78 lines
2.6 KiB
OpenEdge ABL
78 lines
2.6 KiB
OpenEdge ABL
\subsection{Data Number}
|
|
In some points of its life SICS has to write data files. The file names
|
|
usually consist of a header, a serial number and an indicator for the
|
|
year. The serial number must be unique and steadliy increasing. In order to
|
|
achieve this, the serial number are written into a file after any change.
|
|
Incrementing the serial number thus involves the following steps:
|
|
\begin{itemize}
|
|
\item Open file and read current number.
|
|
\item Increment number
|
|
\item Write File and close
|
|
\end{itemize}
|
|
This little task is implemented in this module.
|
|
|
|
The interface to this looks like:
|
|
@d dni @{
|
|
typedef struct __DataNumber *pDataNumber;
|
|
|
|
pDataNumber CreateDataNumber(char *pFilename);
|
|
void DeleteDataNumber(void *pData);
|
|
|
|
int IncrementDataNumber(pDataNumber self, int *iYear);
|
|
|
|
int DecrementDataNumber(pDataNumber self);
|
|
|
|
int DNWrapper(SConnection *pCon, SicsInterp *pSics, void *pData,
|
|
int argc, char *argv[]);
|
|
|
|
int DEWrapper(SConnection *pCon, SicsInterp *pSics, void *pData,
|
|
int argc, char *argv[]);
|
|
|
|
int DNFactory(SConnection *pCon, SicsInterp *pSics, void *pData,
|
|
int argc, char *argv[]);
|
|
@}
|
|
\begin{description}
|
|
\item [CreateDataNumber] creates a data number data structure. It checks if
|
|
the file requested as parameter exists and asserts if not. Returns a pointer
|
|
on success, NULL else.
|
|
\item [DeleteDataNumber] deletes a data number structure form memory.
|
|
\item [IncrementDataNumber] is the main working function of this module.
|
|
It performs the steps listed above. It returns a new id for the data number
|
|
in case of success, a negative value otherwise. iYear is filled with a value
|
|
for the year.
|
|
\item[DecrementDataNumber] decrements the data number and is used for
|
|
implementing the killdata function. Whis is the invalidation of a
|
|
data file by overwriting it.
|
|
\item[DNWrapper] is the wrapper function which makes DataNumber accessible
|
|
from within SICS.
|
|
\item[DEWrapper] is the wrapper for the killdata functionality.
|
|
\item [DNFactory] is the SICS factory function which creates a Data Number
|
|
object from the initialisation file. Only parameter is the filename.
|
|
\end{description}
|
|
|
|
@o danu.h -d @{
|
|
/*-----------------------------------------------------------------------
|
|
D A T A N U M B E R
|
|
|
|
A module to provide a unique data number for data file writing.
|
|
|
|
Mark Koennecke, Juli 1997
|
|
|
|
copyright: see implementation file.
|
|
|
|
---------------------------------------------------------------------------*/
|
|
#ifndef SICSDATANUMBER
|
|
#define SICSDATANUMBER
|
|
|
|
@<dni@>
|
|
|
|
#endif
|
|
@}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|