Problem "pushing" files to the browser as a result of buffer limits when using ASP

My issue is that when I attempt to push hidden downloads to a client browser, it works fine with smaller (less than a few mb) files but fails when you get to several tens of mb files. In my web searches it appears to be an issue with the buffers in IIS but I can't be sure. Here is a test site that uses the code below: http://www.holidaycoro.com/contentdownload/download.asp

I'm wondering if there is a way to fix this code, do it another way (ASP .Net?), if there is some component on DiscountASP that will do it (like the upload stuff) or just some other route I need to take when wanting to share large files with customers without presenting the actual download URL to them.

Thank you,
David


<%

'Constants
Const FOLDER_PATH="e:\web\<site>\htdocs\ContentDownload\<sub directory>" 'full path to the secure folder
Const adTypeBinary = 1
Const adTypeText = 2
Const chunkSize = 2048

'global variables:
Dim strFileName 'name of the file to be downloaded
Dim blnForceDownload 'force the download or allow the file to be opebed in the browser?

'read file from querystring:
strFileName=Request("file")

'execute the function if we got anything:
If Len(strFileName)>0 Then
Call DownloadFile (strFileName)
Response.END
End If

Sub DownloadFile(strFileName)
'local variables:
Dim fso, objFile, strFilePath
Dim fileSize, blnBinary, strContentType
Dim objStream, strAllFile, iSz
Dim i

'----------------------
'first step: verify the file exists
'----------------------

'build file path:
strFilePath=FOLDER_PATH
' add backslash if needed:
If Right(strFilePath, 1)<>"\" Then strFilePath=strFilePath&"\"
strFilePath=strFilePath&strFileName

'initialize file system object:
Set fso=Server.CreateObject("Scripting.FileSystemObject")

'check that the file exists:
If Not(fso.FileExists(strFilePath)) Then
Set fso=Nothing
Err.Raise 20000, "Download Manager", "Fatal Error: file does not exist: "&strFilePath
Response.END
End If

'----------------------
'second step: get file size.
'----------------------
Set objFile=fso.GetFile(strFilePath)
fileSize=objFile.Size
Set objFile=Nothing

'----------------------
'third step: check whether file is binary or not and get content type of the file. (according to its extension)
'----------------------
blnBinary=GetContentType(strFileName, strContentType)
strAllFile=""

'----------------------
'forth step: read the file contents.
'----------------------
Response.AddHeader "Content-Disposition", "attachment; filename="&strFileName

If blnBinary Then
Set objStream=Server.CreateObject("ADODB.Stream")

'Added to breakup chunk
'Response.Buffer = False

'this might be long...
Server.ScriptTimeout = 10000000



'----------------------
objStream.Open
objStream.Type = 1 'adTypeBinary
objStream.LoadFromFile strFilePath

'Added to breakup chunk
iSz = objStream.Size
Response.AddHeader "Content-Length", iSz
'Response.Charset = "UTF-8"
Response.ContentType = strContentType
For i = 1 To iSz \ chunkSize
If Not Response.IsClientConnected Then Exit For
Response.BinaryWrite objStream.Read(chunkSize)
Next
If iSz Mod chunkSize > 0 Then
If Response.IsClientConnected Then
Response.BinaryWrite objStream.Read(iSz Mod chunkSize)
End If
End If
objStream.Close
Set objStream = Nothing
Else
Set objFile=fspenTextFile(strFilePath,1) 'forReading
If Not(objFile.AtEndOfStream) Then
strAllFile=objFile.ReadAll
End If
objFile.Close
Set objFile=Nothing
Response.Write(strAllFile)
End If

'clean up:
Set fso=Nothing
Response.Flush
Response.END
End Sub

Function GetContentType(ByVal strName, ByRef ContentType)
'return whether binary or not, put type into second parameter
Dim strExtension
strExtension="."&GetExtension(strName)
Select Case strExtension
Case ".asf"
ContentType = "video/x-ms-asf"
GetContentType=True
Case ".avi"
ContentType = "video/avi"
GetContentType=True
Case ".doc"
ContentType = "application/msword"
GetContentType=True
Case ".zip"
ContentType = "application/x-msdownload"
'ContentType = "application/zip"
GetContentType=True
Case ".xls"
ContentType = "application/vnd.ms-excel"
GetContentType=True
Case ".gif"
ContentType = "image/gif"
GetContentType=True
Case ".jpg", ".jpeg"
ContentType = "image/jpeg"
GetContentType=True
Case ".wav"
ContentType = "audio/wav"
GetContentType=True
Case ".mp3"
ContentType = "audio/mpeg3"
GetContentType=True
Case ".wma"
ContentType = "audio/wma"
GetContentType=True
Case ".mpg", ".mpeg"
ContentType = "video/mpeg"
GetContentType=True
Case ".pdf"
ContentType = "application/pdf"
GetContentType=True
Case ".rtf"
ContentType = "application/rtf"
GetContentType=True
Case ".htm", ".html"
ContentType = "text/html"
GetContentType=False
Case ".asp"
ContentType = "text/asp"
GetContentType=False
Case ".txt"
ContentType = "text/plain"
GetContentType=False
Case Else
'Handle All Other Files
ContentType = "application/octet-stream"
GetContentType=True
End Select
End Function

Function GetExtension(strName)
Dim arrTmp
arrTmp=Split(strName, ".")
GetExtension=arrTmp(UBound(arrTmp))
End Function
%>

 

I do have an ASP.NET method that I worked on with some of the Microsoft devs that you can use to provide D/Ls without giving the direct folder.
Email me at [email protected] and I'll send you a copy to play with.
All the best,
Mark