );
  final $elem = await _s.xmlFromResponse($result);
  return CreateMultipartUploadOutput(
    bucket: _s.extractXmlStringValue($elem, 'Bucket'),
    key: _s.extractXmlStringValue($elem, 'Key'),
    uploadId: _s.extractXmlStringValue($elem, 'UploadId'),
    abortDate:
        _s.extractHeaderDateTimeValue($result.headers, 'x-amz-abort-date'),
    abortRuleId:
        _s.extractHeaderStringValue($result.headers, 'x-amz-abort-rule-id'),
    bucketKeyEnabled: _s.extractHeaderBoolValue(
        $result.headers, 'x-amz-server-side-encryption-bucket-key-enabled'),
    requestCharged: _s
        .extractHeaderStringValue($result.headers, 'x-amz-request-charged')
        ?.toRequestCharged(),
    sSECustomerAlgorithm: _s.extractHeaderStringValue(
        $result.headers, 'x-amz-server-side-encryption-customer-algorithm'),
    sSECustomerKeyMD5: _s.extractHeaderStringValue(
        $result.headers, 'x-amz-server-side-encryption-customer-key-MD5'),
    sSEKMSEncryptionContext: _s.extractHeaderStringValue(
        $result.headers, 'x-amz-server-side-encryption-context'),
    sSEKMSKeyId: _s.extractHeaderStringValue(
        $result.headers, 'x-amz-server-side-encryption-aws-kms-key-id'),
    serverSideEncryption: _s
        .extractHeaderStringValue(
            $result.headers, 'x-amz-server-side-encryption')
        ?.toServerSideEncryption(),
  );
}

createMultipartUpload method

Implementation

S3 class