(Tcl) Upload File in Blocks and Commit the Block List

See more Azure Cloud Storage Examples

Demonstrates how to upload a file in blocks and then commit the block list. For files larger than 64MB, this is the way to upload to Azure Storage. Azure limits the size of each block to a maximum of 4MB.

For more information, see https://learn.microsoft.com/en-us/rest/api/storageservices/put-block-list?tabs=microsoft-entra-id

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

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: 2021-08-06" header to be automatically added.
CkAuthAzureStorage_put_XMsVersion $azAuth "2021-08-06"
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 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_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]

    # 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_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_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>

# 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_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_CkStringBuilder $sbResponseBody
    delete_CkStringBuilder $uriPath
    delete_CkBinData $dataBlock
    exit
}

puts "Success."

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