CkPython

Azure File Service: Upload Large File

See more Azure Cloud Storage Examples

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. CkPython

import sys
import chilkat

success = False

# 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: 2021-08-06" header to be automatically added.
azAuth.put_XMsVersion("2021-08-06")
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.")