(Tcl) Upload File in Blocks (with Content-MD5 header) and Commit the Block List

Demonstrates how to upload a file in blocks and then commit the block list. This example includes a Content-MD5 header for each block.

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load ./chilkat.dll

# Azure Blob Service Example: Upload a file in blocks, and then commit the block list.
# See also: https://msdn.microsoft.com/en-us/library/azure/dd135726.aspx

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

set rest [new_CkRest]

# Connect to the Azure Storage Blob Service
set bTls 1
set port 443
set bAutoReconnect 1
# In this example, the storage account name is "chilkat".
set success [CkRest_Connect $rest "chilkat.blob.core.windows.net" $port $bTls $bAutoReconnect]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

# Provide Azure Cloud credentials for the REST call.
set azAuth [new_CkAuthAzureStorage]

CkAuthAzureStorage_put_AccessKey $azAuth "AZURE_ACCESS_KEY"
# The account name used here should match the 1st part of the domain passed in the call to Connect (above).
CkAuthAzureStorage_put_Account $azAuth "chilkat"
CkAuthAzureStorage_put_Scheme $azAuth "SharedKey"
CkAuthAzureStorage_put_Service $azAuth "Blob"
# This causes the "x-ms-version: 2020-08-04" header to be automatically added.
CkAuthAzureStorage_put_XMsVersion $azAuth "2020-08-04"
set success [CkRest_SetAuthAzureStorage $rest $azAuth]

# Note: The application does not need to explicitly set the following
# headers: Content-Length, x-ms-date, Authorization.  These headers
# are automatically set by Chilkat.

# As the blocks are uploaded, we'll keep an XML block list for the subsequent commit..
set xml [new_CkXml]

CkXml_put_Tag $xml "BlockList"

# Any type of file can be uploaded in this way.  It can a text file, binary file, anything...
# This example will upload an XML file that is approximately 275K in size.  It can be downloaded
# at http://www.chilkatsoft.com/hamlet.xml
set fac [new_CkFileAccess]

set success [CkFileAccess_OpenForRead $fac "qa_data/xml/hamlet.xml"]
# Assuming success for the example..

# We'll upload in 16K blocks (normally a program would upload in larger block sizes than this,
# but this is just an example...)
set blockSize 16384

# How many 16K blocks?  (Including 1 for the last partial block)
set numBlocks [CkFileAccess_GetNumBlocks $fac $blockSize]

set crypt [new_CkCrypt2]

CkCrypt2_put_HashAlgorithm $crypt "md5"

set sbResponseBody [new_CkStringBuilder]

set uriPath [new_CkStringBuilder]

set dataBlock [new_CkBinData]

set i 0
while {$i < $numBlocks} {

    CkBinData_Clear $dataBlock
    set success [CkFileAccess_ReadBlockBd $fac $i $blockSize $dataBlock]
    if {$success == 0} then {
        puts [CkFileAccess_lastErrorText $fac]
        delete_CkRest $rest
        delete_CkAuthAzureStorage $azAuth
        delete_CkXml $xml
        delete_CkFileAccess $fac
        delete_CkCrypt2 $crypt
        delete_CkStringBuilder $sbResponseBody
        delete_CkStringBuilder $uriPath
        delete_CkBinData $dataBlock
        exit
    }

    # Generate a base64 block ID.  
    # (Chilkat provides a helper method named GenBlockId to make this easy)
    # A pre-base64 encoded block ID length of 4 is sufficient in this case because
    # this file certainly won't have more than 99,999 blocks..
    set blockId [CkFileAccess_genBlockId $fac $i 4 "base64"]

    # Add this blockId to the list of blocks to be committed.
    CkXml_NewChild2 $xml "Latest" $blockId

    # Build the URI path
    CkStringBuilder_Clear $uriPath
    set success [CkStringBuilder_Append $uriPath "/mycontainer/hamlet.xml?comp=block&blockId="]
    set success [CkStringBuilder_Append $uriPath $blockId]

    set contentMd5 [CkCrypt2_hashBdENC $crypt $dataBlock]
    CkRest_AddHeader $rest "Content-MD5" $contentMd5

    # Upload this block..
    CkStringBuilder_Clear $sbResponseBody
    set success [CkRest_FullRequestBd $rest "PUT" [CkStringBuilder_getAsString $uriPath] $dataBlock $sbResponseBody]
    if {$success == 0} then {
        puts [CkRest_lastErrorText $rest]
        delete_CkRest $rest
        delete_CkAuthAzureStorage $azAuth
        delete_CkXml $xml
        delete_CkFileAccess $fac
        delete_CkCrypt2 $crypt
        delete_CkStringBuilder $sbResponseBody
        delete_CkStringBuilder $uriPath
        delete_CkBinData $dataBlock
        exit
    }

    # Verify that we received a 201 status code.
    if {[CkRest_get_ResponseStatusCode $rest] != 201} 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 (if any): [CkStringBuilder_getAsString $sbResponseBody]"
        puts "---"
        puts "LastRequestStartLine: [CkRest_lastRequestStartLine $rest]"
        puts "LastRequestHeader: [CkRest_lastRequestHeader $rest]"
        delete_CkRest $rest
        delete_CkAuthAzureStorage $azAuth
        delete_CkXml $xml
        delete_CkFileAccess $fac
        delete_CkCrypt2 $crypt
        delete_CkStringBuilder $sbResponseBody
        delete_CkStringBuilder $uriPath
        delete_CkBinData $dataBlock
        exit
    }

    set i [expr $i + 1]
}

CkFileAccess_FileClose $fac

# Now commit the blocks.
# Let's have a look at the XML that will commit the blocks:
set xmlStr [CkXml_getXml $xml]
puts "$xmlStr"

# The XML will look like this:

# <?xml version="1.0" encoding="utf-8" ?>
# <BlockList>
#     <Latest>MDAwMA==</Latest>
#     <Latest>MDAwMQ==</Latest>
#     <Latest>MDAwMg==</Latest>
#     <Latest>MDAwMw==</Latest>
#     <Latest>MDAwNA==</Latest>
#     <Latest>MDAwNQ==</Latest>
#     <Latest>MDAwNg==</Latest>
#     <Latest>MDAwNw==</Latest>
#     <Latest>MDAwOA==</Latest>
#     <Latest>MDAwOQ==</Latest>
#     <Latest>MDAxMA==</Latest>
#     <Latest>MDAxMQ==</Latest>
#     <Latest>MDAxMg==</Latest>
#     <Latest>MDAxMw==</Latest>
#     <Latest>MDAxNA==</Latest>
#     <Latest>MDAxNQ==</Latest>
#     <Latest>MDAxNg==</Latest>
#     <Latest>MDAxNw==</Latest>
# </BlockList>

# --------------------------------------------------------------------------
# IMPORTANT: Remove the Content-MD5 header previously set in the loop above.
# --------------------------------------------------------------------------
CkRest_RemoveHeader $rest "Content-MD5"

# Send the PUT Block List...
set responseStr [CkRest_fullRequestString $rest "PUT" "/mycontainer/hamlet.xml?comp=blocklist" $xmlStr]
if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    delete_CkAuthAzureStorage $azAuth
    delete_CkXml $xml
    delete_CkFileAccess $fac
    delete_CkCrypt2 $crypt
    delete_CkStringBuilder $sbResponseBody
    delete_CkStringBuilder $uriPath
    delete_CkBinData $dataBlock
    exit
}

# When successful, the Azure Storage service will respond with a 201 response status code,
# with no response body.

if {[CkRest_get_ResponseStatusCode $rest] != 201} 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 (if any): $responseStr"
    puts "---"
    puts "LastRequestStartLine: [CkRest_lastRequestStartLine $rest]"
    puts "LastRequestHeader: [CkRest_lastRequestHeader $rest]"
    delete_CkRest $rest
    delete_CkAuthAzureStorage $azAuth
    delete_CkXml $xml
    delete_CkFileAccess $fac
    delete_CkCrypt2 $crypt
    delete_CkStringBuilder $sbResponseBody
    delete_CkStringBuilder $uriPath
    delete_CkBinData $dataBlock
    exit
}

puts "Success."

delete_CkRest $rest
delete_CkAuthAzureStorage $azAuth
delete_CkXml $xml
delete_CkFileAccess $fac
delete_CkCrypt2 $crypt
delete_CkStringBuilder $sbResponseBody
delete_CkStringBuilder $uriPath
delete_CkBinData $dataBlock