(CkPython) Azure File Service: Upload Large File

Sample code to upload a large file to a directory in a share in the Azure File Service. A file is uploaded by first creating the file in the Azure share and then writing ranges of bytes to the file. Azure imposes a 4MB limit for each PUT to write a range. Files larger than 4MB need to be uploaded by making multiple "Put Range" calls. This example uploads a large file requiring multiple "Put Range" calls.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

# Azure File Service Example: Upload a large file.  
# See:  https://docs.microsoft.com/en-us/rest/api/storageservices/create-share
# also see: https://docs.microsoft.com/en-us/rest/api/storageservices/put-range

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

rest = chilkat.CkRest()

# Connect to the Azure Storage Blob Service
bTls = True
port = 443
bAutoReconnect = True
# In this example, the storage account name is "chilkat".
success = rest.Connect("chilkat.file.core.windows.net",port,bTls,bAutoReconnect)
if (success != True):
    print(rest.lastErrorText())
    sys.exit()

# This example will upload a larger file.
localFilePath = "qa_data/zips/somethingBig.zip"
fac = chilkat.CkFileAccess()
# Note: The FileSize method returns a signed 32-bit integer.  If the file is potentially larger than 2GB, call FileSizeStr instead to return
# the size of the file as a string, then convert to an integer value.
szLocalFile = fac.FileSize(localFilePath)
if (szLocalFile < 0):
    print(fac.lastErrorText())
    sys.exit()

# Provide Azure Cloud credentials for the REST calls.
azAuth = chilkat.CkAuthAzureStorage()
azAuth.put_AccessKey("AZURE_ACCESS_KEY")
# The account name used here should match the 1st part of the domain passed in the call to Connect (above).
azAuth.put_Account("chilkat")
azAuth.put_Scheme("SharedKey")
azAuth.put_Service("File")
# This causes the "x-ms-version: 2020-08-04" header to be automatically added.
azAuth.put_XMsVersion("2020-08-04")
success = rest.SetAuthAzureStorage(azAuth)

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

# However, a few additional headers are required for the "Create File" operation:
rest.AddHeader("x-ms-type","file")

# This required header specifies the final size of the file (or the maximum size it can be).
sbFileSize = chilkat.CkStringBuilder()
sbFileSize.AppendInt(szLocalFile)
rest.AddHeader("x-ms-content-length",sbFileSize.getAsString())

# Send a PUT request to create the file (or replace the file if it already exists).
# This will initialize the file in the Azure file storage.  To upload content, we'll need
# to do the "Put Range" operation one or more times.

# The following will create the file "somethingBig.zip" in the share "pip"
responseStr = rest.fullRequestNoBody("PUT","/pip/somethingBig.zip")
if (rest.get_LastMethodSuccess() != True):
    print(rest.lastErrorText())
    sys.exit()

# When successful, the Azure File Service will respond with a 201 (Created) response status code,
# with no XML response body.  If an error response is returned, there will be an XML response body.

if (rest.get_ResponseStatusCode() != 201):
    # Examine the request/response to see what happened.
    print("response status code = " + str(rest.get_ResponseStatusCode()))
    print("response status text = " + rest.responseStatusText())
    print("response header: " + rest.responseHeader())
    print("response body (if any): " + responseStr)
    print("---")
    print("LastRequestStartLine: " + rest.lastRequestStartLine())
    print("LastRequestHeader: " + rest.lastRequestHeader())
    sys.exit()

print("Successfully created somethingBig.zip")

# --------------------------------------------------------------------------------
# Upload the file data...

# Make sure the headers from the "Create File" operation are removed.
rest.ClearAllHeaders()

# The x-ms-write header is required for each "Put Range" request.
rest.AddHeader("x-ms-write","update")

sbRange = chilkat.CkStringBuilder()
sbResponseBody = chilkat.CkStringBuilder()
bdFileData = chilkat.CkBinData()

# Open the file.  We'll be reading and uploading in chunks..
success = fac.OpenForRead(localFilePath)
if (success != True):
    print(fac.lastErrorText())
    sys.exit()

numBytesLeft = szLocalFile
curIndex = 0
while numBytesLeft > 0 :

    chunkSize = numBytesLeft
    # Azure allows for 4MB max chunks  (4 x 1024 x 1024 = 4194304)
    if (chunkSize > 4194304):
        chunkSize = 4194304

    # The only tricky part here is to correctly add the x-ms-range header.
    # It will be formatted like this:
    # x-ms-range: bytes=0-759623
    sbRange.Clear()
    sbRange.Append("bytes=")
    sbRange.AppendInt(curIndex)
    sbRange.Append("-")
    sbRange.AppendInt(curIndex + chunkSize - 1)

    # This replaces the header if it already exists..
    rest.AddHeader("x-ms-range",sbRange.getAsString())

    # Read the next chunk from the local file.
    bdFileData.Clear()
    success = fac.FileReadBd(chunkSize,bdFileData)

    success = rest.FullRequestBd("PUT","/pip/somethingBig.zip?comp=range",bdFileData,sbResponseBody)
    if (success != True):
        # This would indicate a failure where no response was received.
        print(rest.lastErrorText())
        sys.exit()

    # A 201 response indicates the chunk was uploaded.
    if (rest.get_ResponseStatusCode() != 201):
        # Examine the request/response to see what happened.
        print("response status code = " + str(rest.get_ResponseStatusCode()))
        print("response status text = " + rest.responseStatusText())
        print("response header: " + rest.responseHeader())
        print("response body (if any): " + responseStr)
        print("---")
        print("LastRequestStartLine: " + rest.lastRequestStartLine())
        print("LastRequestHeader: " + rest.lastRequestHeader())
        sys.exit()

    print("Uploaded chunk from " + str(curIndex) + " to " + str(curIndex + chunkSize - 1))

    curIndex = curIndex + chunkSize
    numBytesLeft = numBytesLeft - chunkSize

fac.FileClose()

print("success.")