PowerBuilder

S3 Upload the Parts for a Multipart Upload

See more Amazon S3 (new) Examples

This example uploads a large file in parts. The multipart upload needs to have been first initiated prior to uploading the parts.

See http://docs.aws.amazon.com/AmazonS3/latest/API/mpUploadUploadPart.html for more information about uploading parts.

PowerBuilder

integer li_rc
integer li_Success
oleobject loo_XmlInit
string ls_UploadId
string ls_FileToUploadPath
integer li_PartSize
oleobject loo_Fac
integer li_NumParts
string ls_PartsListFile
oleobject loo_PartsListXml
oleobject loo_Rest
integer li_BTls
integer li_Port
integer li_BAutoReconnect
oleobject loo_AuthAws
integer li_PartNumber
oleobject loo_SbPartNumber
integer li_BPartAlreadyUploaded
integer li_NumUploadedParts
oleobject loo_XRec0
oleobject loo_FoundRec
oleobject loo_FileStream
string ls_ResponseStr
string ls_Etag
oleobject loo_XPart

li_Success = 0

// In the 1st step for uploading a large file, the multipart upload was initiated
// as shown here: Initiate Multipart Upload

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

// When we initiated the multipart upload, we saved the XML response to a file.  This
// XML response contains the UploadId.  We'll begin by loading that XML and getting
// the Upload ID.

loo_XmlInit = create oleobject
li_rc = loo_XmlInit.ConnectToNewObject("Chilkat.Xml")
if li_rc < 0 then
    destroy loo_XmlInit
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_Success = loo_XmlInit.LoadXmlFile("s3_multipart_uploads/initiate.xml")
if li_Success <> 1 then
    Write-Debug "Did not find the initiate.xml XML file."
    destroy loo_XmlInit
    return
end if

ls_UploadId = loo_XmlInit.GetChildContent("UploadId")
Write-Debug "UploadId = " + ls_UploadId

// When uploading parts, we need to keep an XML record of each part number
// and its corresponding ETag, which is received in the response for each part.
// There can be up to 10000 parts, numbered 1 to 10000.  
// After all parts have been uploaded, the final step will be to complete
// the multipart upload (see Complete Multipart Upload)

// In this example, the large file we want to upload is somethingBig.zip
ls_FileToUploadPath = "s3_multipart_uploads/somethingBig.zip"

// The minimum allowed part size is 5MB (5242880 bytes).  The last part can be smaller because
// it will contain the remainder of the file.  (This minimum is enforced by the AWS service.)
// We'll use the minimum allowed part size for this example.
li_PartSize = 5242880

// Let's use Chilkat's FileAccess API to examine the file to be uploaded.  We'll get the size
// of the file and find out how many parts will be needed, including the final "partial" part.
loo_Fac = create oleobject
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

loo_Fac.OpenForRead(ls_FileToUploadPath)

// How many parts will there be if each part is 5242880 bytes?
li_NumParts = loo_Fac.GetNumBlocks(li_PartSize)
Write-Debug "numParts = " + string(li_NumParts)
loo_Fac.FileClose()

// Imagine that we may be running this for the 1st time, or maybe we already
// attempted to upload parts, and something failed. Maybe there was a network problem
// the resulted in not all parts getting uploaded.  We'll write this code so that if run again,
// it will upload whatever parts haven't yet been uploaded.

// We'll keep a partsList.xml file to record the parts that have already been successfully
// uploaded.  If this file does not yet exist, we'll create it..
ls_PartsListFile = "s3_multipart_uploads/partsList.xml"
loo_PartsListXml = create oleobject
li_rc = loo_PartsListXml.ConnectToNewObject("Chilkat.Xml")

if loo_Fac.FileExists(ls_PartsListFile) = 1 then
    loo_PartsListXml.LoadXmlFile(ls_PartsListFile)
end if

// Make sure the top-level tag is "CompleteMultipartUpload"
loo_PartsListXml.Tag = "CompleteMultipartUpload"

// --------------------------------------
// Before entering the loop to upload parts,
// setup the REST object with AWS authentication,
// and make the initial connection.
loo_Rest = create oleobject
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")

// Connect to the Amazon AWS REST server.
li_BTls = 1
li_Port = 443
li_BAutoReconnect = 1
li_Success = loo_Rest.Connect("s3.amazonaws.com",li_Port,li_BTls,li_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.
loo_AuthAws = create oleobject
li_rc = loo_AuthAws.ConnectToNewObject("Chilkat.AuthAws")

loo_AuthAws.AccessKey = "AWS_ACCESS_KEY"
loo_AuthAws.SecretKey = "AWS_SECRET_KEY"
loo_AuthAws.ServiceName = "s3"
li_Success = loo_Rest.SetAuthAws(loo_AuthAws)

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

li_PartNumber = 1
loo_SbPartNumber = create oleobject
li_rc = loo_SbPartNumber.ConnectToNewObject("Chilkat.StringBuilder")

do while (li_PartNumber <= li_NumParts)
    Write-Debug "---- " + string(li_PartNumber) + " ----"

    // This cumbersome way of converting an integer to a string is because
    // Chilkat examples are written in a script that is converted to many programming languages.
    // At this time, the translator does not have integer-to-string code generation capability..
    loo_SbPartNumber.Clear()
    loo_SbPartNumber.AppendInt(li_PartNumber)

    li_BPartAlreadyUploaded = 0

    // If there are no children, then the XML is empty and no parts have yet been uploaded.
    li_NumUploadedParts = loo_PartsListXml.NumChildren
    if li_NumUploadedParts > 0 then
        // If some parts have been uploaded, check to see if this particular part was already upload.
        // If so, then it can be skipped.

        // Position ourselves at the 1st record.
        loo_XRec0 = loo_PartsListXml.GetChild(0)
        loo_FoundRec = loo_XRec0.FindNextRecord("PartNumber",loo_SbPartNumber.GetAsString())
        if loo_XRec0.LastMethodSuccess = 1 then
            li_BPartAlreadyUploaded = 1
            Write-Debug "Part " + string(li_PartNumber) + " was previously uploaded."
            Write-Debug loo_FoundRec.GetXml()
            destroy loo_FoundRec
        end if

        destroy loo_XRec0
    end if

    // If this part was not already uploaded, we need to upload.
    // Also update the partsListXml and save as each part is successfully uploaded.
    if li_BPartAlreadyUploaded = 0 then
        Write-Debug "Uploading part " + string(li_PartNumber) + " ..."

        // Setup the stream source for the large file to be uploaded..
        loo_FileStream = create oleobject
        li_rc = loo_FileStream.ConnectToNewObject("Chilkat.Stream")

        loo_FileStream.SourceFile = ls_FileToUploadPath
        // The Chilkat Stream API has features to make uploading a parts
        // of a file easy.  Indicate the part size by setting the SourceFilePartSize
        // property.
        loo_FileStream.SourceFilePartSize = li_PartSize

        // Our HTTP start line to upload a part will look like this:
        // PUT /ObjectName?partNumber=PartNumber&uploadId=UploadId HTTP/1.1

        // Set the query params.  We'll need partNumber and uploadId.
        // Make sure the query params from previous iterations are clear.
        loo_Rest.ClearAllQueryParams()
        loo_Rest.AddQueryParam("partNumber",loo_SbPartNumber.GetAsString())
        loo_Rest.AddQueryParam("uploadId",ls_UploadId)

        // Upload this particular file part.
        // Tell the fileStream which part is being uploaded.
        // Our partNumber is 1-based (the 1st part is at index 1), but the fileStream's SourceFilePart
        // property is 0-based.  Therefore we use partNumber-1.
        loo_FileStream.SourceFilePart = li_PartNumber - 1

        // Because the SourceFilePart and SourceFilePartSize properties are set, the stream will 
        // will provide just that part of the file.  
        ls_ResponseStr = loo_Rest.FullRequestStream("PUT","/somethingBig.zip",loo_FileStream)
        if loo_Rest.LastMethodSuccess <> 1 then
            Write-Debug loo_Rest.LastErrorText
            destroy loo_XmlInit
            destroy loo_Fac
            destroy loo_PartsListXml
            destroy loo_Rest
            destroy loo_AuthAws
            destroy loo_SbPartNumber
            destroy loo_FileStream
            return
        end if

        if loo_Rest.ResponseStatusCode <> 200 then
            // Examine the request/response to see what happened.
            Write-Debug "response status code = " + string(loo_Rest.ResponseStatusCode)
            Write-Debug "response status text = " + loo_Rest.ResponseStatusText
            Write-Debug "response header: " + loo_Rest.ResponseHeader
            Write-Debug "response body: " + ls_ResponseStr
            Write-Debug "---"
            Write-Debug "LastRequestStartLine: " + loo_Rest.LastRequestStartLine
            Write-Debug "LastRequestHeader: " + loo_Rest.LastRequestHeader
            destroy loo_XmlInit
            destroy loo_Fac
            destroy loo_PartsListXml
            destroy loo_Rest
            destroy loo_AuthAws
            destroy loo_SbPartNumber
            destroy loo_FileStream
            return
        end if

        // OK, this part was uploaded..
        // The response will have a 0-length body.  The only information we need is the 
        // ETag response header field.
        ls_Etag = loo_Rest.ResponseHdrByName("ETag")
        // It should be present, but just in case there was no ETag header...
        if loo_Rest.LastMethodSuccess <> 1 then
            Write-Debug "No ETag response header found!"
            Write-Debug "response header: " + loo_Rest.ResponseHeader
            destroy loo_XmlInit
            destroy loo_Fac
            destroy loo_PartsListXml
            destroy loo_Rest
            destroy loo_AuthAws
            destroy loo_SbPartNumber
            destroy loo_FileStream
            return
        end if

        // We need to add record to the partsListXml.
        // The record will look like this:
        // &lt;Part>
        //   &lt;PartNumber>PartNumber&lt;/PartNumber>
        //   &lt;ETag>ETag&lt;/ETag>
        // &lt;/Part>
        loo_XPart = loo_PartsListXml.NewChild("Part","")
        loo_XPart.NewChildInt2("PartNumber",li_PartNumber)
        loo_XPart.NewChild2("ETag",ls_Etag)
        destroy loo_XPart

        li_Success = loo_PartsListXml.SaveXml(ls_PartsListFile)
        if li_Success <> 1 then
            Write-Debug loo_PartsListXml.LastErrorText
            destroy loo_XmlInit
            destroy loo_Fac
            destroy loo_PartsListXml
            destroy loo_Rest
            destroy loo_AuthAws
            destroy loo_SbPartNumber
            destroy loo_FileStream
            return
        end if

        Write-Debug "-- Part " + string(li_PartNumber) + " uploaded. ---------------------"
    end if

    li_PartNumber = li_PartNumber + 1
loop

Write-Debug "Finished.  All parts uploaded."


destroy loo_XmlInit
destroy loo_Fac
destroy loo_PartsListXml
destroy loo_Rest
destroy loo_AuthAws
destroy loo_SbPartNumber
destroy loo_FileStream