Re: sequencer feature request

[Eric Norum <norume@aps.anl.gov>]

Mr. Small IOC here.
Rather than allocating the maximum-sized space for every single name,  
why not expand the name into a 'big-enough' buffer and then allocate  
only the required size and copy the result?

On Sep 9, 2009, at 5:13 AM, Dirk Zimoch wrote:

> I found several places in the code where the sequencer uses  
> MAX_STRING_SIZE+1 for string lengths of PV names and macros. In  
> EPICS base MAX_STRING_SIZE is defined as 40. For example in  
> seq_main.c:
>
> /*
> * Evaluate channel names by macro substitution.
> */
> #define		MACRO_STR_LEN	(MAX_STRING_SIZE+1)
> LOCAL void seqChanNameEval(pSP)
> SPROG		*pSP;
> {
> 	CHAN		*pDB;
> 	int		i;
>
> 	pDB = pSP->pChan;
> 	for (i = 0; i < pSP->numChans; i++, pDB++)
> 	{
> 		pDB->dbName = calloc(1, MACRO_STR_LEN);
> 		seqMacEval(pDB->dbAsName, pDB->dbName, MACRO_STR_LEN, pSP->pMacros);
> #ifdef	DEBUG
> 		printf("seqChanNameEval: \"%s\" evaluated to \"%s\"\n",
> 			pDB->dbAsName, pDB->dbName);
> #endif	/*DEBUG*/
> 	}
> }
>
> It might help to replace those uses of MAX_STRING_SIZE+1 with  
> PVNAME_STRINGSZ.
>
> Dirk
>
>
>
> Dirk Zimoch wrote:
> > I tested the sequencer with a long name and it seems that it  
> > truncates the PV name to 41 chars.
> > A seqChanShow shows the difference between the name used in assign  
> > and the actual name used in CA:
> > Channel name: "DZ:45678901234567890123456789012345678901"
> >  Unexpanded (assigned) name: "DZ: 
> > 456789012345678901234567890123456789012345678901234567890"
> > Dirk
> > Mark Rivers wrote:
> > > EPICS base defines the maximum length of the PV name to be  
> > > PVNAME_STRINGSZ, which is currently 61 including the nil terminator.
> > > What length limitation does the sequencer impose?  Is it more  
> > > restrictive than this?
> > > Mark
> > >
> > > ________________________________
> > >
> > > From: tech-talk-bounces@aps.anl.gov on behalf of Patrick Thomas
> > > Sent: Thu 9/3/2009 6:29 PM
> > > To: tech-talk@aps.anl.gov
> > > Subject: sequencer feature request
> > >
> > >
> > >
> > > Hi,
> > >
> > > I was wondering if I could ask for a feature request for the next
> > > version of the sequencer? Is there any chance that it would be  
> > > possible
> > > to use unlimited length record names in assign to statements?
> > >
> > > Thank you,
> > > Patrick
>
> --
> Dr. Dirk Zimoch
> Paul Scherrer Institut, WBGB/006
> 5232 Villigen PSI, Switzerland
> Phone +41 56 310 5182

--
Eric Norum <norume@aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793