(Perl) S3 Upload the Parts for a Multipart Upload

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.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# 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.

$xmlInit = chilkat::CkXml->new();
$success = $xmlInit->LoadXmlFile("s3_multipart_uploads/initiate.xml");
if ($success != 1) {
    print "Did not find the initiate.xml XML file." . "\r\n";
    exit;
}

$uploadId = $xmlInit->getChildContent("UploadId");
print "UploadId = " . $uploadId . "\r\n";

# 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
$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.
$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.
$fac = chilkat::CkFileAccess->new();
$fac->OpenForRead($fileToUploadPath);

# How many parts will there be if each part is 5242880 bytes?
$numParts = $fac->GetNumBlocks($partSize);
print "numParts = " . $numParts . "\r\n";
$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..
$partsListFile = "s3_multipart_uploads/partsList.xml";
$partsListXml = chilkat::CkXml->new();
if ($fac->FileExists($partsListFile) == 1) {
    $partsListXml->LoadXmlFile($partsListFile);
}

# Make sure the top-level tag is "CompleteMultipartUpload"
$partsListXml->put_Tag("CompleteMultipartUpload");

# --------------------------------------
# Before entering the loop to upload parts,
# setup the REST object with AWS authentication,
# and make the initial connection.
$rest = chilkat::CkRest->new();

# Connect to the Amazon AWS REST server.
$bTls = 1;
$port = 443;
$bAutoReconnect = 1;
$success = $rest->Connect("s3.amazonaws.com",$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 = chilkat::CkAuthAws->new();
$authAws->put_AccessKey("AWS_ACCESS_KEY");
$authAws->put_SecretKey("AWS_SECRET_KEY");
$authAws->put_ServiceName("s3");
$success = $rest->SetAuthAws($authAws);

# Set the bucket name via the HOST header.
# In this case, the bucket name is "chilkat100".
$rest->put_Host("chilkat100.s3.amazonaws.com");
# --------------------------------------

$partNumber = 1;
$sbPartNumber = chilkat::CkStringBuilder->new();

while (($partNumber <= $numParts)) {
    print "---- " . $partNumber . " ----" . "\r\n";

    # 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..
    $sbPartNumber->Clear();
    $sbPartNumber->AppendInt($partNumber);

    $bPartAlreadyUploaded = 0;

    # If there are no children, then the XML is empty and no parts have yet been uploaded.
    $numUploadedParts = $partsListXml->get_NumChildren();
    if ($numUploadedParts > 0) {
        # 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.
        # xRec0 is a Xml
        $xRec0 = $partsListXml->GetChild(0);
        # foundRec is a Xml
        $foundRec = $xRec0->FindNextRecord("PartNumber",$sbPartNumber->getAsString());
        if ($xRec0->get_LastMethodSuccess() == 1) {
            $bPartAlreadyUploaded = 1;
            print "Part " . $partNumber . " was previously uploaded." . "\r\n";
            print $foundRec->getXml() . "\r\n";

        }

    }

    # If this part was not already uploaded, we need to upload.
    # Also update the partsListXml and save as each part is successfully uploaded.
    if ($bPartAlreadyUploaded == 0) {
        print "Uploading part " . $partNumber . " ..." . "\r\n";

        # Setup the stream source for the large file to be uploaded..
        $fileStream = chilkat::CkStream->new();
        $fileStream->put_SourceFile($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.
        $fileStream->put_SourceFilePartSize($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.
        $rest->ClearAllQueryParams();
        $rest->AddQueryParam("partNumber",$sbPartNumber->getAsString());
        $rest->AddQueryParam("uploadId",$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.
        $fileStream->put_SourceFilePart($partNumber - 1);

        # Because the SourceFilePart and SourceFilePartSize properties are set, the stream will 
        # will provide just that part of the file.  
        $responseStr = $rest->fullRequestStream("PUT","/somethingBig.zip",$fileStream);
        if ($rest->get_LastMethodSuccess() != 1) {
            print $rest->lastErrorText() . "\r\n";
            exit;
        }

        if ($rest->get_ResponseStatusCode() != 200) {
            # Examine the request/response to see what happened.
            print "response status code = " . $rest->get_ResponseStatusCode() . "\r\n";
            print "response status text = " . $rest->responseStatusText() . "\r\n";
            print "response header: " . $rest->responseHeader() . "\r\n";
            print "response body: " . $responseStr . "\r\n";
            print "---" . "\r\n";
            print "LastRequestStartLine: " . $rest->lastRequestStartLine() . "\r\n";
            print "LastRequestHeader: " . $rest->lastRequestHeader() . "\r\n";
            exit;
        }

        # OK, this part was uploaded..
        # The response will have a 0-length body.  The only information we need is the 
        # ETag response header field.
        $etag = $rest->responseHdrByName("ETag");
        # It should be present, but just in case there was no ETag header...
        if ($rest->get_LastMethodSuccess() != 1) {
            print "No ETag response header found!" . "\r\n";
            print "response header: " . $rest->responseHeader() . "\r\n";
            exit;
        }

        # 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>
        # xPart is a Xml
        $xPart = $partsListXml->NewChild("Part","");
        $xPart->NewChildInt2("PartNumber",$partNumber);
        $xPart->NewChild2("ETag",$etag);

        $success = $partsListXml->SaveXml($partsListFile);
        if ($success != 1) {
            print $partsListXml->lastErrorText() . "\r\n";
            exit;
        }

        print "-- Part " . $partNumber . " uploaded. ---------------------" . "\r\n";
    }

    $partNumber = $partNumber + 1;
}

print "Finished.  All parts uploaded." . "\r\n";