restoreObject method

Future<RestoreObjectOutput> restoreObject({
  1. required String bucket,
  2. required String key,
  3. ChecksumAlgorithm? checksumAlgorithm,
  4. String? expectedBucketOwner,
  5. RequestPayer? requestPayer,
  6. RestoreRequest? restoreRequest,
  7. String? versionId,
})
Restores an archived copy of an object back into Amazon S3

This functionality is not supported for Amazon S3 on Outposts.

This action performs the following types of requests:

  • restore an archive - Restore an archived object
For more information about the S3 structure in the request body, see the following:
Permissions
To use this operation, you must have permissions to perform the s3:RestoreObject action. The bucket owner has this permission by default and can grant this permission to others. For more information about permissions, see Permissions Related to Bucket Subresource Operations and Managing Access Permissions to Your Amazon S3 Resources in the Amazon S3 User Guide.
Restoring objects
Objects that you archive to the S3 Glacier Flexible Retrieval or S3 Glacier Deep Archive storage class, and S3 Intelligent-Tiering Archive or S3 Intelligent-Tiering Deep Archive tiers, are not accessible in real time. For objects in the S3 Glacier Flexible Retrieval or S3 Glacier Deep Archive storage classes, you must first initiate a restore request, and then wait until a temporary copy of the object is available. If you want a permanent copy of the object, create a copy of it in the Amazon S3 Standard storage class in your S3 bucket. To access an archived object, you must restore the object for the duration (number of days) that you specify. For objects in the Archive Access or Deep Archive Access tiers of S3 Intelligent-Tiering, you must first initiate a restore request, and then wait until the object is moved into the Frequent Access tier.

To restore a specific object version, you can provide a version ID. If you don't provide a version ID, Amazon S3 restores the current version.

When restoring an archived object, you can specify one of the following data access tier options in the Tier element of the request body:

  • Expedited - Expedited retrievals allow you to quickly access your data stored in the S3 Glacier Flexible Retrieval storage class or S3 Intelligent-Tiering Archive tier when occasional urgent requests for restoring archives are required. For all but the largest archived objects (250 MB+), data accessed using Expedited retrievals is typically made available within 1–5 minutes. Provisioned capacity ensures that retrieval capacity for Expedited retrievals is available when you need it. Expedited retrievals and provisioned capacity are not available for objects stored in the S3 Glacier Deep Archive storage class or S3 Intelligent-Tiering Deep Archive tier.
  • Standard - Standard retrievals allow you to access any of your archived objects within several hours. This is the default option for retrieval requests that do not specify the retrieval option. Standard retrievals typically finish within 3–5 hours for objects stored in the S3 Glacier Flexible Retrieval storage class or S3 Intelligent-Tiering Archive tier. They typically finish within 12 hours for objects stored in the S3 Glacier Deep Archive storage class or S3 Intelligent-Tiering Deep Archive tier. Standard retrievals are free for objects stored in S3 Intelligent-Tiering.
  • Bulk - Bulk retrievals free for objects stored in the S3 Glacier Flexible Retrieval and S3 Intelligent-Tiering storage classes, enabling you to retrieve large amounts, even petabytes, of data at no cost. Bulk retrievals typically finish within 5–12 hours for objects stored in the S3 Glacier Flexible Retrieval storage class or S3 Intelligent-Tiering Archive tier. Bulk retrievals are also the lowest-cost retrieval option when restoring objects from S3 Glacier Deep Archive. They typically finish within 48 hours for objects stored in the S3 Glacier Deep Archive storage class or S3 Intelligent-Tiering Deep Archive tier.
For more information about archive retrieval options and provisioned capacity for Expedited data access, see Restoring Archived Objects in the Amazon S3 User Guide.

You can use Amazon S3 restore speed upgrade to change the restore speed to a faster speed while it is in progress. For more information, see Upgrading the speed of an in-progress restore in the Amazon S3 User Guide.

To get the status of object restoration, you can send a HEAD request. Operations return the x-amz-restore header, which provides information about the restoration status, in the response. You can use Amazon S3 event notifications to notify you when a restore is initiated or completed. For more information, see Configuring Amazon S3 Event Notifications in the Amazon S3 User Guide.

After restoring an archived object, you can update the restoration period by reissuing the request with a new period. Amazon S3 updates the restoration period relative to the current time and charges only for the request-there are no data transfer charges. You cannot update the restoration period when Amazon S3 is actively processing your current restore request for the object.

If your bucket has a lifecycle configuration with a rule that includes an expiration action, the object expiration overrides the life span that you specify in a restore request. For example, if you restore an object copy for 10 days, but the object is scheduled to expire in 3 days, Amazon S3 deletes the object in 3 days. For more information about lifecycle configuration, see PutBucketLifecycleConfiguration and Object Lifecycle Management in Amazon S3 User Guide.

Responses
A successful action returns either the 200 OK or 202 Accepted status code.
  • If the object is not previously restored, then Amazon S3 returns 202 Accepted in the response.
  • If the object is previously restored, Amazon S3 returns 200 OK in the response.
  • Special errors:
    • Code: RestoreAlreadyInProgress
    • Cause: Object restore is already in progress.
    • HTTP Status Code: 409 Conflict
    • SOAP Fault Code Prefix: Client
    • Code: GlacierExpeditedRetrievalNotAvailable
    • Cause: expedited retrievals are currently not available. Try again later. (Returned if there is insufficient capacity to process the Expedited request. This error applies only to Expedited retrievals and not to S3 Standard or Bulk retrievals.)
    • HTTP Status Code: 503
    • SOAP Fault Code Prefix: N/A
The following operations are related to RestoreObject:

May throw ObjectAlreadyInActiveTierError.

Parameter bucket : The bucket name containing the object to restore.

Access points - When you use this action with an access point for general purpose buckets, you must provide the alias of the access point in place of the bucket name or specify the access point ARN. When you use this action with an access point for directory buckets, you must provide the access point name in place of the bucket name. When using the access point ARN, 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 action with an access point through the Amazon Web Services 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 S3 User Guide.

S3 on Outposts - When you use this action with 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 you use this action with S3 on Outposts, the destination bucket must be the Outposts access point ARN or the access point alias. For more information about S3 on Outposts, see What is S3 on Outposts? in the Amazon S3 User Guide.

Parameter key : Object key for which the action was initiated.

Parameter checksumAlgorithm : Indicates the algorithm used to create the checksum for the object when you use the SDK. This header will not provide any additional functionality if you don't use the SDK. When you send this header, there must be a corresponding x-amz-checksum or x-amz-trailer header sent. Otherwise, Amazon S3 fails the request with the HTTP status code 400 Bad Request. For more information, see Checking object integrity in the Amazon S3 User Guide.

If you provide an individual checksum, Amazon S3 ignores any provided ChecksumAlgorithm parameter.

Parameter expectedBucketOwner : The account ID of the expected bucket owner. If the account ID that you provide does not match the actual owner of the bucket, the request fails with the HTTP status code 403 Forbidden (access denied).

Parameter versionId : VersionId used to reference a specific version of the object.

Implementation

Future<RestoreObjectOutput> restoreObject({
  required String bucket,
  required String key,
  ChecksumAlgorithm? checksumAlgorithm,
  String? expectedBucketOwner,
  RequestPayer? requestPayer,
  RestoreRequest? restoreRequest,
  String? versionId,
}) async {
  final headers = <String, String>{
    if (checksumAlgorithm != null)
      'x-amz-sdk-checksum-algorithm': checksumAlgorithm.value,
    if (expectedBucketOwner != null)
      'x-amz-expected-bucket-owner': expectedBucketOwner.toString(),
    if (requestPayer != null) 'x-amz-request-payer': requestPayer.value,
  };
  final $query = <String, List<String>>{
    if (versionId != null) 'versionId': [versionId],
  };
  final $result = await _protocol.sendRaw(
    method: 'POST',
    requestUri:
        '/${Uri.encodeComponent(bucket)}/${key.split('/').map(Uri.encodeComponent).join('/')}?restore',
    queryParams: $query,
    headers: headers,
    payload: restoreRequest?.toXml('RestoreRequest'),
    exceptionFnMap: _exceptionFns,
  );
  final $elem = await _s.xmlFromResponse($result);
  return RestoreObjectOutput(
    requestCharged: _s
        .extractHeaderStringValue($result.headers, 'x-amz-request-charged')
        ?.let(RequestCharged.fromString),
    restoreOutputPath: _s.extractHeaderStringValue(
        $result.headers, 'x-amz-restore-output-path'),
  );
}