Go Requires Chilkat v11.7.0+

Audit a PDF First, Optimize Only If It Is Worth It

See more PDF Optimization Examples

Demonstrates deciding whether to rewrite a PDF at all. "audit" costs a fraction of a second and changes nothing, so a batch job can audit every file and optimize only those where enough would be saved. Here the threshold is a tenth of the file; a file already as small as it can be is left alone. Go

    success := false

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

    //  The PDF used in this example is available at watersense_accomplishments.pdf

    pdf := chilkat.NewPdf()
    success = pdf.LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        return
    }

    json := chilkat.NewJsonObject()
    jsonOut := chilkat.NewJsonObject()
    success = pdf.Optimize("audit",json,jsonOut)
    if success == false {
        fmt.Println(pdf.LastErrorText())
        pdf.DisposePdf()
        json.DisposeJsonObject()
        jsonOut.DisposeJsonObject()
        return
    }

    fileSize := jsonOut.IntOf("fileSize")
    estimated := jsonOut.IntOf("estimatedSavings.total")
    fmt.Println("fileSize:  ", fileSize)
    fmt.Println("estimated: ", estimated)

    //  Only bother when at least a tenth of the file would go.
    if estimated > (fileSize / 10) {
        fmt.Println("Worth optimizing.")
        success = pdf.Optimize("optimize",json,jsonOut)
        if success == false {
            fmt.Println(pdf.LastErrorText())
            pdf.DisposePdf()
            json.DisposeJsonObject()
            jsonOut.DisposeJsonObject()
            return
        }

        success = pdf.WriteFile("qa_output/watersense_optimized.pdf")
        if success == false {
            fmt.Println(pdf.LastErrorText())
            pdf.DisposePdf()
            json.DisposeJsonObject()
            jsonOut.DisposeJsonObject()
            return
        }

        fmt.Println("bytesSaved: ", jsonOut.IntOf("bytesSaved"))
    } else {
        fmt.Println("Already small enough; left as it is.")
    }


    pdf.DisposePdf()
    json.DisposeJsonObject()
    jsonOut.DisposeJsonObject()