TDfInteract Structure

Summary

Execution time of some of LIBDF functions can appear to be prolonged enough especially in case of big files processing.

That is why in such functions the following features are provided: application program notification of execution phases, phase execution progress, and function interruption.

TDfInteract structure is used particularly fo these purposes, its pointer can be passed to the following functions: dfCompare, dfBuildN, dfBuildH, dfApplyN, dfApplyH.

Syntax

struct TDfInteract

{

PFN_OnDfChangePhase fnOnDfChangePhase;
PFN_OnDfProgress fnOnDfProgress;
int * pAbortFlag;
void * lpUserData;

};

Fields

fnOnDfChangePhase – pointer on a callback-function which will be called when changing function execution phases.

Function must have the following prototype:

void OnDfChangePhase( TDfChangePhase const * pChgPhase );

The only function parameter pChgPhase points on the structure TDfChangePhase which fields are filled by the calling function (see TDfChangePhase structure description for details).

Can be NULL.

fnOnDfProgress - pointer on a callback-function which is called to indicate the progress of current phase execution.

Function must have the following prototype:

void OnDfProgress( TDfProgress const * pPrgs );

The only function parameter pPrgs points on the structure TDfProgress, which fields are filled by the calling function (see TDfProgress structure description for details).

Can be NULL.

pAbortFlag – pointer on the variable of int type which value is periodically checked by executed function. If the value of this variable becomes different from "0", then execution of the function is immediately terminated and function returns EDF_ABORTED error code.

Can be NULL.

lpUserData – pointer on user data.

Can be used by application on its own.