(Tcl) 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.

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load ./chilkat.dll

# 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.

set xmlInit [new_CkXml]

set success [CkXml_LoadXmlFile $xmlInit "s3_multipart_uploads/initiate.xml"]
if {$success != 1} then {
    puts "Did not find the initiate.xml XML file."
    delete_CkXml $xmlInit
    exit
}

set uploadId [CkXml_getChildContent $xmlInit "UploadId"]
puts "UploadId = $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
set 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.
set 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.
set fac [new_CkFileAccess]

CkFileAccess_OpenForRead $fac $fileToUploadPath

# How many parts will there be if each part is 5242880 bytes?
set numParts [CkFileAccess_GetNumBlocks $fac $partSize]
puts "numParts = $numParts"
CkFileAccess_FileClose $fac

# 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..
set partsListFile "s3_multipart_uploads/partsList.xml"
set partsListXml [new_CkXml]

if {[CkFileAccess_FileExists $fac $partsListFile] == 1} then {
    CkXml_LoadXmlFile $partsListXml $partsListFile
}

# Make sure the top-level tag is "CompleteMultipartUpload"
CkXml_put_Tag $partsListXml "CompleteMultipartUpload"

# --------------------------------------
# Before entering the loop to upload parts,
# setup the REST object with AWS authentication,
# and make the initial connection.
set rest [new_CkRest]

# Connect to the Amazon AWS REST server.
set bTls 1
set port 443
set bAutoReconnect 1
set success [CkRest_Connect $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.
set authAws [new_CkAuthAws]

CkAuthAws_put_AccessKey $authAws "AWS_ACCESS_KEY"
CkAuthAws_put_SecretKey $authAws "AWS_SECRET_KEY"
CkAuthAws_put_ServiceName $authAws "s3"
set success [CkRest_SetAuthAws $rest $authAws]

# Set the bucket name via the HOST header.
# In this case, the bucket name is "chilkat100".
CkRest_put_Host $rest "chilkat100.s3.amazonaws.com"
# --------------------------------------

set partNumber 1
set sbPartNumber [new_CkStringBuilder]

while {$partNumber <= $numParts} {
    puts "---- $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..
    CkStringBuilder_Clear $sbPartNumber
    CkStringBuilder_AppendInt $sbPartNumber $partNumber

    set bPartAlreadyUploaded 0

    # If there are no children, then the XML is empty and no parts have yet been uploaded.
    set numUploadedParts [CkXml_get_NumChildren $partsListXml]
    if {$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.
        # xRec0 is a CkXml
        set xRec0 [CkXml_GetChild $partsListXml 0]
        # foundRec is a CkXml
        set foundRec [CkXml_FindNextRecord $xRec0 "PartNumber" [CkStringBuilder_getAsString $sbPartNumber]]
        if {[CkXml_get_LastMethodSuccess $xRec0] == 1} then {
            set bPartAlreadyUploaded 1
            puts "Part $partNumber was previously uploaded."
            puts [CkXml_getXml $foundRec]
            delete_CkXml $foundRec

        }

        delete_CkXml $xRec0

    }

    # 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} then {
        puts "Uploading part $partNumber ..."

        # Setup the stream source for the large file to be uploaded..
        set fileStream [new_CkStream]

        CkStream_put_SourceFile $fileStream $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.
        CkStream_put_SourceFilePartSize $fileStream $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.
        CkRest_ClearAllQueryParams $rest
        CkRest_AddQueryParam $rest "partNumber" [CkStringBuilder_getAsString $sbPartNumber]
        CkRest_AddQueryParam $rest "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.
        CkStream_put_SourceFilePart $fileStream [expr $partNumber - 1]

        # Because the SourceFilePart and SourceFilePartSize properties are set, the stream will 
        # will provide just that part of the file.  
        set responseStr [CkRest_fullRequestStream $rest "PUT" "/somethingBig.zip" $fileStream]
        if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
            puts [CkRest_lastErrorText $rest]
            delete_CkXml $xmlInit
            delete_CkFileAccess $fac
            delete_CkXml $partsListXml
            delete_CkRest $rest
            delete_CkAuthAws $authAws
            delete_CkStringBuilder $sbPartNumber
            delete_CkStream $fileStream
            exit
        }

        if {[CkRest_get_ResponseStatusCode $rest] != 200} then {
            # Examine the request/response to see what happened.
            puts "response status code = [CkRest_get_ResponseStatusCode $rest]"
            puts "response status text = [CkRest_responseStatusText $rest]"
            puts "response header: [CkRest_responseHeader $rest]"
            puts "response body: $responseStr"
            puts "---"
            puts "LastRequestStartLine: [CkRest_lastRequestStartLine $rest]"
            puts "LastRequestHeader: [CkRest_lastRequestHeader $rest]"
            delete_CkXml $xmlInit
            delete_CkFileAccess $fac
            delete_CkXml $partsListXml
            delete_CkRest $rest
            delete_CkAuthAws $authAws
            delete_CkStringBuilder $sbPartNumber
            delete_CkStream $fileStream
            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.
        set etag [CkRest_responseHdrByName $rest "ETag"]
        # It should be present, but just in case there was no ETag header...
        if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
            puts "No ETag response header found!"
            puts "response header: [CkRest_responseHeader $rest]"
            delete_CkXml $xmlInit
            delete_CkFileAccess $fac
            delete_CkXml $partsListXml
            delete_CkRest $rest
            delete_CkAuthAws $authAws
            delete_CkStringBuilder $sbPartNumber
            delete_CkStream $fileStream
            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 CkXml
        set xPart [CkXml_NewChild $partsListXml "Part" ""]
        CkXml_NewChildInt2 $xPart "PartNumber" $partNumber
        CkXml_NewChild2 $xPart "ETag" $etag
        delete_CkXml $xPart

        set success [CkXml_SaveXml $partsListXml $partsListFile]
        if {$success != 1} then {
            puts [CkXml_lastErrorText $partsListXml]
            delete_CkXml $xmlInit
            delete_CkFileAccess $fac
            delete_CkXml $partsListXml
            delete_CkRest $rest
            delete_CkAuthAws $authAws
            delete_CkStringBuilder $sbPartNumber
            delete_CkStream $fileStream
            exit
        }

        puts "-- Part $partNumber uploaded. ---------------------"
    }

    set partNumber [expr $partNumber + 1]
}

puts "Finished.  All parts uploaded."

delete_CkXml $xmlInit
delete_CkFileAccess $fac
delete_CkXml $partsListXml
delete_CkRest $rest
delete_CkAuthAws $authAws
delete_CkStringBuilder $sbPartNumber
delete_CkStream $fileStream