Swift 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. Swift

func chilkatTest() {
    var success: Bool = 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

    let pdf = CkoPdf()!
    success = pdf.loadFile(filePath: "qa_data/pdf/watersense_accomplishments.pdf")
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    let json = CkoJsonObject()!
    let jsonOut = CkoJsonObject()!
    success = pdf.optimize(op: "audit", jsonIn: json, jsonOut: jsonOut)
    if success == false {
        print("\(pdf.lastErrorText!)")
        return
    }

    var fileSize: Int = jsonOut.int(of: "fileSize").intValue
    var estimated: Int = jsonOut.int(of: "estimatedSavings.total").intValue
    print("fileSize:  \(fileSize)")
    print("estimated: \(estimated)")

    //  Only bother when at least a tenth of the file would go.
    if estimated > (fileSize / 10) {
        print("Worth optimizing.")
        success = pdf.optimize(op: "optimize", jsonIn: json, jsonOut: jsonOut)
        if success == false {
            print("\(pdf.lastErrorText!)")
            return
        }

        success = pdf.writeFile(path: "qa_output/watersense_optimized.pdf")
        if success == false {
            print("\(pdf.lastErrorText!)")
            return
        }

        print("bytesSaved: \(jsonOut.int(of: "bytesSaved").intValue)")
    }
    else {
        print("Already small enough; left as it is.")
    }


}