PureBasic Requires Chilkat v11.7.0+

PDF Object Streams: generate, preserve or disable

See more PDF Optimization Examples

Demonstrates the objectStreams option. An object stream packs many small objects (dictionaries, not stream data) into one compressed stream, which is usually a worthwhile saving in a document with many pages or tags. "generate" (the default) packs them and writes a cross-reference stream; "preserve" keeps the file as it is -- packed if it already was, not packed if it was not; "disable" writes every object on its own with a classic cross-reference table, which is what a PDF 1.4 reader needs. Object streams require PDF 1.5 and are skipped for PDF/A-1. PureBasic

IncludeFile "CkPdf.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkFileAccess.pb"

Procedure ChilkatExample()

    success.i = 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 grand_canyon_hiking_guide.pdf

    fac.i = CkFileAccess::ckCreate()
    If fac.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    jsonOut.i = CkJsonObject::ckCreate()
    If jsonOut.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  generate: pack the objects (the default).
    pdf1.i = CkPdf::ckCreate()
    If pdf1.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPdf::ckLoadFile(pdf1,"qa_data/pdf/grand_canyon_hiking_guide.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf1)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(json,"objectStreams","generate")
    success = CkPdf::ckOptimize(pdf1,"optimize",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf1)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        ProcedureReturn
    EndIf

    success = CkPdf::ckWriteFile(pdf1,"qa_output/grand_canyon_objstm_generate.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf1)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        ProcedureReturn
    EndIf

    Debug "generate: " + Str(CkFileAccess::ckFileSize(fac,"qa_output/grand_canyon_objstm_generate.pdf")) + " bytes, objects packed: " + Str(CkJsonObject::ckIntOf(jsonOut,"actions.objectStreams.count"))

    ;  disable: every object on its own, with a classic cross-reference table.
    pdf2.i = CkPdf::ckCreate()
    If pdf2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPdf::ckLoadFile(pdf2,"qa_data/pdf/grand_canyon_hiking_guide.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf2)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(json,"objectStreams","disable")
    success = CkPdf::ckOptimize(pdf2,"optimize",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf2)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        ProcedureReturn
    EndIf

    success = CkPdf::ckWriteFile(pdf2,"qa_output/grand_canyon_objstm_disable.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf2)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        ProcedureReturn
    EndIf

    Debug "disable:  " + Str(CkFileAccess::ckFileSize(fac,"qa_output/grand_canyon_objstm_disable.pdf")) + " bytes"

    ;  preserve: leave the file's own structure alone.  Use it when the output must stay readable by
    ;  whatever reads the input today.
    pdf3.i = CkPdf::ckCreate()
    If pdf3.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkPdf::ckLoadFile(pdf3,"qa_data/pdf/grand_canyon_hiking_guide.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf3)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        CkPdf::ckDispose(pdf3)
        ProcedureReturn
    EndIf

    CkJsonObject::ckUpdateString(json,"objectStreams","preserve")
    success = CkPdf::ckOptimize(pdf3,"optimize",json,jsonOut)
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf3)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        CkPdf::ckDispose(pdf3)
        ProcedureReturn
    EndIf

    success = CkPdf::ckWriteFile(pdf3,"qa_output/grand_canyon_objstm_preserve.pdf")
    If success = 0
        Debug CkPdf::ckLastErrorText(pdf3)
        CkFileAccess::ckDispose(fac)
        CkJsonObject::ckDispose(json)
        CkJsonObject::ckDispose(jsonOut)
        CkPdf::ckDispose(pdf1)
        CkPdf::ckDispose(pdf2)
        CkPdf::ckDispose(pdf3)
        ProcedureReturn
    EndIf

    Debug "preserve: " + Str(CkFileAccess::ckFileSize(fac,"qa_output/grand_canyon_objstm_preserve.pdf")) + " bytes"


    CkFileAccess::ckDispose(fac)
    CkJsonObject::ckDispose(json)
    CkJsonObject::ckDispose(jsonOut)
    CkPdf::ckDispose(pdf1)
    CkPdf::ckDispose(pdf2)
    CkPdf::ckDispose(pdf3)


    ProcedureReturn
EndProcedure