(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkXml.pb"
IncludeFile "CkRest.pb"
IncludeFile "CkAuthAws.pb"

Procedure ChilkatExample()

    ; 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.

    xmlInit.i = CkXml::ckCreate()
    If xmlInit.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkXml::ckLoadXmlFile(xmlInit,"s3_multipart_uploads/initiate.xml")
    If success <> 1
        Debug "Did not find the initiate.xml XML file."
        CkXml::ckDispose(xmlInit)
        ProcedureReturn
    EndIf

    uploadId.s = CkXml::ckGetChildContent(xmlInit,"UploadId")
    Debug "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.)
    xmlPartsList.i = CkXml::ckCreate()
    If xmlPartsList.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkXml::ckLoadXmlFile(xmlPartsList,"s3_multipart_uploads/partsList.xml")
    If success <> 1
        Debug "Did not find the partsList.xml XML file."
        CkXml::ckDispose(xmlInit)
        CkXml::ckDispose(xmlPartsList)
        ProcedureReturn
    EndIf

    rest.i = CkRest::ckCreate()
    If rest.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Connect to the Amazon AWS REST server.
    bTls.i = 1
    port.i = 443
    bAutoReconnect.i = 1
    success = CkRest::ckConnect(rest,"s3.amazonaws.com",port,bTls,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.
    authAws.i = CkAuthAws::ckCreate()
    If authAws.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkAuthAws::setCkAccessKey(authAws, "AWS_ACCESS_KEY")
    CkAuthAws::setCkSecretKey(authAws, "AWS_SECRET_KEY")
    CkAuthAws::setCkServiceName(authAws, "s3")

    success = CkRest::ckSetAuthAws(rest,authAws)

    ; Set the bucket name via the HOST header.
    ; In this case, the bucket name is "chilkat100".
    CkRest::setCkHost(rest, "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:
    CkRest::ckAddQueryParam(rest,"uploadId",uploadId)

    ; Our ObjectName in this case is "somethingBig.zip".
    responseXml.s = CkRest::ckFullRequestString(rest,"POST","/somethingBig.zip",CkXml::ckGetXml(xmlPartsList))
    If CkRest::ckLastMethodSuccess(rest) <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkXml::ckDispose(xmlInit)
        CkXml::ckDispose(xmlPartsList)
        CkRest::ckDispose(rest)
        CkAuthAws::ckDispose(authAws)
        ProcedureReturn
    EndIf

    ; When successful, the S3 Storage service will respond with a 200 response code,
    ; with an XML body.  
    If CkRest::ckResponseStatusCode(rest) <> 200
        ; Examine the request/response to see what happened.
        Debug "response status code = " + Str(CkRest::ckResponseStatusCode(rest))
        Debug "response status text = " + CkRest::ckResponseStatusText(rest)
        Debug "response header: " + CkRest::ckResponseHeader(rest)
        Debug "response body: " + responseXml
        Debug "---"
        Debug "LastRequestStartLine: " + CkRest::ckLastRequestStartLine(rest)
        Debug "LastRequestHeader: " + CkRest::ckLastRequestHeader(rest)
    EndIf

    ; Load the XML response into Chilkat XMl and emit via GetXml to see the XML in a pretty-printed (indented) readable format.
    xml.i = CkXml::ckCreate()
    If xml.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkXml::ckLoadXml(xml,responseXml)
    Debug CkXml::ckGetXml(xml)
    Debug "----"

    Debug "Multipart upload completed."


    CkXml::ckDispose(xmlInit)
    CkXml::ckDispose(xmlPartsList)
    CkRest::ckDispose(rest)
    CkAuthAws::ckDispose(authAws)
    CkXml::ckDispose(xml)


    ProcedureReturn
EndProcedure