Xbase++ 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. Xbase++

LOCAL nSuccess
LOCAL oPdf
LOCAL oJson
LOCAL oJsonOut
LOCAL nFileSize
LOCAL nEstimated

nSuccess := 0

//  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

oPdf := CreateObject("Chilkat.Pdf")
nSuccess := oPdf:LoadFile("qa_data/pdf/watersense_accomplishments.pdf")
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    RETURN
ENDIF

oJson := CreateObject("Chilkat.JsonObject")
oJsonOut := CreateObject("Chilkat.JsonObject")
nSuccess := oPdf:Optimize("audit", oJson, oJsonOut)
IF (nSuccess == 0)
    ? oPdf:LastErrorText
    oPdf:destroy()
    oJson:destroy()
    oJsonOut:destroy()
    RETURN
ENDIF

nFileSize := oJsonOut:IntOf("fileSize")
nEstimated := oJsonOut:IntOf("estimatedSavings.total")
? "fileSize:  " + Str(nFileSize)
? "estimated: " + Str(nEstimated)

//  Only bother when at least a tenth of the file would go.
IF (nEstimated > (nFileSize / 10))
    ? "Worth optimizing."
    nSuccess := oPdf:Optimize("optimize", oJson, oJsonOut)
    IF (nSuccess == 0)
        ? oPdf:LastErrorText
        oPdf:destroy()
        oJson:destroy()
        oJsonOut:destroy()
        RETURN
    ENDIF

    nSuccess := oPdf:WriteFile("qa_output/watersense_optimized.pdf")
    IF (nSuccess == 0)
        ? oPdf:LastErrorText
        oPdf:destroy()
        oJson:destroy()
        oJsonOut:destroy()
        RETURN
    ENDIF

    ? "bytesSaved: " + Str(oJsonOut:IntOf("bytesSaved"))
ELSE
    ? "Already small enough; left as it is."
ENDIF

oPdf:destroy()
oJson:destroy()
oJsonOut:destroy()