(Perl) AWS S3 File Streaming Upload

Demonstrates how to do a streaming upload from a file to the AWS S3 storage service. The AWS authorization presents some difficulties when the REST request body is to be streamed from a file (or from some other source). The issue is that the SHA-256 hash of the file data must be calculated. There are only two possible ways to do this: (1) stream the file into memory in its entirety and calculate the SHA-256 hash prior to uploading, or (2) pre-calculate the SHA-256 in a streaming fashion, and then provide it to the AWS authentication object.

If the application does NOT pre-compute the SHA-256, then Chilkat (internally) is forced to stream into memory, calculate the SHA-256, and then upload from the in-memory copy of the file.

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

use chilkat();

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# This first part is optional.  AWS authentication requires
# the SHA-256 hash of the request body (i.e. the contents of the file
# to be uploaded).  We can choose to pre-calculate the SHA-256 in a streaming fashion
# and then provide it to the authenticator object.  This way, if the file is
# extremely large, it never needs to completely reside in memory.
$crypt = chilkat::CkCrypt2->new();
$crypt->put_EncodingMode("hex");
$crypt->put_HashAlgorithm("sha-256");
$fileToUploadPath = "qa_data/xml/hamlet.xml";
$hashStr = $crypt->hashFileENC($fileToUploadPath);

$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");
# Provide the pre-computed SHA-256 here:
$authAws->put_PrecomputedSha256($hashStr);

$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");

$fileStream = chilkat::CkStream->new();
$fileStream->put_SourceFile($fileToUploadPath);

# Upload to the S3 Storage service.
# If the application provided the SHA-256 hash of the file contents (as shown above)
# then file is streamed and never has to completely reside in memory.
# If the application did NOT provide the SHA-256, then Chilkat will (internally) 
# load the entire file into memory, calculate the SHA-256, and then upload.
$responseStr = $rest->fullRequestStream("PUT","/hamlet.xml",$fileStream);
if ($rest->get_LastMethodSuccess() != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# When successful, the S3 Storage service will respond with a 200 response code,
# with an XML body.  
if ($rest->get_ResponseStatusCode() == 200) {
    print $responseStr . "\r\n";
    print "File uploaded." . "\r\n";
}
else {
    # 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";
}