How to analyze the performance impact of a code snippet in ADVPL?

Question

I have the following code in ADVPL:

Static Function linhaJson(cTabela, cChave, lVerificaExclusao)
    local cTipo
    local xResult
    local cJson := "{"

    dbSelectArea("ZX1")
    ZX1->(dbSetOrder(1))
    ZX1->(dbGoTop())
    ZX1->(dbSeek(cChave))

    While !(ZX1->(EOF())) .AND. cChave == ZX1->(ZX1_FILIAL + ZX1_COD)
        If ZX1->ZX1_TIPO == 'B'
            xResult := &(conv2Json(ZX1->ZX1_CP_PRO, cTabela))
            cTipo := ValType(xResult)//ValType(ZX1->ZX1_CP_PRO) 
            If cTipo == 'C'
                if AllTrim(xResult) != "NULL"
                    cJson += '"' + AllTrim(Lower(ZX1->ZX1_CP_GEO)) + '":"' + ESCENVST(SUBS(AllTrim(xResult),1,ZX1->ZX1_TAM)) + '",'
                EndIf
            ElseIf cTipo == 'N'
                cJson += '"' + AllTrim(Lower(ZX1->ZX1_CP_GEO)) + '":"' + AllTrim(STR(&(cTabela + "->"+ZX1->ZX1_CP_PRO))) + '",'
            ElseIf cTipo == 'D'
                cJson += '"' + AllTrim(Lower(ZX1->ZX1_CP_GEO)) + '":"' + AllTrim(DtoS(&(cTabela + "->"+ZX1->ZX1_CP_PRO))) + '",'
            EndIf
        ElseIf ZX1->ZX1_TIPO == 'S'
            cJson += '"' + AllTrim(Lower(ZX1->ZX1_CP_GEO)) + '":"' + AllTrim(ZX1->ZX1_CP_PRO) + '",'
        ElseIf ZX1->ZX1_TIPO == 'V'
            cJson += '"' + AllTrim(Lower(ZX1->ZX1_CP_GEO)) + '":"",'
        Else //ZX1->ZX1_TIPO == 'N'
            cJson += ""
        EndIf
        ZX1->(dbSkip())
    EndDo
    ZX1->(dbCloseArea())

    cJson := SUBS(cJson, 1, len(cJson) - 1)

    If lVerificaExclusao //Se for excluso
        cJson += ',"data_delete":"' + getCurrentDate() + '" '
    EndIf
    cJson += "}"
Return cJson

Your unique obligation is to mine data from a query in Protheus and turn it into a JSON for me to consume on my server. It runs for every line of every mining I do.

I believe the iteration in ZX1 to redeem the same information in 80,000 lines of the same query have some weight in performance, but I do not know any profiler to be sure of how much is being dedicated to that particular piece of code. I have no security to make time measurement within the code without that measurement does not change the measurement object and its measurement.

For the iteration in ZX1, I refer to the whole process, since the initialization with dbSelectArea("ZX1") up to the teardown of the tie with ZX1-> (dbCloseArea())

Another point of doubt I have about performance is about substrings, in that passage: cJson := SUBS(cJson, 1, len(cJson) - 1). This could generate some memory fragmentation allocated to the strings more than I’m already fragmenting. Again, I don’t know profiler to do so, and this time I have no knowledge of how to measure from within the memory code used, called garbage collectors or fragmentation.

So I repeat my question of the title:

How to analyze the performance impact of a code snippet?

The intention here is to avoid doing some unnecessary refactoring in the code, which ultimately has little gain and is difficult to do. Just to change the hotspots of the code snippet.

Answer 1

Superficially analyzing the code, whether it is STATIC FUNCTION linhaJson() is often called, from within the same execution context, REMOVE lines : ZX1->(dbGoTop()) e ZX1->(dbCloseArea()). You don’t need to open and close the alias ZX1 each loop. This will already give you one with performance gain, blindfolded. And also do not need to position in the first order record to make a DBSeek().

Now, to measure the time spent by this function, and the calls coming from within it, the best alternative is to use the Profiler of Advpl. For now, check on TDN at link How to Run a Profiler. Although in that way the log generated will generate information about the entire routine, the analysis of the console.log Protheus Server generated after routine execution allows you to identify which functions were called from which source point, including all function calls LinhaJson(), and all calls from functions called from within it.