(Swift 3,4,5...) S3 Complete a Multipart Upload

This operation completes a multipart upload by assembling previously uploaded parts.

Processing of a Complete Multipart Upload request could take several minutes to complete. After Amazon S3 begins processing the request, it sends an HTTP response header that specifies a 200 OK response. While processing is in progress, Amazon S3 periodically sends whitespace characters to keep the connection from timing out. Because a request could fail after the initial 200 OK response has been sent, it is important that you check the response body to determine whether the request succeeded.

This example sends a POST request to complete a multipart upload, which looks like this:

POST /ObjectName?uploadId=UploadId HTTP/1.1
Host: BucketName.s3.amazonaws.com
Date: Date
Content-Length: Size
Authorization: authorization string

<CompleteMultipartUpload>
  <Part>
    <PartNumber>PartNumber</PartNumber>
    <ETag>ETag</ETag>
  </Part>
  ...
</CompleteMultipartUpload>

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // The 1st step in an S3 multipart upload is to initiate it,
    // as shown here: Initiate S3 Multipart Upload

    // The 2nd step is to upload the parts
    // as shown here: S3 Upload Parts

    // The 3rd and final step (this example) is to complete the multipart upload.

    // Other S3 Multipart Upload Examples:
    // Abort Multipart Upload
    // List Parts

    // When the multipart upload was initiated, an UploadId was provided in the XML response, and it 
    // was saved to a file.  Steps 2 and 3 begin by loading the XML and getting
    // the Upload ID.

    let xmlInit = CkoXml()!
    var success: Bool = xmlInit.loadFile("s3_multipart_uploads/initiate.xml")
    if success != true {
        print("Did not find the initiate.xml XML file.")
        return
    }

    var uploadId: String? = xmlInit.getChildContent("UploadId")
    print("UploadId = \(uploadId!)")

    // We'll also need the XML file that contains a record of the parts
    // with part numbers and ETags.  (This file was produced when parts were being uploaded.)
    let xmlPartsList = CkoXml()!
    success = xmlPartsList.loadFile("s3_multipart_uploads/partsList.xml")
    if success != true {
        print("Did not find the partsList.xml XML file.")
        return
    }

    let rest = CkoRest()!

    // Connect to the Amazon AWS REST server.
    var bTls: Bool = true
    var port: Int = 443
    var bAutoReconnect: Bool = true
    success = rest.connect("s3.amazonaws.com", port: port, tls: bTls, autoReconnect: bAutoReconnect)

    // ----------------------------------------------------------------------------
    // Important: For buckets created in regions outside us-east-1,
    // there are three important changes that need to be made.
    // See Working with S3 Buckets in Non-us-east-1 Regions for the details.
    // ----------------------------------------------------------------------------

    // Provide AWS credentials for the REST call.
    let authAws = CkoAuthAws()!
    authAws.accessKey = "AWS_ACCESS_KEY"
    authAws.secretKey = "AWS_SECRET_KEY"
    authAws.serviceName = "s3"

    success = rest.setAuthAws(authAws)

    // Set the bucket name via the HOST header.
    // In this case, the bucket name is "chilkat100".
    rest.host = "chilkat100.s3.amazonaws.com"

    // The "uploadId=UploadId" must be added as a query parameter.  This allows it to be 
    // incorporated into the AWS signature calculation, which is a requirement.
    // Therefore, we use AddQueryParam:
    rest.addQueryParam("uploadId", value: uploadId)

    // Our ObjectName in this case is "somethingBig.zip".
    var responseXml: String? = rest.fullRequest("POST", uriPath: "/somethingBig.zip", bodyText: xmlPartsList.getXml())
    if rest.lastMethodSuccess != true {
        print("\(rest.lastErrorText!)")
        return
    }

    // When successful, the S3 Storage service will respond with a 200 response code,
    // with an XML body.  
    if rest.responseStatusCode.intValue != 200 {
        // Examine the request/response to see what happened.
        print("response status code = \(rest.responseStatusCode.intValue)")
        print("response status text = \(rest.responseStatusText!)")
        print("response header: \(rest.responseHeader!)")
        print("response body: \(responseXml!)")
        print("---")
        print("LastRequestStartLine: \(rest.lastRequestStartLine!)")
        print("LastRequestHeader: \(rest.lastRequestHeader!)")
    }

    // Load the XML response into Chilkat XMl and emit via GetXml to see the XML in a pretty-printed (indented) readable format.
    let xml = CkoXml()!
    xml.load(responseXml)
    print("\(xml.getXml()!)")
    print("----")

    print("Multipart upload completed.")

}