int
dcemergeprojectionlists(NClist* dst, NClist* src)
{
int i;
NClist* cat = nclistnew();
int ncstat = NC_NOERR;
#ifdef DEBUG
fprintf(stderr,"dapmergeprojection: dst = %s\n",dcetostring((DCEnode*)dst));
fprintf(stderr,"dapmergeprojection: src = %s\n",dcetostring((DCEnode*)src));
#endif
/* get dst concat clone(src) */
nclistsetalloc(cat,nclistlength(dst)+nclistlength(src));
for(i=0;i<nclistlength(dst);i++) {
DCEprojection* p = (DCEprojection*)nclistget(dst,i);
nclistpush(cat,(void*)p);
}
for(i=0;i<nclistlength(src);i++) {
DCEprojection* p = (DCEprojection*)nclistget(src,i);
nclistpush(cat,(void*)dceclone((DCEnode*)p));
}
nclistclear(dst);
/* Repeatedly pull elements from the concat,
merge with all duplicates, and stick into
the dst
*/
while(nclistlength(cat) > 0) {
DCEprojection* target = (DCEprojection*)nclistremove(cat,0);
if(target == NULL) continue;
if(target->discrim != CES_VAR) continue;
for(i=0;i<nclistlength(cat);i++) {
DCEprojection* p2 = (DCEprojection*)nclistget(cat,i);
if(p2 == NULL) continue;
if(p2->discrim != CES_VAR) continue;
if(dcesamepath(target->var->segments,
p2->var->segments)!=0) continue;
/* This entry matches our current target; merge */
ncstat = dcemergeprojections(target,p2);
/* null out this merged entry and release it */
nclistset(cat,i,(void*)NULL);
dcefree((DCEnode*)p2);
}
/* Capture the clone */
nclistpush(dst,(void*)target);
}
nclistfree(cat);
return ncstat;
}
/*
Given a set of projections and a projection
representing a variable (from, say vara or prefetch)
construct a single projection for fetching that variable
with the proper constraints.
*/
int
daprestrictprojection(NClist* projections, DCEprojection* var, DCEprojection** resultp)
{
int ncstat = NC_NOERR;
int i;
DCEprojection* result = NULL;
#ifdef DEBUG1
fprintf(stderr,"restrictprojection.before: constraints=|%s| vara=|%s|\n",
dumpprojections(projections),
dumpprojection(var));
#endif
ASSERT(var != NULL);
/* the projection list will contain at most 1 match for the var by construction */
for(result=null,i=0;i<nclistlength(projections);i++) {
DCEprojection* p1 = (DCEprojection*)nclistget(projections,i);
if(p1 == NULL || p1->discrim != CES_VAR) continue;
if(p1->var->annotation == var->var->annotation) {
result = p1;
break;
}
}
if(result == NULL) {
result = (DCEprojection*)dceclone((DCEnode*)var); /* use only the var projection */
goto done;
}
result = (DCEprojection*)dceclone((DCEnode*)result); /* so we can modify */
#ifdef DEBUG1
fprintf(stderr,"restrictprojection.choice: base=|%s| add=|%s|\n",
dumpprojection(result),dumpprojection(var));
#endif
/* We need to merge the projection from the projection list
with the var projection
*/
ncstat = dcemergeprojections(result,var); /* result will be modified */
done:
if(resultp) *resultp = result;
#ifdef DEBUG
fprintf(stderr,"restrictprojection.after=|%s|\n",
dumpprojection(result));
#endif
return ncstat;
}
