Performance problem in base64 string to XML

Asked Mar 03 '21 at 14:13

Active Mar 04 '21 at 21:41

Viewed 170 times

I am using the VBA code below to decode base64 to XML. It works, but only for small size base64 strings. How can I improve it for long strings ?

Function f_textBase64Decode(strBase64)
    Dim b
    With CreateObject("Microsoft.XMLDOM").createElement("b64")
        .DataType = "bin.base64": .Text = strBase64
        b = .nodeTypedValue
        With CreateObject("ADODB.Stream")
            .Open: .Type = 1: .Write b: .Position = 0: .Type = 2: .Charset = "utf-8"
            f_textBase64Decode = .ReadText
            .Close
        End With
    End With
End Function

edited Mar 04 '21 at 21:41

ZygD

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asked Mar 03 '21 at 14:13

Shlomo

1

"small" and "long" are relative terms: what size are your "long" strings? – Tim Williams Mar 03 '21 at 16:28
The xml file size is 15MG – Shlomo Mar 04 '21 at 17:23
Do you mean `strBase64` is 15MB ? – Tim Williams Mar 04 '21 at 17:26
Yes. If i save it as xml file it will be 15MG the file contain around 20000 rows – Shlomo Mar 04 '21 at 17:28
What is a "MG" ? That's not a standard unit. – Tim Williams Mar 04 '21 at 17:31
The ".ReadText" takes 3-4 minutes for those heavy files. for light xml files it works ok – Shlomo Mar 04 '21 at 17:36
Sorry MG = Mega bit – Shlomo Mar 04 '21 at 17:37
The strbase64 come from SOAP request – Shlomo Mar 04 '21 at 17:39
If you save the encoded text to a file you can try the method from user pizza here: https://stackoverflow.com/questions/496751/base64-encode-string-in-vbscript/3029969#3029969 – Tim Williams Mar 04 '21 at 17:51
You meam to save the file on my local PC and then to read it? – Shlomo Mar 04 '21 at 17:56
At the end i need the xml file to be converted to table in the excel sheet. – Shlomo Mar 04 '21 at 17:59
Yes - that way it can be processed line-by-line instead of as one large block – Tim Williams Mar 04 '21 at 17:59
The Excel conversion seem like a separate question – Tim Williams Mar 04 '21 at 17:59
OK. Thank you very much – Shlomo Mar 04 '21 at 18:11

Performance problem in base64 string to XML

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